### Re: Measuring a system in a superposition of states vs in a mixed state

```On Wed, Oct 31, 2018 at 7:30 AM Bruno Marchal  wrote:

>
> On 30 Oct 2018, at 14:21, agrayson2...@gmail.com wrote:
>
>
>
> On Tuesday, October 30, 2018 at 8:58:30 AM UTC, Bruno Marchal wrote:
>>
>>
>> On 29 Oct 2018, at 13:55, agrays...@gmail.com wrote:
>>
>>
>>
>> On Monday, October 29, 2018 at 10:22:02 AM UTC, Bruno Marchal wrote:
>>>
>>>
>>> On 28 Oct 2018, at 13:21, agrays...@gmail.com wrote:
>>>
>>>
>>>
>>> On Sunday, October 28, 2018 at 9:27:56 AM UTC, Bruno Marchal wrote:

On 25 Oct 2018, at 17:12, agrays...@gmail.com wrote:

On Tuesday, October 23, 2018 at 10:39:11 PM UTC, agrays...@gmail.com
wrote:
>
> If a system is in a superposition of states, whatever value measured,
> will be repeated if the same system is repeatedly measured.  But what
> happens if the system is in a mixed state? TIA, AG
>

If you think about it, whatever value you get on a single trial for a
mixed state, repeated on the same system, will result in the same value
measured repeatedly. If this is true, how does measurement distinguish
superposition of states, with mixed states? AG

That is not correct. You can distinguish a mixture of particles in the
up or down states with a set of 1/sqrt(2)(up+down) by measuring them with
the {1/sqrt(2)(up+down), 1/sqrt(2)(up-down}) discriminating apparatus. With
the mixture, half the particles will be defected in one direction, with the
pure state, they will all pass in the same direction. Superposition would
not have been discovered if that was not the case.

>>>
>>>
>>> *And someone will supply the apparatus measuring (up + down), and (up -
>>> down)? No such apparatuses are possible since those states are inherently
>>> contradictory. We can only measure up / down. AG*
>>>
>>>
>>> You can do the experience by yourself using a simple crystal of calcium
>>> (CaCO3, Island Spath), or with polarising glass. Or with Stern-Gerlach
>>> devices and electron spin. Just rotating (90° or 180°) an app/down
>>> apparatus, gives you an (up + down)/(up - down) apparatus.
>>>
>>
>> *I don't understand. With SG one can change the up/down axis by rotation,
>> but that doesn't result in an (up + down), or (up - down) measurement. If
>> that were the case, what is the operator for which those states are
>> eigenstates? Which book by Albert? AG *
>>
>>
>> David Z Albert, Quantum Mechanics and Experience, Harvard University
>> Press, 1992.
>>
>> https://www.amazon.com/Quantum-Mechanics-Experience-David-Albert/dp/0674741137
>>
>> Another very good books is
>>
>> D’Espagnat B. Conceptual foundations of Quantum mechanics,  I see there
>> is a new edition here:
>>
>>
>> It explains very well the difference between mixtures and pure states.
>>
>> Bruno
>>
>
> *Thanks for the references. I think I have a reasonable decent
> understanding of mixed states. Say a system is in a mixed state of phi1 and
> phi2 with some probability for each. IIUC, a measurement will always result
> in an eigenstate of either phi1 or phi2 (with relative probabilities
> applying). *
>
>
> If the measurement is done with a phi1/phi2 discriminating apparatus. Keep
> in mind that any state can be seen as a superposition of other oblique or
> orthogonal states.
>

I don't know if you're restricting the definition of phi1 and phi2 to some
particular type of eigenstate or not, but in general aren't there pure
states that are not eigenstates of any physically possible measurement
apparatus, so there is no way to directly measure that a system is in such
a state?

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### Re: Non-locality and MWI

```On Mon, May 2, 2016 at 1:10 AM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 2/05/2016 1:31 pm, Jesse Mazer wrote:
>
> On Sun, May 1, 2016 at 8:49 PM, Bruce Kellett <bhkell...@optusnet.com.au>
> wrote:
>
>> On 2/05/2016 7:52 am, Jesse Mazer wrote:
>>
>> On Fri, Apr 29, 2016 at 8:32 PM, Bruce Kellett <
>> <bhkell...@optusnet.com.au>bhkell...@optusnet.com.au> wrote:
>>
>>> That is a semantic matter. There is a problem if one insists that
>>> "non-local" means the propagation of a real physical influence (particle of
>>> wave) faster-than-light. But "non-locality" in standard quantum usage means
>>> the above -- the entangled state acts as a single physical unit even when
>>> its components are widely separated.
>>
>>
>>
>> I agree it's a semantic matter, but your description of the "standard
>> quantum usage" doesn't seem to be accurate. Among physicists, the standard
>> understanding of "local" and "non-local" in the context of Bell's theorem
>> and relativity is the one I cited earlier--a theory is "local" if and only
>> if the function that gives you the value of local variables at any given
>> point P in spacetime (or gives the best possible probabilistic prediction
>> about their values, in the case of a non-deterministic theory) only
>> requires as input the values of local variables at other points that lie
>> within P's past light cone, whereas a "non-local" theory would be one where
>> the function requires knowledge of variables at a spacelike separation from
>> P to generate the best possible prediction. As I mentioned, I think this is
>> explained most clearly in Bell's paper "La nouvelle cuisine" which you can
>> find in the collection "Speakable and Unspeakable in Quantum Mechanics",
>> and you can also find it discussed in other sources,
>> http://arxiv.org/abs/0707.0401 for example. As for "acts as a single
>> physical unit", that seems like a decidedly non-mathematical definition
>> which physicists would steer clear of, unless you can provide a
>> mathematical formalization or what you mean, or cite a mainstream source
>> that provides one.
>>
>>
>> I don't see any paper of the title you mention in my copy of "Speakable
>> and Unspeakable in Quantum Mechanics", could you give a page number
>> reference?
>>
>
>
> It's on p. 232 of the 2nd edition, chapter 24.
>
>
> I have now looked at the paper by Norsen. It seems that the more detailed
> definiton of locality does little more than remove the notion of
> "superdeterminism" from the equation -- the idea that things in the common
> past of A and B could conspire to give rise to the correlations.
>

The paper by Norsen at http://arxiv.org/pdf/0707.0401v3.pdf does mention
the issue of ruling out superdeterminism, but that wasn't what I was
referring to when I talked about the definition in La nouvelle cuisine
which is repeated in Norsen's paper. Rather I was talking about equation 1
on page 4 whose physical meaning in terms of past light cones is show in
Fig. 2 on the same page. Referring to the diagram and equation, b1 refers
to the physical state of local variables in region 1, b2 refers to the
physical state of local variables in another region 2 at a spacelike
separation of 1, and B3 refers to some sufficiently detailed set of local
states in region 3 which is in the past light cone of region 1, but
entirely outside the past light cone of region 2. The idea is that by
picking a sufficiently detailed set for your B3, you can have it so that
once you know B3, additional knowledge of b2 is irrelevant to your
prediction of what's going on in b1, i.e. you don't need anything outside
the past light cone of 1 to make the best possible physical prediction
about the physical facts in that region. So, nothing to do with
superdeterminism, just a more formal statement of the idea I described
depending only on facts in the past light cone of that region.

Jesse

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### Re: Non-locality and MWI

```On Mon, May 2, 2016 at 12:13 AM, Bruce Kellett
wrote:

>
> No, I disagree. The setting *b* has no effect on what happens at a remote
> location is sufficiently precise to encapsulate exactly what physicists
> mean by locality. In quantum field theory, this is generalized to the
> notion of local causality, which is the statement that the commutators of
> all spacelike separate variables vanish -- as you mention below.
>

And if you used full quantum description of the measuring apparatus and
experimenter, and didn't assume any collapse on measurement, then there
would in general be no single "setting b" in the region of spacetime where
one experimenter was choosing a setting, but rather a superposition of
different settings. Do you think your preferred definition can be
meaningfully applied to this case, and if so how?

>
> My qualitative definition of non-locality is not non-standard -- it is the
>> definition frequently used by Bell, and (almost) everyone else. Your
>> definition seems to want to take account of some sort of hidden variables,
>> such that the quantum state as written does not contain all the information
>>
>
>
> There are no hidden variables in the MWI (though the definition of
> locality should be general enough to cover theories with hidden variables
> as well as ones with no hidden variables, since Bell's theorem is meant to
> rule out local realist theories of either type). The "quantum state as
> written" does not give any definite outcomes of measurements, only a set of
> amplitudes on different eigenvectors associated with particular
> eigenvalues, which are understood as possible measurement results.
>
>
> True, but not relevant for these purposes. I am not ruling out an
> Everettian interpretation of the state vector -- my definition of locality
> simply rules out faster than light (FTL) transfer of information. Given the
> standard quantum treatment of the entangled singlet state, non-locality is
> unavoidable.
>

Without any assumption of "collapse", the *amplitudes* assigned to local
measurements on either member of an entangled pair could be determined
solely from amplitudes on locally-measurable variables in the past light
cone--do you disagree?

> That does not mean that there is actually a physical transfer of particles
> or waves FTL, it simply means that the state is a unity, and changing one
> part changes the whole state. That is the nature of quantum non-locality --
> it does not have a local explanation, even a FTL explanation.
>

There are no non-mathematical "explanations" for anything whatsoever in
physics (obviously there can be explanations in words, but these are
understood as shorthand for arguments that could be formalized
mathematically). And in terms of mathematical physics, the "explanation"
for a local physical fact about what's happening in one point in spacetime
is just the mathematical function representing the "laws of physics" along
with whatever initial boundary conditions have to be fed into the function
to generate the prediction about that local physical fact. If the boundary
conditions are all confined to the past light cone, I would say there is
nothing FTL in this mathematical explanation--you may disagree, but so far
you have been unable to provide any alternate precisely-defined conditions
for distinguishing locality from non-locality, ones which we could still
obviously make sense of even if we didn't assume a unique real-valued
measurement setting and measurement outcome.

> And if you just want the amplitudes for locally-measurable quantities in a
> given region of spacetime, in quantum field theory my understanding is that
> you can determine this using only knowledge of amplitudes for
> locally-measurable quantities in the past light cone of that region (I
> don't understand the details, but this is supposed to have to do with the
> fact that the commutators for spacelike-separated points always vanish).
> Only if you assume there is an objective "collapse" of the wavefunction at
> the point of measurement does the quantum formalism become incompatible
> with locality in the light cone sense.
>
>
> That is not correct. You have not given a local account in MWI either.
>

What does "account" mean? A mathematical description, or a conceptual
explanation in the English language?

> Your "light cone sense" of locality would only add something to the
> traditional sense if the quantum state were not a complete description of
> the system. In other words, a hidden variable theory.
>

I have no idea why you think this, and you haven't made any argument for
it. Your traditional sense seems to be simply ill-defined if we assume a
superposition of different detecter settings in a single location in
spacetime, and a superposition of measurement results at another location,
whereas the "light-cone sense" is still well-defined here since it can
cover local variables of any kind, including a ```

### Re: Non-locality and MWI

```On Sun, May 1, 2016 at 8:49 PM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 2/05/2016 7:52 am, Jesse Mazer wrote:
>
> On Fri, Apr 29, 2016 at 8:32 PM, Bruce Kellett <bhkell...@optusnet.com.au>
> wrote:
>
>> That is a semantic matter. There is a problem if one insists that
>> "non-local" means the propagation of a real physical influence (particle of
>> wave) faster-than-light. But "non-locality" in standard quantum usage means
>> the above -- the entangled state acts as a single physical unit even when
>> its components are widely separated.
>
>
>
> I agree it's a semantic matter, but your description of the "standard
> quantum usage" doesn't seem to be accurate. Among physicists, the standard
> understanding of "local" and "non-local" in the context of Bell's theorem
> and relativity is the one I cited earlier--a theory is "local" if and only
> if the function that gives you the value of local variables at any given
> point P in spacetime (or gives the best possible probabilistic prediction
> about their values, in the case of a non-deterministic theory) only
> requires as input the values of local variables at other points that lie
> within P's past light cone, whereas a "non-local" theory would be one where
> the function requires knowledge of variables at a spacelike separation from
> P to generate the best possible prediction. As I mentioned, I think this is
> explained most clearly in Bell's paper "La nouvelle cuisine" which you can
> find in the collection "Speakable and Unspeakable in Quantum Mechanics",
> and you can also find it discussed in other sources,
> http://arxiv.org/abs/0707.0401 for example. As for "acts as a single
> physical unit", that seems like a decidedly non-mathematical definition
> which physicists would steer clear of, unless you can provide a
> mathematical formalization or what you mean, or cite a mainstream source
> that provides one.
>
>
> I don't see any paper of the title you mention in my copy of "Speakable
> and Unspeakable in Quantum Mechanics", could you give a page number
> reference?
>

It's on p. 232 of the 2nd edition, chapter 24.

> What I did find was chapter 8, "Locality in quantum mechanics: reply to
> critics" (pp. 63-66).  In that chapter, Bell says: "...now we add the
> hypothesis of l*ocality*, that the setting *b* of a particular instrument
> has no effect on what happens, A, in a remote region, and likewise that
> *a* has no effect on B. With these *local* forms, it is *not *possible
> to find functions A and B and a probability distribution *rho* which give
> the correlations  = -*a.b*."
>
> This is an informal statement of exactly the notion of locality or
> non-locality that I have been using all along. Your more convoluted
> statement may bear some relation to Bell's theory of local beables (chapter
> 7 of his book), but the complications are unnecessary -- the informal
> definition is the one most physicists would use in practice.
>

I disagree, physicists generally only use informal definitions if it's
obvious they could be formalized, or if they are *implied* by some more
precise technical definition (the looser definition you mention above would
be implied by the more precise one I mentioned, *if* one assumes there is a
unique truth about the setting at b and the measurement A).

> My qualitative definition of non-locality is not non-standard -- it is the
> definition frequently used by Bell, and (almost) everyone else. Your
> definition seems to want to take account of some sort of hidden variables,
> such that the quantum state as written does not contain all the information
>

There are no hidden variables in the MWI (though the definition of locality
should be general enough to cover theories with hidden variables as well as
ones with no hidden variables, since Bell's theorem is meant to rule out
local realist theories of either type). The "quantum state as written" does
not give any definite outcomes of measurements, only a set of amplitudes on
different eigenvectors associated with particular eigenvalues, which are
understood as possible measurement results. And if you just want the
amplitudes for locally-measurable quantities in a given region of
spacetime, in quantum field theory my understanding is that you can
determine this using only knowledge of amplitudes for locally-measurable
quantities in the past light cone of that region (I don't understand the
details, but this is supposed to have to do with the fact that the
commutators for spacelike-separated points always vanish). Only if you
assume there is an objective "collapse" of ```

### Re: Non-locality and MWI

```On Fri, Apr 29, 2016 at 8:32 PM, Bruce Kellett
wrote:
>
> That is a semantic matter. There is a problem if one insists that
> "non-local" means the propagation of a real physical influence (particle of
> wave) faster-than-light. But "non-locality" in standard quantum usage means
> the above -- the entangled state acts as a single physical unit even when
> its components are widely separated.

I agree it's a semantic matter, but your description of the "standard
quantum usage" doesn't seem to be accurate. Among physicists, the standard
understanding of "local" and "non-local" in the context of Bell's theorem
and relativity is the one I cited earlier--a theory is "local" if and only
if the function that gives you the value of local variables at any given
point P in spacetime (or gives the best possible probabilistic prediction
about their values, in the case of a non-deterministic theory) only
requires as input the values of local variables at other points that lie
within P's past light cone, whereas a "non-local" theory would be one where
the function requires knowledge of variables at a spacelike separation from
P to generate the best possible prediction. As I mentioned, I think this is
explained most clearly in Bell's paper "La nouvelle cuisine" which you can
find in the collection "Speakable and Unspeakable in Quantum Mechanics",
and you can also find it discussed in other sources,
http://arxiv.org/abs/0707.0401 for example. As for "acts as a single
physical unit", that seems like a decidedly non-mathematical definition
which physicists would steer clear of, unless you can provide a
mathematical formalization or what you mean, or cite a mainstream source
that provides one.

Bruno should be aware that in the discussion you and I had earlier, you
used this sort of qualitative non-standard definition to argue even if the
function giving values of physical variables at each point *does* depend
solely on data from the past light cone, that is "irrelevant" to deciding
whether the theory is "local" in your sense, presumably because you think
there can be qualitative features of the function itself that can make it
"non-local" for reasons unrelated to the question of what data the function
takes as input.

Jesse

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### Re: Non-locality and MWI

```On Wed, Apr 27, 2016 at 2:35 AM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 27/04/2016 4:13 pm, Jesse Mazer wrote:
>
> On Wed, Apr 27, 2016 at 1:40 AM, Bruce Kellett <bhkell...@optusnet.com.au>
> wrote:
>
>> On 27/04/2016 3:22 pm, Jesse Mazer wrote:
>>
>> On Wed, Apr 27, 2016 at 12:47 AM, Bruce Kellett <
>> <bhkell...@optusnet.com.au>bhkell...@optusnet.com.au> wrote:
>>
>>> Your simulation assumes the quantum mechanical results. In other words,
>>> it assumes non-locality in order to calculate the statistics. Where does
>>> the cos^2(theta/2) come from in your analysis?
>>>
>>
>> The question I asked you was whether you thought you could definitively
>> disprove the idea that all the observable statistics of QM could be
>> reproduced by rules that are "local" in the specific narrow sense I had
>> described to you--remember all that stuff about having computers
>> determining what the value of local variables at each point in spacetime
>> should be, using only information about the value of local variables in the
>> past light cone of that point, plus the general rules programmed into them
>> (which take that information about the past light cone as input, and spit
>> out the value of local variables at that point as output)? This is a narrow
>> and mathematically well-defined question (and is based specifically on how
>> Bell defined 'locality'), it's completely irrelevant to the question
>> whether or not the *idea* for the rules that I programmed into the
>> computers that perform these local calculations came from looking at some
>> equations that are written in a 'non-local' way (i.e., the equations
>> generate their predictions by evolving a single 'state vector' for the
>> entire spatially-distributed system). Do you understand this distinction
>> between the narrow, well-defined definition of "local rules" (if you're
>> inspired the rules themselves? And are you claiming that even if we
>> restrict our attention to the narrow definition of "local rules", you can
>> still say with 100% certainty that no such "local rules" can accurately
>>
>>
>> Your question, as outlined above, is completely devoid of interest to me
>> as a physicist. I am interested in physical models that give an insight
>> into how things come about.
>>
>> And yes, I am 100% certain that local rules, with local models for
>> deciding what statistics should be reproduced to mimic quantum results on
>> entangled systems, are impossible.
>>
>
> And are you 100% certain of that last statement even if we define "local
> rules" in the specific narrow sense I have described? Your comment that my
> question concerning this narrow definition of locality is 'devoid of
> interest' to you makes it unclear whether you were actually willing to
> stick to the narrow definition in addressing my question, as I had
> requested.
>
>
> It is of no interest. You, and Rubin, advertised your work as a local
> explanation of the EPR statistics. On detailed examination and pressing,
> you admit that this is not the case
>

No, we use a definition of "locality" where it *is* the case, a
mathematical definition that seems to correspond to how pretty much all
mainstream physicists use the term "locality". You seem to say that even if
a function takes as input only variables from the past light cone of a
region to generate predictions about the values of variables within that
region, it can be non-local because of something to do with where the idea
for the function itself came from, a fuzzy notion that doesn't seem like
it's likely to have any clear mathematical definition (if you think it can,
please provide a general set of mathematical criteria for deciding whether
some arbitrary mathematical function for generating predictions from
boundary conditions is 'local', such that even a function that only uses
variables in the past light cone as input may still fail to qualify as
local).

And since you answer my direct request to address my question with "it is
of no interest", should I presume you are just refusing to answer the
questions I take that as a sign they are not really interested in making a
good-faith effort at mutual understanding, on figuring out what points we
can (grudgingly) agree on as well as where we disagree (as opposed to just
making a rhetorical case for a preferred view, or against a disli```

### Re: Non-locality and MWI

```On Wed, Apr 27, 2016 at 1:50 AM, Brent Meeker <meeke...@verizon.net> wrote:

>
>
> On 4/26/2016 10:29 PM, Jesse Mazer wrote:
>
>
>
> On Tue, Apr 26, 2016 at 11:51 PM, Brent Meeker <meeke...@verizon.net>
> wrote:
>
>>
>>
>> On 4/26/2016 8:38 PM, Jesse Mazer wrote:
>>
>>> OK, let's say experimenter A measures particle 1, and experimenter B
>>> measures particle 2. Any given copy of particle 1 has a "label" that says
>>> something about the state of 2--we can imagine that the copy of particle 1
>>> carries a little clipboard on which is written down both its own quantum
>>> state, and a quantum state it assigns to particle 2. When that copy of 1 is
>>> measured, it not only adjusts its own state (to an eigenstate of the
>>> measurement operator), it also adjusts the state it has written down for 2.
>>> You seem to be assuming, in effect, that when a copy of 1 adjusts what it
>>> has written down for the state of 2 on its own clipboard, this must mean
>>> that copies of 2 also instantaneously adjust what they have written down
>>> about *their* own state. However, in a copying-with-matching scheme,
>>> there's no reason this need be the case!
>>>
>>
>> That's pretty much the many-universes model that Bruno proposes. But it's
>> non-local in the sense that the "matching scheme" must take account of
>> which measurements are compatible, i.e. it "knows" the results even while
>> they are  spacelike separated.
>>
>
> Why do you say that? Do you understand that in the type of scheme I am
> talking about (and Mark Rubin too, I think), no "matching" between copies
> of measurement-outcomes at different locations takes place at any location
> in spacetime that doesn't lie in the future light cone of both measurements?
>
>
> I think I understand it.  Consider a spacelike slice that contains the
> earliest overlap of the A and B measurment events forward lightcones.  On
> this slice the proper correlated results must obtain, which means that
> observers at opposite sides of the lightcones from the overlap must also
> observe the proper correlation - even though they are spacelike relative to
> the overlap and spacelike relative to one of the measurement events.
>

I think you're misunderstanding--if we imagine a cellular-automata-like
implementation where we have separate computers calculating the state of
each small region of space, it's not as if a mapping calculated by a
computer at one point in a spacelike slice needs to be instantaneously
transmitted to all the other computers in that same spacelike slice.
Correlations don't need to obtain across entire spacelike slices,
information about mappings is itself local information associated with
particular copies of localized systems (like copies of an experimenter that
experimenter has a state that is determined by the outcome of both
measurements, and hence qualifies as a physical 'mapping' between
particular copies of the measurements themselves)

Jesse

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### Re: Non-locality and MWI

```On Wed, Apr 27, 2016 at 1:40 AM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 27/04/2016 3:22 pm, Jesse Mazer wrote:
>
> On Wed, Apr 27, 2016 at 12:47 AM, Bruce Kellett <bhkell...@optusnet.com.au
> > wrote:
>
>> Your simulation assumes the quantum mechanical results. In other words,
>> it assumes non-locality in order to calculate the statistics. Where does
>> the cos^2(theta/2) come from in your analysis?
>>
>
> The question I asked you was whether you thought you could definitively
> disprove the idea that all the observable statistics of QM could be
> reproduced by rules that are "local" in the specific narrow sense I had
> described to you--remember all that stuff about having computers
> determining what the value of local variables at each point in spacetime
> should be, using only information about the value of local variables in the
> past light cone of that point, plus the general rules programmed into them
> (which take that information about the past light cone as input, and spit
> out the value of local variables at that point as output)? This is a narrow
> and mathematically well-defined question (and is based specifically on how
> Bell defined 'locality'), it's completely irrelevant to the question
> whether or not the *idea* for the rules that I programmed into the
> computers that perform these local calculations came from looking at some
> equations that are written in a 'non-local' way (i.e., the equations
> generate their predictions by evolving a single 'state vector' for the
> entire spatially-distributed system). Do you understand this distinction
> between the narrow, well-defined definition of "local rules" (if you're
> inspired the rules themselves? And are you claiming that even if we
> restrict our attention to the narrow definition of "local rules", you can
> still say with 100% certainty that no such "local rules" can accurately
>
>
> Your question, as outlined above, is completely devoid of interest to me
> as a physicist. I am interested in physical models that give an insight
> into how things come about.
>
> And yes, I am 100% certain that local rules, with local models for
> deciding what statistics should be reproduced to mimic quantum results on
> entangled systems, are impossible.
>

And are you 100% certain of that last statement even if we define "local
rules" in the specific narrow sense I have described? Your comment that my
question concerning this narrow definition of locality is 'devoid of
interest' to you makes it unclear whether you were actually willing to
stick to the narrow definition in addressing my question, as I had
requested.

To try to restate this "specific narrow sense" one more time, note that at
the broadest level, any dynamical "law of physics" is a mathematical
function that takes some boundary conditions as input, and generates a
prediction about some other physical state as output--for example, for
Newtonian gravity the inputs could be the positions, velocities and masses
of some objects at time T1, and the output could be their positions and
velocities at some later time T2. So "local" in the specific narrow sense
I'm using is a condition that ONLY deals with what inputs are necessary to
generate outputs, and has NOTHING to do with the function itself. If the
function takes as input boundary conditions that are restricted to the past
light cone of some region of spacetime R, and as output tells you the
values of local physical variables in that region R, and it can do this for
*any* region of spacetime R where you want to predict the local variables,
then this automatically qualifies the laws of physics as "local" according
to the narrow sense I am using (which again matches how Bell used it, if
can be found in the collection 'Speakable and Unspeakable in Quantum
Mechanics'). Hopefully this definition is clear, even if you find it
uninteresting.

> Rules that deal with non-locally produced statistical distributions can do
> anything you want -- vide my urn model -- they simply have nothing to do
> with physics, can teach us nothing about physics.
>

Your urn model does not qualify as "local" in my narrow sense above, in the
generate predictions about the results of each experimenter's measurement
in the region of spacetime where they performed the measurement, using only
information about physical variables in the past light cone of that region
(where the other experimenter's choic```

### Re: Non-locality and MWI

```On Tue, Apr 26, 2016 at 11:51 PM, Brent Meeker <meeke...@verizon.net> wrote:

>
>
> On 4/26/2016 8:38 PM, Jesse Mazer wrote:
>
>> OK, let's say experimenter A measures particle 1, and experimenter B
>> measures particle 2. Any given copy of particle 1 has a "label" that says
>> something about the state of 2--we can imagine that the copy of particle 1
>> carries a little clipboard on which is written down both its own quantum
>> state, and a quantum state it assigns to particle 2. When that copy of 1 is
>> measured, it not only adjusts its own state (to an eigenstate of the
>> measurement operator), it also adjusts the state it has written down for 2.
>> You seem to be assuming, in effect, that when a copy of 1 adjusts what it
>> has written down for the state of 2 on its own clipboard, this must mean
>> that copies of 2 also instantaneously adjust what they have written down
>> about *their* own state. However, in a copying-with-matching scheme,
>> there's no reason this need be the case!
>>
>
> That's pretty much the many-universes model that Bruno proposes. But it's
> non-local in the sense that the "matching scheme" must take account of
> which measurements are compatible, i.e. it "knows" the results even while
> they are  spacelike separated.
>

Why do you say that? Do you understand that in the type of scheme I am
talking about (and Mark Rubin too, I think), no "matching" between copies
of measurement-outcomes at different locations takes place at any location
in spacetime that doesn't lie in the future light cone of both measurements?

Jesse

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### Re: Non-locality and MWI

```On Wed, Apr 27, 2016 at 12:47 AM, Bruce Kellett
wrote:

> Your simulation assumes the quantum mechanical results. In other words, it
> assumes non-locality in order to calculate the statistics. Where does the
> cos^2(theta/2) come from in your analysis?
>

The question I asked you was whether you thought you could definitively
disprove the idea that all the observable statistics of QM could be
reproduced by rules that are "local" in the specific narrow sense I had
described to you--remember all that stuff about having computers
determining what the value of local variables at each point in spacetime
should be, using only information about the value of local variables in the
past light cone of that point, plus the general rules programmed into them
(which take that information about the past light cone as input, and spit
out the value of local variables at that point as output)? This is a narrow
and mathematically well-defined question (and is based specifically on how
Bell defined 'locality'), it's completely irrelevant to the question
whether or not the *idea* for the rules that I programmed into the
computers that perform these local calculations came from looking at some
equations that are written in a 'non-local' way (i.e., the equations
generate their predictions by evolving a single 'state vector' for the
entire spatially-distributed system). Do you understand this distinction
between the narrow, well-defined definition of "local rules" (if you're
inspired the rules themselves? And are you claiming that even if we
restrict our attention to the narrow definition of "local rules", you can
still say with 100% certainty that no such "local rules" can accurately

Jesse

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### Re: Non-locality and MWI

```On Tue, Apr 26, 2016 at 9:16 PM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 27/04/2016 1:13 am, Jesse Mazer wrote:
>
> On Tue, Apr 26, 2016 at 6:45 AM, Bruce Kellett <bhkell...@optusnet.com.au>
> wrote:
>
>>
>> You think that "the state of the other particle" refers to the quantum
>> state that would be assigned to B given only knowledge of the state of A
>> (as well as knowledge of how they were entangled originally). Actually,
>> that is the interpretation I gave the words, except I teased out what that
>> actually meant. From the entangled state, given A's state (result, say
>> |+>), you would assign a state |-> to B. But this is wrong for spacelike
>> separations -- the state B actually measures is exactly the same as the
>> state A measured: |psi> = (|+>|-> - |->|+>)/sqrt(2).
>>
>
> You use the full state if you just want to generate the total
> probabilities for various possible *joint* outcomes. But if you want a
> conditional probability of various outcomes *just for B* given knowledge of
> what measurement A got, this can be done in QM, in the Schroedinger picture
> you could project |psi> onto on eigenstate that corresponds to whatever
> definite outcome was measured on A, resulting in a different state vector
> for the combined system |psi'> which may lead to different probabilities of
> getting various results for B, but which does not assume any knowledge of
> what measurement was actually performed on B. I assume something similar is
> possible in the Heisenberg picture which Rubin is using, so I was
> speculating that he meant something like this when he talked about a label
> on one particle which says something about the state of the other particle.
>
>
> I am well aware of this, and I also thought that was probably what Rubin
> had in mind. The problem is that this simply sneaks non-locality in the
> back door -- neither Rubin nor you appear to realize this. This is often
> the problem I find with these attempts to give a local account of EPR --
> non-locality is built in unobtrusively!
>
> That is why I said that, in any strictly local account, if A gets |+>, B
> still measures the original |psi>. The measurement by A cannot *locally*
> affect the state that B measures (or vice versa).
>

OK, let's say experimenter A measures particle 1, and experimenter B
measures particle 2. Any given copy of particle 1 has a "label" that says
something about the state of 2--we can imagine that the copy of particle 1
carries a little clipboard on which is written down both its own quantum
state, and a quantum state it assigns to particle 2. When that copy of 1 is
measured, it not only adjusts its own state (to an eigenstate of the
measurement operator), it also adjusts the state it has written down for 2.
You seem to be assuming, in effect, that when a copy of 1 adjusts what it
has written down for the state of 2 on its own clipboard, this must mean
that copies of 2 also instantaneously adjust what they have written down
about *their* own state. However, in a copying-with-matching scheme,
there's no reason this need be the case! The state that particle 1 assigns
to particle 2 on its clipboard may just be for the purposes of later
matching--deciding which copy of 2 to "partner up with" once it can meet
them (or get some type of causal influence from them). The fraction of
copies of 2 that show a given result when B measure can still be totally
independent of what the various copies of 1 have written down on their
clipboards about the state *they* assign to 2.

For example, say we are using a particular setup where if particle 1 is
measured along a spatial vector V (say, one parallel to to the x-axis and
pointing in the +x direction) and gives a result +, that means if particle
2 is measured at a 120-degree angle from V, it will have a 75% chance of
giving the result + and a 25% chance of giving the result -. So if a given
copy of particle 1 is indeed measured along V and does give a result +, it
can adjust the state it assigns to particle 2 on its clipboard accordingly,
assigning 2 a state (or reduced density matrix) which has an
amplitude-squared of 0.75 for + at an orientation of 120 degrees from V. It
can pass on this clipboard information (Rubin's 'label') to copies of other
systems it interacts with, like the experimenter, who carry their own
clipboards/labels. Then if that copy of the experimenter later interacts
with particle 2 (or with some other particle or system that conveys
information about particle 2), the state assigned to 2 on the
experimenter's clipboard is used to decide which copy of particle 2 it
should be matched with. In this case, this could ensure that if it gets
matched to a copy of particle 2 that was indeed measured at an angle of 120
deg```

### Re: Non-locality and MWI

```On Tue, Apr 26, 2016 at 6:45 AM, Bruce Kellett
wrote:
>
>
> You think that "the state of the other particle" refers to the quantum
> state that would be assigned to B given only knowledge of the state of A
> (as well as knowledge of how they were entangled originally). Actually,
> that is the interpretation I gave the words, except I teased out what that
> actually meant. From the entangled state, given A's state (result, say
> |+>), you would assign a state |-> to B. But this is wrong for spacelike
> separations -- the state B actually measures is exactly the same as the
> state A measured: |psi> = (|+>|-> - |->|+>)/sqrt(2).
>

You use the full state if you just want to generate the total probabilities
for various possible *joint* outcomes. But if you want a conditional
probability of various outcomes *just for B* given knowledge of what
measurement A got, this can be done in QM, in the Schroedinger picture you
could project |psi> onto on eigenstate that corresponds to whatever
definite outcome was measured on A, resulting in a different state vector
for the combined system |psi'> which may lead to different probabilities of
getting various results for B, but which does not assume any knowledge of
what measurement was actually performed on B. I assume something similar is
possible in the Heisenberg picture which Rubin is using, so I was
speculating that he meant something like this when he talked about a label
on one particle which says something about the state of the other particle.

There is also another possibility along the same lines, which is that for
any entangled system in a pure state, you can construct a "reduced density
matrix" for some subsystem, which gives the probabilities of various
outcomes for measurements just on the subsystem alone (and the subsystem
could just be one particle in a multiparticle entangled system). This is
important in the analysis of decoherence, for example, where the approach
apparently involves treating both the subsystem and its environment as
being in a pure state, and then looking at how interactions between
subsystem and environment change the reduced density matrix for the
subsystem.

That is clearly wrong, so the details are irrelevant. If you think like a
> physicist, rather than as a mathematician, you look for the physics of what
> a paper is saying.
>
>
It isn't obviously wrong in my interpretation above, and I think it's
wrongheaded to imagine you can be confident about the interpretation of any
verbal statement by a physicist if you don't have a detailed grasp on the
mathematics of the model the physicist is talking about--if you don't you
may miss possible interpretations, like the ones above that you don't seem
to have considered.

Also, do you plan to respond to the rest of my comment? In particular, do
you think you can come up with any simple numerical examples that show a
local-copies-with-matching model can't correctly reproduce some observed
statistics at a given location if we assume that location has been
"shielded" from any physical influences from Alice or Bob (and assuming
'matching' between copies of Alice and copies of Bob can only be done in
regions that have received measurable physical signals from them), as you
seemed to claim earlier?

Jesse

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### Re: Non-locality and MWI

```On Mon, Apr 25, 2016 at 10:16 PM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 26/04/2016 5:52 am, Jesse Mazer wrote:
>
> On Mon, Apr 25, 2016 at 2:58 AM, Bruce Kellett <bhkell...@optusnet.com.au>
> wrote:
>
>>
>>
>> I think you may have missed a salient feature of my little story about
>> mismatching. The point to which I wish to draw attention is that Alice and
>> Bob do not know that they are in an impossible world until after they have
>> compared their experimental notes. In general, in order to do the matching
>> in a way that will preserve the quantum correlations, you have to know the
>> probabilities of the combined worlds in advance. But these probabilities
>> can be calculated only after Alice and Bob exchange notes.
>>
>
> What do you mean by "in advance"? There is no need to do any matching at
> all until you look at a patch of spacetime that is in the overlap of the
> future light cone of Alice's measurement and the future light cone of Bob's
> measurement; and at that point, of course information about what detector
> setting each one used can be available without violating locality.
>
>
> That, of course, is the issue. How is that information available? It only
> becomes available when Alice and Bob exchange notes -- there is no external
> indication of that information before that time.
>

Available to who? The human experimenters? Of course in a general
mathematical reformulation of quantum physics it would not actually be
necessary for any humans to be aware of some information for it to have a
physical effect. Any explicitly local model of physics should work a bit
like a cellular automata--imagine a tiny computer at each point in
(Bell's 'beables') at points in the past light cone, and uses them to
determine what the value of the local variables at that point should be.
The twist here would just be that the local variables at a given point
would be a superposition of different possible values--the "copies"--and we
can imagine the tiny computer at a given point C may need to do some
matching of copies of events at A and copies of events at B in order to
determine the set of copies at C.

> So you need to know the relative orientations and results in order to
>> calculate the probabilities required to get consistent matchings, but these
>> probabilities become available only after the matching is complete. In
>> other words, the model as proposed is incoherent.
>>
>
> To do the matching, you only need the statistics of the fraction of copies
> of Alice that used each setting, and the fraction of copies of Bob that
> used each setting, which were determined at the time each one made their
> measurement.
>
>
> The matching must be made separately for each copy of Alice and Bob.
> Overall statistics are relevant for matchings over repeated runs of the
> experiment, but not otherwise.
>

I don't know what you mean by "made separately for each copy". Say for
example a measurement made by Alice at one point in spacetime resulted in 3
copies A1, A2, A3 and a measurement made by Bob at a different point in
spacetime resulted in 3 copies B1, B2, B3. And say each copy sends a causal
influence (like a photon or some other particle) towards a third point P
that lies in the future light cone of both of these points, with the exact
nature of this causal influence being slightly different for each copy (for
example, A1 might send a photon with a different frequency than A2, and A3
might send a photon with a third different frequency). The computer at P
then receives the 3 slightly different copies of a causal influence from
Alice, and the 3 slightly different copies of a causal influence from Bob.
Then to determine the effect of the causal influences on copies P1,P2,P3 of
some physical system located at P, it uses some kind of matching rule;
let's say for example that it decides P1 was causally influenced by the
matched pair (A1,B2), P2 was influenced by the matched pair (A2,B1), and P3
was influenced by the matched pair (A3,B3). Does this fit your criteria for
a matching "made separately for each copy", and if not what part of this
account violates it?

>>
> Well, if they have some ideal perfect shielding that perfectly prevents
> any information from getting to a given point in the overlap of the future
> light cones, then by definition the probabilities for physical events at
> that point in spacetime won't depend on what result each got, so there's no
> need to do any matching up of their measurement results at that point.
>
>
> In which case their shielding has thwarted the quantum predictions.
>

I disagree, but if you think so, please present a specific ```

### Re: Non-locality and MWI

```On Mon, Apr 25, 2016 at 2:58 AM, Bruce Kellett
wrote:

>
>
> I think you may have missed a salient feature of my little story about
> mismatching. The point to which I wish to draw attention is that Alice and
> Bob do not know that they are in an impossible world until after they have
> compared their experimental notes. In general, in order to do the matching
> in a way that will preserve the quantum correlations, you have to know the
> probabilities of the combined worlds in advance. But these probabilities
> can be calculated only after Alice and Bob exchange notes.
>

What do you mean by "in advance"? There is no need to do any matching at
all until you look at a patch of spacetime that is in the overlap of the
future light cone of Alice's measurement and the future light cone of Bob's
measurement; and at that point, of course information about what detector
setting each one used can be available without violating locality.

>
> So you need to know the relative orientations and results in order to
> calculate the probabilities required to get consistent matchings, but these
> probabilities become available only after the matching is complete. In
> other words, the model as proposed is incoherent.
>

To do the matching, you only need the statistics of the fraction of copies
of Alice that used each setting, and the fraction of copies of Bob that
used each setting, which were determined at the time each one made their
measurement. These fractions can depend arbitrarily on what rule each one
used to pick their setting--for example, Alice could have used a
deterministic pseudorandom algorithm in which case all copies of Alice will
have chosen the same detector setting, or she could have used some
independent quantum experiment (say, one involving radioactive decay) to
choose her setting randomly with whatever probabilities she wanted, like
1/19 chance of setting 1, 5/19 chance of setting 2, and 13/19 chance of
setting 3, in which case those will be the fraction of copies of Alice that
chose each of those settings. Regardless of what the fractions were for
each of Alice and Bob individually, once you reach the first point in
spacetime where the future light cones of their measurements overlap, that
it doesn't necessarily have to, see below), and given that information it's
always possible to match them in a one-to-one way that gives the correct
quantum statistics. Do you disagree with this, and if so which point?

>
> Again, Alice and Bob might try to thwart such a scenario by careful
> shielding of their apparatus and not communicating with anyone. Once more,
> I don't think quantum mechanics can be stymied by silence and lead
> shielding.
>

Well, if they have some ideal perfect shielding that perfectly prevents any
information from getting to a given point in the overlap of the future
light cones, then by definition the probabilities for physical events at
that point in spacetime won't depend on what result each got, so there's no
need to do any matching up of their measurement results at that point.
Similarly, in the idealized Schroedinger's cat thought-experiment where the
inside of the box is perfectly shielded from leaking any information to the
outside, there is no need to match up copies of the experimenter outside
with copies of the cat inside, even if the experimenter is in the future
light cone of the event of the cat having been saved/killed. Only when
there is some physical event C whose local probability depends on the
results of both prior events A and B is there a need to do any
matching--and by definition, such a physical event C must have had some
nonzero probability of getting a "signal" from both measurement-events. And
in the many-worlds interpretation, C would actually be receiving a cluster
of copies of different possible signals whose statistics would reflect the
statistics of different measurement results.

>
> The real problem is that any theory which enables the gathering of such
> information from the results of environmental decoherence would have to
> involve radically new physics, of a kind that has never been seen before.
> This would have to be universal physics -- we can't just dream up an ad hoc
> theory that applies only to the correlations of entangled particles!
>

You still haven't given a clear answer the basic question I've been
persistently asking you about: do you claim there is any airtight argument,
akin to Bell's theorem (or perhaps based on Bell's theorem itself), which
would allow us to prove mathematically it's not *possible* to come up with
a local theory of copies and matching which is "general" in the sense of
reproducing the correct quantum predictions for *arbitrary* experiments? Or
what such a theory would need to look like, without claiming it's possible
to rule out ```

### Re: Non-locality and MWI

```On Fri, Apr 22, 2016 at 2:35 AM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 22/04/2016 2:46 pm, Jesse Mazer wrote:
>
> On Thu, Apr 21, 2016 at 11:25 PM, Bruce Kellett <bhkell...@optusnet.com.au
> > wrote:
>
>> On 22/04/2016 12:53 pm, Jesse Mazer wrote:
>>
>> On Thu, Apr 21, 2016 at 9:49 PM, Bruce Kellett <
>> <bhkell...@optusnet.com.au>bhkell...@optusnet.com.au> wrote:
>>
>>>
>>>
>>> The point here is that some combinations of results are forbidden. How
>>> can this happen?
>>>
>>
>> By the appropriate matching rules for locally-generated copies in
>> different locations, as in my toy model. There's no reason you can't have
>> something similar in a more general model, which I think is exactly what
>> people like Rubin are presenting.
>>
>>
>> The best I can make of this is that you have some theory that is not
>> quantum mechanics. Quantum mechanics does not give any such "matching rules"
>>
>
> It's important to distinguish between theories of physics and the
> mathematical models used to express them--a physical theory is defined
> entirely by the predictions about observable outcomes, not any elements of
> the model that are not directly measurable even in principle. For example,
> curved spacetime is not essential to general relativity as a theory, though
> it is a feature of the most commonly-used mathematical model (there is an
> alternate formulation that only uses flat spacetime, but has a field
> defined on this spacetime which varies the length of rulers and the ticking
> rate of clocks at different points in the spacetime, and physicists would
> still call this 'general relativity'). Likewise, a state vector in Hilbert
> space is not essential to quantum mechanics as a theory. And if one *could*
> come up with a model involving "matching rules" that would be equivalent in
> its predictions about observable measurement results as the existing
> mathematical models, this would merely be a new mathematical model for the
> same physical theory.
>
>
> It would seem that you are not a physicist! What you claim here about
> physics is actually quite contentious. It seems to constitute an extreme
> form of instrumentalism.
>

I don't think that's the case, I'm basically just talking about how
physicists *define* the physical content of a theory. But it would help if
you would define what you mean by "instrumentalism". For example, some
articles I found googling the term seem to say that it suggests we should
not assign any "reality" to elements of the theory beyond the predictions
about empirical measurements; I would say any talk of "reality" beyond
measurements is more of a philosophical issue than a scientific one, but I
don't see anything wrong with having opinions on such philosophical issues.
In particular, if there is an element that seems to show up in *all* our
mathematical models, like the notion of an "electron" which isn't absent
from any formulation of quantum electrodynamics, it certainly makes sense
to me to call it "real". Likewise, although we can't ever get evidence that
space and matter continue beyond the boundary of the observable universe,
it would require a very contrived model to avoid it (one which treated us
as being at the exact center of real space, for example), so disbelieving
it would to me seem like a ridiculous philosophical view, akin to solipsism
(speaking of which, I could also potentially come up with a solipsistic
interpretation of quantum physics in which I and only I am capable of
collapsing the wavefunction with my observations, but this would seem
equally ridiculous despite the fact that I can't come up with any
experiment that would falsify it for me).

Also, it seems from my googling that many instrumentalists would define the
validity of scientific theories solely in terms of what we humans can
actually verify in principle, giving up the notion of any objective truth
about nature independent of what humans know. If so, I am not taking this
position either. I'm saying the physical content of a theory is defined in
terms of the complete set of predictions about things that could *in
principle* be measured by some arbitrarily advanced physical being at the
right place and time (so the fact that we may have no way of verifying most
of the predictions of string theory at any time in the forseeable theory
does not disqualify it as a scientific theory, for example), and I
personally believe there is some objective truth about what mathematical
relationship describes the complete set of in-principle-measurable facts

The basic point I was making with my point about physics theories vs.
mathematical models is that I```

### Re: Non-locality and MWI

```On Thu, Apr 21, 2016 at 11:25 PM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 22/04/2016 12:53 pm, Jesse Mazer wrote:
>
> On Thu, Apr 21, 2016 at 9:49 PM, Bruce Kellett <bhkell...@optusnet.com.au>
> wrote:
>
>>
>>
>> The point here is that some combinations of results are forbidden. How
>> can this happen?
>>
>
> By the appropriate matching rules for locally-generated copies in
> different locations, as in my toy model. There's no reason you can't have
> something similar in a more general model, which I think is exactly what
> people like Rubin are presenting.
>
>
> The best I can make of this is that you have some theory that is not
> quantum mechanics. Quantum mechanics does not give any such "matching rules"
>

It's important to distinguish between theories of physics and the
mathematical models used to express them--a physical theory is defined
entirely by the predictions about observable outcomes, not any elements of
the model that are not directly measurable even in principle. For example,
curved spacetime is not essential to general relativity as a theory, though
it is a feature of the most commonly-used mathematical model (there is an
alternate formulation that only uses flat spacetime, but has a field
defined on this spacetime which varies the length of rulers and the ticking
rate of clocks at different points in the spacetime, and physicists would
still call this 'general relativity'). Likewise, a state vector in Hilbert
space is not essential to quantum mechanics as a theory. And if one *could*
come up with a model involving "matching rules" that would be equivalent in
its predictions about observable measurement results as the existing
mathematical models, this would merely be a new mathematical model for the
same physical theory.

If you disagree with any of this, please explain your disagreement. And if
you don't disagree that physics theories are defined solely in terms of
their predictions about measurement results, but you think there is
something intrinsically impossible about the idea that a mathematical model
involving "matching rules" could reproduce these predictions, please
explain the argument, because it clearly can't just be Bell's theorem.

> nor does it give any dynamics whereby such matching could be effected. So
> you no longer have an interpretation of quantum mechanics, you have a
> different theory. It remains for you to develop this in a way that is
> convincing.
>

But I am not claiming I can definitely present such a model--though as I
said, my *impression* is that Rubin's paper seems to be doing that--I'm
just disputing the idea that you can state with certainty that no such
model is possible, such that you are confident that Rubin's paper can't
contain an example without actually needing to read and understand it in
detail.

> Following back the train of information exchange between the participants,
>> and accepting that worlds, once decohered, cannot suddenly disappear, it
>> becomes apparent that the zero probability branches cannot arise because
>> they are forbidden at the stage when A and B are still at spacelike
>> separations. So they are forbidden non-locally.
>>
>
> But that clearly isn't true in my model, so there's no reason to think it
> *must* be true in more general models that reproduce arbitrary quantum
> measurements. In my model *and* in more general models of the sort that
> people like Rubin seem to be proposing, until matching between Alice and
> Bob has happened there *are* no "branches" containing facts about both of
> their results, only a set of local branches for one region and a different
> unrelated set of branches for another region. And once the two sets of
> branches can interact, they can be matched up in a way that creates zero
> probability of matching up a version of Alice who got + at zero degrees and
> a version of Bob who got + at zero degrees.
>
>
> But your model only reproduces the quantum correlations because you have
> put them in by hand. That is not a viable model of physics.
>

I didn't claim it was, I only claimed it demonstrated that Bell's theorem
does not present any fundamental obstacle to coming up with such a model.
Remember, Bell's theorem too deals only with the predicted quantum
correlations in specific experiments, and the proof doesn't depend at all
on what mathematical theory was used to derive those predicted correlations.

You claim that there are no branches containing facts about both A and B
> until this matching takes place. The rules for this matching presumably say
> that one must not match incompatible results. How is the matching done:
> does one pick one result, and search about for a match that does not
> violate the quantum statistics? You will ```

### Re: Non-locality and MWI

```On Thu, Apr 21, 2016 at 9:49 PM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 22/04/2016 5:17 am, Jesse Mazer wrote:
>
> On Wed, Apr 20, 2016 at 7:51 PM, Bruce Kellett <bhkell...@optusnet.com.au>
> wrote:
>
>> On 21/04/2016 1:34 am, Jesse Mazer wrote:
>>
>> On Tue, Apr 19, 2016 at 8:54 PM, Bruce Kellett <
>> <bhkell...@optusnet.com.au>bhkell...@optusnet.com.au> wrote:
>>
>>> So, the fact that these simulated results were supposed to have come
>>> from an entangled singlet pair has not been used anywhere in your
>>> simulation. It has only ever been used to link the copies of Alice and Bob,
>>> the statistics that they observe come entirely from what you happen to put
>>> in you accumulator for each setting of the relative orientations.
>>>
>>
>> Saying the idea of a singlet pair "has not been used anywhere in your
>> simulation" and then saying it has "been used to link the copies of Alice
>> and Bob" seems like a contradiction--isn't the linking itself part of the
>> simulation?
>>
>> No, there is no contradiction. You have used the fact that they are
>> measuring parts of an entangled system only to link the sets of results.
>> Nowhere have you used the quantum properties of the entangled singlet pair
>> in the simulation to calculate the probabilities: you have imposed those
>> probabilities from outside by fiat.
>>
>
> Sure, it's a toy model so I just tailor it to give the correct statistics
> for a single type of quantum experiment. But if I were to try to do the
> same thing in a scheme where there *weren't* multiple copies of Alice and
> Bob, so that each had to get a unique result *at the place and time they
> make a measurement* (not just later when they compare results), then Bell's
> theorem absolutely rules out doing this in any classical setup that
> respects locality, even toy models. So, the toy model is just mean to
> illustrate the principle that Bell's theorem isn't applicable to situations
> where measurements don't yield unique outcomes but just yield a bunch of
> different copies of a system at a given location in space at a given time.
>
>
> interesting. So you agree that you just feed in the statistics that you
> want to come out -- they do not come from any principle physics that your
> computers simulate.
>

Yes, but they do come from rules which generate the results at each point
in spacetime in a local way, depending only one what's in the past light
cone of that point, and which generate the desired statistics. This proves
the principle that Bell's theorem does not forbid rules of this "locally
generated results on arbitrary patches" sort from reproducing the
statistics of the particular experiments that Bell's theorem analyzes.
Thus, Bell's theorem presents no fundamental obstacle to the hope of
developing a set of rules that would generate correct results for *all*
possible measurable behaviors of quantum systems, and which are still of
the "locally generated results on arbitrary patches" type. Do you disagree?

>
> I am glad you agree that if you consider the actual physical situation,
> locality is ruled out by the observed statistics.
>

Why should I agree to that? As I said, it obviously isn't ruled out by
Bell's theorem, and if you have an alternate argument, you didn't respond
to my request to present it in detail.

> The fact that a measurement might yield one of a series of different
> results does not alter the fact that, in the multiworlds picture, there is
> only one result in each possible branch.
>

There are no such things as global "branches" in my toy model, only local
copies of Alice and local copies of Bob that retroactively get matched up.
Similarly, What Deutsch/Hayden/Rubin are all saying is that the same is
true in their view of the many-worlds interpretation--there are no global
branches, only local ones that join together in retrospect. If you disagree
that this is what *they* are suggesting, I can give some quotes that show
that this is their interpretation (along with other physicists talking
about the MWI and saying the same thing--for example, I was just looking
over a paper by the founder of the study of decoherence, H. Dieter Zeh,
where he said essentially the same thing). If you agree this is what *they*
try to suggest but think this is somehow incoherent, please present an
argument for *why* it's incoherent as a general model of the laws of
physics, when it clearly works fine in the toy model.

> Once you accept this general principle, you can see that Bell's theorem
> doesn't offer any fundamental obstacle to reformulating the general laws of
> quantum mechanics in a way that yields the same predictions```

### Re: Non-locality and MWI

```On Wed, Apr 20, 2016 at 7:51 PM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 21/04/2016 1:34 am, Jesse Mazer wrote:
>
> On Tue, Apr 19, 2016 at 8:54 PM, Bruce Kellett <bhkell...@optusnet.com.au>
> wrote:
>
>> So, the fact that these simulated results were supposed to have come from
>> an entangled singlet pair has not been used anywhere in your simulation. It
>> has only ever been used to link the copies of Alice and Bob, the statistics
>> that they observe come entirely from what you happen to put in you
>> accumulator for each setting of the relative orientations.
>>
>
> Saying the idea of a singlet pair "has not been used anywhere in your
> simulation" and then saying it has "been used to link the copies of Alice
> and Bob" seems like a contradiction--isn't the linking itself part of the
> simulation?
>
> No, there is no contradiction. You have used the fact that they are
> measuring parts of an entangled system only to link the sets of results.
> Nowhere have you used the quantum properties of the entangled singlet pair
> in the simulation to calculate the probabilities: you have imposed those
> probabilities from outside by fiat.
>

Sure, it's a toy model so I just tailor it to give the correct statistics
for a single type of quantum experiment. But if I were to try to do the
same thing in a scheme where there *weren't* multiple copies of Alice and
Bob, so that each had to get a unique result *at the place and time they
make a measurement* (not just later when they compare results), then Bell's
theorem absolutely rules out doing this in any classical setup that
respects locality, even toy models. So, the toy model is just mean to
illustrate the principle that Bell's theorem isn't applicable to situations
where measurements don't yield unique outcomes but just yield a bunch of
different copies of a system at a given location in space at a given time.

Once you accept this general principle, you can see that Bell's theorem
doesn't offer any fundamental obstacle to reformulating the general laws of
quantum mechanics in a way that yields the same predictions about *all*
observations using purely local equations, of the kind that could be
simulated on a computer where you have a bunch of separate computers
calculating how physical variables are evolving in a confined region of
space, and each computer can only get data from other computers
representing neighboring regions, in a locality-respecting way. As I said,
my reading of the non-mathematical parts of Mark Rubin's paper suggests
that the paper is coming up with exactly such a model, albeit one that is
only equivalent to a non-relativistic quantum field theory (perhaps the
math of doing it for a relativistic field theory would be more difficult).

You seem to be saying this is impossible in principle, and you're confident
enough of this to dismiss the possibility Rubin's paper has done this
without apparently understanding the mathematical details either. So, given
what I said above, should I take this to mean you think you have an
argument for the impossibility which is entirely independent of Bell's
theorem? If so you could you try to spell it out in a more detailed,
step-by-step way?

> No, I am simulating the system as it stands after Alice and Bob have
> communicated, written their results on the tokens, and put them in the
> appropriate urns. All completely local.
>

But then you are not simulating the observations each one gets at arbitrary
times in a local way (the condition I mentioned earlier about all results
being generated by the computers in realtime), your method is limited to a
specific time after they have communicated. Bell's theorem is specifically
about the impossibility of a local theory in which the results of each
measurement must be generated when neither measurement result (or choice of
detector setting) can have had a causal influence on the other (a spacelike
separation in the context of relativity), and getting the correct
statistics on the joint results. My toy model is meant to illustrate the
point that Bell's theorem depends on the implicit assumption that each
measurement yields a single unique result, and if you relax this and allow
multiple copies, then you can have a theory which is still local and still
generates the initial measurements at a spacelike separation, and also
yields the correct joint outcomes for a randomly-selected copy of the
experimenter once there's been time for the results to be communicated.

>
> Since you are accumulating joint results according to the statistics that
> you have calculated on the basis of standard quantum mechanics, completely
> independently of the properties of the actual singlets states that Alice
> and Bob measure, my example is exactly equivalent to yours.
>

My example is relevant to Bell's theorem for the```

### Re: Non-locality and MWI

```On Tue, Apr 19, 2016 at 8:54 PM, Bruce Kellett
wrote:
>
> So, the fact that these simulated results were supposed to have come from
> an entangled singlet pair has not been used anywhere in your simulation. It
> has only ever been used to link the copies of Alice and Bob, the statistics
> that they observe come entirely from what you happen to put in you
> accumulator for each setting of the relative orientations.
>

Saying the idea of a singlet pair "has not been used anywhere in your
simulation" and then saying it has "been used to link the copies of Alice
and Bob" seems like a contradiction--isn't the linking itself part of the
simulation? After all, getting a message from Bob is part of the simulated
world that Alice experiences, just as much as her own measurement. What we
have here is just a single distributed simulation being run on multiple
computers computing different parts of it in parallel, and communicating
data in order to determine interactions between those parts. Any local
physics model can be simulated in such a way, including ones that don't
involve "copies" existing in parallel in a given region--for example, space
can be divided into a cubic grid and each computer can compute the internal
dynamics in each cube, and computers that simulate cubes that share a face
in common can share there data so that particles or waves leaving one cube
through a given face will appear in the neighboring cube from the same
face. This would still be one big simulation, just computed in a
distributed way. And the fact that you *can* distribute the computation of
the whole universe into a bunch of local sub-simulations that communicate
only with their neighbors is true if and only if the laws of physics
governing your universe are "local" ones.

>
> I agree that you can generate the required statistics locally in this way.
> In fact, I can do it even more simply by taking a number of urns and
> labelling each with a particular relative orientation, say parallel,
> antiparallel, 90 degrees, and so on. In the "parallel" urn I place a number
> of tokens labeled (A+B-) and an equal number labelled (A-B+). In the
> "antiparallel" urn, I place a number of tokens labelled (A+B+), and an
> equal number labelled (A-B-). In the "90 degree" urn I place a number of
> tokens labelled (A+B+), an equal number labelled (A+B-), an equal number
> labelled (A-B+), and finally an equal number labelled (A-B-).
>

I don't see how your method would be a *local* simulation though. In order
for it to be local, you'd need to set things up so Alice first picks her
result from one of three urns at her location, and Bob first picks his
result from one of three urns at his location, and they can see the result
of their own pick before either one knows which urn the other one picked
from.

> But that is precisely what you toy model does. It has absolutely no
> connection with EPR or real experiments. One could generate any arbitrary
> set of statistics to satisfy any theory whatsoever by this method. You have
> demonstrated absolutely nothing about the locality or otherwise of EPR.
>

Would you agree that in my toy model the results at each location can be
generated in realtime (each experimenter finds out their own result before
finding out the other one's result, and before they have any way of knowing
what detector setting the other one used), and in a local way (the rule
that generates a result that appears at a particular position and time
doesn't depend on anything outside the past light cone of that event), and
that the subjective probabilities for each experimenter match those of the
EPR experiment? If you agree but think your urn model is doing the same,
please explain it in more detail because as I said, your short description
above doesn't seem to me to have these characteristics.

Jesse

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```

### Re: Non-locality and MWI

```On Tue, Apr 19, 2016 at 12:06 AM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 19/04/2016 10:23 am, Jesse Mazer wrote:
>
> On Mon, Apr 18, 2016 at 3:45 AM, Bruce Kellett <bhkell...@optusnet.com.au>
> wrote:
>
>>
>> The local mathematical rule in this case, say for observer A, is that
>> measurement on his own local particle with give either |+> or |->, with
>> equal probability. It does not matter how many copies you generate, the
>> statistics remain the same. I am not sure whether your multiple copies
>> refer to independent repeats of the experiment, or simply multiple copies
>> of the observer with the result he actually obtained. The set of outcomes
>> on the past light cone for this observer is irrelevant for the single
>> measurement that we are considering. Taking such copies can be local, but
>> the utility remains to be demonstrated.
>>
>
>
> Sorry if I was unclear, I thought we were on the same page about the
> notion of "copies". The copies in my toy model are supposed to represent
> the idea in the many-worlds that there are multiple equally-real versions
> of a single system at a single location at a single time, including human
> experimenters, and that in any quantum experiment some versions will record
> one result and others will record a different one. So the copies represent
> different parallel versions of a simulated observer, and just as in the
> MWI, some copies see one result and other copies see a different result for
> any *single* experiment (and each copy retains a memory, so different
> copies remember different sequences of past results as well). And as in the
> MWI, these copies would be unaware of one another--just imagine several
> simulations of the same experimenter at the same time running in parallel,
> with different variations on what results the simulation feeds to them.
>
>
> I have a couple of questions. Firstly, does the ensemble generated in this
> way differ in any significant respect from the one generated if the same
> Alice and Bob perform their (random orientation) measurements a large
> number of times?
>

If the probability of them selecting each possible detector setting on this
single measurement is the same as the frequency with which they would
select each detector setting on a large number of trials, then the
statistics of results will also be the same.

> And secondly, what exactly are they performing their measurements on? On
> random unpolarized particles? or always on one of the particles of an
> entangled singleton pair?
>

Within the context of the simulation, they are measuring the two members of
an entangled pair. But the computer doesn't use any *actual* input from
real-world instruments measuring entangled particle pairs, all computations
and inputs are classical ones.

> In the latter case, one would assume that we have to keep track of which
> Alice result comes from the same pair as which Bob result. In other words,
> the ensemble is identical to the one generated by many runs of the same
> experiment, on entangled pairs, by the same observes.
>

That's true, the point here is just that you can generate these statistics
using what I would define to be a "local" set of rules (see the bottom of
this message for a discussion of what I understand 'local' rules to mean),
and each copy has the *experience* of making only a single measurement and
getting a single reported measurement from the other experimenter.

>
>
> A common topic of discussion on everything-list is the subject of
> "first-person indeterminacy", which would be expected to result when the
> pattern of a given physical brain is duplicated (I haven't been following a
> lot of recent threads so I don't know if you've already weighed in on this
> topic before). You could imagine an actual atom-for-atom duplicate of a
> biological person, but to avoid objections based on the uncertainty
> principle and no-cloning theorem, let's instead suppose the person in
> question is that of a "mind upload"--a very realistic simulation of a human
> brain (at the level of synapses or lower) running on a computer, which most
> on this list would assume would be just as conscious as a biological brain.
> If the computer is a deterministic classical one, then if the simulated
> brain is in a simulated body in a simulated environment which is closed off
> from outside input and that also evolves deterministically, then if a copy
> is made of the program with the same starting conditions and the copies run
> in parallel on two different computers, the behavior (and presumably inner
> experiences) of the upload should be the same. But say that after the two
> programs have been running in paralle```

### Re: Non-locality and MWI

```On Mon, Apr 18, 2016 at 3:45 AM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 18/04/2016 5:00 pm, Jesse Mazer wrote:
>
> On Mon, Apr 18, 2016 at 1:37 AM, Bruce Kellett <bhkell...@optusnet.com.au>
> wrote:
>
>> On 18/04/2016 2:53 pm, Jesse Mazer wrote:
>>
>> On Sun, Apr 17, 2016 at 9:19 PM, Bruce Kellett <
>> <bhkell...@optusnet.com.au>bhkell...@optusnet.com.au> wrote:
>>
>>> On 18/04/2016 10:11 am, Jesse Mazer wrote:
>>>
>>> On Sun, Apr 17, 2016 at 7:34 PM, Bruce Kellett <
>>> <bhkell...@optusnet.com.au>bhkell...@optusnet.com.au> wrote:
>>>
>>>>
>>>> The future light cones of the observers will overlap at a time
>>>> determined by their initial separation, regardless of whether they send
>>>> signals to each other or not.
>>>>
>>>
>>> Of course, I never meant to suggest otherwise. Imagining a central
>>> simpler than imagining an arbitrary system that is affected in some
>>> unspecified way by each experimenter's results along with every other part
>>> of that system's past light cone. But you certainly don't *need* to use
>>> that particular example.
>>>
>>>
>>> The issue is to find a local explanation of the correlations: appealing
>>> to some arbitrary system that is affected in some unspecified way. But my
>>> example shows that no exchange of information after the separate worlds of
>>> the two experimenters have fully decohered can ever explain the quantum
>>> correlations.
>>>
>>
>> Why do you think it shows that? Does "explain" mean something more than
>> giving a mathematical model that generates the correct correlations, or is
>> that sufficient?
>>
>>
>> Have you not understood my argument? The specified experiment results in
>> four possible combinations of results: |+>|+'>, |+>|-'>, |->|+'>, and
>> |->|-'>. It is relatively easy to show, either by looking at special cases,
>> or by consideration of a repeated sequence of such experiments, that the
>> probabilities are different for each of the four sets of results. The
>> differences in probability depend only on the relative orientations of the
>> measuring magnets. Conveying this angle information after the experiment
>> has been completed, and each of the measurements has totally decohered,
>> cannot explain these correlations.
>>
>> What is required is an account of how these correlations can arise
>> *before* A and B speak to each other, because once they have their
>> results in hand, it may be weeks before they actually communicate. Rubin's
>> argument (following from Deutsch) does not achieve this.
>>
>
>
> But as I said, you can achieve it if there is no fact of the matter about
> *both* results except in the overlap region of the future light cone of
> both measurements, where a single localized system may be causally
> influenced by both measurements (see below for more on what I mean by this
> if you're unclear).
>
>
>
>>
>>
>> This so-called "matching up" is pure fantasy. Who does this matching? If
>>>> the central umpire is to do the matching, he has to have the power to
>>>> eliminate cases that disagree with the quantum prediction. Who has that
>>>> power?
>>>>
>>>
>>>
>>> The laws of physics would do the matching in some well-defined
>>> mathematical way.
>>>
>>>
>>> I agree that the laws of physics will 'prevent' the formation of any
>>> worlds in which the laws of physics are violated. That is not the issue.
>>> The issue is: how do the laws of physics act in order to achieve this. Do
>>> they act locally or non-locally? If they act locally, then you are required
>>> to provided the local mechanism whereby they so act. You are not doing this
>>> at the moment.
>>>
>>
>> Similar to my question above, what do you mean by "mechanism" ? Do you
>> mean something more than simply "mathematical rule that gives you the set
>> of possible outcomes (with associated probabilities or at least probability
>> amplitudes) at each local region of spacetime, given only the set of
>> possible outcomes at regions in the past light cone"?
>>
>>
>> The mathematical rule that gives the differing probabilities for each
>> outcome depending on the relative angle of the magnets is just qua```

### Re: Non-locality and MWI

```On Mon, Apr 18, 2016 at 1:37 AM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 18/04/2016 2:53 pm, Jesse Mazer wrote:
>
> On Sun, Apr 17, 2016 at 9:19 PM, Bruce Kellett <bhkell...@optusnet.com.au>
>  wrote:
>
>> On 18/04/2016 10:11 am, Jesse Mazer wrote:
>>
>> On Sun, Apr 17, 2016 at 7:34 PM, Bruce Kellett <
>> <bhkell...@optusnet.com.au>bhkell...@optusnet.com.au> wrote:
>>
>>>
>>> The future light cones of the observers will overlap at a time
>>> determined by their initial separation, regardless of whether they send
>>> signals to each other or not.
>>>
>>
>> Of course, I never meant to suggest otherwise. Imagining a central
>> simpler than imagining an arbitrary system that is affected in some
>> unspecified way by each experimenter's results along with every other part
>> of that system's past light cone. But you certainly don't *need* to use
>> that particular example.
>>
>>
>> The issue is to find a local explanation of the correlations: appealing
>> to some arbitrary system that is affected in some unspecified way. But my
>> example shows that no exchange of information after the separate worlds of
>> the two experimenters have fully decohered can ever explain the quantum
>> correlations.
>>
>
> Why do you think it shows that? Does "explain" mean something more than
> giving a mathematical model that generates the correct correlations, or is
> that sufficient?
>
>
> Have you not understood my argument? The specified experiment results in
> four possible combinations of results: |+>|+'>, |+>|-'>, |->|+'>, and
> |->|-'>. It is relatively easy to show, either by looking at special cases,
> or by consideration of a repeated sequence of such experiments, that the
> probabilities are different for each of the four sets of results. The
> differences in probability depend only on the relative orientations of the
> measuring magnets. Conveying this angle information after the experiment
> has been completed, and each of the measurements has totally decohered,
> cannot explain these correlations.
>
> What is required is an account of how these correlations can arise
> *before* A and B speak to each other, because once they have their
> results in hand, it may be weeks before they actually communicate. Rubin's
> argument (following from Deutsch) does not achieve this.
>

But as I said, you can achieve it if there is no fact of the matter about
*both* results except in the overlap region of the future light cone of
both measurements, where a single localized system may be causally
influenced by both measurements (see below for more on what I mean by this
if you're unclear).

>
>
> This so-called "matching up" is pure fantasy. Who does this matching? If
>>> the central umpire is to do the matching, he has to have the power to
>>> eliminate cases that disagree with the quantum prediction. Who has that
>>> power?
>>>
>>
>>
>> The laws of physics would do the matching in some well-defined
>> mathematical way.
>>
>>
>> I agree that the laws of physics will 'prevent' the formation of any
>> worlds in which the laws of physics are violated. That is not the issue.
>> The issue is: how do the laws of physics act in order to achieve this. Do
>> they act locally or non-locally? If they act locally, then you are required
>> to provided the local mechanism whereby they so act. You are not doing this
>> at the moment.
>>
>
> Similar to my question above, what do you mean by "mechanism" ? Do you
> mean something more than simply "mathematical rule that gives you the set
> of possible outcomes (with associated probabilities or at least probability
> amplitudes) at each local region of spacetime, given only the set of
> possible outcomes at regions in the past light cone"?
>
>
> The mathematical rule that gives the differing probabilities for each
> outcome depending on the relative angle of the magnets is just quantum
> mechanics. But that is intrinsically non-local
>

I specified that I was talking about a local mathematical rule--I said the
rule would give out the outcomes at one location in spacetime "given only
the set of possible outcomes at regions in the past light cone". Did you
miss that part, or do you disagree that if I mathematically determine the
state of some region of spacetime using *only* information about the states
of regions in the past light cone, that is by definition a local theory?

>
> You are claiming to have a```

### Re: Non-locality and MWI

```On Sun, Apr 17, 2016 at 9:19 PM, Bruce Kellett <bhkell...@optusnet.com.au>
wrote:

> On 18/04/2016 10:11 am, Jesse Mazer wrote:
>
> On Sun, Apr 17, 2016 at 7:34 PM, Bruce Kellett <bhkell...@optusnet.com.au>
>  wrote:
>
>>
>> The future light cones of the observers will overlap at a time determined
>> by their initial separation, regardless of whether they send signals to
>> each other or not.
>>
>
> Of course, I never meant to suggest otherwise. Imagining a central
> simpler than imagining an arbitrary system that is affected in some
> unspecified way by each experimenter's results along with every other part
> of that system's past light cone. But you certainly don't *need* to use
> that particular example.
>
>
> The issue is to find a local explanation of the correlations: appealing to
> some arbitrary system that is affected in some unspecified way. But my
> example shows that no exchange of information after the separate worlds of
> the two experimenters have fully decohered can ever explain the quantum
> correlations.
>

Why do you think it shows that? Does "explain" mean something more than
giving a mathematical model that generates the correct correlations, or is
that sufficient?

> This so-called "matching up" is pure fantasy. Who does this matching? If
>> the central umpire is to do the matching, he has to have the power to
>> eliminate cases that disagree with the quantum prediction. Who has that
>> power?
>>
>
>
> The laws of physics would do the matching in some well-defined
> mathematical way.
>
>
> I agree that the laws of physics will 'prevent' the formation of any
> worlds in which the laws of physics are violated. That is not the issue.
> The issue is: how do the laws of physics act in order to achieve this. Do
> they act locally or non-locally? If they act locally, then you are required
> to provided the local mechanism whereby they so act. You are not doing this
> at the moment.
>

Similar to my question above, what do you mean by "mechanism" ? Do you mean
something more than simply "mathematical rule that gives you the set of
possible outcomes (with associated probabilities or at least probability
amplitudes) at each local region of spacetime, given only the set of
possible outcomes at regions in the past light cone"? Or would you say that
such a mathematical rule would in itself be sufficient to qualify as what
you mean by "mechanism"? If the latter, I already showed that you can have
a mathematical rule that generates the correct correlations locally in a
simple toy model involving experimenters at different locations measuring
entangled particles, and I think the quote from Mark Rubin's paper at least
strongly suggests he has a general mathematical model like this for
arbitrary sets of particles, one where as he says, information is
transferred from one location to another by a strictly "local differential
equation".

> If you don't yet see the difference, then you need to think about it a bit
> more.
>

Could you please explain what *you* think is the difference? Just because
someone doesn't come to the same conclusion as you doesn't mean they have
simply failed to think about it sufficiently, it may be that there is some
genuine foundational disagreement, but it's hard to determine unless the
argument for the differing conclusion is made explicit.

> Of course, what else? But the final claim is invalid: the EPR correlations
> are not explained in such a way in the Everett (or any other)
> interpretation. You either have non-locality or you have magic, unless you
> go for 't Hooft's version of superdeterminism. You seem to be plumping for
> magic.
>

Well, as above, I don't know whether "magic" simply refers to the lack of a
mathematical rule, or if you think some rules that are mathematically
well-defined and generate the correct statistics in a local way would
nevertheless be dismissed as too magical.

Jesse

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### Re: Non-locality and MWI

```On Sun, Apr 17, 2016 at 7:34 PM, Bruce Kellett
wrote:

>
> The future light cones of the observers will overlap at a time determined
> by their initial separation, regardless of whether they send signals to
> each other or not.
>

Of course, I never meant to suggest otherwise. Imagining a central observer
than imagining an arbitrary system that is affected in some unspecified way
by each experimenter's results along with every other part of that system's
past light cone. But you certainly don't *need* to use that particular
example.

>
>> This so-called "matching up" is pure fantasy. Who does this matching? If
> the central umpire is to do the matching, he has to have the power to
> eliminate cases that disagree with the quantum prediction. Who has that
> power?
>

The laws of physics would do the matching in some well-defined mathematical
way. I don't see this as fundamentally different from the fact that the
laws of electromagnetism can be written in a form where the electric and
magnetic potentials at each point in spacetime can be found by summing the
potentials from all the charges and currents on the entire past light cone
of that point (this neat approach is known as 'Lienard-Wiechert
potentials', see https://www.av8n.com/physics/lienard-wiechert.htm for some
discussion). Is it meaningful in that case to ask "who" is keeping track of
each individual charge or current on the past light cone and adding up
their potentials correctly to get the total?

Also, what do you mean "eliminate cases"? Are you suggesting the
frequencies of copies of each experimenter that get different possible
results would have to be retroactively changed? I'm pretty sure that
wouldn't be necessary, at least it isn't in the toy model I suggested. If
on the other hand you just mean the laws are ensuring that you don't get
combinations that aren't allowed by the laws themselves, again that just
seems like the sort of thing you'd expect mathematical laws of physics to
do. As I said, I don't understand the details of the Mark Rubin papers, but
on p. 19-20 of the paper at http://arxiv.org/abs/quant-ph/0204024 he gives
a more qualitative description of the model that the prior parts of the
paper have explained mathematically, and it at least sounds as though it
works in this way:

"Information encoded in an operator at one place at an earlier time is
transfered to operators at other places at later times in accordance with a
local differential equation. (In a relativistic theory information is only
transferred to later-time operators within the future light cone of the
earlier-time operator.) Operator- valued wave packets corresponding to
initially-separated particles may come into contact and exchange
information. At any time, at any location, the value of the field operator
is a weighted sum of products of initial-time field operators, as in (154),
(155) (of course higher-order terms will in general be present). As one
wave packet passes by another it may acquire contributions to this weighted
sum which were “carried” to the interaction region by another wave packet
corresponding to another particle. (E.g., via the O(ε) change to φ_V,[r]i
due to the interaction term in eq. (154).) At later times operators in this
wave packet will retain these contributions, serving as labels indicating
that the encounter with the other wave packet took place. Depending on the
nature of the initial conditions and the interaction, distant field
operators at times subsequent to the interaction may be entangled in such a
way that the results of measurements made upon them (when compared at still
later times by means of some other causal interaction) are correlated to a
degree in excess of that allowed by Bell’s theorem.5 As discussed in Ref.
22, correlations in the Everett interpretation are correlations of
information exchanged in a causal manner between copies of measuring
instruments and/or the states of awareness of observers, so these excess
correlations in no way imply the presence of nonlocality."

Jesse

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### Re: Non-locality and MWI

```"A and B perform their measurements at spacelike separation, but each
chooses the measurement orientation outside the light cone of the other.
There are four possible combinations of results, corresponding to four
worlds in the MWI: |+>|+'>, |+>|-'>, |->|+'>, and |->|-'>. Since each
observer has a 50% chance of getting |+> and 50% of getting |->, and the
two measurements are completely independent of each other, it would seem
that each of these four worlds is equally likely."

I don't think this is how it's supposed to work for those who argue the MWI
is local like Deutsch. Rather the idea is that "splitting" into worlds is
local, not global; so one experimenter locally splits into copies that see
|+> and |-> when they measure their particle, likewise the other
experimenter splits into copies that saw |+'> and |-'>. But until their
future light cones overlap there are no "worlds" containing facts about
what *both* experimenters saw. And once they do overlap--say, because they
both sent signals about their results to an experimenter at the midpoint
between them--then they can be matched up appropriately based on
information in the past light cone of the overlap region, including
information about what detector setting each copy of each experimenter
used. So if both experimenters used the same detector setting, then if we
consider the copy of the middle observer who gets matched up with the copy
of the left experimenter that got |+>, he must also be matched up with the
copy of the right experimenter that got |-'>, and likewise the copy of the
middle observer who gets matched up with the copy of the left experimenter
who got |-> must be matched up with the copy of the right experimenter that
got |+'>. You could design a cellular-automata like system that keeps track
of multiple copies of each system at a given "cell" in this sort of way,
and reproduces the statistics seen in Bell experiments, so the idea is at
least in principle consistent (I described a simple toy model at
). Although from what I've read, the "preferred basis problem" means the
current formulation of the MWI has trouble getting probabilities from the
universal wavefunction in any simple frequentist way (one where you have a
well-defined "fraction of copies with property X vs. fraction with property
Y" for each local region of spacetime, and probability is simply
interpreted in terms of this fraction), instead probabilities are usually
derived in non-frequentist ways using things like decision theory. Maybe in
the future a nice frequentist version of the Everett interpretation will be
found though...I don't understand the details, but I think Mark Rubin has
been trying to get closer to something like this in the papers at
http://arxiv.org/abs/quant-ph/0204024 and
http://arxiv.org/abs/quant-ph/0511188 and http://arxiv.org/abs/0909.2673

Jesse

On Fri, Apr 15, 2016 at 8:33 PM, Bruce Kellett
wrote:

> On 16/04/2016 12:20 am, Bruno Marchal wrote:
>
> On 14 Apr 2016, at 14:31, Bruce Kellett wrote:
>
> Although all possible combinations of measurement outcomes exist in MWI,
> it is not clear what limits the results of the two observers to agree with
> quantum mechanics when they meet up in just one of the possible worlds.
>
>
> Because they have separated locally, and Alice's measurement just inform
> both of them (directly for Alice and indirectly for Bob once some classical
> bit of information is communicated by Alice to Bob by the usual means).
>
>
> This is the purported solution given by Deutsch and Hayden, amongst many
> others. Unfortunately, it does not work, as can be demonstrated by working
> through a specific example.
>
> Consider the usual case of a spin singlet that splits into two spin-half
> components that separate and are measured by A and B at spacelike
> separation. There are two possible measurement results for each observer,
> call them |+> and |->. The entangled state can then be written as:
>
>|psi> = (|+>|-> - |->|+>).
>
> ignoring normalization factors for simplicity. The first ket applies to
> observer A and the second to observer B.
>
> This is the general expression for the singlet state in any basis, such as
> would be define by the orientation of the measuring magnets. We denote the
> measurement results in some other direction as |+'> and |-'>.
>
> A and B perform their measurements at spacelike separation, but each
> chooses the measurement orientation outside the light cone of the other.
> There are four possible combinations of results, corresponding to four
> worlds in the MWI: |+>|+'>, |+>|-'>, |->|+'>, and |->|-'>. Since each
> observer has a 50% chance of getting |+> and 50% of getting |->, and the
> two measurements are completely independent of each other, it would seem
> that each of these four worlds is equally likely.
>
> But this conclusion is contradicted ```

### Re: Anna Stubblefield

```Isn't there a pretty strong consensus among the experts that "facilitated
communication" is actually a Ouija board like phenomenon where the
facilitator is actually determining all the letters through small muscle
movements (the 'ideomotor effect'), whether consciously or subconsciously?
>From what I understand, whenever they do tests where the disabled person is
exposed to some sensory information that the facilitator doesn't have
access to, they always appear to be ignorant of this information in the
against it:

http://www.skeptic.com/eskeptic/06-05-25/

This is also discussed in the article Brent linked to, and although it
mentions that Anna believed some studies showed it work, no mention is made
of any studies with this type of protocol where the facilitator has no way
of knowing the answer but the disabled person should. The explanation that
the facilitators don't want to put the disabled subjects on display like
"show ponies" is unconvincing--surely it should be up to the disabled
subjects to decide for themselves, and it would be a rather amazing
uniformity of opinion among a large and diverse group if they *all* refused
to participate in such tests (especially given that solid evidence of
facilitated communication being genuine would probably result in
considerable mainstreaming, meaning a lot more disabled people would get
the opportunity to use it in the future).

Jesse

On Tue, Oct 20, 2015 at 6:59 PM, Brent Meeker  wrote:

> A strange, and sad, case.  But Facilitated Communication would seem to be
> a corollary of Bruno's idea that conscious persons are "out there" in
> platonia and just need the proper physics in order to interact with us.
>
>
> http://www.nytimes.com/2015/10/25/magazine/the-strange-case-of-anna-stubblefield.html?_r=0
>
> Brent Meeker
>
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### Re: MGA revisited paper

```On Sun, Aug 17, 2014 at 11:49 PM, Stathis Papaioannou stath...@gmail.com
wrote:

On Sunday, August 17, 2014, meekerdb meeke...@verizon.net wrote:

On 8/16/2014 10:16 AM, Stathis Papaioannou wrote:

On 16 August 2014 10:16, meekerdb meeke...@verizon.net wrote:
On 8/15/2014 4:34 PM, Stathis Papaioannou wrote:

I think these sorts of considerations show that the physical states
cannot
be responsible for generating or affecting consciousness.

How do they show that?  I thought they only showed that CC and
environmental
reference were necessary to consciousness.  Are you assuming that the
playback of a recording IS conscious?

If it is true that a recording is conscious or the random states of a
rock are conscious then I think that does imply that physical states are
irrelevant to consciousness. But the argument goes that this irrelevance of
physical states is absurd, so some restriction is imposed on what can be
conscious in order to avoid the absurdity. One possible restriction is that
consciousness only occurs if the computations are implemented relative to
an environment, another is that the counterfactuals be present. But these
are ad hoc restrictions, no better than saying that consciousness can only
occur in a biological substrate.

The immediate objection to this is that physical changes in the brain
*do*
affect consciousness. But if physical states cannot be responsible for
generating or affecting consciousness, there can be no evidence for a
separate, fundamental physical world. What we are left with is the
platonic
reality in which all computations are realised and physical reality
is a
simulation. It is meaningless to ask if consciousness supervenes on
the
computations implemented on the simulated rock or the simulated
recording.

It's not meaningless to ask if there must be simulated physics for the
simulated consciousness to supervene on.  Do you think you could be
conscious of a world with no physics?

Both consciousness and physics supervene on the computations, which
exist necessarily. Consciousness does not supervene on the physics.

Yes, I agreed to that.  The question was can consciousness supervene on
computations that do not instantiate any physics?  I think not.

I think that a sustained stream of consciousness will probably be part of
a computation that instantiates physics - instantiates a whole universe
complete with physics. However, the point that I wanted to make was that if
computation can instantiate consciousness then there is nothing to stop a
recording, a Boltzmann Brain, a rock and so on from doing so; for these
possibilities have been used as arguments against computationalism or to
arbitrarily restrict computationalism.

As I argued earlier though, if you hypothesize that consciousness
supervenes on the logical structure of computations, you can avoid the
conclusion that a rock or a recording contributes just as much to the
measure of a given human observer-moment as an actual human brain (or a
detailed simulation of one, or any other physical process that contains the
same pattern of logical relations between propositions about events within
the process). Would you disagree that consciousness supervening on logical
structure is one way to have a form of computationalism that avoids the
conclusion that *any* system (including a rock) can be interpreted as an
instantiation of any computation?

This doesn't cover the issue of Boltzmann brains, since in a universe
lasting an infinite time you could occasionally have systems randomly
assemble that would perform the correct computations in the logical
structure sense, but physicists who consider such things often suggest
that in an inflationary multiverse, there would be some *physical* measure
on different systems such that most instances of complex brain-like systems
would appear in the early stages of an inflationary bubble universe, and
that brain-like systems appearing randomly in very late high-entropy eras
of bubble universes would be comparatively rare.

Jesse

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### Re: MGA revisited paper

```On Sat, Aug 16, 2014 at 12:48 AM, Pierz pier...@gmail.com wrote:

On Saturday, August 16, 2014 2:28:32 PM UTC+10, jessem wrote:

On Fri, Aug 15, 2014 at 11:09 PM, meekerdb meek...@verizon.net wrote:

On 8/15/2014 5:30 PM, Jesse Mazer wrote:

On Fri, Aug 15, 2014 at 1:27 AM, Russell Standish li...@hpcoders.com.au
wrote:

On Thu, Aug 14, 2014 at 09:41:00PM -0700, meekerdb wrote:
On 8/14/2014 8:32 PM, Russell Standish wrote:
On Thu, Aug 14, 2014 at 08:12:30PM -0700, meekerdb wrote:
That does seem strange, but I don't know that it strikes me as
*absurd*.  Isn't it clearer that a recording is not a computation?
And so if consciousness supervened on a recording it would prove
that consciousness did not require computation?

To be precise supervening on the playback of a recording. Playback
of a recording _is_ a computation too, just a rather simple one.

In other words:

#include stdio.h
int main()
{
printf(hello world!\n);
return 1;
}

is very much a computer program (and a playback of recording of the
words hello world when run). I could change hello world to the
contents of
Wikipedia, to illustrate the point more forcibly.
OK.  So do you think consciousness supervenes on such a simple
computation - one that's functionally identical with a recording? Or
does instantiating consciousness require some degree of complexity
such that CC comes into play?

My opinion on whether the recording is conscious or not aint worth a
penny.

Nevertheless, the definition of computational supervenience requires
countefactual correctness in the class of programs being supervened
on.

AFAICT, the main motivation for that is to prevent recordings being
conscious.

I think it is possible to have a different definition of when a
computation is instantiated in the physical world that prevents
recordings from being conscious, a solution which doesn't actually depend
on counterfactuals at all. I described it in the post at
GC6bwqCqsfQ/rFvg1dnKoWMJ on google groups). Basically the idea is that
in any system following mathematical rules, including both abstract Turing
machines and the physical universe, everything about its mathematical
structure can be encoded as a (possibly infinite) set of logical
propositions. So if you have a Turing machine running whose computations
over some finite period are supposed to correspond to a particular
observer moment, you can take all the propositions dealing with the
Turing machine's behavior during that period (propositions like on
changed the digit there from 0 to 1, and changed its internal state from M
to Q), and look at the structure of logical relations between them (like
proposition A and B together imply proposition C, proposition B and C
together do not imply A, etc.). Then for any other computation or even any
physical process, you can see if it's possible to find a set of
propositions with a completely *isomorphic* logical structure.

But physical processes don't have *logical* structure.  Theories of
physical processes do, but I don't think that serves your purpose.

Propositions about physical processes have a logical structure, don't
they? And wouldn't such propositions--if properly defined using variables
that appear in whatever the correct fundamental theory turns out to
be--have objective truth-values?

Also, would you say physical processes don't have a mathematical
structure? If you would say that, what sort of structure would you say
they *do* have, given that we have no way of empirically measuring any
properties other than ones with mathematical values? Any talk of physical
properties beyond mathematical ones gets into the territory of some kind of
thing-in-itself beyond all human comprehension.

And even restricting the domain to Turing machines, I don't see what
proposition A and proposition B are?

They could be propositions about basic events in the course of the
computation--state changes of the Turing machine and string on each
time-step, like the example I gave on time-increment 107234320 the
read/write head moved to square 2398311 and changed the digit there from 0
to 1, and changed its internal state from M to Q. There would also have to
be propositions for the general rules followed by the Turing machine, like
if the read/write head arrives at a square with a 1 and the machine's
internal state is P, change the 1 to a 0, change the internal state to S,
and advance along the tape by 3 squares.

Aren't they just they transition diagram of the Turing machine?  So if
the Turing machine goes thru the same set of states that set defines an
equivalence class of computations.  But what about a different Turing
machine that computes```

### Re: MGA revisited paper

```On Sat, Aug 16, 2014 at 9:44 AM, Pierz pier...@gmail.com wrote:

On Saturday, August 16, 2014 11:26:08 PM UTC+10, jessem wrote:

I think you're being misled by the particular example you chose
involving addition, in general there is no principle that says finding the
appropriate entry in a lookup table involves a computation just as
complicated as the original computation without a lookup table. Suppose
instead of addition, the lookup table is based on a Turing test type
situation where an intelligent AI is asked to respond to textual input, and
the lookup table is created by doing a vast number of runs, all starting
from the same initial state but feeding the AI *all* possible strings of
characters under a certain length (the vast majority will just be nonsense
of course). Then all the possible input strings can be stored
alphabetically, and if I interact with the lookup table by typing a series
of comment to the AI, it just has to search through the recordings
alphabetically to find one where the AI responded to that particular
comment (after responding to my previous comments which constitute the
earlier parts of the input string), it doesn't need to re-compute the AI's
brain processes or anything like that. And ultimately regardless of the
type of program, the input will be encoded as some string of 1's and 0's,
so for *all* lookup tables the possible input strings can be stored in
numerical order, analogous to alphabetical order for verbal statement

No of course, a lookup table can help, as I went on to say a few minutes
later in a different reply when I realized the mistake. But I've explained
in my longer reply to Liz what I was trying to say here. It depends on what
level we wish to simulate to. A mere lookup table of outer behaviours such
as speech acts won't be sufficient for a complete simulation. The more fine
grained and responsive I wish to make my simulation, the more computation
will be required to select the correct recordings, and the shorter and
shallower the recordings will be. But read my reply to Liz. Hopefully I
explain myself better there.

Well, in my example of the Turing test, if the AI was a mind upload, then
the output could easily a detailed playback of all the activity in its
simulated brain at the synaptic level as it was answering my questions, in
addition to the AI's textual output. But it would still just be a
*recording* of the brain activity it went through during the original
creation of the lookup table, when the upload was simulated responding to
every possible input sequence. By talking to the lookup table, I don't
think I increase the measure of the experiences associated with the upload
seeing my side of the dialogue and responding, though the original creation
of the lookup table would have increased the measure associated with the
all the experiences of seeing all the possible input strings.

Note that even though an output showing detailed brain activity is very
fine grained, it isn't true that more computation is required to select
the correct recordings then if I just got textual output, nor are the
recordings shorter and shallower. Perhaps you were talking about making
the *input* more fine-grained? Suppose instead of just interacting with the
upload via text, I want to have a virtual puppet body in the upload's
simulated world (where the upload has his own simulated body), and I have a
system that detects all the nerve signals leaving my brain and transfers
them to the simulated motor neurons of the puppet body that the upload sees
in front of him, and his physical responses (along with any changes in
other physical objects in the virtual world) are translated into the
appropriate signals to my sensory neurons, a la The Matrix. So here both
the input and output are quite fine-grained.

To create the lookup table, someone would have to run a host of simulations
in which the puppet body interacting with the upload is fed *all* possible
combinations of signals to its motor neurons, the vast majority of which
would presumably lead it to flail around randomly, or perhaps be
immobilized due to equal numbers of signals arriving at opposing muscle
groups. This original work to create the lookup table is obviously
computationally intensive, but if I want to later interact with the
finished lookup table, finding the right recorded output to feed to my
sensory neurons in response to my bodily output should be much less
difficult then the original simulation needed to create that recording. The
original simulation would require simulating all the physical changes in
the virtual world, including the upload's brain activity, moment-by-moment
to see how everything reacts to the motor neuron outputs fed to the puppet
body. On the other hand, finding the appropriate response to my motor
neuron outputs on the lookup table is just a matter of coding my motor
neuron outputs as 1's and 0's, then looking up that sequence in a table of
sequences ```

### Re: MGA revisited paper

```On Fri, Aug 15, 2014 at 1:27 AM, Russell Standish li...@hpcoders.com.au
wrote:

On Thu, Aug 14, 2014 at 09:41:00PM -0700, meekerdb wrote:
On 8/14/2014 8:32 PM, Russell Standish wrote:
On Thu, Aug 14, 2014 at 08:12:30PM -0700, meekerdb wrote:
That does seem strange, but I don't know that it strikes me as
*absurd*.  Isn't it clearer that a recording is not a computation?
And so if consciousness supervened on a recording it would prove
that consciousness did not require computation?

To be precise supervening on the playback of a recording. Playback
of a recording _is_ a computation too, just a rather simple one.

In other words:

#include stdio.h
int main()
{
printf(hello world!\n);
return 1;
}

is very much a computer program (and a playback of recording of the
words hello world when run). I could change hello world to the
contents of
Wikipedia, to illustrate the point more forcibly.
OK.  So do you think consciousness supervenes on such a simple
computation - one that's functionally identical with a recording? Or
does instantiating consciousness require some degree of complexity
such that CC comes into play?

My opinion on whether the recording is conscious or not aint worth a
penny.

Nevertheless, the definition of computational supervenience requires
countefactual correctness in the class of programs being supervened
on.

AFAICT, the main motivation for that is to prevent recordings being
conscious.

I think it is possible to have a different definition of when a computation
is instantiated in the physical world that prevents recordings from being
conscious, a solution which doesn't actually depend on counterfactuals at
all. I described it in the post at
(or
google groups). Basically the idea is that in any system following
mathematical rules, including both abstract Turing machines and the
physical universe, everything about its mathematical structure can be
encoded as a (possibly infinite) set of logical propositions. So if you
have a Turing machine running whose computations over some finite period
are supposed to correspond to a particular observer moment, you can take
all the propositions dealing with the Turing machine's behavior during that
moved to square 2398311 and changed the digit there from 0 to 1, and
changed its internal state from M to Q), and look at the structure of
logical relations between them (like proposition A and B together imply
proposition C, proposition B and C together do not imply A, etc.). Then
for any other computation or even any physical process, you can see if it's
possible to find a set of propositions with a completely *isomorphic*
logical structure. In the case of the physical world, it seems to me you
could do this using only propositions about physical events that actually
occur, along with the general laws governing them--no propositions about
counterfactuals would be needed.

I suggested something like this to Bruno, and he seemed to agree that at
least in the case of computational *simulations* of the physical world, if
you use a rule like this to define when a simpler computation is
instantiated within some more detailed physical simulation, it would be
the case that a detailed simulation of a physical computer running some
simpler program P would qualify as instantiating P, whereas a detailed
simulation of a physical device that was really just playing back a
recording of a computer program (like Bruno's movie graph where all the
optical gates have been replaced by projected images) would *not*
instantiate P. See my comment at
and Bruno's response at

Assuming this idea for defining instantiations of sub-computations within
larger computations makes sense, why wouldn't it make just as much sense if
physical laws (but not counterfactuals) that are true in the physical
universe, and looked for collections of propositions whose internal logical
relations were isomorphic to those of some program?

Jesse

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### Re: MGA revisited paper

```On Fri, Aug 15, 2014 at 11:09 PM, meekerdb meeke...@verizon.net wrote:

On 8/15/2014 5:30 PM, Jesse Mazer wrote:

On Fri, Aug 15, 2014 at 1:27 AM, Russell Standish li...@hpcoders.com.au
wrote:

On Thu, Aug 14, 2014 at 09:41:00PM -0700, meekerdb wrote:
On 8/14/2014 8:32 PM, Russell Standish wrote:
On Thu, Aug 14, 2014 at 08:12:30PM -0700, meekerdb wrote:
That does seem strange, but I don't know that it strikes me as
*absurd*.  Isn't it clearer that a recording is not a computation?
And so if consciousness supervened on a recording it would prove
that consciousness did not require computation?

To be precise supervening on the playback of a recording. Playback
of a recording _is_ a computation too, just a rather simple one.

In other words:

#include stdio.h
int main()
{
printf(hello world!\n);
return 1;
}

is very much a computer program (and a playback of recording of the
words hello world when run). I could change hello world to the
contents of
Wikipedia, to illustrate the point more forcibly.
OK.  So do you think consciousness supervenes on such a simple
computation - one that's functionally identical with a recording? Or
does instantiating consciousness require some degree of complexity
such that CC comes into play?

My opinion on whether the recording is conscious or not aint worth a
penny.

Nevertheless, the definition of computational supervenience requires
countefactual correctness in the class of programs being supervened
on.

AFAICT, the main motivation for that is to prevent recordings being
conscious.

I think it is possible to have a different definition of when a
computation is instantiated in the physical world that prevents
recordings from being conscious, a solution which doesn't actually depend
on counterfactuals at all. I described it in the post at
(or
on google groups). Basically the idea is that in any system following
mathematical rules, including both abstract Turing machines and the
physical universe, everything about its mathematical structure can be
encoded as a (possibly infinite) set of logical propositions. So if you
have a Turing machine running whose computations over some finite period
are supposed to correspond to a particular observer moment, you can take
all the propositions dealing with the Turing machine's behavior during that
moved to square 2398311 and changed the digit there from 0 to 1, and
changed its internal state from M to Q), and look at the structure of
logical relations between them (like proposition A and B together imply
proposition C, proposition B and C together do not imply A, etc.). Then
for any other computation or even any physical process, you can see if it's
possible to find a set of propositions with a completely *isomorphic*
logical structure.

But physical processes don't have *logical* structure.  Theories of
physical processes do, but I don't think that serves your purpose.

Propositions about physical processes have a logical structure, don't they?
And wouldn't such propositions--if properly defined using variables that
appear in whatever the correct fundamental theory turns out to be--have
objective truth-values?

Also, would you say physical processes don't have a mathematical structure?
If you would say that, what sort of structure would you say they *do*
have, given that we have no way of empirically measuring any properties
other than ones with mathematical values? Any talk of physical properties
beyond mathematical ones gets into the territory of some kind of
thing-in-itself beyond all human comprehension.

And even restricting the domain to Turing machines, I don't see what
proposition A and proposition B are?

They could be propositions about basic events in the course of the
computation--state changes of the Turing machine and string on each
time-step, like the example I gave on time-increment 107234320 the
read/write head moved to square 2398311 and changed the digit there from 0
to 1, and changed its internal state from M to Q. There would also have to
be propositions for the general rules followed by the Turing machine, like
if the read/write head arrives at a square with a 1 and the machine's
internal state is P, change the 1 to a 0, change the internal state to S,
and advance along the tape by 3 squares.

Aren't they just they transition diagram of the Turing machine?  So if
the Turing machine goes thru the same set of states that set defines an
equivalence class of computations.  But what about a different Turing
machine that computes the same function?  It may not go thru the same
states even for the same input and output.  In fact there is one such
Turing machine that just executes```

### Re: CTM and the UDA (again!)

```On Sun, Jul 27, 2014 at 10:46 AM, David Nyman da...@davidnyman.com wrote:

On 23 July 2014 17:49, Jesse Mazer laserma...@gmail.com wrote:

So, why not adopt a Tegmark-like view where a physical universe is
*nothing more* than a particular abstract computation, and that can give
us
a well-defined notion of which sub-computations are performed within it
by
various physical processes?

Essentially because of the argument of Step 7 of the UDA. The
assumption here is that consciousness (i.e. the logic of the
first-person) is derived from computation. It then follows that we
cannot ignore the possibility in principle of building a computer
that not only implements a UD but also runs it for long enough to
generate its infinite trace, UD* (incorporating, by the way, a
fractal-like infinity of such dovetailing). If denying such a
possibility on grounds of a lack of primitively-physical resources
is evasive, to deny it on grounds of a lack of mathematical
resources is surely merely incoherent.

But if we do not deny it, but rather embrace it, we can see that such
a structure would inevitably dominate any observational reality.

I don't see why that should follow at all, as long as there are multiple
infinite computations running rather than the UDA being the only one,
there's no particular reason why the UDA computation should dominate in
terms of its contribution to measure. See my most recent post to Bruno at
, particularly this paragraph where I give a possible definition for how
one could define physical measure:

'For example, say after N steps of the universal computation U, we can
count the number of times that some computation A has been executed within
it, and the number of times that another computation B has been executed
within it, and take the ratio of these two numbers; if this ratio
approaches some limit in the limit as N goes to infinity, then this limit
ratio could be defined as the ratio of the physical measure of A and B
within the universe/multiverse. So if A and B are two possible future
observer-moments for my current observer moment (say, an observer-moment
finding itself in Washington and another finding itself in Moscow in your
thought-experiment), then the ratio of their physical measure could be the
subjective probability that I will experience either one as my
next-observer moment.'

Would you say that even if we define physical measure this way, and even
if multiple infinite computations are running alongside the UDA
computation, for some reason the UDA computation will dominate? Consider
the situation I imagined in this paragraph of the same post:

'Also note that even if we have two different candidates for the physical
universe computation, call them U and U', and even if both contain a
never-ceasing universal dovetailer computation within them, it seems to me
this is not enough to guarantee that U and U' will both assign the same
physical measure to any two computations A and B, if we use a procedure
like the one I outlined to define physical measure. Even though U and U'
will both compute all the same programs eventually since they both contain
a universal dovetailer, some programs might be computed more frequently
(more copies have been run after N steps) in U than in U'. For example, U
might be a physical simulation of a universe containing one physical
computer that's computing the universal dovetailer along with 1000 physical
computers computing copies of my brain experiencing being in Washington,
while U' might be a physical simulation of a universe containing one
physical computer that's computing the universal dovetailer along with 1000
physical computers computing copies of my brain experiencing being in
Moscow.'

To be more specific, imagine that these 1000 other simulated computers are
running *infinite* iterations of the me in Washington simulation--for
example, first it could spawn a copy of me arriving in Washington at 3 PM
and simulate my 1st hour experienced in Washington from 3 PM to 4 PM, then
it could spawn a newly-minted copy #2 of my brain and newly-minted copy of
Washington at 3 PM and re-simulate my brain's 1st hour in Washington from 3
PM to 4 PM, then it could go back to copy #1 and simulate its second hour
in Washington, then it could simulate copy #1's third hour, then it could
simulate copy #2's second hour, then it could spawn a new copy #3 and
simulate its first hour, and keep going this way following the same
ordering that Cantor used to order the rational numbers as shown at
http://www.homeschoolmath.net/teaching/rationals-countable.gif (with the
numerator as the copy # and the denominator as the hour #). Since such a
computer is constantly simulating copies of me in Washington, while the UDA
is only very occasionally simulating copies of me in Washington or Moscow
between all the other Turing machine programs it must simulate, then if I
want```

### Re: CTM and the UDA (again!)

```On Sun, Jul 27, 2014 at 1:13 PM, David Nyman da...@davidnyman.com wrote:

On 27 July 2014 17:27, Jesse Mazer laserma...@gmail.com wrote:

I don't see why that should follow at all, as long as there are multiple
infinite computations running rather than the UDA being the only one,

I may be missing some other point you're making, but I think this is
already dealt with after Step 8 of the UDA (universal dovetailer
argument). By this point in the argument, we have abandoned the notion
of a primitively-physical universe.

But when you say by this point in the argument, do you mean there was
some earlier step that established some good *reasons* for why we should
abandon the notion of a primitively-physical universe (or primitive
universal computation), or is it just something that was posited at some
point for the purposes of exploring the consequences, without any claim
that this posit was implied by earlier steps in the argument? As I said, it
seems that someone could accept everything in steps 1-6 of Bruno's argument
but still posit that the measure of each observer-moment would be
determined by its limit frequency in some unique universe-computation U.

Given that we are assuming CTM,
we need some ontology to fix the notion of computation, and
arithmetical relations suffice for this purpose.

Sorry, what does CTM stand for? It doesn't appear anywhere in Bruno's
Comp (2013) paper which I'm using for reference.

BTW, I suggested an ontology in the earlier comment to Bruno at
-- basically using an axiomatic system which allows you to deduce the
truth-value of various propositions about a computation, propositions
equivalent to statements like after N time steps, the read/write head of
the Turing machine moves to space 1185 on the Turing tape, finds a 0 there,
changes its internal state from #5 to #8 and changes the digit there to 1.
Then, a given computation can be defined in terms of the logical relations
between a set of propositions, so one computation A can contain an
instance of another computation B if some subset of propositions about A
have an isomorphic structure of logical relations to the logical relations

Since the structure of arithmetic can also be defined in terms of a set of
propositions with logical relations between them, and any statement about a
particular computation can be decided by determining the truth-value of a
corresponding statement about arithmetic, it may be that defining
computations in terms of arithmetical relations would lead to all the
same conclusions as the definition I suggest above, though I'm not sure.

Such a  Library must in particular contain universal dovetailers
that themselves generate every possible program and execute each of
them in sequence by means of dovetailing. This must include
recursively regenerating themselves in an infinitely fractal manner.
This characteristic implies a quite extraordinarily explosive
regenerative redundancy. Hence it seems plausible a priori, even
without a detailed calculus, that the resulting computational
structure (i.e. the infinite trace of the UD, or UD*) must completely
dominate any measure competition within the computational landscape
defined by arithmetical truth (or the small part of it needed for the
assumption).

That seems very handwavey to me, and while it might seem plausible
initially I think it becomes less so when you think more carefully about
how measure might actually be assigned. Do you disagree that if we use the
particular definition of measure I suggest, in the example I gave with U
and U' (both containing a universal dovetailer alongside a bunch of other
computers churning out endless copies of me in Washington or me in Moscow)
the UD will *not* dominate the measure competition, in that U and U' will
give very different answers to the relative likelihood that I find myself
in Washington vs. Moscow in Bruno's thought-experiment?

Jesse

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### Re: CTM and the UDA (again!)

```On Sun, Jul 27, 2014 at 2:04 PM, David Nyman da...@davidnyman.com wrote:

On 27 July 2014 18:46, Jesse Mazer laserma...@gmail.com wrote:

But when you say by this point in the argument, do you mean there was
some
earlier step that established some good *reasons* for why we should
abandon
the notion of a primitively-physical universe (or primitive universal
computation), or is it just something that was posited at some point for
the
purposes of exploring the consequences, without any claim that this posit
was implied by earlier steps in the argument?

No, it is the strong implication of Step 7 on the basis of Steps 0-6,

Well, this is precisely what I'm asking about, I don't see why abandoning
the notion of a primitive universal computation is *implied* by anything
that comes in steps 0-6, even after reading Bruno's Comp (2013) paper. Do
you see any way in which the hypothesis I've suggested, which assigns
measure to various sub-computations based on their frequency within a
single universal computation U, contradicts anything in steps 0-6? I'm
still identifying each observer-moment with one of those sub-computations,
and saying the subjective probabilities of various possible next moments
should depend on their measure (perhaps combined with some kind of
informational continuity, since I'm presumably not going to experience
becoming a brain-pattern with a totally different set of memories and
personality, even if that brain-pattern has a high measure of its own), not
on any sort of physical continuity.

and the only option available after Step 8,

suggested? Bruno seemed to agree in previous discussion that a simulated
world containing a movie-graph version of me would *not* contain my
program in the isomorphic logical structure sense I discussed, whereas a
simulated world containing a simulated physical computer running my program
would.

and while it might seem plausible initially
I think it becomes less so when you think more carefully about how
measure
might actually be assigned. Do you disagree that if we use the particular
definition of measure I suggest, in the example I gave with U and U'
(both
containing a universal dovetailer alongside a bunch of other computers
churning out endless copies of me in Washington or me in Moscow) the UD
will
*not* dominate the measure competition, in that U and U' will give very
different answers to the relative likelihood that I find myself in
Washington vs. Moscow in Bruno's thought-experiment?

Well, a bunch of other computers still seems to assume something
more primitive than the simple assumption of arithmetic for the
ontology. In terms of the UDA, all bunches of computers are already
subsumed within the infinite redundancy of UD*.

Again I am asking about the logic that explains *why* we should abandon the
notion of a primitive universal computation given that we agree with
steps 1-6. I thought when you said the UD would dominate, you were trying
to give an argument for why any notion of a primitive universal
computation would somehow become irrelevant to determining measure as long
as we assume it contains an eternally-running UD (which if true would
certainly be a good argument for abandoning the primitive universal
computation as an irrelevant hypothesis, like the argument for abandoning
an absolute reference frame in relativity because even if it existed it
would have no measurable consequences). Maybe I misunderstood you, though.

Jesse

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### Re: CTM and the UDA (again!)

```On Thu, Jul 24, 2014 at 2:44 PM, Bruno Marchal marc...@ulb.ac.be wrote:

HI Jesse, David,

On 23 Jul 2014, at 18:49, Jesse Mazer wrote:

Had some trouble following your post (in part because I don't know all the
acronyms), but are you talking about the basic problem of deciding which
computations a particular physical process can be said to implement or
instantiate? If so, see my post at
and Bruno's response at
. I think from Bruno's response that he agrees that there is a well-defined
way of deciding whether one abstract computation implements/instantiates
some other abstract computation within itself (like if I have computation
A which is a detailed molecular-level simulation of a physical computer,
and the simulated computer is running another simpler computation B, then
the abstract computation A can be said to implement computation B within
itself).

So, why not adopt a Tegmark-like view where a physical universe is
*nothing more* than a particular abstract computation, and that can give us
a well-defined notion of which sub-computations are performed within it by
various physical processes? This approach could also perhaps allow us to
define the number of separate instances of a given sub-computation within
the larger computation that we call the universe, giving some type of
measure on different subcomputations within that computational universe
(useful for things like Bostrom's self-sampling assumption, which in this
case would say we should reason as if we were randomly chosen from all
self-aware subcomputations). So for example, if many copies of a given AI
program are run in parallel in a computational universe, that AI could have
a larger measure within that computational universe than an AI program that
is only ever run once within it...of course, this does not rule out the
possibility that there are other parallel computational universes where
the second program is run more often, as would be implied by Tegmark's
thesis and also by Bruno's UDA. But there is still at least the theoretical
possibility that the multiverse is false and that only one unique
computational universe exists, so the idea that all possible
universes/computations are equally real cannot be said to follow logically
from COMP.

To have the computations, all you need is a sigma_1 complete theory and/or
a Turing universal machine, or system, or language.

Not sure I understand what you mean by have the computations, and I
didn't understand the mathematical arguments you made following that. My
point above is basically that even if one accepts steps 1-6 of your
argument, which together imply that I should identify my self/experience
with a particular computation (or perhaps a finite sequence of
computational steps rather than an infinite computation, but I'll just call
such a finite sequence a 'computation' to save time), it still seems to me
that there is an open possible that the *measure* on different computations
is defined by how often each one is physically instantiated. Are you
talking about some deriving some unique measure on all computations when
you say to have the computations, all you need... or are you not talking
about the issue of measure at all?

The idea I'm suggesting for a physically based measure involves
identifying the physical universe/multiverse with a particular unique
computation--basically, consider a computation corresponding to something
like a Planck-level simulation of our universe, or an exact simulation of
the evolution of the the universal wavefunction, then say that this
computation *is* what we mean by the physical universe/multiverse. Then,
if you agree there is some well-defined notion of whether a given
computation contains within it some other computation (and that we can
count the number of times some sub-computation has run within the larger
computation after N steps of the larger computation), the measure on all
computations could be determined by how frequently they each appear in the
unique computation that we identify with the physical universe/multiverse.

For example, say after N steps of the universal computation U, we can count
the number of times that some computation A has been executed within it,
and the number of times that another computation B has been executed within
it, and take the ratio of these two numbers; if this ratio approaches some
limit in the limit as N goes to infinity, then this limit ratio could be
defined as the ratio of the physical measure of A and B within the
universe/multiverse. So if A and B are two possible future observer-moments
for my current observer moment (say, an observer-moment finding itself in
Washington and another finding itself in Moscow in your
thought-experiment), then the ratio of their physical measure could be the
subjective probability```

### Re: CTM and the UDA (again!)

```Had some trouble following your post (in part because I don't know all the
acronyms), but are you talking about the basic problem of deciding which
computations a particular physical process can be said to implement or
instantiate? If so, see my post at
and Bruno's response at
. I think from Bruno's response that he agrees that there is a well-defined
way of deciding whether one abstract computation implements/instantiates
some other abstract computation within itself (like if I have computation
A which is a detailed molecular-level simulation of a physical computer,
and the simulated computer is running another simpler computation B, then
the abstract computation A can be said to implement computation B within
itself).

So, why not adopt a Tegmark-like view where a physical universe is
*nothing more* than a particular abstract computation, and that can give us
a well-defined notion of which sub-computations are performed within it by
various physical processes? This approach could also perhaps allow us to
define the number of separate instances of a given sub-computation within
the larger computation that we call the universe, giving some type of
measure on different subcomputations within that computational universe
(useful for things like Bostrom's self-sampling assumption, which in this
case would say we should reason as if we were randomly chosen from all
self-aware subcomputations). So for example, if many copies of a given AI
program are run in parallel in a computational universe, that AI could have
a larger measure within that computational universe than an AI program that
is only ever run once within it...of course, this does not rule out the
possibility that there are other parallel computational universes where
the second program is run more often, as would be implied by Tegmark's
thesis and also by Bruno's UDA. But there is still at least the theoretical
possibility that the multiverse is false and that only one unique
computational universe exists, so the idea that all possible
universes/computations are equally real cannot be said to follow logically
from COMP.

Jesse

On Wed, Jul 23, 2014 at 9:38 AM, David Nyman da...@davidnyman.com wrote:

Recent discussions, mainly with Brent and Bruno, have really got me
thinking again about the issues raised by CTM and the UDA. I'll try to
summarise some of my thoughts in this post. The first thing to say, I
think, is that the assumption of CTM is equivalent to accepting the
existence of an effectively self-contained computationally-observable
regime (COR). By its very definition, the COR sets the limits of possible
physical observation or empirical discovery. In principle, any physical
phenomenon, whatever its scale, could be brought under observation if only
we had a big enough collider. But by the same token, no matter how big the
collider, no such observable could escape its confinement within the limits
of the COR.

If we accept that the existence of a COR is entailed by assuming CTM, we
come naturally to the question of what might be doing the computation. In
terms of the UDA, by the time we get to Step 7, it should be obvious that,
in principle, we could build a computer from primitive physical
components that would effectively implement the infinite trace of the UD
(UD*). Furthermore, if such a computer were indeed to be implemented, the
COR would necessarily exist in its entirety somewhere within the infinite
redundancy of that trace. This realisation alone might well persuade us, on
grounds of explanatory parsimony and the avoidance of somewhat strained or
ad hoc reservations, to accept FAPP that UD*-COR. Should we be so
become effectively redundant to further explanation.

Notwithstanding this, we may still feel the need to retain reservations of
practicability. Perhaps the physical universe isn't actually sufficiently
robust to permit the building of such a computer? Or, even if that were
granted, could it not just be the case that no such computer actually
exists? Reservations of this sort can indeed be articulated, although
worryingly, they may still seem to leave us rather vulnerable to being
captured by Bostrom-type simulation scenarios. The bottom line however
seems to be this: Under CTM, can we justify the singularisation, or
confinement, of a computation, and hence whatever is deemed to be
observable in terms of that computation, to some particular physical
computer (e.g. a brain)? More generally, can we limit all possibility of
observation to a particular class of computations wholly delimited by the
activity of a corresponding sub-class of physical objects (uniquely
characterisable as physical computers) within the limits of a
definitively physical universe?

This is ```

### Re: The Higgs and SUSY vs the Multiverse

```Hopefully someone with a better understanding of these things will comment,
but I believe it has to do with what physicists call the hierarchy

http://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-hierarchy-problem/

http://profmattstrassler.com/articles-and-posts/some-speculative-theoretical-ideas-for-the-lhc/supersymmetry/supersymmetry-what-is-it/

http://scienceblogs.com/startswithabang/2013/05/15/the-rise-and-fall-of-supersymmetry/

http://www.quantumdiaries.org/2012/07/01/the-hierarchy-problem-why-the-higgs-has-a-snowballs-chance-in-hell/

http://en.wikipedia.org/wiki/Hierarchy_problem

And I don't think the physicists are really saying that 115 GeV Higgs would
rule out any sort of multiverse or need for anthropic arguments to explain
various constants of nature, just that it would allow for a non-anthropic,
supersymmetery-based explanation for *this particular* lucky (for life)
value of the Higgs mass, that is neither zero nor near the Planck scale.

Jesse

On Sat, Jul 19, 2014 at 11:38 PM, LizR lizj...@gmail.com wrote:

We've just been watching Particle Fever - a documentary about the LHC
(from 2007 to the discovery of the Higgs boson last year). In it, at least
a couple of people (Monica Dunbar and David Kaplan, IIRC) say that a 115GeV
Higgs would be a clear sign of Supersymmetry, while a 140GeV (or greater)
would indicate a Multiverse (meaning a String Landscape, I assume). The
measured value is 126GeV, which apparently leaves everything open for now.

They seem quite certain that there is a dichotony - SUSY vs MV - and that
the MV answer would effectively be the end of physics, I assume because
the fundamental physics underlying the string landscape is only accessible
at scales/energies far beyond those accessible to any currently conceivable
experiment.

I can't quite see this, so perhaps someone could elaborate. That is, it
seems to me unlikely that there is a theory that is going to say the ratio
of electron to proton masses is exactly what it is (1:1836.15267245 or so,
I believe) and that this emerges from simple principles. Since the proton
is a composite particle a better example might be the ratio of the
electron to muon masses, which I believe is around 1:206.7682821476077.

When the chemical elements were being discovered, it became clear that
there were simple principles underlying the apparently complexity. There
were what seemed like completely different substances, which turned out to
be related by simple numbers, e.g. if you take something like 2 grams of
hydrogen and 16 grams of oxygen and mix them you get 18 grams of water. (Or
whatever the correct figures are.) The point being that these small integer
(or almost-integer, but they couldn't measure them accurately enough to
realise that at the time) values indicate something simpler underlying the
observed complexity, whereas 1:1836.15267245 or 1:206.7682821476077, it
seems to me, don't.

And so on for the various other dimensionless ratios that abound in the
Standard Model, plus the fact that we see neutrinos with only one
handedness, the absence of antimatter and various other apparent symmetry
breakings

This seems to me to indicate that a multiverse could easily be involved,
and that the (ahem) string of apparently random values we observed emerge
from something like there being 10^500 ways to knot a piece of string in 11
dimensions.

What I don't understand is why this would not *also* allow supersymmetry
to exist? Or why would SUSY rule out a multiverse, as the people in the
film seemed to think? Or maybe I misunderstood them.

Anyone out there with the ability to explain advanced physics to dummies?

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### Re: Interesting Google tech talk on QM

```On Tue, Apr 29, 2014 at 3:02 PM, John Mikes jami...@gmail.com wrote:

*Brent(?) wrote*:
No I never read that, but hell yeah, MWI worries me! Doesn't it worry you?
I mean I know at one level that in a very real sense it doesn't matter
whether it's true or not, since the other universes can never affect me,
but at another the reality that everything happens to me that I can imagine
is just plain terrifying. And the 'me' isn't just the versions of me that
are still called by my name, I can't escape the conclusion that I am
everyone and everyone is me and that *everyone's* experience is my
experience at some level. If MWI ever does become the accepted conception
of reality, we have a huge amount of philosophical reorientation ahead of
us. For instance, if I take some risk (like drink-driving, a relevant topic
on another thread), and 'get away with it', MWI suggests I am still
responsible for other realities in which I crashed and injured or killed
myself and/or others. My whole approach to risk management becomes quite
different if all outcomes are realised.

In what ways would your approach to risk management need to change if there
was still some notion of different outcomes having different measures
that correspond to normal classical probabilities? In a MWI context you
might have a scenario where you can say if I take action X, then I expect
in 95% of worlds outcome Y will occur, but in 5% of worlds outcome Z will
occur, but in what cases would your choice about whether to take outcome X
be any different than a one-world scenario where you can say if I take
action X, then I expect there's a 95% probability outcome Y will occur, but
a 5% probability outcome Z will occur? Can you think of any specific
examples where this would change your decision?

the article at
http://www.newscientist.com/article/mg17122994.400-taming-the-multiverse.htmlwhich

By making good choices, doing the right thing, we thicken the stack of
universes in which versions of us live reasonable lives. When you succeed,
all the copies of you who made the same decision succeed too. What you do
for the better increases the portion of the multiverse where good things
happen.

Jesse

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### Re: Interesting Google tech talk on QM

```On Tue, Apr 29, 2014 at 10:24 PM, Russell Standish li...@hpcoders.com.auwrote:

On Tue, Apr 29, 2014 at 04:19:01PM -0400, Jesse Mazer wrote:

the article at

http://www.newscientist.com/article/mg17122994.400-taming-the-multiverse.htmlwhich

By making good choices, doing the right thing, we thicken the stack of
universes in which versions of us live reasonable lives. When you
succeed,
all the copies of you who made the same decision succeed too. What you do
for the better increases the portion of the multiverse where good things
happen.

Jesse

Makes no sense to me. You do not thicken the stack of universes, nor
do you increase the portion of the multiverse where good things
happen. The Multiverse just is - proportions do not change because of
choices of inhabitants.

I agree that we don't change the multiverse itself since the MWI is
deterministic, but thicken and increase could just be taken as a
comparison between those whose personalities and beliefs make them more
likely to make good choices and those whose brains make them less likely.
And given the power of habit, perhaps each good choice modifies your brain
somewhat to make subsequent good choices more likely. If that's the case,
then a good choice at decision point A thickens the stack of branches
where you make further good choices about events BC that follow A, in
comparison to the thinner stack of branches where your subsequent choices
about BC were good after you made an immoral choice at A.

Jesse

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### Re: Interesting Google tech talk on QM

```On Wed, Apr 23, 2014 at 7:08 AM, LizR lizj...@gmail.com wrote:

On 23 April 2014 22:29, Telmo Menezes te...@telmomenezes.com wrote:

Hi Liz,

The billions make sense to me, to be honest. Even before the earth, we
still didn't exist. It sounds like poetic liberty for a mind blowing
amount of time.

Sure, but I think at the time millions of years was a mind-blowing
amount of time - actually it still is - and it would appear the comment
doesn't have any known source. So although I'd be happily proved wrong on
this, it just feels a bit anachronistic for Samuel Clemens. Maybe just my
personal bias.

The people at the snopes board did some looking around for the quote at
appearances before 2002, so it's probably not a real quote. However, they
did turn up the following quote from Twain's autobiography which the fake
quote was probably a paraphrase of:

Annihilation has no terrors for me, because I have already tried it before
I was born—a hundred million years—and I have suffered more in an hour, in
this life, than I remember to have suffered in the whole hundred million
years put together.

see http://harpers.org/blog/2008/03/no-terrors-for-me/ for confirmation.

Jesse

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### Re: The situation at Fukushima appears to be deteriorating

```On Fri, Mar 21, 2014 at 7:20 AM, Edgar L. Owen edgaro...@att.net wrote:

Spud,

But reducing human overpopulation IS the main problem facing the planet,
the ecosystem, and the human species itself.

Assuming that increasing technology will somehow solve the problem is, I
fear, naive. It is precisely the use of more and more powerful technology
that has resulted in the exponential destruction of the environment by the
exponentially increasing number of humans.

So it's not better technology we need, but the wisdom to use it
sustainably

Edgar

Most demographers project that the population will level off at around 10
billion, because of various trends that tend to reduce the number of
children like populations becoming more urban and women being more
educated--see https://en.wikipedia.org/wiki/World_population#Projectionsfor
some info. Of course predicting human behavior is never purely
scientific and there are some who think this projection is too optimistic,
see
http://e360.yale.edu/feature/what_if_experts_are_wrong_on_world_population_growth/2444/

Jesse

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### Re: The situation at Fukushima appears to be deteriorating

```On Fri, Mar 21, 2014 at 12:19 PM, John Clark johnkcl...@gmail.com wrote:

On Wed, Mar 19, 2014 at 10:50 AM, Quentin Anciaux allco...@gmail.comwrote:

The thing I most want to know about  RCP4.5 is what RCP stands for,
Google seems to think it's Rich Client Platform but that doesn't sound
quite right. It must be pretty obscure, Wikipedia has never heard of RCP
either.

For your information, that means Regional Climate Prediction

I'm pretty sure it's not Russian Communist Party but are you sure it's
not Representative Concentration Pathways?  Wikipedia lists 21 possible
meanings of the acronym RCP and that's the only one that has anything at
all to do with the environment. Wikipedia has never heard of Regional
Climate Prediction.

http://en.wikipedia.org/wiki/RCP

It seems you're correct here, the RCP4.5 scenario I discussed was one of
four reprentative concentration pathway scenarios as indicated by the
https://en.wikipedia.org/wiki/Representative_Concentration_Pathways wiki
page. Of course, this doesn't change the fact that you chose to use a
rhetorical question about the meaning of the acronym as a lame excuse to
totally duck my point that it shows emissions being reduced in a
non-drastic way but with a significantly better range of projected
temperature rises by 2100 than the business-as-usual scenarios. But this
was in keeping with your 100% non-substantive response which ducked every
single issue I brought up, like the fact that plenty of people who want to
take action on the climate are pro-nuclear (your only response was
smartass-teenager style mockery of my use of the word strawman, ignoring
was entirely cherry-picked and non-representative), or the fact that water
vapor is not a climate forcing factor like CO2, or the question of what
general standard you use to judge the merit of scientific claims in areas
you have no expertise in (though your various ignorant claims about physics
suggest your standard is something like treat scientific expertise as
worthless whenever it doesn't match what I'd prefer to believe, and place
unerring faith in whatever handwavey verbal analysis of a scientific
question happens to pop into my head, arguing for this view with supreme
confidence regardless of whether I can find any expert support for it).

Jesse

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### Re: The situation at Fukushima appears to be deteriorating

```On Fri, Mar 21, 2014 at 12:59 PM, Telmo Menezes te...@telmomenezes.comwrote:

On Fri, Mar 21, 2014 at 5:24 PM, Quentin Anciaux allco...@gmail.comwrote:

2014-03-21 17:19 GMT+01:00 John Clark johnkcl...@gmail.com:

On Wed, Mar 19, 2014 at 10:50 AM, Quentin Anciaux allco...@gmail.comwrote:

The thing I most want to know about  RCP4.5 is what RCP stands for,
Google seems to think it's Rich Client Platform but that doesn't sound
quite right. It must be pretty obscure, Wikipedia has never heard of RCP
either.

For your information, that means Regional Climate Prediction

I'm pretty sure it's not Russian Communist Party but are you sure it's
not Representative Concentration Pathways?

I'm pretty sure you must be dumb as dumb if you really think this... As I

This thread seems to be mostly about politics. To be fair, John seems to
be in the minority here in wanting to discuss this from a scientific and
technological perspective.

Only if by discuss this from a scientific and technological perspective
you mean cast vague aspersions at various scientific claims (use of climate
models to predict future climates, analyze prehistoric glaciation
thresholds, predict how climate would respond to specific GHG reduction
scenarios like RCP4.5) and technical projections (like the specific plan to
get 69% of electricity from solar by 2050), based on whatever verbal
argument appeals to him and without any expert opinion of his own to cite
in support of this skepticism.

He raises a number of points that I have raised myself in previous
discussions. Instead of focusing on such issues, pop culture distractions
(Fox News etc.) and political tribalism seem to get all of the attention.

I haven't talked about such political issues at all, although John seems to
have plenty of enthusiasm for politically-based caricature of what
environmentalists believe, based on cherry-picking the worst plans he can
find trawling various websites rather than attempting any fair-minded
survey of how many groups and prominent climate activists would agree with
those plans.

- Given the number of climate models and the fact that the majority of
them failed to predict the climate of the last decade, how confident can we
be in further predictions?

Climate models predict that there should be plenty of statistical
fluctuation on the level of individual decades, so this amount of
an ensemble of such models. And current temperatures do still fall within
the range predicted by models from earlier dates like 2000 and 1988. I
addressed both the issue of how well models have done in their predictions
and the issue of the 15-year warming pause (which climate scientists seem
to think they understand the causes of fairly well) in this post:

The page at http://grist.org/climate-energy/climate-models-are-unproven/(from
the series of responses to common climate skeptic arguments at
http://grist.org/series/skeptics/ ) also has a basic summary of some of the
evidence supporting the reliability of climate models.

More generally, I would repeat the general point that I think the only
Bayesian prior when looking at scientific questions is assign a high a
priori likelihood that experts in the field are correct when they broadly
agree on the answer to some question, only revise that in light of changes
in expert opinion, obvious failed predictions that don't line up with their
theories, or acquiring enough expertise in the subject yourself to have an
informed opinion on the detailed evidence. So if the experts in climate
science are in broad agreement about climate models being reliable in the
sense that actual temperatures will very likely fall within the *range*
that they predict over many different runs (a statistical prediction rather
than an exact one obviously), given the right emissions scenario, my
default is to trust their judgment. To ignore expert opinion and think that
you, as a layman, are just as qualified to draw conclusions about the
reliability of models in *any* area of natural science seems to me to be a
basically anti-scientific, anti-intellectual attitude.

- With current technology, how much would we have to shrink the global
energy budget to transition to sustainable sources? What would the human
impact of that be? This is too serious an issue for wishful thinking.
Theres 7 billion of us and counting. We need hard numbers here, that take
into account the energy investment necessary to bootstrap the renewable
sources, their efficiency and so on.

The usual idea is not to significantly shrink the global energy budget
(although some shrinkage may be possible without sacrificing living
standards if we can find more energy-efficient ways of achieving the same
goals, as with things like hybrid vehicles ```

### Re: Entropy and curved spacetime

```On Fri, Mar 21, 2014 at 3:00 PM, John Clark johnkcl...@gmail.com wrote:

On 18 Mar 2014, at 22:33, LizR wrote:

Am I right in assuming that in a quantum mechanical universe you can
trace the history backwards?

Absolutely not because in Quantum mechanics 2 very different states can
evolve into the exact same state.

Not if you're just talking about the evolution of the quantum state vector
according to the Schroedinger equation, which is totally deterministic. As
I said to Liz, non-reversibility only appears if you assume the collapse
of the wavefunction to a new quantum state on measurement is a real
physical phenomenon distinct from normal wavefunction evolution, rather
than an approximate description of something that happens due to
decoherence (as would be true in the many-worlds interpretation where the
universal state vector is all there is, and also in Bohm's hidden variables
interpretation which is deterministic at all stages).

Jesse

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### Re: Entropy and curved spacetime

```On Fri, Mar 21, 2014 at 5:15 PM, Bruno Marchal marc...@ulb.ac.be wrote:

On 21 Mar 2014, at 20:17, Jesse Mazer wrote:

On Fri, Mar 21, 2014 at 3:00 PM, John Clark johnkcl...@gmail.com wrote:

On 18 Mar 2014, at 22:33, LizR wrote:

Am I right in assuming that in a quantum mechanical universe you can
trace the history backwards?

Absolutely not because in Quantum mechanics 2 very different states can
evolve into the exact same state.

Not if you're just talking about the evolution of the quantum state vector
according to the Schroedinger equation, which is totally deterministic.

Deterministic is compatible with the fact that 2 very different states can
evolve into the exact same state, making it non reversible.

But the solution of the SWE are more than deterministic, they are
reversible. In QM (without collapse) 2 different states evolves into two
different states.

True. I spoke too quickly, I guess my mind jumped to determinism rather
than reversibility (which is a type of reverse determinism) because I
figured John was thinking of quantum randomness, which only enters in QM if
you adopt the postulate of a random collapse on measurement.

But John was correct in thinking that determinism does not entail
reversibility. He gave the example of the game of life. But most
arithmetical operations are like that too.   2+3 gives 5, but from 5 you
can't necessarily retrieve 2+3, it might be 1+ 4 or 101 - 96.

I agree with what you say, but I was actually the one who brought up the
Game of Life in the discussion with John, because I was using it to make
the point that the second law of thermodynamics is more than a tautology,
that it actually depends on some specific properties of the laws of physics
such as satisfying Liouville's theorem. With the appropriate choice of
macrostates (namely, defining a macrostate by the ratio of live to dead
cells), in the Game of Life the odds can favor a higher-entropy state
evolving to a lower-entropy one (since if you start with a random 50:50 mix
of live and dead cells, after enough time you are likely to end up in a
state where most or all the cells are dead).

Jesse

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### Re: The situation at Fukushima appears to be deteriorating

```On Thu, Mar 20, 2014 at 9:55 AM, spudboy...@aol.com wrote:

Very well, go ahead and power it all down. Shut off the cars, kill the
lights, take a bike. Are you suggesting that we continue to burn filthy
coal, or horrible uranium, while we try to goose up solar and wind to
replace it?!! Why that will take decades and the catastrophe is already
upon us. The heating of the atmosphere and the degradation of the lands and
seas, cannot wait (your guys tell us).

No, nobody says it cannot wait and therefore we have to shut off all
fossil fuel based power now, what some people say cannot wait is adopting
some long-term plan that will transition away from fossil fuel gradually
warming would be happy if we adopted any one of a number of plans which
would end with a transition to majority-renewables by 2050, such as the
ones below:

http://www.sciencedirect.com/science/article/pii/S0301421508004072 (the
solar grand plan I mentioned to you earlier which is summarized at

http://www.nrel.gov/analysis/re_futures/ (articles summarizing this one at
http://blogs.denverpost.com/thebalancesheet/2012/07/09/renewable-energy/5430/
and
http://www.technologyreview.com/view/428284/the-us-could-run-on-80-percent-renewable-electricity-by-2050/
)

http://news.stanford.edu/news/2009/october19/jacobson-energy-study-102009.htmland
http://news.stanford.edu/news/2014/february/fifty-states-renewables-022414.html(other
articles discussing this plan at
http://blogs.ei.columbia.edu/2013/07/30/charting-the-course-to-a-100-percent-renewable-energy-future/and
http://theenergycollective.com/hermantrabish/352551/another-blueprint-100-percent-renewables-mid-centuryand
a Scientific American summary by the authors at

http://www.udel.edu/V2G/resources/BudischakEtAl-2013-CostMinimizedWindSolarPJM.pdf(discussed
at

Or what are they really saying, put into motion in real life? It comes
down to a culture of complaint from the green-reds, rather than actual
workable solutions. I want technical solutions, but then, I am in the
minority

By technical solutions do you just mean technical plans laying out in
detail how the transition to a renewable-dominated power grid would work,
and how much it would cost? If so, see above. On the other hand, maybe you
mean I'm waiting for some technological breakthrough that will make
renewable energy so cost-effective that the free market will rush to
abandon fossil fuels without the government having to lift a finger, until
then we should do nothing  to cut back on emissions even if it would be
economically feasible. In that case, no that hasn't happened, but at least
the plans above show that fearmongering about how trying to curb emissions
would destroy the economy don't have any basis in fact.

Jesse

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### Re: Entropy and curved spacetime

```Yes, if you have the exact present quantum state and you're assuming the
normal quantum rules for continuous wavefunction evolution, you can
determine the past quantum state. The answer might change if you assume
that there's an objective physical reality to the collapse of
wavefunction with measurement, distinct from the normal wavefunction
evolution rules.

Jesse

On Tue, Mar 18, 2014 at 5:33 PM, LizR lizj...@gmail.com wrote:

Am I right in assuming that in a quantum mechanical universe you can trace
the history backwards?

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### Re: The situation at Fukushima appears to be deteriorating

```reductions goals the EU has set for itself (and they have successfully
reduced emissions by 18% since 1990 when they set these goals, as I
mentioned earlier). Proposals like a carbon tax and a carbon cap would be
included in this, since the proposals involve starting with a tax/cap that
wouldn't require any major immediate change in what fossil fuel companies
are doing, and then gradually make it a tiny bit stricter each year over a

What do they want us to do, a rational person may ask (assuming we can
find one)?

The great booming word from environmentalists is conservation, followed by
the sound of chirping crickets, yes, there's a few crickets still alive
after massive species decimation.

As I said to John Clark, no scientists really claim there has been a
massive decimation of species (percentage-wise anyway) at present, the
claim is that the RATE of extinction (percent of species going extinct PER
YEAR) has shot up in recent years, and that if it continues at this rate
for another century (or a few centuries depending on the estimate of the
current rate) then we will have a true mass extinction.

Jesse

When the discussion turns from technology to government control, and the
necessity for it as promoted by pols who cite scientists, my spider-sense
becomes active. Yes, there a few spiders left after environmental
-Original Message-
From: Jesse Mazer laserma...@gmail.com
Sent: Thu, Mar 13, 2014 12:47 am
Subject: Re: The situation at Fukushima appears to be deteriorating

On Wed, Mar 12, 2014 at 7:36 PM, spudboy...@aol.com wrote:

My integrity is not the issue,

error you simply ignore the issue even when I repeatedly question you about
it.

for someone who states-
*This all falls under gossipy political speculations about human
motivations, I'm not interested in dragging this stuff into a conversation

Not sure what connection you think there is between this statement of
mine and integrity. Would you respect my integrity more if I made up
unfalsifiable fantasy narratives about the nefarious motives of
conservatives and global warming deniers to counter your equally
unfalsifiable fantasy narratives about the nefarious motives of liberals
and environmentalists?

Again, its science when its on your own terms, and it suits your
ideology.

Not at all, as I said to John Clark I treat it as the default position
that whenever scientists in a field of natural science express confidence
about ANY technical claim in their field, and there doesn't seem to be
substantial disagreement among them, then my starting assumption is that
likely to change if I acquired enough knowledge the field to understand the
detailed basis for the claims myself and find technical reasons to doubt
them, or if I found out that some substantial number of other scientists
disputed the claim). This is a blanket view of all natural science claims
that has nothing to do with political ideology, for example I have no
patience with the view (all too common among those on the left) that GMOs
are a dangerous health risk since all the scientific experts I've seen say
that extensive study has shown no more health risks from GMOs than from
crops created through selective breeding.

Anyone who does NOT adopt this blanket view of scientific claims is
almost certainly filtering their evaluations of science through their
personal ideology, and lacking respect for the importance of detailed
technical understanding when evaluating scientific issues. I suspect your
understanding of the detailed evidence behind many other scientific claims,
like estimates of the age of the universe in cosmology, is just as poor as
your understanding of the evidence surrounding global warming, but I
imagine you don't put forth fantasy narratives of cosmologists
peer-pressuring each other into accepting each other's models and wildly
exaggerating the strength of the evidence for their theories, presumably
because you have no ideological reason to dispute the idea that the Big
Bang happened 13.75 billion years ago. Unless you are equally skeptical
about *all* scientific claims whose technical basis you don't understand,
you have a clear double standard--mistrust the scientists when their claims
conflict with your ideology, but trust them when there is no such
ideological conflict.

Your nuclear energy remediation proposal will be violent opposed by your
green chums, so it becomes, effectively, no answer.

Certainly there are plenty of greens who oppose nuclear power (and
examples like Fukushima show the risks are not to be scoffed at, although
they are mainly```

### Re: The situation at Fukushima appears to be deteriorating

```On Wed, Mar 12, 2014 at 10:29 AM, John Clark johnkcl...@gmail.com wrote:

On Tue, Mar 11, 2014 at 11:39 AM, Chris de Morsella cdemorse...@yahoo.com
wrote:

*On Behalf Of *LizR

I must admit I've heard the extinction rate is way higher than usual
- asteroid / methane burp high. (Although if it's us or them, as I said,
that's a different story...)

Liz - it is not hearsay [...] There is substantial, incontrovertible
evidence that the extinction rate has literally spiked through the roof.

That's not just hearsay it's idiotic. 66 million years ago 2/3 of all
species, not individual animals but entire species, became extinct quite
literally overnight, and 252 million years ago it was even worse, the
extinction rate was 90%.  What we're experiencing now is not even a burp.

You fail to understand the distinction between the extinction
RATE--percentage of species going extinct PER UNIT TIME--and the actual
percentage of species that have gone extinct in total (akin to rate of
travel in a car, i.e. speed, vs. total distance traveled). 90% is not a
rate at all, it's a total. The argument is that the rate has gone way up
from the background extinction rate in recent history, and if the rate
REMAINS this high for another century or two, then the total percentage of
species that go extinct will reach mass-extinction levels, even though it
hasn't yet.

Apparently there is some controversy about the current rate, see discussion
of an optimistic paper by Costello et al. at
http://www.sciencedaily.com/releases/2013/01/130124150806.htm along with
the response from some other scientists at
http://www.soc.hawaii.edu/mora/Publications/Mora%20036.pdf ...the response
notes that the Costello et al. paper presents an estimate (0.001%-0.1% per
year) that's very low compared with nearly all previous estimates, and that
a previous paper by one of the coauthors of the optimistic paper, Nigel
Stork, had compiled a number of estimates which together gave an average of
0.72% per year, and that Removing all rates derived from species-area
relationships, which are currently debated [(12), but see (14)], still
yields a mean extinction rate of ~0.22% or ~11,000 species a year if there
are 5 million species. Fig. 1 gives some curves showing the TOTAL FRACTION
of species that will have gone extinct in the next few centuries if the
rates remain at either 0.72% per year (solid red curve) or 0.22% per year
(dotted red curve), you can see that about half of all species would go
extinct by 2100 if the rate was 0.72% per year, and about half would go
extinct by 2300 if the rate was 0.22% per year. Either one would be a
near-instantaneous mass extinction on geological timescales.

Jesse

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### Re: The situation at Fukushima appears to be deteriorating

```On Wed, Mar 12, 2014 at 2:52 PM, spudboy...@aol.com wrote:

Autism, schmatism. Let me address this situation in concise terms, and if
you want to discuss, we can discuss.

paper, apparently (I take this as a sign that you probably recognize from
my comments that you misread it, but don't have the intellectual integrity

Here goes-
1. The models to date have not predicted successfully.

Well, yes they have, for example the first graph in the article at
what the CMIP3 dataset, which was based on collecting the
predictions of a number of different climate models, predicted for 2000 on.
The gray area shows the range in which 95% of the model simulations stayed
within, and the black line is the average prediction of all the simulated
runs, you can see that the actual climate as remained well within the gray
area. Even simpler climate models going back as far as 1988 have proved
pretty accurate, for example see the article at
Hansen's 1988 temperature predictions using a number of different
emissions scenarios--the first graph shows that actual emissions proved to
be closest to the emissions scenario he labeled scenario B, and the
second graph shows that the actual observed temperature up to 2007 (when
the article was written), shown in red and black, hewed pretty closely to
his predicted temperature for scenario B in blue.

As for the recent pause in the warming trend over the last 15 years, this
article has good discussion:

http://www.realclimate.org/index.php/archives/2013/12/the-global-temperature-jigsaw/

One thing they note is that the models themselves predict pauses on those
timescales should happen occasionally, as shown in a graph of one simulated
run of a CMIP3 model in Fig. 2. They also note that the El Nino Southern
Oscillation (ENSO) seems to be a major factor in the pause, along with
some other factors like the recent low in solar activity and increased
volcanic activity, and Fig 3 shows the data after adjusting for ENSO,
volcanoes and solar activity by a multivariate correlation
analysis--apparently when they attempt to subtract these recent changes
out using some statistical techniques, the adjusted temperature in red
would actually have been fairly steadily rising over the past 15 years.

And here's another relevant article which discusses the growing consensus
on the causes of the pause, saying A very consistent understanding is thus
emerging of the coupled ocean and atmosphere dynamics that have caused the
recent decadal-scale departure from the longer-term global warming trend:

http://www.realclimate.org/index.php/archives/2014/02/going-with-the-wind/

I predict, however, that you will duck any detailed quantitative discussion
of what the models predict since you only talk about science as an
afterthought, you are mostly focused on gossipy political speculations

2. We have not as of this day, a technology to replace the dirty with the
clean on energy.

Nuclear power could certainly do it (although obviously that comes with its
own risks distinct from global warming), and there's more than enough solar
energy hitting the US to supply energy needs. Here's an article discussing
a hypothetical proposal to supply *all* the U.S.'s energy needs with solar,
with a price tag of about a trillion dollars (pricey obviously, but no more
so than the Iraq war which didn't bankrupt us and probably wasn't a major
cause of the recession):

3. The elites of the world would be ordering thousands of dams/dikes all
over the world, in order to save their own asses-if your IPCC guys were
really true and, or, on time!
4. The elites are not behaving in this way, but they are declaring a
disaster. If there's no disaster at hand, they are not building dams along
the coastlines of the world, then I grow suspicious.
5. Apparently, many progressives/greens want to promote energy starvation,
even though they have no technology, except their Amory Lovins type
conservations crap from 25 years ago.
6. Which leads me to believe that because its cherry-picked data from
scientists who would have no career if they didn't go along, it is the
ideology of the progressives and the elites-mostly 1 in the same.

This all falls under gossipy political speculations about human
motivations, I'm not interested in dragging this stuff into a conversation
about natural science (but it certainly supports my speculation that you
are much more comfortable with obsessing about why people do the things
they do than you are with discussing anything more impersonal like science
and math).

Jesse

--

### Re: The situation at Fukushima appears to be deteriorating

```On Wed, Mar 12, 2014 at 7:36 PM, spudboy...@aol.com wrote:

My integrity is not the issue,

error you simply ignore the issue even when I repeatedly question you about
it.

for someone who states-
*This all falls under gossipy political speculations about human
motivations, I'm not interested in dragging this stuff into a conversation

Not sure what connection you think there is between this statement of mine
and integrity. Would you respect my integrity more if I made up
unfalsifiable fantasy narratives about the nefarious motives of
conservatives and global warming deniers to counter your equally
unfalsifiable fantasy narratives about the nefarious motives of liberals
and environmentalists?

Again, its science when its on your own terms, and it suits your
ideology.

Not at all, as I said to John Clark I treat it as the default position that
whenever scientists in a field of natural science express confidence about
ANY technical claim in their field, and there doesn't seem to be
substantial disagreement among them, then my starting assumption is that
likely to change if I acquired enough knowledge the field to understand the
detailed basis for the claims myself and find technical reasons to doubt
them, or if I found out that some substantial number of other scientists
disputed the claim). This is a blanket view of all natural science claims
that has nothing to do with political ideology, for example I have no
patience with the view (all too common among those on the left) that GMOs
are a dangerous health risk since all the scientific experts I've seen say
that extensive study has shown no more health risks from GMOs than from
crops created through selective breeding.

Anyone who does NOT adopt this blanket view of scientific claims is almost
certainly filtering their evaluations of science through their personal
ideology, and lacking respect for the importance of detailed technical
understanding when evaluating scientific issues. I suspect your
understanding of the detailed evidence behind many other scientific claims,
like estimates of the age of the universe in cosmology, is just as poor as
your understanding of the evidence surrounding global warming, but I
imagine you don't put forth fantasy narratives of cosmologists
peer-pressuring each other into accepting each other's models and wildly
exaggerating the strength of the evidence for their theories, presumably
because you have no ideological reason to dispute the idea that the Big
Bang happened 13.75 billion years ago. Unless you are equally skeptical
about *all* scientific claims whose technical basis you don't understand,
you have a clear double standard--mistrust the scientists when their claims
conflict with your ideology, but trust them when there is no such
ideological conflict.

Your nuclear energy remediation proposal will be violent opposed by your
green chums, so it becomes, effectively, no answer.

Certainly there are plenty of greens who oppose nuclear power (and
examples like Fukushima show the risks are not to be scoffed at, although
they are mainly risks to human health rather than environmental risks), but
also plenty of greens who have come around to the view that nuclear power
is a lesser evil when compared to fossil fuels, see for example this
article that details many leading environmentalists who have become more
nuclear-friendly (I suspect the number would be higher if we had thorium
reactors, which should be significantly safer):

http://www.washingtonpost.com/wp-dyn/content/article/2009/11/23/AR2009112303966.html

Meanwhile, you completely ignored my point about it being well within the
range of possibility to get all our energy from solar.

I will prove your prediction correct with pure volition. I read the Nature
realclimate link, article and my take away is its a struggle to try to
figure out where the IPCC predictions went wrong? Was it el nino, heat
sinks in the Pacific, etc.

I'm glad you at least looked at it, but as with the Royal Society/National
quite poor (perhaps because you read with the attitude of looking for
flaws rather than just trying to understand what's being argued). No one
says the cooling is because of El Niño, but rather because La Niña has
replaced El Niño for a while (part of a long-term cycle called
'pacific-decadal oscillation'), and the La Niña stage is thought to be
ASSOCIATED WITH more heat being stored in the pacific, not a separate
phenomenon that could be construed as a conflicting explanation. From the
http://www.realclimate.org/index.php/archives/2013/12/the-global-temperature-jigsaw/--

Leading U.S. climatologist Kevin Trenberth has studied this for ```

### Re: The situation at Fukushima appears to be deteriorating

```On Tue, Mar 11, 2014 at 12:33 PM, spudboy...@aol.com wrote:

Thrre was a report judt last week released by the NAS and the UK Royal
Society indicating that switching power sources will not help.

You're just repeating yourself, did you actually read my response? I asked
if you were talking about the report at
http://dels.nas.edu/resources/static-assets/exec-office-other/climate-change-full.pdf,
which was released by the Royal Society and NAS on Feb. 27 (I don't
know
if you'd call that last week)-- just tell me yes or no, please.

If your answer is yes--and I'm pretty sure that the NAS and Royal Society
didn't release any OTHER climate reports besides this one in the last
couple weeks--then as I already explained before, it's clear you simply
didn't understand it well (or didn't read the entire thing), since while
the report did say on p. 22 that CO2 levels wouldn't drop quickly if
emissions were halted, p. B8 also clearly shows that temperature wouldn't
rise much beyond present levels in an aggressive emissions reduction
scenario, whereas it would rise to levels that would likely be pretty
catastrophic for human civilization in a business as usual emissions
scenario.

Secondly, the behavior of pols and the super rich are not consistent with
this new report, or fears of an insurging ocean.

Most politicians and super rich, like most people in general, have a bias
towards preserving their near-term interests over long-term issues
(especially issues that are only likely to become really serious after
their death). The effects of climate change aren't fast enough that they're
likely to have much effects on a politician's reelection prospects, or a
rich person's stock portfolio over the next couple decades. Still, plenty
article I posted to John Clark about how the EU's emissions reduction
policy has brought down emissions by 18% since 1990 levels, on track with
the goals they set at the Kyoto conference:

http://ec.europa.eu/clima/news/articles/news_2013100901_en.htm

And here's an article about how Apple CEO Tim Cook shot down investors who
didn't approve of the policy of reducing emissions by relying more on
renewable energy:

http://www.slate.com/blogs/the_slatest/2014/03/01/apple_ceo_tim_cook_shoots_down_global_warming_deniers_at_shareholders_meeting.html

This peaks my suspicion. But fear not, I am but a submicron with zero
influence on public policy. I just am suspicious of the ruling class using
academic hucksters to glom more power-highly intelligent hucksters though
they may be.

So you think scientists are academic hucksters if they reach conclusions
about objective reality that might favor policies that are inconvenient for
haven't made any attempt to understand the science on its own terms,
independent of politics and crude us vs. them tribalistic thinking
(liberals are worried about global warming while U.S. conservatives and
libertarians typically aren't, liberals=bad, therefore it must be a power
grab!)

Jesse

-Original Message-
From: Jesse Mazer laserma...@gmail.com
Sent: Mon, Mar 10, 2014 1:15 pm
Subject: Re: The situation at Fukushima appears to be deteriorating

On Mon, Mar 10, 2014 at 12:31 PM,  lt;spudboy...@aol.comgt; wrote:
According to Chris, Climate is not the weather or the local weather. So
if this suggestion is correct, its local anomalies over the years, driven
onward, by El Nino' or La Nina' ? According to a report released, last
week, by the Royal Climate Group and the US national academy of sciences, a
change in energy sources will not help us. I had to read it twice to
comprehend what the report indicated.

Are you talking about the report at http://dels.nas.edu/
resources/static-assets/exec-office-other/climate-
change-full.pdf ? If so you have totally misunderstood what the report
indicated, page B8 shows that climate models predict the Aggressive
emissions reduction scenario would result in much lower global temperature
in 2100 than the 'Business as usual' emissions scenario. They do say on
p. 22 that If emissions of CO2 stopped altogether, it would take many
due to its very slow transfer to the deep ocean and ultimate burial in
ocean sediments, but even if temperatures don't drop for a while, as long
as they don't rise to levels much above what we have today, the
consequences probably wouldn't be too bad (for a discussion of the likely
consequences of each 1 degree rise, check out the book Six Degrees: Our
Future on a Hotter Planet by Mark Lynas).

Jesse

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email```

### Re: The situation at Fukushima appears to be deteriorating

```On Tue, Mar 11, 2014 at 1:50 PM, John Clark johnkcl...@gmail.com wrote:

On Mon, Mar 10, 2014 at 3:58 PM, Jesse Mazer laserma...@gmail.com wrote:

because before you initiate a policy that will impoverish the world
for many generations and kill lots and lots and lots of people

What policies are you talking about that would have these supposed
effects?

Shut down all nuclear reactors immediately.
Stop using coal.
Stop all dam construction and dismantle the ones already built.
Stop all oil and gas fracking.
Stop using geothermal energy.
Drastically reduce oil production and place a huge tax on what little that
is produced.
Don't Build wind farms in places where they look ugly, reduce wind
currents, kill birds or cause noise.
Don't use insecticides.
Don't use Genetically Modified Organisms.
Don't use herbicides.
Do exactly what the European Greens say.

So, like a creationist you're unwilling to accurately depict the beliefs of
those you disagree with, and instead you attack a boogeyman that has sprung
mostly out of your own fevered imagination. There may be some radical
environmentalists who believe these things, but the mainstream
environmental groups (all the ones with any real influence) favor policies
that will gradually scale back emissions without causing any abrupt changes
in our living standards or power generation.

The EU has been on track in their goals of emissions reductions, already
cutting them by 18% from 1990 levels,

And Germany alone spent 110 billion dollars to accomplish that, about \$660
for every ton of CO2 they're cutting. And the net outcome of that
staggering amount of money and effort is that by the end of this century
global warming will be delayed by about 37 hours.

Did you just made that number up? And why focus only on Germany, when the
effects of the entire E.U.'s collective emissions reductions are presumably
larger than those due solely to any individual country? Also, I brought
this up to counter your wild claim that this would lead to economic
depression and starvation--since it hasn't in the EU it presumably wouldn't
in other countries like the U.S., and if the whole world (or even just the
U.S.) followed the E.U.'s lead, do you deny that according to mainstream
climate models, this would lead to significant temperature reduction from
business as usual scenarios where no effort is made to curb emissions?

Global warming is real and if it turns out to be a bad thing then we're
going to have to fix it, but we need to do it in a smart way.

When there is widespread expert consensus on how sure we should be
about a scientific matter, and I have no expertise in the matter myself, I
tend to assume as a default that the scientific experts likely have good
grounds for believing what they do. Of course it's possible on occasion
that expert consensus can turn out to be badly wrong but [...]

There is consensus in the scientific community that things are slightly
warmer now than they were a century ago, but there is most certainly NOT a
consensus about how much hotter it will be a century from now, much less
what to do about it or even if it's a bad thing.

The study I linked to wasn't just about the fact that warming has occurred,
it was specifically on the question of whether the recent warming is
PRIMARILY CAUSED BY HUMAN ACTIVITIES, and it found that 97% of
peer-reviewed papers that addressed the issue agreed with the consensus
that it was. Obviously pretty much any scientist who agrees with this would
also say that human emissions over the next century will have a large
determining effect on the temperature in 2100. And note that the only way
to reach such a consensus about the cause of past warming is if there is a
consensus that climate models are broadly reliable in how they model the
effects of various climate forcings like greenhouse gas emissions and
solar input. Although there is plenty of range in what the models predict
about temperatures in 2100 under any specific emissions scenario, if you
look at a large number of models the likely temperature range goes up
significantly under scenarios where we make no concerted effort to curb
emissions vs. those where we do. I would say the precautionary principle
applies here, if the higher ends of the likely range for a given emissions
scenario are just as plausible as the lower ends, and if the higher ends of
the likely range (or even both ends, under certain emissions scenarios)
would be disastrous for human civilization, then we should make an effort
to prevent that emissions scenario from becoming the reality.

If anyone reading wants to know the actual ranges predicted by models
(probably not John Clark, who will likely just make some vague comment
about models being unreliable), the last IPCC report picked a number of
possible future emissions scenarios and then applied a large number of
different climate models to each one, the figure at
http://www.climate-lab```

### Re: The situation at Fukushima appears to be deteriorating

```So, no response to my question about whether the paper I linked to was the
one you were talking about, and my pointing out that p. B8 of the paper
clearly indicates that it'll make a major difference to the temperature in
100 years whether we reduce emissions or carry on with business as usual?

As for your comments, all I can say is that you seem to be one of those
people who's only interested in thinking about issues in personal,
narrative terms--us vs. them conceptions of which side supports a given
position, speculations about the personal motivations people may have for
taking the positions they do, etc. Discussion of more impersonal approaches
to understanding the world, approaches based on math and quantitative
evaluation of evidence, seems to be something you're entirely uninterested
in. Sometimes I think we would have a much saner world if the average
person was just, say, 5 points higher on the autism quotient scale (
http://www.wired.com/wired/archive/9.12/aqtest.html )...

On Tue, Mar 11, 2014 at 2:48 PM, spudboy...@aol.com wrote:

My point is Jesse, yes the truth is repeatable, is that the rich and their
kept politicians, do behave in the short run, or as class-hero, John
Maynard Keynes, said: in the long run, we're all dead. I maintain that
their behavior is aligned with a great exaggeration, rather then a great
dilemma. It's not like they do not partake the same bread with most of the
media. Example, the NY Times is majority owned, by billionaire Carlos Slim
Helu, and both Helu and pinchie Sulzberger, dine from identical world
views. My view is that we are alive now, for a while, focus, then, on the
issues, at hand. However, the rich and their pet pols know a good scheme
when they see one. Or, as Henry Kissinger once noted, power is the greatest
aphrodisiac.

-Original Message-
From: Jesse Mazer laserma...@gmail.com
Sent: 11-Mar-2014 14:03:15 +
Subject: Re: The situation at Fukushima appears to be deteriorating

On Tue, Mar 11, 2014 at 12:33 PM, spudboy...@aol.com wrote:

Thrre was a report judt last week released by the NAS and the UK Royal
Society indicating that switching power sources will not help.

You're just repeating yourself, did you actually read my response? I asked
if you were talking about the report at
http://dels.nas.edu/resources/static-assets/exec-office-other/climate-change-full.pdf,
which was released by the Royal Society and NAS on Feb. 27 (I don't know
if you'd call that last week)-- just tell me yes or no, please.

If your answer is yes--and I'm pretty sure that the NAS and Royal
Society didn't release any OTHER climate reports besides this one in the
last couple weeks--then as I already explained before, it's clear you
simply didn't understand it well (or didn't read the entire thing), since
while the report did say on p. 22 that CO2 levels wouldn't drop quickly if
emissions were halted, p. B8 also clearly shows that temperature wouldn't
rise much beyond present levels in an aggressive emissions reduction
scenario, whereas it would rise to levels that would likely be pretty
catastrophic for human civilization in a business as usual emissions
scenario.

Secondly, the behavior of pols and the super rich are not consistent with
this new report, or fears of an insurging ocean.

Most politicians and super rich, like most people in general, have a bias
towards preserving their near-term interests over long-term issues
(especially issues that are only likely to become really serious after
their death). The effects of climate change aren't fast enough that they're
likely to have much effects on a politician's reelection prospects, or a
rich person's stock portfolio over the next couple decades. Still, plenty
article I posted to John Clark about how the EU's emissions reduction
policy has brought down emissions by 18% since 1990 levels, on track with
the goals they set at the Kyoto conference:

http://ec.europa.eu/clima/news/articles/news_2013100901_en.htm

And here's an article about how Apple CEO Tim Cook shot down investors who
didn't approve of the policy of reducing emissions by relying more on
renewable energy:

http://www.slate.com/blogs/the_slatest/2014/03/01/apple_ceo_tim_cook_shoots_down_global_warming_deniers_at_shareholders_meeting.html

This peaks my suspicion. But fear not, I am but a submicron with zero
influence on public policy. I just am suspicious of the ruling class using
academic hucksters to glom more power-highly intelligent hucksters though
they may be.

So you think scientists are academic hucksters if they reach conclusions
about objective reality that might favor policies that are inconvenient for
haven't made any attempt to understand the science on its own terms```

### Re: The situation at Fukushima appears to be deteriorating

```On Mon, Mar 10, 2014 at 12:31 PM, spudboy...@aol.com wrote:

According to Chris, Climate is not the weather or the local weather. So
if this suggestion is correct, its local anomalies over the years, driven
onward, by El Nino' or La Nina' ? According to a report released, last
week, by the Royal Climate Group and the US national academy of sciences, a
change in energy sources will not help us. I had to read it twice to
comprehend what the report indicated.

Are you talking about the report at
http://dels.nas.edu/resources/static-assets/exec-office-other/climate-change-full.pdf?
If so you have totally misunderstood what the report indicated, page
B8
shows that climate models predict the Aggressive emissions reduction
scenario would result in much lower global temperature in 2100 than the
'Business as usual' emissions scenario. They do say on p. 22 that If
emissions of CO2 stopped altogether, it would take many thousands of years
for atmospheric CO2 to return to 'pre-industrial' levels due to its very
slow transfer to the deep ocean and ultimate burial in ocean sediments,
but even if temperatures don't drop for a while, as long as they don't rise
to levels much above what we have today, the consequences probably wouldn't
be too bad (for a discussion of the likely consequences of each 1 degree
rise, check out the book Six Degrees: Our Future on a Hotter Planet by
Mark Lynas).

Jesse

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### Re: The situation at Fukushima appears to be deteriorating

```On Mon, Mar 10, 2014 at 1:52 PM, John Clark johnkcl...@gmail.com wrote:

On Sun, Mar 9, 2014 at 2:47 PM, Jesse Mazer laserma...@gmail.com wrote:

That looks like a pretty crappy match to me. What the hell happened
450 million years ago? And why did the CO2 start to drop 150 million years
ago but the temperature start to climb at the same time?

I suspect you are asking these questions not because you are genuinely
curious, and have an open-minded attitude about the possibility that
climate scientists might have reasonable answers, but [...]

OK OK, I'm closed minded, stupid, enjoy bad environments and am in general
am just a terrible human being;

I never accused you of being stupid or enjoying bad environments. I do
think, as our previous discussion on thermodynamics on the What are
that you seem to have an overly high opinion of your ability to make
informed judgments about scientific ideas in areas that you clearly haven't
studied on a technical level, a very common trait among those who attack
mainstream science (creationists, people who think vaccines cause autism,
people who don't think HIV causes AIDS, etc.).

but my questions are still valid and deserve good answers

Which I gave you.

because before you initiate a policy that will impoverish the world for
many generations and kill lots and lots and lots of people

What policies are you talking about that would have these supposed
effects? The EU has been on track in their goals of emissions reductions,
already cutting them by 18% from 1990 levels, and I don't see them becoming
impoverished or killing lots of their citizens, see
http://ec.europa.eu/clima/news/articles/news_2013100901_en.htm

you should be at least as sure of yourself as President Bush was that
there were weapons of mass destruction in Iraq. Are you?

When there is widespread expert consensus on how sure we should be about
a scientific matter, and I have no expertise in the matter myself, I tend
to assume as a default that the scientific experts likely have good grounds
for believing what they do. Of course it's possible on occasion that expert
consensus can turn out to be badly wrong, but if you look at the history of
science in the post-Newtonian era (pre-Newton, it's harder to say what
counts as science) this is actually very rare, and I can't think of any
cases where the flaw in expert consensus was discovered by someone with no
training in the subject themselves.

So, given that the overwhelming majority of scientific papers discussing
causes of the recent temperature rise agree that human activity is the main
cause (97% of peer-reviewed papers according to the study at
http://www.theguardian.com/environment/climate-consensus-97-per-cent/2013/may/16/climate-change-scienceofclimatechange)
I take it as an operating assumption that this is very likely to be
the
objective reality. What policies we should take in response to that reality
is another matter, but it's irrational to let the fact that you would
scientific matters (wishful thinking).

Speaking of Bush and Iraq, given that we in the U.S. could spend over a
trillion dollars on the Iraq war without bankrupting the country or leading
to mass starvation (I don't think economists would say the crash of 2008
was caused in any direct way by this expenditure either), then it might be
worth pointing out that it's been proposed that for about the same price
(spread out over many years), the U.S. could convert to generating nearly
all its power from solar:

On the question of what happened 450 million years ago in the Ordovician
period, I googled Ordovician temperature and found a discussion of some
scientific research at
http://www.skepticalscience.com/CO2-levels-during-the-late-Ordovician.htmlwhich
suggests there are at least some viable hypotheses about how the
temperature drop could be explained in the framework of existing climate
models:

Hypotheses that answer scientific puzzles are a dime a dozen,  hypotheses
that correctly answer scientific puzzles are not.

That's exactly the sort of vague response a creationist would give to being
shown there are reasonable hypotheses about their own claimed puzzles.
The point is, when you have a theory supported by a lot of evidence but
some specific phenomena that fall under the theory aren't completely
understood (like the causes of the Cambrian explosion in evolutionary
history, or the evolutionary development of some organ whose fossil record
is poor), if there are reasonable hypotheses about how the phenomena could
be explained within the context of the theory, it's irrational to take a
guilty until proven innocent stance where```

### Re: The situation at Fukushima appears to be deteriorating

```On Sun, Mar 9, 2014 at 1:34 PM, John Clark johnkcl...@gmail.com wrote:

A black market degenerates into a cutthroat cartel

True, but the blackness of the market has nothing to do with the nature of
the commodity being transacted, it's black because somebody in government
decided to make it black. Tobacco has killed many orders of magnitude more
people than Meth and all other illegal drugs put together, but the market
for tobacco is not black because somebody in government decided that
particular drug is not illegal; so when tobacco deals go bad they don't
machine gun each other, they sue each other.

John, I repeat my question from earlier--if you disapprove of laws to make
it illegal for people to make and sell drugs that lawmakers judge too
damaging to society, do you also disapprove of laws to make it illegal for
people to make and sell pharmaceutical drugs that some pharmaceutical
company owns the patent for and wants to have exclusive rights to sell at a
much higher cost than the cost of manufacture? Is the black market in drugs
that violates pharmaceutical companies' intellectual property an example
of the free market at work, or not?

Jesse

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### Re: Block Universes

```On Fri, Mar 7, 2014 at 8:37 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

I guess I'm supposed to take that as a yes? You do agree that A's world
line is actually shorter than C's (even though it is depicted as longer)
because A's proper time along it is less than C's from parting to meeting?
Correct? Strange how resistant you are to ever saying you agree when we
actually do agree. Remember we are not counting points here, at least I'm
not, we are trying to find the truth

I'm not resistant in general, I have said I agree to a number of
agree/disagree questions you asked in the past. But in this one case I was
expressing irritation because from your question it seemed pretty obvious
lengths in the post you were responding to. If you really, really can't
deduce my opinion on this from statements like this:

in terms of proper times C  B  A which is the opposite of how it works
with spatial lengths

or:

in spatial terms a straight line is the SHORTEST path between two points,
but in spacetime a straight (constant-velocity) worldline is the one with
the LARGEST proper time between points

...then just tell me why you think these statements are ambiguous and I
will then tell you whether I agree that A's world line is actually shorter
than C's (even though it is depicted as longer) because A's proper time
along it is less than C's from parting to meeting. But if reading those
statements does answer your question, then I would suggest that part of
trying to find the truth is actually reading through the responses you
get, not skimming/skipping over parts of it.

First, note you don't actually have to calculate anything. A and C just
compare clocks when they meet and that gives the actual world line lengths.

Sure, but I'm talking about the theoretical analysis.

But, if you want to calculate to predict what that comparison will be,
then you have to be careful to do it correctly.

C can't just use the Pythagorean theorem on A's world line from his
perspective on the x and y distances, he has to use it on the time
dimension as well squareroot((y2-y1)^2 + (x2-x1)^2 - c(t2-t1)^2).

You have the right idea, although that formula (with c^2 rather than c)
actually calculates proper length on a spacelike interval, if you want
proper time on a timelike interval the equivalent formula would be
squareroot((t2-t1)^2 - (1/c)^2*(x2-x1)^2 - (1/c)^2*(y2-y1)^2). And since we
were talking about a 2D spacetime diagram where all motion was along a
single spatial axis, I dropped the y-coordinate, and as I mentioned I was
also assuming units where c=1, like years for time and light-years for
distance. That's why I just wrote the formula as sqrt((t2 - t1)^2 - (x2 -
x1)^2).

It is the subtraction of this time term that will reduce the length of the
slanting blue lines of A and B to THEIR PROJECTIONS ON C'S OWN WORLDLINE.

That statement appears wrong, although you'd have to give me a definition
of what you mean by projections on C's own worldline for me to be sure.
It seems to me that by the normal definition of projection, projecting
one of the slanted blue line segments onto the C's vertical worldline would
give a new segment parallel to the vertical axis, whose length is just
equal to the vertical separation between the ends of the original slanted
blue segment. If so, the length of that sort of projection is NOT equal
to the proper time of the original slanted blue segment, instead it's equal
to the coordinate time between its endpoints, in C's rest frame.

For example, looking at the diagram at
http://www.jessemazer.com/images/tripletparadox.jpg , let's say the bottom
blue segment on A's worldline begins in 2001 in C's rest frame, and ends in
2008, and it has a velocity of 0.6c. In that case, by the normal meaning of
projection, projecting this segment onto C's vertical worldline would
just create a vertical segment that goes from 2001 to 2008, and thus has a
coordinate time of 7 years (and for any vertical segment of a worldline
parallel to the time coordinate axis, proper time is supposed to be equal
to coordinate time). But because of time dilation, the proper time along
the original blue segment (before it was projected to make it vertical)
is less than the coordinate time by a factor of sqrt(1 - (0.8c/c)^2) =
sqrt(1 - 0.64) = sqrt(0.36) = 0.6, so relativity says the correct proper
time along that original slanted blue segment is 7*0.6 = 4.2 years. Do you
agree or disagree with these numbers?

I think that is what you are saying as well, but my point is that that
NULLIFIES any effect on the length of the world lines by the SLANTING of
the blue lines NO MATTER WHAT THEIR LENGTHS, and LEAVES ONLY the effects of
the red curves.

Suppose that both A and B go through the same sequence of 3 accelerations:

ACCELERATION 1: starting from ```

### Re: Block Universes

```On Sat, Mar 8, 2014 at 9:31 AM, Jesse Mazer laserma...@gmail.com wrote:

And B's worldline consists of the following five segments:

Segment 1 (blue): Remaining at rest in C's frame, from t=1999 to t=2009
Segment 2 (red): ACCELERATION 1 from t=2009 to t=2011
Segment 3 (blue): Moving inertially at 0.6c in the +x direction, from
t=2011 to t=2013
Segment 4 (red): ACCELERATION 2 from t=2013 to t=2017
Segment 5 (blue): Moving inertially at 0.6c in the -x direction, from
t=2017 to t=2019
Segment 6 (red): ACCELERATION 3 from t=2019 to t=2019

Correction--that last line for B's worldline should read

Segment 6 (red): ACCELERATION 3 from t=2019 to t=2021

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### Re: The situation at Fukushima appears to be deteriorating

```On Sat, Mar 8, 2014 at 1:56 AM, John Clark johnkcl...@gmail.com wrote:

On Fri, Mar 7, 2014 at 9:09 PM, Chris de Morsella
cdemorse...@yahoo.comwrote:

Then who would ever want to live under a free market system if as you
admit the transnational drug gangs are an exemplar of a well evolved free
market?

There is no disputing matters of taste so you could say if you wished that
markets, and therefore people, shouldn't have too much freedom; but you
can't say that the Black Market isn't a free market.

There is a black market in pharmaceutical drugs as well as one in illegal
drugs, would you say you can't say that the Black market isn't a free
market in this case too? Or is the crime of violating a company's
intellectual property rights sufficient to disqualify something from being
a free market, unlike the crime of violating laws about what drugs are
allowed to be used at all?

Jesse

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### Re: Block Universes

```On Sat, Mar 8, 2014 at 2:03 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

calculate what you say is the proper time on a time-like interval. Using
your method, which I assume is correct I do see that A's proper time will
be greater than B's. The reason is basically that A has to travel further
in space to get from t1 to t2 and consequently must also travel less far in
time. Correct?

It's true in C's rest frame that A travels a greater distance than B, but
this needn't be true if you used a different frame. For example, if you
analyze the problem using an inertial frame D in which A is at rest during
the first blue leg of his trip, then A and B should travel the same
distance between departing and reuniting, because neither ever turns around
and travels in the wrong direction in this frame, they are both always at
rest in this frame or traveling in the -x direction towards the position in
this frame where they will reunite. So if you imagine that A and B are cars
that are driving along a piece of flat ground at rest in frame D, and both
start out with odometers reading 0 when A first departs from B, then A and
B's odometer will show the same reading when they reunite, since they have
both traveled in a consistent direction (but varying speed) along the same
straight road between the position in frame D where they departed and the
position where they reunited.

To confirm, consider a simplified twin example with only straight lines so
we can ignore accelerations. A remains at rest with a straight vertical
line from t1 to t3. B travels away from t1 in a straight oblique line,
reverses direction midpoint (call this t2) and travels in a straight
oblique line back to t3.

The two halves of B's trip are symmetric (have the same velocities away
from and back towards A) therefore B's proper time, calculated by A, will
be = 2 x sqrt((t2 - t1)^2 - (x2 - x1)^2).  In other words we have to
multiply by 2 to get the proper time of B for the entire trip. Correct?

Yes, that's correct.

OK, now consider another case with A and B just moving with constant
relative motion and their world lines crossing at t1 and then diverging.
There is NO acceleration.

In this case using the Lorentz transform both A and B will observe each
other's time running slow relative to their own. And using your formula
above both A and B will also observe each other's proper times SLOWED
RELATIVE TO THEIR OWN.

But doesn't this mean that since A and B get different results about each
other's proper times that this method of calculating proper times is NOT
INVARIANT, and thus is not actually calculating proper times which you say
are invariant?

The method gives an invariant answer for the proper time between any two
specific events on an inertial worldline, events which are known to have
coordinates (x1,t1) and (x2,t2) in whatever frame you're using.  But in
your example, they haven't agreed on a specific pair of points on each
worldline to calculate the proper time between. Suppose their worldlines
cross at the moment of their births, when they are both 0 years old, and
subsequently they move apart with arelative velocity of 0.6c so the time
dilation factor is 0.8c. If A wants to use his own rest frame to predict
how old B will be at the same moment that A turns 20, he is picking the
event b1 on B's worldline that is SIMULTANEOUS IN A's REST FRAME with A
turning 20, and calculate the proper time between the event of B's birth
and b1, which is 16. On the other hand, if B wants to use his own rest
frame to predict how old he'll be at the same moment that A turns 20, he
must pick the event b2 on B's worldline that is SIMULTANEOUS IN B'S REST
FRAME with A turning 20, and calculate the proper time between B's birth
and b2, which is 25. Both frames agree that the proper time between B's
birth and b1 is 16, and that the proper time between B's birth and b2 is
25, they just disagree about whether b1 or b2 is simultaneous with A
turning 20. So that's why they disagree about whether A is older or younger
than B at any specified point on A's worldline, like A turning 20 (and of
course the logic works the same if you specify a point on B's worldline and
ask about A's age at the same moment). Of course, this sort of ambiguity
about what events to choose doesn't arise in a twin-paradox type scenario
where the twins depart from each other at one specific point on their
worldlines, and reunite at some other specific point on their worldlines.

If you want further evidence that the method gives an invariant answer, you
can use the Lorentz transformation to check that this is so. Pick two
events on the worldline of an inertial clock of arbitrary velocity in the
frame you're using, and assume that the spacetime origin is chosen so that
the first event is labeled with coordinates x1=0, t1=0. Then the second
event can be anything (so long as the ```

### Re: Block Universes

```On Sat, Mar 8, 2014 at 3:11 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

PS: And in your nice long numerical example, which I thank you for, it
seems to me what you are doing is calculating the proper time length of
every segment of A's trip in terms of C's proper time. Isn't that correct?

No, it's in terms of coordinate time in C's rest frame. C's proper time
can only be defined between pairs of events on C's own worldline. Of course
if C is inertial as in this example, then the coordinate time of events on
C's worldline is the same as the proper time between those events, but it
doesn't make sense to talk about C's proper time between events that are
NOT on C's worldline.

But if so aren't you in fact establishing a 1:1 correlation of proper
times between A and C with your method?

And isn't that what you keep telling me CAN'T BE DONE?

You can of course define a correlation in proper times of separated clocks
A and B if you specify what frame's definition of simultaneity you want to
use. Then you can find a pair of events a1 and b1 that are simultaneous in
this frame, and a pair of events a2 and b2 that are simultaneous in this
frame, and compare the proper time on A's worldline between a1 and a2 with
the proper time on B's worldline between b1 and b2. But this sort of
correlation will differ depending on what frame you choose (because the
simultaneous events will differ), and what can't be done is find any basis
in relativity for saying that one frame's correlation represents the real
correlation while other frames' do not.

Jesse

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### Re: Block Universes

```On Fri, Mar 7, 2014 at 4:02 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Finally hopefully getting a minute to respond to at least some of your
posts.

I'm looking at the two 2 world line diagram on your website and I would
argue that the world lines of A and B are exactly the SAME LENGTH due to
the identical accelerations of A and B rather than different lengths as you
claim.

The length of a world line is the PROPER TIME along that world line. Thus
the length of a world line is INVARIANT. It is the length of the world line
according to its proper clock and NOT the length according to C's clock
which is what this diagram shows.

I don't understand what you mean by the length according to C's
clock--are you just talking about the numbers on the vertical time axis,
2000-2020? That axis represents the coordinate time in C's rest frame, and
obviously the coordinate time between 2000 at the bottom of the diagram
and 2020 at the top is 20 years regardless of what path you're talking
about, so I don't see how it makes sense to call this the length of any
particular path. But you can also use C's rest frame to assign x and t
coordinates to the endpoints of any straight blue segment, x1 and t1 for
one endpoint and x2 and t2 for the other, and then C can calculate the
proper time along that segment as squareroot[(t2 - t1)^2 - (x2 - x1)^2] and
get the correct INVARIANT answer (note that I am using units of light-years
and years where c=1 so it doesn't appear in the equation, otherwise the
second term in the square root would have to be (1/c^2)*(x2 - x1)^2).

What the diagram is trying to show is that even though the different paths
have identical red acceleration curves, they have different SPATIAL
lengths, i.e. the length you'd measure if you printed out the diagram and
laid a flexible cloth tape measure along each path to measure the distance
ALONG THE PATH between the point at the bottom of the diagram where the
paths diverge and the point at the top where they rejoin. It is true that
if you just look at the spatial lengths of each path on the diagram, the
ratio between the spatial lengths doesn't actually match up with the ratio
between the proper times that would be calculated using relativity. If you
use any Cartesian spatial coordinate system to draw x-y axes on the
diagram, then you can use this coordinate system to assign x and y
coordinates to the endpoints of any straight blue segment, x1 and y1 for
one endpoint and x2 and y2 for the other, and then calculate the spatial
length of that segment using the Pythagorean theorem: squareroot[(y2 -
y1)^2 + (x2 - x1)^2]. Note that you ADD the squares of the two terms in
parentheses when calculating spatial length, but my earlier equation showed
that you SUBTRACT the square of the two terms in parentheses when
calculating proper time, which explains why this sort of spatial path
length on a spacetime diagram can be misleading. For example, in spatial
terms a straight line is the SHORTEST path between two points, but in
spacetime a straight (constant-velocity) worldline is the one with the
LARGEST proper time between points.

Nevertheless, the math for calculating the invariant spatial path length
using a Cartesian coordinate system is closely analogous to the math for
calculating the invariant proper time using an inertial frame. The diagrams
show the spatial length of the paths being different despite identical red
acceleration segments, and this remains true if you actually calculate
proper time, even though in terms of proper times C  B  A which is the
opposite of how it works with spatial lengths. If you assign time
coordinates to the beginning and end of each acceleration phase, and you
specify the proper acceleration involved, then you can calculate the proper
time along elapsed on each worldline during both the acceleration phases
(using the relativistic rocket equations given at
http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html ) as well
as the proper time during the constant-velocity phases (using the method I
mentioned above with squareroot[(t2 - t1)^2 - (x2 - x1)^2] for each
segment). If you do this, you do find that in a detailed numerical version
of the scenario in the diagram, A ELAPSES LESS TOTAL PROPER TIME THAN B
DESPITE HAVING IDENTICAL ACCELERATIONS. I can give the detailed
calculations using the relativistic rocket equations if you want, or you
can just take my word for it.

So to calculate the length of A's and B's world lines in C's frame (which
this diagram represents) we must take the apparent lengths as shown from
C's frame view on the diagram, and SHORTEN each section by the apparent
slowing of ITS CLOCK relative to C's CLOCK.

Yes, that would be another way to calculate proper time along the blue
constant-velocity segments: just take the times t2 and t1 of the beginning
and end of each segment in C's frame, and multiply by the time dilation
factor which depends on the speed v in C's frame during ```

### Re: Block Universes

```On Fri, Mar 7, 2014 at 7:20 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Do you understand why the world line that is depicted as LONGER in the
typical world line diagram is ACTUALLY SHORTER?

E.g. in your diagram do you understand why even though A's world line
looks longer than C's world line, it is ACTUALLY SHORTER?

Edgar

Are you actually reading my posts carefully all the way through, or just
skimming them or something? I spent a whole extended section of my post
discussing just this point, read it again:

'It is true that if you just look at the spatial lengths of each path on
the diagram, the ratio between the spatial lengths doesn't actually match
up with the ratio between the proper times that would be calculated using
relativity. If you use any Cartesian spatial coordinate system to draw x-y
axes on the diagram, then you can use this coordinate system to assign x
and y coordinates to the endpoints of any straight blue segment, x1 and y1
for one endpoint and x2 and y2 for the other, and then calculate the
spatial length of that segment using the Pythagorean theorem:
squareroot[(y2 - y1)^2 + (x2 - x1)^2]. Note that you ADD the squares of the
two terms in parentheses when calculating spatial length, but my earlier
equation showed that you SUBTRACT the square of the two terms in
parentheses when calculating proper time, which explains why this sort of
spatial path length on a spacetime diagram can be misleading. For example,
in spatial terms a straight line is the SHORTEST path between two points,
but in spacetime a straight (constant-velocity) worldline is the one with
the LARGEST proper time between points.

Nevertheless, the math for calculating the invariant spatial path length
using a Cartesian coordinate system is closely analogous to the math for
calculating the invariant proper time using an inertial frame. The diagrams
show the spatial length of the paths being different despite identical red
acceleration segments, and this remains true if you actually calculate
proper time, even though in terms of proper times C  B  A which is the
opposite of how it works with spatial lengths.'

On Friday, March 7, 2014 5:15:57 PM UTC-5, jessem wrote:

On Fri, Mar 7, 2014 at 4:02 PM, Edgar L. Owen edga...@att.net wrote:

Jesse,

Finally hopefully getting a minute to respond to at least some of your
posts.

I'm looking at the two 2 world line diagram on your website and I would
argue that the world lines of A and B are exactly the SAME LENGTH due to
the identical accelerations of A and B rather than different lengths as you
claim.

The length of a world line is the PROPER TIME along that world line. Thus
the length of a world line is INVARIANT. It is the length of the world line
according to its proper clock and NOT the length according to C's clock
which is what this diagram shows.

I don't understand what you mean by the length according to C's
clock--are you just talking about the numbers on the vertical time axis,
2000-2020? That axis represents the coordinate time in C's rest frame, and
obviously the coordinate time between 2000 at the bottom of the diagram
and 2020 at the top is 20 years regardless of what path you're talking
about, so I don't see how it makes sense to call this the length of any
particular path. But you can also use C's
...

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### Re: Block Universes

```On Thu, Mar 6, 2014 at 11:02 AM, Edgar L. Owen edgaro...@att.net wrote:

Liz,

Sure, but aren't the different lengths of world lines due only to
acceleration and gravitational effects? So aren't you saying the same thing
I was?

Isn't that correct my little Trollette? (Note I wouldn't have included
this except in response to your own Troll obsession.)

Anyway let's please put our Troll references aside and give me an honest
scientific answer for a change if you can... OK?

It would be nice to get an answer from Brent or Jesse as well if they care
to chime in..

In the case of the traditional twin paradox where one accelerates between
meetings while the other does not, the one that accelerates always has the
greater path length through spacetime, so in this case they are logically
equivalent. But you can have a case in SR (no gravity) where two observers
have identical accelerations (i.e. each acceleration lasts the same
interval of proper time and involves the same proper acceleration
throughout this interval), but because different proper times elapse
*between* these accelerations, they end up with worldlines with different
path lengths between their meetings (and thus different elapsed aging)...in
an online discussion a while ago someone drew a diagram of such a case that
I saved on my website:

In this example A and B have identical red acceleration phases, but A will
have aged less than B when they reunite (you can ignore the worldline of C,
who is inertial and naturally ages more than either of them).

You can also have cases in SR where twin A accelerates more than B
(defined in terms of the amount of proper time spent accelerating, or the
value of the proper acceleration experienced during this time, or both),
but B has aged less than A when they reunite, rather than vice versa. As
always the correct aging is calculated by looking at the overall path
through spacetime in some coordinate system, and calculating its length
(proper time) with an equation that's analogous to the one you'd use to
calculate the spatial length of a path on a 2D plane.

Jesse

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### Re: Block Universes

```On Thu, Mar 6, 2014 at 11:32 AM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Yes, from the point any two observers in the same inertial frame
synchronize clocks, their clocks will be synchronized in p-time BUT ONLY
FROM THEN ON (we can't know if they were previously synchronized unless we
know their acceleration histories). And only SO LONG AS they continue in
the same inertial frame OR undergo symmetric accelerations.

Same ages is just a way to ensure synchronized clocks at the birth event
and make examples simpler. It has nothing to do with p-time synchrony per
se.

So in your next paragraph your and Jimbo's proper clocks ARE synchronized
in p-time from then on under the conditions stated.

But I don't understand the rest of your example since you just stated that
we are to ignore their PREVIOUS and SUBSEQUENT acceleration histories to
preserve the synchronies but then you start giving an example with
accelerations, which will obviously change their synchrony UNLESS they are
symmetric.

I clearly stated that the reason I was giving an example of accelerations
was in case you DIDN'T accept the clocks were synchronized in p-time in my
example with Jimbo, which ignored my and Jimbo's past acceleration
histories and ages. My words were:

OK, I don't think it should be necessary to specify acceleration histories
or ages if you agree with my statement about me and Jimbo above, but if you
disagree with that statement I can give details about each pair's past
history, though it makes the example a bit more complicated.

Since you do accept my statement about p-time simultaneity in the Jimbo
example, then there's really no NEED to assume anything about A/B and C/D's
past accelerations being symmetric, we can just assume that at some point
before the experiment happened, A and B came to rest in frame F and
synchronized their clocks in frame F, and C and D came to rest in frame F'
and synchronized their clocks in frame F', and subsequently their x(t) and
T(t) functions in frame F were as I described. However, in the rest of your
post you are responding to my example of a history where A and B had
symmetrical accelerations before the experiment, and so did C and D, so I
will discuss that example; maybe it makes the statements about p-time
simultaneity conceptually clearer to think of their history that way,
although if you think it'd be simpler I'd also be just as happy to make the
assumption above that each pair synchronized clocks after they came to rest
in the same frame.

You seem to claim that the accelerations are symmetric but you keep
describing them as stopping in different frames at different times which
indicates they are NOT symmetric.

In my example both accelerations were totally symmetric in the frames where
the twins started out at rest next to each other with synchronized clocks.
A and B's accelerations were totally symmetric in the unprimed frame F
where they started out both at rest at position x=12.5, and C and D's
accelerations were totally symmetric in the primed frame F' where they
started out both at rest at position x'=7.5. Of course since C and D
stopped accelerating simultaneously in the primed frame F' (at time t'=-12
in F'), they stopped accelerating at different times in the unprimed frame
F which I had used to describe their x(t) and T(t) functions, but surely
your criteria for symmetrical accelerations is just that there is ONE
specific frame where all their proper accelerations are simultaneous,
namely the frame where they started out at rest and next to each other with
synchronized clocks? Assuming that's your criteria, then F' is that one
specific frame for C and D (and note that according to relativity, C and
D's proper times T also remain synchronized in frame F' at all coordinate
times), and F is that one specific frame for A and B (and A and B's proper
times T also remain synchronized in F at all coordinate times).

The only way to ensure the accelerations are symmetric is for both A and B
to have the same proper accelerations at the same proper times AFTER they
synchronize clocks. Are you doing that? If not you are not using MY method.

Yes, I was doing that. In my example I said that in the unprimed frame F, A
and B were originally at rest at position x=12.5, with both having the same
ages, and let's say that their proper time clocks have been set to read T =
-18 years at the moment they were born. Since they were right next to each
other with the same ages and their proper time clocks both showing a time
that's just their age minus 18, naturally their clocks were originally
synchronized. Then they accelerated in a completely symmetrical way in
frame F, with all changes in acceleration being simultaneous in F,
including the event of their both ceasing their acceleration and coming to
rest again in F, which happened at t=-12 in F.

Also you seem to be switching from synchronized proper clocks which I
assumed did NOT reflect actual ages ```

### Re: Block Universes

```Just realized in retrospect that it was a very confusing choice of
terminology to use reference frame to refer to the frame that's used to
label other frame's relative velocities--I was thinking of the idea that
other frame's velocities are labeled in reference to this one choice of
frame, but somehow it didn't occur to me that reference frame is a
synonym for frame of reference, which is what ALL frames are called. So I
edited my post below to use the term index frame instead, since I'm
indexing other frames by their velocity relative to this frame:

On Thu, Mar 6, 2014 at 12:51 PM, Jesse Mazer laserma...@gmail.com wrote:

I don't know what you mean by the frame view of all frame views. I agree
that for a given pair of clocks A and B that are at rest relative to each
other and synchronized in their rest frame, each frame has only ONE answer
to how much clock A is ahead of B (a number which can be zero if the frame
in question is their rest frame, and can also be negative if the frame in
question sees clock A as having a time that's behind clock B's time). But
if we want to LABEL each such frame by velocity (so we can do an integral
or sum over frames with different velocities to take the average), then we
must use some specific index frame, and label the velocity of every other
frame relative to the index frame. So for example if a given frame X has a
velocity of 0.9c relative to a pair of clocks that are 2 light-year apart
in their own rest frame, then in X they are out-of-sync by 2*0.9 = 1.8
years. If we use as our index frame the rest frame of the clocks
themselves, then X is labeled with v=0.9c since that's its velocity
relative to the index frame, and thus our amount out of sync as a function
of v function will have a value of 1.8 at v=0.9c. On the other hand, if we
use as our index frame a frame moving at 0.8c relative to the clocks,
then frame X will have to be labeled with v=0.357c since that's its
velocity relative to the new index frame--it's still the same frame X, and
it still has the same amount-out-of-sync of 1.8, but it just has a
different velocity label. So using this index frame, our amount out of
sync as a function of v function will have a value of 1.8 at v=0.357c.

Point is, depending on the index frame we use to define the v of every
other frame, our amount out of sync as a function of v function will look
different, and thus if we integrate over that function to find some sort of
average value for the amount the clocks are out of sync, or just do an
average over a finite number of values of the function at regular intervals
of v, then we'll get different answers depending on what index frame we
chose.

Jesse

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### Re: Block Universes

```On Wed, Mar 5, 2014 at 8:19 AM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

First I see no conclusion that demonstrates INtransitivity here or any

No, I was just asking if you agreed with those two steps, which show that
different pairs of readings are simultaneous using ASSUMPTION 2. If you
agreed with those, I would show that several further pairs of readings must
also be judged simultaneous in p-time using ASSUMPTION 1, and then all
these individual simultaneity judgments would together lead to a
this out in the original Alice/Bob/Arlene/Bart post, but since you
apparently didn't understand that post I wanted to go over everything more
carefully with the exact x(t) and T(t) functions given, and every point

I thought you would be more likely to answer if I just gave you two
statements to look over and verify rather than a large collection of them,
but if you are going to stubbornly refuse to answer the opening questions
until I lay out the whole argument, here it is in full:

ASSUMPTION 1. If two observers are at rest in the same inertial frame, then
events on their worldlines that are simultaneous in their rest frame are
also simultaneous in p-time

ASSUMPTION 2. If two observers cross paths at a single point in spacetime
P, and observer #1's proper time at P is T1 while observer #2's proper time
at P is T2, then the event of observer #1's clock showing T1 is
simultaneous in p-time with the event of observer #2's clock showing T2.

ASSUMPTION 3. p-time simultaneity is transitive

Please have another look at the specific numbers I gave for x(t),
coordinate position as a function of coordinate time, and T(t), proper time
as a function of coordinate time, for each observer (expressed using the
inertial frame where A and B are at rest, and C and D are moving at 0.8c),
and then tell me if you agree or disagree with the following two statements:

For A: x(t) = 25, T(t) = t
For B: x(t) = 0, T(t) = t
For C: x(t) = 0.8c * t, T(t) = 0.6*t
For D: x(t) = [0.8c * t] + 9, T(t) = 0.6*t - 12

STATEMENT 1. Given the x(t) functions for B and C, we can see that they
both pass through the point in spacetime with coordinates x=0, t=0. Given
their T(t) functions, we can see that B has a proper time T=0 at those
coordinates, and C also has a proper time T=0 at those coordinates.
Therefore, by ASSUMPTION 2 above, the event of B's proper time clock
reading T=0 is simultaneous in p-time with the event of C's proper time
clock reading T=0. Agree or disagree?

STATEMENT 2. Given the x(t) functions for A and D, we can see that they
both pass through the point in spacetime with coordinates x=25, t=20. Given
their T(t) functions, we can see that A has a proper time T=20 at those
coordinates, and D has a proper time T=0 at those coordinates. Therefore,
by ASSUMPTION 2 above, the event of A's proper time clock reading T=20 is
simultaneous in p-time with the event of D's proper time clock reading T=0.
Agree or disagree?

STATEMENT 3. At t=0 in this frame, both A and B have a proper time of T=0;
these readings are simultaneous in this frame. Since A and B are both at
rest in this frame, by ASSUMPTION 1 above, the event of A's proper time
clock reading T=0 is simultaneous in p-time with the event of B's proper
time clock reading T=0. Agree or disagree?

STATEMENT 4. C's worldline passes through the point x=0, t=0, and at this
point C's proper time clock reads T=0. D's worldline passes through the
point  x=25, t=20, and at this point D's proper time clock reads T=0. These
events are not simultaneous in this frame, but using the Lorentz
transformation we can see that they ARE simultaneous in the frame where C
and D are at rest. Therefore, by ASSUMPTION 1 above, the event of C's
proper time clock reading T=0 is simultaneous in p-time with the event of
D's proper time clock reading T=0. Agree or disagree?

Note: This statement is perhaps the subtlest if you aren't too familiar
with the math of SR--in case you didn't know, the Lorentz transformation is
used when we know the coordinates x,t of an event in one inertial frame,
and we want to find the coordinates x',t' of the SAME event in a second
inertial frame which is moving at speed v relative to the first (a good
intro to various aspects of SR including the Lorentz transform can be found
at http://en.wikibooks.org/wiki/Special_Relativity ). Assuming that the
spatial origins of the two frames coincide when t=0 in the first frame and
t'=0 in the second, and assuming that the first frame subsequently sees the
origin of the second frame moving at speed v along the first frame's
x-axis, the transformation equations are:

x' = gamma*(x - v*t)
t' = gamma*(t - (v*x)/c^2 )

Where gamma is the commonly-used relativistic factor 1/sqrt(1 - (v/c)^2).
So with v=0.8c in this example, gamma works out to 1/sqrt(1 - 0.64) =
```

### Re: Block Universes

```On Wed, Mar 5, 2014 at 8:38 AM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Here's another point for you to ponder:

You claim that all frame views are equally valid. What would you say the
weighted mean of all frame views is?

Weighted how? I can't see any weighing that doesn't itself depend on
privileging one frame over others. For example, suppose I label frames
using velocity relative to my rest frame, and use a uniform distribution on
velocity values as my weight function, which implies that the collection of
frames with velocities between 0.1c and 0.1c + dV will have the same total
weight as the collection of frames with velocities between 0.9c and 0.9c +
dV, since these are equal-sized velocity intervals (for example, if
dV=0.05c then we are looking at the frames from 0.1c to 0.15c, and the
frames from 0.9c to 0.95c). But if we look at all the frames in these two
intervals, and translate from their velocities relative to ME to their
velocities relative to another frame B that is moving at say 0.8c relative
to me, then these two bunches of frames do NOT occupy equal-sized velocity
intervals when we look at their velocities relative to frame B (an interval
from 0.1c to 0.15c in my frame translates to the interval from -0.761c to
-0.739c in B's frame, while an interval of 0.9c to 0.95c in my frame
translates to an interval from 0.357c to 0.625c in B's frame). So if we
weigh them equally using MY velocity labels, that would translate to an
unequal weighing relative to B's velocity labels, so we are privileging my
frame's definitions over the definitions of other frames like B.

I would suspect that it converges towards my solution. It is clear from
your own analysis that it does converge to my solution as separation and
relative motion diminishes, so I strongly suspect it converges towards my
solution in all cases.

Correct? And if so I would argue that this also tends to validate my
solution as the actual correct 1:1 correlation of proper ages, even though
I agree completely that all observers cannot direct observe this
correlation...

In fact this is tantalizingly similar to the notion of a wavefunction
representing the probabilities of all possible locations of a particle. If
we take all possible frame views as a continuous 'wavefunction' of the
actual age correlation can we begin to assign probabilities based on their
weighted mean, and if so isn't that going to be my solution?

for the continuous infinity of different possible frames that doesn't
itself privilege one frame's definitions from the start.

Jesse

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### Re: Block Universes

```On Wed, Mar 5, 2014 at 1:27 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Yes, you are right. I phrased it incorrectly.

What I meant to say was not that each individual view was somehow
weighted, but that all views considered together would tend to cluster
around my results for any distance and motion difference pairs.

Too vague. What does all views considered together mean mathematically,
if not a weighted average using some specific weighting function?

In other words there would be a lot more views that were close to my
solution, than views that were far from my solution.

How do you count more when there are a continuous infinity of frame's
views? The only way to count different subsets of an infinite set is
using some sort of measure function (see
https://en.wikipedia.org/wiki/Measure_(mathematics) ), which is equivalent
to a weighting function--whatever you choose to call it, the idea would be
that if you want to compare the number or weight of frames with
velocity between v1 and v2 (the velocities defined relative to some other
specific frame, of course) vs. the number or weight with velocity
between v3 and v4, you use a measure/weight function W(v) which gives a
value for every specific frame velocity v, and you integrate the function
W(v) from v1 to v2, and compare the result to integrating W(v) between v3
and v4 (and if you want to do a weighted average of some specific
quantity Q(v) that varies from one frame to another, like the amount by
which two clocks are out-of-sync, you would integrate Q(v)*W(v) over the
frame velocity interval over which you want the weighted average of Q).

And that we can see this because, as you yourself pointed out, as distance
separation and relative motion differences decrease all other frame views
DO tend to converge on my results.

Thus the aggregate WEIGHT OF ALL VIEWS tends to converge on my solution,
which is what I meant to say. Sort of like a Bell curve distribution with a
point at top representing my solution

Would you agree to that?

In the case of two clocks at rest and synchronized in a common frame, the
only convergence I think we agree on is if you consider a series of cases
where the distance between the two clocks approaches 0, or where the
velocity of the frame whose opinion you're considering relative to the rest
frame of the two clocks approaches 0 (which may be what you meant by as
distance separation and relative motion differences decrease all other
frame views DO tend to converge on my results). If you are talking about a
FIXED value for the distance between two clocks in their rest frame, and
doing a weighted average of larger and larger sets of different frame's
opinions about the time difference between the two clocks (eventually
including frames with a very large velocity relative to the clocks), then
what value this average would converge to would depend entirely on the
weighting function. As I said a weighting function that looks uniform in
one frame (equal velocity intervals have equal weight when you integrate
over the integral) will look non-uniform in other frames, so I can't see a
way to define a weighting function that doesn't privilege one frame at the
outset.

Jesse

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### Re: Block Universes

```On Wed, Mar 5, 2014 at 2:42 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Yes, but respectfully, what I'm saying is that your example doesn't
represent my method OR results.

In your example of A and B separated but moving at the same velocity and
direction, and C and D separated but moving at the same velocity and
direction, BUT the two PAIRS moving at different velocities, AND where B
and C happen to pass each other at the same point in spacetime here is my
result.

Assuming the acceleration/gravitation histories of A and B are the same
and they are twins; AND the acceleration/gravitation histories of C and D
are the same and they are twins, then A(t1)=B(t1)=C(t2)=D(t2) which is
clearly transitive between all 4 parties.

You earlier agreed that if two observers are at rest relative to each
other, then if they synchronize clocks in their rest frame, their clocks
will also be synchronized in p-time from then on. In your post at
responded to one of my questions in this way:

'Yes is the answer to your question if two clocks are at rest relative to
one another and synchronized according to the definition of simultaneity
in their mutual rest frame, do you automatically assume this implies they
are synchronized in p-time? '

You didn't say anything about their ages having to be equal, or about their
needing to have had identical acceleration histories before this. For
example, if I and some stranger named Jimbo are at rest relative to each
other in an inertial frame in flat SR spacetime (no gravity), and in this
frame my 37th birthday is simultaneous with Jimbo's 20th birthday, then if
I set my clock to T=0 on my 37th birthday and he sets his clock to T=0 on
his 20th birthday, isn't this sufficient to demonstrate that our clocks
will be synchronized in p-time from then on (provided we both remain at
rest in this frame), regardless of how either of us may have accelerated
*before* we came to rest in this frame? (assuming of course that I came to
rest before my 37th birthday, and Jimbo came to rest before his 20th)

Even if you somehow don't agree with this, I can easily fill in some
details about the past history of my example to give A/B and C/D
symmetrical accelerations, if you wish--see below.

We don't know what t1 and t2 are because you haven't specified their
acceleration histories or birth dates, but whatever they are the equation
above will hold.

OK, I don't think it should be necessary to specify acceleration histories
or ages if you agree with my statement about me and Jimbo above, but if you
disagree with that statement I can give details about each pair's past
history, though it makes the example a bit more complicated.

Say that in the frame F where A and B are at rest during the period I
described, A and B were originally at rest at position x=12.5, with both
having the same ages, and let's say that their proper time clocks have been
set to read T = -18 years at the moment they were born (it is the custom in
their society to have their proper time clock tell how far from voting age
they are, so for example when they turn 15 their clock reads T=-3, when
they turn 28 their clock reads T=10, etc.). Then each of them
simultaneously began to accelerate in opposite directions with a fixed
proper acceleration of 1 light year/year^2, and after each had traveled a
distance of 6.25 light years from their starting position in this frame,
they began to decelerate (i.e. turn their rockets around and accelerate in
the opposite direction, lowering their speed in this frame) at the same
proper acceleration of 1 light year/year^2. After they each had traveled
another 6.25 light years and come to rest in this frame, they stopped
decelerating and simply remained at rest. Each of them will have then
traveled a distance of 12.5 light years from their original starting
position of x=12.5 light years, with A at position x=25 light years, and B
at position x=0 light years. Hopefully you agree that because their
accelerations are completely symmetrical in the frame where they were
originally at rest with the same ages, in this frame identical ages will
still be simultaneous after they finish the acceleration/deceleration phase
and come to rest. So, let's just say that they come to rest simultaneously
at t=-12 in this frame, and at this moment their clocks both read T=-12,
meaning they are both turning 6 at the moment they stop accelerating. After
this, their x(t) and T(t) functions are just as I described.

As for C and D, let's switch over to the frame F' where THEY are at rest
during the period I describe, whose coordinates I had previously labeled as
x' and t' (and given the Lorentz transformation equations for converting
from x,t to x',t'). Say that in frame F', they were both originally at rest
at position x'=7.5, again with both having the same ages, and both having
their proper time clocks read a time of T ```

### Re: Block Universes

```On Wed, Mar 5, 2014 at 2:52 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Yes, the views are infinite on several axes, but that can be addressed
simply by enumerating views at standard intervals on those axes.

But velocity intervals which are equal when the velocities are defined
relative to one frame are not equal when the velocities are defined
relative to a different frame. I already mentioned an example where if a
frame 1 has velocity v=0.1c relative to me and another frame 2 has velocity
v=0.15c relative to me, then the interval between them is 0.05c from my
perspective, and likewise if a frame 3 has velocity v=0.9c relative to me
and another frame 4 has velocity v=0.95c relative to me, then they have the
same interval of 0.05c from my perspective; but for another observer moving
at v=0.8c relative to me, frame 1 has a velocity of -0.761c and frame 2 has
a velocity of -0.739c (so the interval between 1 and 2 is 0.022 for this
observer), whereas frame 3 has a velocity of 0.357c and frame 4 has a
velocity of 0.625c (so the interval between 3 and 4 is 0.268c for this
observer, more than ten times larger than the interval between 1 and 2).
These velocities are calculated using the relativistic velocity formula at
http://math.ucr.edu/home/baez/physics/Relativity/SR/velocity.html where u =
-0.8c is my velocity relative to the second observer, and v is the velocity
of any given frame 1,2,3, or 4 relative to me.

Point is, if your intervals are equal relative to one frame but unequal
relative to all other frames, then you are privileging a particular frame's
perspective from the start.

Or you could equally integrate over the continuous functions.

As I said, the only way to do this is to use some sort of weight/measure
function, and a weight/measure function which is uniform when plotted
against velocity in one frame will be non-uniform when plotted against
velocity in other frames, so there doesn't seem to be a way of picking such
a function that doesn't privilege one frame from the start.

Considered together simply means you plot the correlation each frame view
(at the standard intervals as above) gives and see how they cluster. Which
I'm pretty sure will be around my result.

The will cluster around the judgment of whatever frame you choose to
privilege from the start, either by your definition of equal intervals or
by your weighting/measure function. So, using this to conclude anything
about the actual correlation would just be another piece of circular
reasoning.

Jesse

You don't need to view the resulting graph from any frame as you seem to
suggest, because the graph is OF the actual all frame view results.

For every frame you simply calculate the apparent lack of simultaneity
between two events Nonsiimultaneity=(t1-t2) and plot it relative to the
simultaneity that my method claims is actual.

Edgar

On Wednesday, March 5, 2014 2:13:24 PM UTC-5, jessem wrote:

On Wed, Mar 5, 2014 at 1:27 PM, Edgar L. Owen edga...@att.net wrote:

Jesse,

Yes, you are right. I phrased it incorrectly.

What I meant to say was not that each individual view was somehow
weighted, but that all views considered together would tend to cluster
around m

...

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### Re: Block Universes

```On Wed, Mar 5, 2014 at 3:12 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

PS: It is well known that accelerations and gravitation are the ONLY
causes that produce real actual age rate changes. These real actual age
rate changes are real and actual because 1. ALL OBSERVERS AGREE on them
when they meet up and check them, and 2.BECAUSE THEY ARE PERMANENT.

No, they produce real actual differences in TOTAL ELAPSED PROPER TIME
BETWEEN MEETINGS, which all frames agree on. This tells us nothing about
the moment-by-moment rates of each clock between meetings, unless you are
simply talking about the AVERAGE ticking rate between meetings (and all
frames do agree on the ratio between two clock's AVERAGE ticking rate
between meetings, since the average ticking rate for clock #1 between
meetings in any frame is [proper time elapsed on #1 between meetings /
coordinate time between meetings] and the average ticking rate for clock #2
is [proper time elapsed on #2 between meetings / coordinate time between
meetings], thus the ratio of the two averages is [proper time elapsed on #1
between meetings / proper time elapsed on #2 between meetings] which all
frames will agree on).

Relativity agrees on this when the parties MEET. All my method does is to
give a method to calculate these real actual changes BEFORE they meet, when
the parties are still separated or in relative motion or acceleration or
gravitation.

It gives a method which is based on simply ASSUMING FROM THE START that
the clock rates behave a certain way between the meetings, without ever
deriving or demonstrating this from more basic premises. Even a fellow
presentist could easily disagree with your assumptions, and you would have
no ARGUMENT for convincing him that your assumptions are correct, using
starting premises that you both could agree on.

And as always, my example with two pairs of twins demonstrates that your
methods lead to a direct contradiction where two different ages of A have
to labeled simultaneous in p-time--if you disagree, the only intellectually
honest way to show I'm wrong is to go through my numbered STATEMENTs
about p-time simultaneity, and tell me which is the first that is not a

This is incredibly simple to understand if you can just escape the notion
that all VIEWS of an age relationship are somehow the same as the ACTUAL
relationship itself. The views DO differ and these VIEWS ARE VALID VIEWS,
but they don't affect the actual RELATIONSHIP THEY ARE VIEWING which is
what my method calculates.

Again, this is a difference in INTERPRETATIONS of relativity. It does NOT
contradict the equations of relativity itself. It simply uses the one that
describes the actual relationship rather than ones that describe VIEWS of
that relationship.

Aren't you at least able to understand what I'm saying even if you don't
agree with it? I see no evidence you are even able to do that

I understand that your method gives a way of deciding which events are
simultaneous in p-time in your theory, it just that:

a) I don't think you have any argument for the validity of your method that
doesn't simply assume p-time simultaneity works the way you want it to from
the start, something that even another presentist who believes in absolute
simultaneity could reasonably disagree with

b) I think your method can be used to derive a contradiction, even though
you don't understand that yet and seem to be refusing to engage with the
nitty-gritty details of my example.

Jesse

On Wednesday, March 5, 2014 2:13:24 PM UTC-5, jessem wrote:

On Wed, Mar 5, 2014 at 1:27 PM, Edgar L. Owen edga...@att.net wrote:

Jesse,

Yes, you are right. I phrased it incorrectly.

What I meant to say was not that each individual view was somehow
weighted, but that all views considered together would tend to cluster
around m

...

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### Re: Block Universes

```On Wed, Mar 5, 2014 at 4:47 PM, LizR lizj...@gmail.com wrote:

If you have a continuum of inertial frames with velocities ranging from +c
to -c in all possible directions, how are you going to integrate over them?
Isn't there a measure problem over an uncountably infinite set?

There's no inherent problem with defining measures on uncountably infinite
sets--for example, a bell curve is a continuous probability measure defined
over the infinite real number line from -infinity to +infinity, which can
be integrated over any specific range to define a probability that a result
will fall in that range. But as I've said, the problem is that although you
can define a measure over all frames in relativity, if it looks like a
uniform distribution when you state the velocity of each frame relative to
a particular reference frame A, then it will be a non-uniform distribution
when you state the velocity of each frame relative to a different reference
frame B, so any such measure will be privileging one frame from the start.

Jesse

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### Re: Block Universes

```On Tue, Mar 4, 2014 at 12:19 PM, Jesse Mazer laserma...@gmail.com wrote:

So you are just going to COMPLETELY IGNORE my response, which pointed out
that your supposed error relied on using the ambiguous phrase B's and
C's proper ages are simultaneous in p-time because they are at the same
place in spacetime to describe my views, and interpreting it in a way that
I would never had agreed with? Again, this phrase could be interpreted two
possible ways:

1. If B's proper age at this point in spacetime in T, then C's proper age
at this point in spacetime must be T as well (i.e. their proper ages are
simultaneous in the sense that they must reach the same age
simultaneously).

2. If B and C's worldlines both pass through a specific point in spacetime
P, and B's age is T1 when she passes through P, while C's age is T2 when
she passes through P, then B must be at age T1 simultaneously with C being
at age T2 (i.e. whatever two specific ages they have at P, they must reach
those two ages simultaneously, even if the two ages are different)

Minor typo in #1 there, it should read If B's proper age at this point in
spacetime is T, not in T.

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### Re: Block Universes

```On Tue, Mar 4, 2014 at 4:04 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

BTW, in spite of your claim it can't be done, here is another simple way
for any two observers at rest with respect to each other but separated by
any arbitrary distance in space to determine their 1:1 age correlation.

If A and B are separated at any distance but at rest with respect to each
other A sends B a light message telling B what A's current age is, and B
immediately reflects that light message back to A with B's current age

Because they are at rest A knows that the actual age difference is A's
CURRENT age - B's REPORTED age + 1/2 delta c (half the light signal's round
trip time). In this way A determines a unique 1:1 age correlation between
his and B's age that will hold for as long as they are at rest. B can use
the same method to determine his 1:1 age correlation with A. A and B do NOT
have to synchronize the signals to do this.

This is a valid method for determining what ages are simultaneous in the
inertial frame where they are both at rest. But there is no basis in
relativity for judging this frame's views on simultaneity to be any more
valid than another frame's.

This gives both A and B their single correct 1:1 age correlation at any
distance which holds so long as they are at rest with respect to each
other.

Again, you present no argument for why this is the single correct
correlation, you just assert it.

Of course other observers may see this differently but IT'S NOT THEIR AGE
CORRELATION, IT'S ONLY A'S AND B'S AGE CORRELATION and A and B can
determine exactly what that correlation is.

Do you agree?

No. You already agreed in an earlier post that for an inertial observer to
label the frame where they are at rest as their own frame is purely a
matter of HUMAN CONVENTION, not an objective reality that is forced on them
by nature. So even if we ignore these other observers, there is nothing
stopping A and B from using a different convention to define their own
frame, such as the inertial frame where they both have a velocity of 0.99c
along the x-axis.

I know you will claim it's not valid since other observers may view it
differently, but frankly A and B's age correlation is NONE OF THEIR

Again, you are conflating observers with frames, even though you earlier
acknowledged that any link between particular observers and particular
frames is just a matter of convention.

I'll respond to the rest of your post later when I have more time...

OK, thanks. Please prioritize my latest post discussing the scenario with
A/B and C/D and statement #1 vs. statement #2, since it seems that your
original argument for an error in my analysis was based on falsely
imagining I was asserting statement #1 rather than statement #2. Since the
analysis really only depends on #2 which you seem to agree with, I would
like to proceed with the analysis of this scenario to see if you can find
any other reason to object  to any other step in the reasoning--if you
can't, then presumably you will have no basis for denying the final
conclusion that two different ages of the same observer A would have to be
simultaneous in p-time, according to your own rules.

Jesse

On Tuesday, March 4, 2014 2:19:46 PM UTC-5, jessem wrote:

On Tue, Mar 4, 2014 at 2:02 PM, Edgar L. Owen edga...@att.net wrote:

Jesse,

You ask me to choose between 1. and 2.

1. If B's proper age at this point in spacetime is T, then C's proper age
at this point in spacetime must be T as well (i.e. their proper ages are
simultaneous in the sense that they must reach the same age
simultaneously).

2. If B and C's worldlines both pass through a specific point in
spacetime P, and B's age is T1 when she passes through P, while C's age is
T2 when she passes through P, then B must be at age T1 simultaneously with
C being at age T2 (i.e. whatever two specific ages they have at P, they
must reach those two ages simultaneously, even if the two ages are
different)

First I assume that by passing through the same point in spacetime you
mean that the worldlines cross at P simultaneously by the operational
definition of no light delay.

1. is true only in a SYMMETRIC case. In the symmetric case they would
have the same ages as they pass through the same point P, but in that case
they have the same ages during the WHOLE trip so no big surprise.

2. is true in all cases. The actual ages T1 and T2 at which they
simultaneously cross will stand in a 1:1 correlation, but ONLY AT THAT
POINT P because their ages could be different due to acceleration
differences either before or after.

Thanks for the clear answer. So now you hopefully see that you must
scenario with the two pairs of twins A/B and C/D, since I never asserted
anything remotely resembling #1, my point about ages that occur at the same
point in spacetime being ```

### Re: Block Universes

```On Tue, Mar 4, 2014 at 4:57 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Good, we agree it's a valid method for determining 1:1 age correlations in
a common inertial frame in which they are both at rest. I claim that frame
is the correct one to determine the actual age correlation because it
expresses the actual relation in a manner both A and B agree

You are avoiding my question of whether identifying this frame with A and
B's view or perspective is just a matter of convention as you
previously seemed to agree, or whether it is tied to them in some more
fundamental way. If it's just a matter of convention, then A and B could
equally well agree to define any other frame as their own view of the
situation.

is transitive among all observers, AND is the exact same method that gives
the correct answer WHEN A AND B MEET and everyone, even you, agrees on the
1:1 age correlation.

Our disagreement over choice of frames is spinning its wheels and not
getting anywhere. It's a matter of how to INTERPRET relativity, rather than
relativity itself. And I have given very convincing reasons why a
privileged frame that preserves the actual physical facts that affect age
changes is appropriate. You just don't agree with them.

like my question about whether you ASSUME FROM THE START that a particular
definition of simultaneity (the one you prefer) is the actual reality, or
whether you claim to have convincing reasons for this definition of
simultaneity representing reality that don't simply assume it from the
start.

just give me the bottom line, a simple synopsis. I don't have the time to
wade through a detailed example only to find the only disagreement is over
choice of frames again.

I promise you the example has nothing to do with any frames other than the
ones in which each pair is at rest. Again, the only assumptions about
p-time that I make in deriving the contradiction are:

ASSUMPTION 1. If two observers are at rest in the same inertial frame, then
events on their worldlines that are simultaneous in their rest frame are
also simultaneous in p-time

ASSUMPTION 2. If two observers cross paths at a single point in spacetime
P, and observer #1's proper time at P is T1 while observer #2's proper time
at P is T2, then the event of observer #1's clock showing T1 is
simultaneous in p-time with the event of observer #2's clock showing T2.

ASSUMPTION 3. p-time simultaneity is transitive

That's it! I make no other assumptions about p-time simultaneity. But if
you want to actually see how the contradiction is derived, there's really
no shortcut besides looking at the math. If you are willing to do that, can
what I asked again, with a few cosmetic modifications:

Please have another look at the specific numbers I gave for x(t),
coordinate position as a function of coordinate time, and T(t), proper time
as a function of coordinate time, for each observer (expressed using the
inertial frame where A and B are at rest, and C and D are moving at 0.8c),
and then tell me if you agree or disagree with the following two statements:

For A: x(t) = 25, T(t) = t
For B: x(t) = 0, T(t) = t
For C: x(t) = 0.8c * t, T(t) = 0.6*t
For D: x(t) = [0.8c * t] + 9, T(t) = 0.6*t - 12

--given the x(t) functions for B and C, we can see that they both pass
through the point in spacetime with coordinates x=0, t=0. Given their T(t)
functions, we can see that B has a proper time T=0 at those coordinates,
and C also has a proper time T=0 at those coordinates. Therefore, by
ASSUMPTION 1 above, the event of B's proper time clock reading T=0 is
simultaneous in p-time with the event of C's proper time clock reading T=0.
Agree or disagree?

--given the x(t) functions for A and D, we can see that they both pass
through the point in spacetime with coordinates x=25, t=20. Given their
T(t) functions, we can see that A has a proper time T=20 at those
coordinates, and D has a proper time T=0 at those coordinates. Therefore,
by ASSUMPTION 1 above, the event of A's proper time clock reading T=20 is
simultaneous in p-time with the event of D's proper time clock reading T=0.
Agree or disagree?

(if you don't understand the math of how to use x(t) to determine whether
someone passed through a given point in spacetime with known x and t
coordinates, or how to determine their proper time T at this point, then
just ask and I will elaborate)

If you agree with both of these, then I will proceed to the next few
agree/disagree statements that follow from the three assumptions, and if
you agree with them all you'll have no way to avoid the contradiction.

On the other hand if you ASSUME privileged frames the way I do and think
my method of using them leads to a contradiction that isn't just another
disagreement over ```

### Re: Block Universes

```On Tue, Mar 4, 2014 at 5:45 PM, Jesse Mazer laserma...@gmail.com wrote:

I promise you the example has nothing to do with any frames other than the
ones in which each pair is at rest. Again, the only assumptions about
p-time that I make in deriving the contradiction are:

ASSUMPTION 1. If two observers are at rest in the same inertial frame,
then events on their worldlines that are simultaneous in their rest frame
are also simultaneous in p-time

ASSUMPTION 2. If two observers cross paths at a single point in spacetime
P, and observer #1's proper time at P is T1 while observer #2's proper time
at P is T2, then the event of observer #1's clock showing T1 is
simultaneous in p-time with the event of observer #2's clock showing T2.

ASSUMPTION 3. p-time simultaneity is transitive

That's it! I make no other assumptions about p-time simultaneity. But if
you want to actually see how the contradiction is derived, there's really
no shortcut besides looking at the math. If you are willing to do that, can
what I asked again, with a few cosmetic modifications:

Please have another look at the specific numbers I gave for x(t),
coordinate position as a function of coordinate time, and T(t), proper time
as a function of coordinate time, for each observer (expressed using the
inertial frame where A and B are at rest, and C and D are moving at 0.8c),
and then tell me if you agree or disagree with the following two statements:

For A: x(t) = 25, T(t) = t
For B: x(t) = 0, T(t) = t
For C: x(t) = 0.8c * t, T(t) = 0.6*t
For D: x(t) = [0.8c * t] + 9, T(t) = 0.6*t - 12

--given the x(t) functions for B and C, we can see that they both pass
through the point in spacetime with coordinates x=0, t=0. Given their T(t)
functions, we can see that B has a proper time T=0 at those coordinates,
and C also has a proper time T=0 at those coordinates. Therefore, by
ASSUMPTION 1 above, the event of B's proper time clock reading T=0 is
simultaneous in p-time with the event of C's proper time clock reading T=0.
Agree or disagree?

--given the x(t) functions for A and D, we can see that they both pass
through the point in spacetime with coordinates x=25, t=20. Given their
T(t) functions, we can see that A has a proper time T=20 at those
coordinates, and D has a proper time T=0 at those coordinates. Therefore,
by ASSUMPTION 1 above, the event of A's proper time clock reading T=20 is
simultaneous in p-time with the event of D's proper time clock reading T=0.
Agree or disagree?

Another little correction--in the last two paragraphs there, where I said
Therefore, by ASSUMPTION 1 above, I should have written ASSUMPTION 2,
since in both cases I was deriving p-time simultaneity from the fact that
two clock readings happened at the same point in spacetime.

Jesse

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```

### Re: Block Universes

```On Mon, Mar 3, 2014 at 10:03 AM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Your position becomes more and more absurd.

My position is simply that for any question on which different frames
give different answers, there is no physical basis for judging one frame's
judgments to be reality while others are not. I guarantee you that any
physicist would agree with this.

You claim they DO have a unique 1:1 correlation of their ages when they
are together but they DON'T when they separate.

So how far do they have to separate before this correlation is lost? 1
meter? 1 kilometer, 1 light year?

Any finite number--one trillionth of a nanometer, say. The theory says that
no matter how small the distance D you choose, if you have an inertial
frame where two clocks are at rest and synchronized a distance D apart,
then in another inertial frame where the two clocks are moving along the
axis between them at speed v, at any given moment in this new frame one
clock's time will be ahead of the other's by vD/c^2. There is a maximum to
how far their times can be out-of-sync since v must be smaller than c, this
implies that no inertial frame will see them as being out-of-sync by a time
greater than or equal to D/c (so if the two clocks are 1 light-second apart
in their rest frame, or 299792458 meters apart, any other frame will see
them out-of-sync by less than a second). And this means that if you are
rounding ages off at some point, in practice you may not have to worry
about disagreements in simultaneity between frames--if two people are
precisely the same age in their rest frame and are standing only a meter
apart in their inertial rest frame, all other frames will say their ages
differ by less than 1/299792458 of a second, so obviously if you're
rounding their ages to the nearest second you'll still say they're the
same age no matter what inertial frame you're using. But if you want to
talk about physical reality rather than mere practical approximations,
the fact remains that different frames will disagree somewhat on which ages
are simultaneous for ANY finite separation, and in relativity there can
NEVER be a physical basis for saying that one frame's judgments are a true
representation of physical reality while other's are not.

And is the correlation lost all at once as they separate or gradually? And
if all at once, what is the threshold distance where correlation is lost?

And if gradually what is the relativistic formula that determines how much
the correlation falls off with distance?

See above, if the clocks are at rest a distance D apart and synchronized in
their own rest frame, then in another frame moving at speed v along the
axis between the two clocks, at any given moment in this new frame the
clocks are out-of-sync by vD/c^2. This can be derived directly from the
Lorentz transformation which tells you the coordinates of any event in
frame #2 if you already have its coordinates in frame #1.

The fact is that both twins DO HAVE AN ACTUAL AGE AT ALL TIMES. You've
already agreed to this obvious fact. Thus there absolutely MUST be an
actual correlation of those ages. That is pure logic, not relativity.

That isn't logical at all, in fact it's a complete non sequitur (note
that you make no attempt to actually explain the 'logic' that leads you
from the premise to the conclusion here).

Once again I would mention the geometric analogy:

--If you have two spatial paths between points A and B on a 2D plane, then
at any given point P on a specific path, there is an actual distance along
the path between point A and point P, which could be measured by a flexible
measuring tape laid along the path. This distance along the path from A to
P--call it the proper path distance from A to P--is totally
coordinate-independent, in the sense that if different Cartesian coordinate
systems have different coordinate descriptions of the same path, they can
each use their own coordinates to calculate this proper path distance
from A to P and they will all get the same answer. But if you use different
Cartesian coordinate systems to assign x,y coordinates to points on the
plane, two points P1 and P2 on *different* paths may have the same
y-coordinate in one coordinate system, but different y-coordinates in
another coordinate system. So the question do two points on different
paths share a common y-coordinate?, unlike the question what is the
proper path distance between two points on a single path?, is one that
different Cartesian coordinate systems answer differently. But I don't
think anyone would ever claim that one Cartesian coordinate system's answer
to the latter question would be physically correct while other coordinate
systems are objectively physically wrong--the notion of separated points
in space having the same y-coordinate is an INTRINSICALLY
coordinate-based idea, it HAS no physical reality independent of an
arbitrary choice of coordinate system.

All of this is exactly analogous ```

### Re: Block Universes

```On Mon, Mar 3, 2014 at 12:36 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

OK, this is some progress.

Now you've gone from saying there is NO correlation at all, to the ages
ARE CORRELATED WITHIN SOME LIMIT. In other words we DO know that for any
set of twins we can always say that their ages ARE the same within some
limits. Correct?

This is a VERY BIG CHANGE in your stated position, from NO correlation at
all to SOME correlation...

Once again your argument turns on vague use of language. You were
consistently talking about a 1:1 correlation, so naturally I was using
correlation in this sense too. If we say all inertial frames agree that
my age T' is simultaneous with my twin's age having some value between T1
and T2, but they disagree on the precise value that is NOT a 1:1
correlation, period. So there's been no change in my position, it's you
whose changing the meaning of correlation in mid-argument in an attempt
to prove me wrong.

You though continue to claim that all frames are equally valid, even if
they DO NOT preserve the actual age changing acceleration effects between
the twins,

What do you mean by actual age changing acceleration effect? If you're
talking about things that are directly measurable without use of a
particular frame--like each twin's proper age at any specific event on his
worldline (including their identical proper ages at the point in spacetime
where they reunite), or each twin's proper acceleration as a function of
proper age, then all frames DO preserve these effects. If instead you mean
the idea that identical ages of separated symmetrically-accelerating twins
are simultaneous in absolute, non-frame-dependent terms, then YOUR ARGUMENT
IS TOTALLY CIRCULAR--you are simply assuming from the start that
symmetrical acceleration implies that identical ages are simultaneous in
actual, absolute terms, WITHOUT DERIVING THIS IDEA FROM ANY MORE BASIC
PREMISES.

while I claim that IF we properly choose a frame that DOES preserve the
actual age changing acceleration effects that we narrow that limit to zero
resulting in an EXACT 1:1 age correlation.

Yep, that sounds pretty circular all right. As near as I can tell, the
structure of your argument is this:

1. Assume without any prior argument that for symmetrically-accelerating
twins, the actual truth about simultaneity is that identical ages are
simultaneous.

2. Observe that there is only one frame that preserves this actual
truth.

3. Therefore, only this frame is valid, other frames are not.

4. If we use this valid frame we can find a unique 1:1 correlation in
their ages--and that is supposed to demonstrate the validity of premise #1
above!

Hopefully you can see that this argument would be completely circular. If
you think this isn't a fair representation of your own argument, then
perhaps you can lay your argument out in a step-by-step manner as above,
with each successive step being obviously derivable from only the previous
steps.

You, in fact, have previously agreed that IF we choose the frame in which
the symmetric accelerations were preserved

All frames agree the proper accelerations as a function of each twin's
proper time are symmetric. By the frame in which symmetric accelerations
were preserved do you mean that each twin's acceleration as a function of
COORDINATE time in that frame is symmetric?

that we DO get an exact 1:1 correlation, you just disagree that that frame
is privileged because it preserves the actual age changing symmetric
accelerations like I claim.

Do you have any argument to DERIVE the conclusion that one frame's
acceleration and aging as a function of COORDINATE time is actual, or is
this just something you assume from the start and have no way to derive
from any more basic premises?

So I suggest that for the moment we ASSUME we should choose that frame,
and then see if it can be consistently applied in a transitive manner to
achieve a common age correlation between ALL observers.

If it can't my theory is falsified. If it can then we can still agree to
disagree about how frames should be applied to analyze specific physical
relationships.

Would you consider it a falsification of your theory to show that your
assumption about simultaneity for symmetrically-moving observers (combined
with transitivity and the idea that events at the same space and time
coordinates in some inertial frame are automatically simultaneous in
p-time) can lead in certain scenarios to a situation where we are forced to
conclude that two different proper times of the SAME observer (Bob's proper
time clock reading 0 and Bob's proper time clock reading 20, say) are
simultaneous in p-time? If so, this sort of falsification is exactly what I
have derived in my Alice/Bob/Arlene/Bart scenario from Feb. 9 at
you have CONSISTENTLY FAILED TO ADDRESS on all the myriad occasions I
have reminded you of ```

### Re: Block Universes

```On Mon, Mar 3, 2014 at 3:45 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

No, it was you that said there was NO correlation.

Jeez Edgar, you really need to work on your reading comprehension. I just
got through AGREEING that I had said that there wasn't a correlation, but I
explained that this was because I was using correlation in the way YOU
had consistently been using it up until now, to refer to a 1:1 correlation
in which each proper age of a twin is matched up to one unique proper age
of the other twin. The archive at
search function than google's archive (returning individual posts rather
than threads), so I searched for posts from Edgar L. Owen with correlate
or correlation in them, results here:

Earliest posts on the block time thread I could find in these searches
(that were directed at me, and not some other poster) were these from Feb.
12 and 13 (shown in order below), where you can see from the quotes that
you were talking specifically about 1:1 correlations that map clock times
of one to specific clock times of the other:

So all observers are always in the same p-time moment. Now it's just a
matter of correlating their clock times to see which clock times occurred
in any particular current moment of p-time.

Do you see how this mutual agreed on understanding of how each's clock
time varies in the other's frame always allows each to correlate their own
comoving clock time with the comoving (own) clock time of the other? In
other words for A to always know what B's clock time was reading when A's
clock time was reading t, and for B to always know what A's clock time was

Do you understand that if we have equations for t' in terms of t in A's
frame, and t in terms of t' in B's frame, that we can always establish a 1:
1 correlation between t in A's frame and t' in B's frame?

And in subsequent posts I'm pretty sure you always used correlation in the
same manner, repeating the phrase 1:1 correlation many times (you may
have gotten this phrase from ghibbsa, who used it in a Feb. 6 post at
you quoted in one of your posts that came up in the search results). A
similar search for posts by me that use correlate or correlation
doesn't show any posts of mine using these words on the thread prior to
your three posts to me above, and subsequently I always used correlation
in the same sense that YOU had been consistently using it, to refer to a
precise 1:1 correlation in ages/proper times.

In any case that's irrelevant if we know you now accept that there is a
very LARGE correlation in most situations, and a definable correlation in
ALL situations. That there is always SOME correlation.

By actual age changing effect I mean proper accelerations and gravitations
measurable by a comoving scale at specific clock tick events on his proper
clock. There is no doubt these are real actual CAUSES with specific
measurable values that thus must have real actual EFFECTS with specific
actual values. So you are now saying that all frames DO preserve these
effects?

What EFFECTS do you think they cause? Can you name a SPECIFIC effect on a
SPECIFIC variable used in relativity? As I've told you before, if you are
talking about some notion of a change in clock rate, then in relativity
there is no frame-independent way to assign a specific actual value to
the concept of a clock rate, the clock rate can only be defined relative
to a particular coordinate system, so the clock rate at a particular
event on the clock's worldline can have DIFFERENT values depending on what
coordinate system you use. So, if this is in fact what you mean by
effects, then I would DENY that proper accelerations have real actual
EFFECTS with specific actual values. If you mean something else by real
actual EFFECTS, you'll have to name the specific effect or your argument
will be hopelessly vague.

Your 4 point representation of my method MAY BE circular, but my actual
method is NOT circular.

Your statement 1. is an incorrect statement of my theory. What I assume
FIRST in the symmetric case is NOT simultaneity of ages but simultaneity of
the AGE CHANGING EFFECTS that relativity itself identifies, namely
acceleration and gravitation.

Not ```

### Re: Block Universes

```On Sat, Mar 1, 2014 at 7:09 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

1. Yes, you said that proper ages are invariant. But note the important
point that the proper age of A to himself is a direct observation (he looks
at his age clock), but to anyone else is a computation and NOT an
observation.

If he looks at his age clock, that's a direct measurement that is not
specifically tied to ANY frame, including his own comoving frame. And
there's nothing stopping an observer who is moving relative to him from
stealing a glance at his age clock too as she passes him nearby (or looks
at him through her telescope), so she can make a direct measurement of his
age just as easily.

A reference frame only needs to be used when you want to PREDICT some fact
you don't already know through direct measurement, given some other known
facts. For example, if you know that someone has a coordinate velocity v at
coordinate time t0 in some frame, and you know their proper age is T0 at
coordinate time t0, then as long as they move inertially, you can PREDICT
that at some later coordinate time t1, their proper age T1 will be equal to
T0 + (t1 - t0)*sqrt[1 - (v/c)^2]. Of course if you happen to be using the
person's inertial rest frame where v=0, this formula reduces to the simple
one T1 = T0 + (t1 - t0), but this still qualifies as a CALCULATION to
predict his proper age at a later coordinate time t1, not a direct
measurement.

In fact from their native comoving frames they will observe A at some
other age than their calculation. So the calculations trump the views.

Huh? You're not making any sense--you just got through agreeing proper
ages are invariant, how can you still maintain they'll observe A at some
other age than their calculation if you agree all frames will predict
exactly the same age for him at any event on his worldline, and this will
also be the age that he will be observed to have on his personal clock at
that event?

Do you just mean that the time coordinate they assign to that event may be
different than his proper age? That would be true, but no one familiar with
relativity would conflate a time coordinate with an age, and anyway it's
quite possible to have an inertial coordinate system where he's at rest but
his age still doesn't match the coordinate time, because his birth is
assigned some time coordinate different from t=0.

Thus it is valid in relativity to CALCULATE things we CANNOT OBSERVE from
our frame.

Actual physical measurements can be seen by any observer, like the example
of looking at the age clock of someone you're in motion relative to, so
there's nothing that one person can observe that someone else cannot
observe just because they're in a different rest frame, if by observe
you mean measure using a physical instrument. Of course, actual physical
measurements may be interpreted differently depending on what frame we
use--for example, if I see an object pass the x=10 meters mark on some
ruler when the clock there reads t=5 seconds, and later pass the x=20
meters mark on the same ruler when the clock there reads t=6 seconds, then
if I am using a frame that defines the ruler and clocks to be at rest and
the clocks to be synchronized, I'll say these measurements imply the object
had a velocity of 10 meters per second, but if I'm using a frame where the
ruler itself is moving and the clocks are out of sync, I can say that the
velocity of the object itself was larger or smaller.

That's what I do to establish 1:1 correlations of actual ages. I use
calculations that trump Views, that trump observations. We don't always
have to use frame views to establish relativistic truth. Do you agree with
that? You must if you accept proper age invariance.

Of course, you can determine relativistic truth by direct measurement, like
looking at someone's clock. But this only applies to quantities that are
frame-invariant, like proper time or proper acceleration. Other quantities
are DEFINED with respect to reference frames, there's absolutely no way to
determine them in a way that doesn't involve a frame. The x-coordinate of
an event would be an example of a quantity that's defined in terms of a
reference frame, you can't determine some object's x-coordinate except in
reference to a particular coordinate system that has a particular spatial
origin and its x-axis oriented in a particular direction. Likewise, the
t-coordinate of an event can only be defined relative to a particular
frame, and since simultaneity is DEFINED in relativity to mean nothing more
than events that have the same t-coordinate, simultaneity can only be
defined relative to a particular frame (talking specifically about physical
definitions of simultaneity in relativity--this doesn't preclude the
possibility of some metaphysical truth about simultaneity that's
impossible to demonstrate experimentally, and of course it's conceivable
that relativity will turn out to be ```

### Re: Block Universes

```On Sun, Mar 2, 2014 at 12:13 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

then I agree with all 3. Though I suspect we understand them differently.
When you spring your 'proof' we will find that out.

Thanks for addressing the question. As I mentioned in my previous comment
to you, the proof has already been sprung--it is the Alice/Bob/Arlene/Bart
example from Feb. 9 at
I have asked you to address in at least ten different posts since
then.

And to your first points. I agree completely that there is no objective or
actual truth about VIEWS of simultaneity from different frames. That is
standard relativity which I accept completely. But you still find it
impossible to understand we can DEDUCE or calculate an ACTUAL physical
simultaneity irrespective of VIEWS of it.

And just as proper time invariance is NOT ANY VIEW but a deduction or
calculation, we CAN use deductions and calculations that DO NOT correspond
to any particular view to determine relativistic truth That such a
methodology is permissible?

Do you agree that the symmetric relationship defined by the twins
executing the exact same proper accelerations at their exact same proper
times is a meaningful physical concept? That we can speak meaningfully

Only in terms of coordinate-invariant characterizations of their paths,
like the proper acceleration as a function of proper time, or the total
proper time elapsed between departing and reuniting. There is no logical
reason that this symmetry in coordinate-invariant aspects of their trips
somehow forces us to say that a coordinate system where
coordinate-dependent aspects of their trips are symmetrical too represents
actual physical reality where other coordinate systems do not.

Suppose we lay out two measuring tapes on different paths between two
intersection points A and B, and these paths are geometrically symmetrical
in the sense that each one looks like a mirror image of the other if your
mirror is laid out straight between points A and B. Both tapes have their 0
markings coincide with the first intersection point A, and obviously since
the two paths are symmetrical, both measuring tapes will have the same
marking coincide with the second intersection point B. Obviously we could
draw different spatial coordinate axes on the plane, and in some coordinate
systems their paths would be symmetrical in coordinate terms--for example,
a pair of identical markings on each tape would have the same
y-coordinates, and their slopes at these markings would have the same
absolute value--while in others they would not.

I can sketch out a diagram if you can't visualize what I'm talking about,
but assuming you can, do you think that coordinate-based statements based
on a symmetrical coordinate system, like the 4-centimeter marks on each
measuring tape have the same y-coordinate would represent actual
reality, whereas coordinate-based statements in other coordinate systems
would not?

You've been referring to it as if you do. Note that the twins certainly
consider it a meaningful physical scenario because they can exchange and
execute specific flight plans on that basis.

If so you agree that some frames preserve that real physical relationship
and some don't?

No, I don't agree. ALL frames preserve the only symmetries I would
recognize as objective ones--same proper acceleration as a function of
proper time, same proper time when the twins reunite--while other
coordinate-depedent statements are not ones I would call a real physical
relationship. Note that they are perfectly free to agree to use a
coordinate system where the coordinate descriptions of their paths are not
symmetrical, and exchange and execute specific flight plans on that basis.

If so please tell me why if we want to analyze that ACTUAL real physical
relationship we should not choose a frame that preserves it?

And second, do you agree my method is consistently calculating something,
and that something is transitive, even if you don't agree it's a physically
meaningful concept?

If you consider more than one pair of twins whose paths cross one another,
as I do in my Alice/Bob/Arlene/Bart scenario, then either your method leads
to a contradiction where two different ages of the same observer are judged
simultaneous, or else you'd have to drop one of the assumptions in your
method (meaning it'd no longer be quite the same method). One of those
assumptions was transitivity, so in principle you could drop that if you
wanted to avoid the contradiction I describe, but as I said in my previous
comment, it seems like a much more reasonable assumption to drop is the one
that says inertial clocks at rest relative to one another that are
synchronized in their rest frame must also be synchronized in p-time.
Though as I ```

### Re: Block Universes

```On Sun, Mar 2, 2014 at 2:25 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

I'll address your points in a later post, but first let me run this simple
new case by you.

Imagine the symmetric trips of the twins continually criss cross each
other at 1 second intervals (of their own proper clocks) for the duration
of the entire trip.

At each 1 second meeting I'm sure you would agree their proper times are
in a 1:1 correlation so their proper times are in a 1:1 correlation every
second of the duration of the trip and both twins agree on that.

There is a 1:1 correlation of proper age clocks at the criss crosses
because they are in the same point of space and time by your operational
reflected light definition AND they both compute both their 1 second proper
time intervals since the last criss cross as the same invariant number as
each other, AND they BOTH HAVE AGREED TO CRISS CROSS WHEN EACH OF THEIR
PROPER TIMES READS 1 SECOND INTERVALS which in itself ensures the 1:1
correlation of proper times.

Sure, there is complete agreement about their respective ages at each
crossing-point.

Now just take the limit of that and imagine a vanishingly small interval
for the criss crosses. If we do that then clearly we can say the twins have
a 1:1 correlation of their proper ages at EVERY MOMENT during the entire
trip to any limit of accuracy we wish.

The problem is that in this limit, they also approach a state of simply
moving right alongside each other (since the spatial separation they can
achieve between crossings approaches zero), remaining at exactly the same
point in space at any given time, so their worldlines are identical. Of
course it is true in such a case that their ages will remain the same at
every moment in a frame-invariant sense, but this tell us anything about
simultaneity in a case where they have a finite spatial separation
throughout the trip.

Since a criss cross symmetric trip is no different in principle than our
previous symmetric trip (only a single meeting) it is clear that we have
proven there is a 1:1 proper age correlation for any symmetric trip during
EVERY MOMENT of the trip.

Edgar

On Sunday, March 2, 2014 1:18:27 PM UTC-5, jessem wrote:

On Sat, Mar 1, 2014 at 7:09 PM, Edgar L. Owen edga...@att.net wrote:

Jesse,

1. Yes, you said that proper ages are invariant. But note the important
point that the proper age of A to himself is a direct observation (he looks
at his age clock), but to anyone else is a computation and NOT an
observation.

If he looks at his age clock, that's a direct measurement that is not
specifically tied to ANY frame, including his own comoving frame. And
there's nothing stopping an observer who is moving relative to him from
stealing a glance at his age clock too as she passes him nearby (or looks
at him through her telescope), so she can make a direct measurement of his
age just as easily.

A reference frame only needs to be used when you want to PREDICT some
fact you don't already know through direct measurement, given some other
known facts. For example, if you know that someone has a coordinate
velocity v at coordinate time t0 in some frame, and you know their proper
age is T0 at coordinate time t0, then as long as they move inertially, you
can PREDICT that at some later coordinate time t1, their proper age T1 will
be equal to T0 + (t1 - t0)*sqrt[1 - (v/c)^2]. Of course if you happen to be
using the person's inertial rest frame where v=0, this formula reduces to
the simple one T1 = T0 + (t1 - t0), but this still qualifies as a
CALCULATION to predict his proper age at a later coordinate time t1, not a
direct measurement.

In fact from their native comoving frames they will observe A at some
other age than their calculation. So the calculations trump the views.

Huh? You're not making any sense--you just got through agreeing proper
ages are invariant, how can you still maintain they'll observe A at some
other age than their calculation if you agree all frames will predict
exactly the same age for him at any event on his worldline, and this will
also be the age that he will be observed to have on his personal clock at
that event?

Do you just mean that the time coordinate they assign to that event may
be different than his proper age? That would be true, but no one familiar
with relativity would conflate a time coordinate with an age, and anyway
it's quite possible to have an inertial coordinate system where he's at
rest but his age still doesn't match the coordinate time, because his birth
is assigned some time coordinate different from t=0.

Thus it is valid in relativity to CALCULATE things we CANNOT OBSERVE from
our frame.

Actual physical measurements can be seen by any observer, like the
example of looking at the age clock of someone you're in motion relative
to, so there's nothing that one person can observe that someone ```

### Re: Block Universes

```On Sun, Mar 2, 2014 at 6:49 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Just checking but I'm sure you would agree that twins AT REST with respect
to each other are the same actual age (have a 1:1 proper age correlation)
even if they are SEPARATED by distance? You just don't agree that if they
are separated by distance AND in symmetric acceleration that there is any
correlation of actual ages possible. Is that correct?

No, of course I wouldn't agree that there is any unique actual truth
about their ages in this case, nor would any mainstream physicist. What
part of all frames are equally valid don't you understand? Or do you not
get that if we use an inertial frame where the twins are both moving with
the same constant velocity, they do NOT have identical ages at any given
moment in this frame? (assuming they had identical ages at any given moment
in their rest frame)

Jesse

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### Re: Block Universes

```On Sun, Mar 2, 2014 at 6:40 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Glad we agree on the first point but, even if there is some minimum time
limit to the criss crosses, you miss the real point of my example. Let me
restate it:

Since a criss cross symmetric trip is NO DIFFERENT IN PRINCIPLE than our
previous symmetric trip (only a single meeting) it is clear that we have
proven there is a 1:1 proper age correlation for any symmetric trip during
EVERY minimum time interval of the trip EVEN IF THERE ARE NO CRISS CROSSES.

Nonsense. We both agree that in case A where they are right next to each
other throughout the whole trip (same spatial position at every single
moment), there is an objective 1:1 correlation in their ages throughout the
trip. We disagree about whether there is a 1:1 correlation throughout the
trip in case B, where they do NOT occupy the same position through the
trip. So now you think you can prove your belief about CASE B by
considering a series of cases that IN THE LIMIT would have a 1:1
correlation throughout the trip, even though IN THE LIMIT this just reduces
to CASE A, which we already agreed on? Sorry, but this fails basic logic.

Jesse

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### Re: Block Universes

```On Sun, Mar 2, 2014 at 7:01 PM, Jesse Mazer laserma...@gmail.com wrote:

No, of course I wouldn't agree that there is any unique actual truth
about their ages in this case, nor would any mainstream physicist.

Sorry, I wrote too quickly here--what I meant is that I don't agree there
is any unique actual truth about the CORRELATION between their ages, i.e.
whether or not they reach the same age simultaneously (of course there is
still a unique truth about each one's age at any specific event on his
worldline). They do reach the same age simultaneously in their comoving
inertial frame, but this frame's judgments can't be considered any more
valid than a different inertial frame.

Jesse

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### Re: Block Universes

```On Sun, Mar 2, 2014 at 7:44 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

OK good, that's what I assumed you meant.

BUT now take the two twins at rest standing on opposite sides of the
earth, and then they each start walking in different directions. By your
criterion you then have to say that suddenly and instantly there is NO more
1:1 correlation of their ages, that they COMPLETELY AND ABSOLUTELY lose
their 1:1 age correlation they had at rest even if they take a SINGLE STEP!

You seem to have misunderstood me, although I thought I was pretty clear--I
said that they did NOT have a unique actual correlation in their ages
when they were at rest relative to each other but at different positions in
space, so nothing changes if they start walking, they still don't have any
unique actual correlation in their ages. Try reading what I wrote again
(with the correction I mentioned that 'any unique actual truth about
their ages' has been changed to 'any unique actual truth about the
correlation between their ages'):

'No, of course I wouldn't agree that there is any unique actual truth
about the correlation between their ages in this case, nor would any
mainstream physicist. What part of all frames are equally valid don't you
understand? Or do you not get that if we use an inertial frame where the
twins are both moving with the same constant velocity, they do NOT have
identical ages at any given moment in this frame? (assuming they had
identical ages at any given moment in their rest frame)'

Jesse

On Sunday, March 2, 2014 7:13:31 PM UTC-5, jessem wrote:

On Sun, Mar 2, 2014 at 7:01 PM, Jesse Mazer laser...@gmail.com wrote:

No, of course I wouldn't agree that there is any unique actual truth
about their ages in this case, nor would any mainstream physicist.

Sorry, I wrote too quickly here--what I meant is that I don't agree there
is any unique actual truth about the CORRELATION between their ages, i.e.
whether or not they reach the same age simultaneously (of course there is
still a unique truth about each one's age at any specific event on his
worldline). They do reach the same age simultaneously in their comoving
inertial frame, but this frame's judgments can't be considered any more
valid than a different inertial frame.

Jesse

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### Re: Block Universes

```On Sat, Mar 1, 2014 at 9:55 AM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Of course there is a rational justification for selecting one frame over
another in many cases. All frames are NOT equal when it comes to
representing ACTUAL physical facts.

E.g. we can choose various frames to make someone's age pretty much any
number we like but nevertheless they are still actually the age they think
they are. If Alice is really 30 we can choose a frame in which she is all
sorts of different ages

I've already told you that proper time at an event on Alice's worldline is
frame-independent, did you forget already? If one frame says Alice is 30 at
a particular event in her worldline, like the event of her passing a
particular object or observer (or her age when she reunites with her twin),
then ALL frames say this, there is no need to use her comoving frame to get
Alice's age is at the same moment that Bob turns 40, at a distant spatial
location--but this is precisely why physicists don't believe there is any
actual physical fact about simultaneity in relativity (this doesn't rule
out presentism since there could still be a metaphysical fact about
simultaneity, but no physical experiment would be able to determine it if
there was, unless relativity turns out to be incorrect in its physical
predictions).

but she is still actually 30. Different VIEWS of her age don't change her
actual age. Isn't that obvious, and don't you agree with this?

Don't change her actual age WHEN? Doesn't change her age at some specific
event on her worldline, or doesn't change what her age is now at the same
moment that some distant observer like Bob reaches a particular age, say
40? If the first I agree that she has an actual age at any given event on
her wrodline, but there ARE no different views of this since all frames
agree on her proper age at any specific event on her worldline. If the
latter I don't agree there is any physical basis for saying she has a
unique actual age when Bob is 40, since relativity doesn't give any
physical basis for a preferred definition of simultaneity.

Your expertise in relativity is clear but you don't seem to understand
that all frames are NOT equal when it comes to representing actual physical
fact. You don't understand the fundamental notion in relativity that some
frames represent actual physical fact, but others represent only HOW OTHER
OBSERVERS VIEW those physical facts.

Not a physicist in the world would agree with you that there is a
fundamental notion in relativity that some frames represent actual
physical facts, you appear to be completely confused about the difference
between your own p-time views and mainstream relativity. In special
relativity there can NEVER be a basis for considering one inertial frame
more correct than any other. There are only two kinds of facts in
relativity:

1. Facts about frame-independent matters like the proper time of an
observer at a particular event on their worldline; all frames agree in
their predictions about these, so they don't give any reason to prefer one
frame over another.

2. Facts about frame-dependent matters like the coordinate velocity of an
object at a particular event on its worldline, or the question of which
point on worldline B is simultaneous with a particular point on worldline
A; different frames disagree on these matters, and in relativity NO FRAME'S
STATEMENTS ABOUT FRAME-DEPENDENT MATTERS ARE CONSIDERED MORE VALID THAN ANY
OTHER FRAME'S.

If you don't believe me that it's a basic principle of relativity that all
frames are considered equally valid and none are preferred over others,
here are some quotes from books written by physicists that I found on

If one reference frame moves uniformly relative to another, then the two
are equally good frames for observing nature, and two identical experiments
performed in the two frames will give identical results.

--From Relativity for the Questioning Mind by Daniel Styer, at

The descriptions of the two sets of observers are equally real and equally
valid, each within their own frame of reference. Since no preferred frame
exists, there is no objective basis for ascribing any more reality to one
description than the other.

--From Understanding Relativity: A Simplified Approach to Einstein's
Theories by Leo Sartori, at

If Albert and Betty clap nearly simultaneously, one observer may report
that Albert clapped first, whereas a second observer, in motion with
respect to the first, may report that Betty clapped first. It makes no
sense to ask, 'Who really clapped first?' The question assumes that one
viewpoint, one reference frame, is valid or 'real' and the other is not.
But time is not absolute; it is a property of a particular frame of
reference. Both ```

### Re: Block Universes

```On Sat, Mar 1, 2014 at 5:35 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Let me ask you one simple question.

In the symmetric case where the twins part and then meet up again with the
exact same real actual ages isn't it completely logical to conclude they
must also have been the exact same real actual ages all during the trip?

If, as you claim, the same exact proper accelerations do NOT result in the
exact same actual ages all during the trip then how in hell can the twins
actually have the exact same actual ages when they meet up?

It's not that I'm claiming that there's an objective truth that they DON'T
have the same ages during the trip. I'm just saying that as far as physics
is concerned, there simply IS NO OBJECTIVE OR ACTUAL TRUTH ABOUT
SIMULTANEITY, and thus there is neither an actual truth that they are the
same age or an actual truth that they are different ages. These things
are purely a matter of human coordinate conventions, like the question of
which pairs of points on different measuring-tapes have the same y
coordinates in any given Cartesian coordinate system. Similarly, questions
of simultaneity reduce to questions about which pairs of points on
different worldlines have the same t coordinate in any given inertial
coordinate system, nothing more.

What is the mysterious mechanism you propose that causes twins that do not
have the same actual ages during the trip to just happen to end up with the
exact same actual ages when they meet?

Again, I do not say there is any objective truth that they do not have the
same actual ages, I simply say there is no objective truth about which
ages are actually simultaneous in some sense that is more than just an
work in FRAMES where they don't have the same actual ages during the trip,
the answer is that in such a frame you always find that the answer to which
twin's clock is ticking faster changes at some point during the trip, so
the twin whose clock was formerly ticking faster is now ticking slower
after a certain time coordinate t, and it always balances out exactly so
that their clocks have elapsed the same total time when they reunite. If
you like I could give you a simple numerical example where I analyze a
symmetric trip both from the frame where their velocities are symmetrical,
and a different frame where their velocities are non-symmetrical, and show
that it does work out that the second frame predicts their ages will be the
same when they reunite despite them aging at different rates during
different phases of the trip in this frame.

Meanwhile, are you going to address the question about whether you agree
with the 3 premises that I claim together lead to a contradiction? I'll
repost the question from my last post:

'Again, the 3 premises are:

1. If a pair of inertial observers are at rest relative to one another,
then events (like clock readings) that are simultaneous in their comoving
frame are also simultaneous in p-time

2. Any two events that happen at precisely the same position and time
coordinate in a particular inertial frame must be simultaneous in p-time

3. p-time simultaneity is transitive

premises, or if there is one or more you disagree with or aren't sure about
and require clarification on. And if you disagree with or are not sure
about #2, this is the same point in spacetime issue we had been
discussing earlier before you stopped responding, so in this case please go
back to my last post on the subject at
respond to that.'

Jesse

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### Re: Block Universes

```On Fri, Feb 28, 2014 at 11:18 AM, Edgar L. Owen edgaro...@att.net wrote:

You point out that from the POV of all arbitrary frames they won't be, BUT
the point is we MUST use a frame that MAINTAINS the real and actual
symmetry to determine the ACTUAL REALITY of this situation.

Why? You give no rational justification for why reality should coincide
with the frame where the coordinates assigned to their paths are
symmetrical as opposed to any other frame which makes the same physical
predictions, this just seems like a quasi-aesthetic intuition on your part.
But I also have a more definitive argument against identifying
simultaneity in the frame where their paths look symmetrical with any
sort of absolute simultaneity--because, as I have said over and over, it
pairs of observers, and the transitive nature of absolute
simultaneity/p-time. If you will just respond to my Feb 24 post at
you promised to do earlier, then as soon as we are completely settled on
the matter of whether events that have the same space and time coordinates
in an inertial frame must have happened at the same p-time, we can go back
and look at the Alice/Bob/Arlene/Bart example at
premise that events with the same space and time coordinates in an inertial
frame happened at the same p-time.

Do you agree that if we choose a frame that preserves the real and actual
symmetry of the trip that we do get EQUAL proper times between all markers
on the twins respective trips? And thus that we CAN establish a 1:1
correlation of proper times in this case?

The real and actual symmetry is that they have symmetrical proper
accelerations as a function of proper time, but ALL frames preserve this
symmetry. I agree that we are free to use a frame where their coordinate
velocities and proper time as a function of coordinate time are ALSO
symmetrical, but these are simply statements about coordinates, I see no
reason to consider them any more real and actual than the coordinates
assigned to their paths in any other frame.

Jesse

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### Re: Block Universes

```On Fri, Feb 28, 2014 at 12:38 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

First I would appreciate it if you didn't snip my proximate post that you

Anyway we MUST choose a frame that preserves the symmetry because remember
we are trying to establish a 1:1 proper time correlation BETWEEN THE TWINS
THEMSELVES (not them and anyone else), and it is only a symmetric frame
that preserves the facts as EXPERIENCED BY THE TWINS THEMSELVES. ALL we
need to do in my p-time theory is demonstrate that each twin can correlate
his OWN proper time with that of the other twin.

But you agreed earlier (in your post at
that the idea of calling the comoving inertial frame of an observer their
own frame is purely a matter of CONVENTION, not anything imposed on them
by reality. So, we could easily choose a different convention--one in
which each twin defines their own frame, or what they experience
themselves, as the inertial frame in which they have a velocity of 0.99c
along the x-axis. If they both agreed to define the facts as experienced
by the twins themselves in this way, by convention, they could also agree
on a 1:1 correlation between their proper times, one that would be
different from the 1:1 correlation they'd get if they used the comoving
frame.

Do you wish to take back your earlier agreement that phrases like their
own frame, their view, what they observe/experience are only by
CONVENTION understood to refer to the comoving inertial frame, that this
isn't something forced on us by reality? If you still agree this is a
matter of convention, then it seems to me that trying to use something
that's merely a matter of human linguistic convention to prove something
absolute about reality is obviously silly, like trying to prove something
about the essential nature of God by noting that according to the spelling
conventions of English, God is dog spelled backwards.

All the other frames are the views of OTHER observers, not the views of
the twins themselves which is all that we need to consider to establish
whether the TWINS THEMSELVES can establish a 1:1.

Obviously if all observers agreed on an invariant 1:1 correlation we never
would have to establish the 1:1 on a successive observer pair basis and
then try to prove it transitive as I've consistently worked on doing.

MY theory establishes this 1:1 correlation BETWEEN THE ACTUAL TWINS
THEMSELVES on a pairwise basis, not on the basis of any invariance.
Therefore it obviously uses a symmetric frame that is consistent with how
those two twins experience their own and each other's realities and doesn't
require input from any other frames to do that.

That isn't obvious at all--I don't see how the symmetric frame reflects
their experience in any way that isn't purely a matter of convention,
they certainly don't experience their proper times and velocities being
equal at each coordinate time if they don't CHOOSE to use a particular
coordinate system. All that they directly experience in a way that
doesn't depend on coordinate systems is the way that their proper
acceleration varied as a function of their proper time.

MY theory then attempts to prove these correlations are transitive on a
pair by pair basis, not by considering all irrelevant frames and trying to
establish some invariance that I agree is impossible.

Does this make it clear what my theory is trying to do? The theory is
based on pair wise correlations, not invariance

other frames you consider irrelevant either, it is based SOLELY on the
following premises:

1. If a pair of inertial observers are at rest relative to one another,
then events (like clock readings) that are simultaneous in their comoving
frame are also simultaneous in p-time

2. Any two events that happen at precisely the same position and time
coordinate in a particular inertial frame must be simultaneous in p-time

3. p-time simultaneity is transitive

Your only response was to dispute premise #2, but subsequent discussion
suggested you were originally misunderstanding what I meant by same
position and time coordinate and that properly understood, you would most
like agree with premise #2 after all. That's why I want you to address my
last few questions about the same position and time coordinate issue at
you promised to address earlier, but have subsequently ignored all my
requests to get back to. Once again, if you continue to just ignore the
requests, that indicates a lack of respect for me and for the two-way
nature of discussions. Here, I'll even repost those questions to save you
the time of going back through your inbox to find the original post to

On Mon, Feb 24, 2014 at 6:53 PM, Edgar L. Owen edgaro...@att.netwrote:

Jesse,

Well, I ```

### Re: Block Universes

```On Thu, Feb 27, 2014 at 9:25 AM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

I haven't answered those questions out of any disrespect or rudeness but
because I was working on a new explanation which I think does specifically
address and answer all of them which I present in this post. I will be
happy to answer any of your questions if you think they are still relevant
after reading this post which I think solves the 1:1 age correlation to

That's the problem, you continually come up with new arguments and
explanations that you think resolve the questions I asked and therefore
mean you don't need to address them, but inevitably I disagree. Please just
respect my judgment about what's relevant TO ME, and answer the questions
that I ask ALONGSIDE any new arguments or explanations you might want to
supply. You say above I will be happy to answer any of your questions if
you think they are still relevant after reading this post, so I will hold
you to that by repeating a question I'd like you to answer at the end of
this post.

If you find any of the terminology confusing please let me know what you
think it SHOULD be rather than just saying it's wrong.

Twins A and B start at the same location in deep space. No acceleration,
no gravitation. Their ages are obviously the same, and their age clocks are
running at the same rate.

They exchange flight plans and embark on their separate trips according to
those flight plans.

Now the only effects that will alter the rates of their age clocks are
acceleration or gravitation. But each twin can continually measure the
amount of acceleration or gravitation he experiences with a scale.

Let's consider just the issue of accelerations in flat SR spacetime for
now, since it's simpler. The problem with this statement is that although
it's true each twin can measure their proper acceleration, there is no
FRAME-INDEPENDENT equation in relativity for how a given acceleration
affects the rates of their age clocks, the only equations dealing with
clock rates and acceleration in SR deal with how changes in coordinate
velocity (determined by acceleration) affect the rate a clock is ticking
relative to coordinate time in some specific coordinate system.

So each twin can always calculate how much his age has slowed relative to
what his age WOULD HAVE BEEN had he NOT experienced any gravitation or
acceleration. Let's call that his 'inertial age', the age he WOULD have
been had he NOT experienced any acceleration or gravitation.

I see no way to define this in any frame-independent way. The only version
of this that relativity would allow you to calculate is what your age would
have been at a PARTICULAR COORDINATE TIME if you had remained inertial, and
you can compare that to what your age is at that SAME COORDINATE TIME given
your acceleration history. But this comparison obviously gives different
results in different coordinate systems. So, I don't agree with your
subsequent conclusion that this allows two twins to define a 1:1
correlation in their ages in a frame-independent way.

There are a number of questions I asked in the last few posts that none of
now:

'Also, do you understand that even for inertial observers, the idea that an
observer's own rest frame can be labeled his view or taken to describe
his observations is PURELY A MATTER OF CONVENTION, not something that is
forced on us by the laws of nature? Physicists just don't want to have to
write out in the observer's comoving inertial frame all the time, so they
just adopt a linguistic convention that lets them write simpler things like
from this observer's perspective or in his frame as a shorthand for the
observer's comoving inertial frame. Physically there is no reason an
observer can't assign coordinates to events using rulers and clocks that
are moving relative to himself though, lots of real-world experiments
involve measuring-instruments that move relative to the people carrying out
the experiment.'

Do you agree with the above paragraph?

Jesse

On Wednesday, February 26, 2014 10:45:51 PM UTC-5, jessem wrote:

On Wed, Feb 26, 2014 at 8:52 PM, Edgar L. Owen edga...@att.net wrote:

Can you agree to this at least?

To repeat what I said in my second-to-last post:

'If you continue to ask me Do you agree? type questions while ignoring
the similar questions I ask you, I guess I'll have to take that as a sign
of contempt, in which case as I said I won't be responding to further posts
of yours. Any response is better than just completely ignoring questions,
even if it's something like I find your questions ambiguous or you've
asked too many questions and I don't have time for them all right now,
please narrow it down to one per post.'

If you decide to treat me with the same basic level of respect I have
treated you, rather than making a show of asking me questions while you
```

### Re: Block Universes

```On Thu, Feb 27, 2014 at 2:38 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Yes, of course I agree. Again that's just standard relativity theory.
However as you point out by CONVENTION it means the observer's comoving
inertial frame which is the way I was using it.

Thanks, it seemed like you might have been suggesting there was some
natural truth to calculations done in the comoving frame of two
obserervers at rest relative to each other, even though they could equally
well agree to calculate things from the perspective of a totally different
frame.

Now to your replies to my post beginning with your first paragraph.

Certainly there are equations that do what you say they do, but I don't
see why what I say isn't correct based on that. Why do you claim it is
impossible to just take proper acceleration and calculate what my age would
have been if there was not any proper acceleration?

I don't claim it's impossible, just that it can only be done relative to a
particular frame. I can make statements like I am now 30, but in frame A,
if I hadn't accelerated I would now be 20 and I am now 30, but in frame
B, if I hadn't accelerated I would now be 25.

An observer knows what his proper acceleration is, and he knows how much
various accelerations are slowing his proper time relative to what it would
be if those accelerations didn't happen.

Slowing his proper time only has meaning relative to a particular frame,
there is no frame-independent sense in which clocks slow down (or speed up)
due to acceleration in relativity.

He has a frame independent measure of acceleration. He knows that
particular acceleration will slow his proper time by 1/2 so he can define
and calculate an 'inertial time' whose rate is 2x his proper rate.

Given the exact same proper acceleration, there may be one frame A where at
the end of the acceleration his clock has slowed by 1/2 (relative to the
time coordinate of that frame), and another frame B where it has slowed by
1/3, and even another frame where it has *sped up* by a factor of 10. Do
you disagree?

You seem to think it would be necessary to MEASURE THIS FROM SOME FRAME
for the concept to be true. It's not an observable measure, it's the
CALCULATION of a useful variable. Therefore there is NO requirement that
it's measurable in any frame because it's a frame independent concept, a
calculation rather than an observable.

Calculations are always calculations of the values of particular numerical
quantities, like the rate a clock is ticking. So, what matters is whether
the quantity in question is frame-dependent (like velocity, or rate of
clock ticking) or frame-independent (like proper time at a specific event
on someone's worldine), there is nothing inherent in the notion of
calculations that make them frame-independent.

Also, *all* calculated quantities in relativity can also be
observables--it's straightforward to observe frame-independent quantities
like proper time (just look at the clock the observer carries), and
frame-dependent ones can also be observed if you have a physical grid of
rulers and coordinate clocks as I have described before (for example, to
find the rate a clock is ticking relative to a coordinate system, you
look at the time T1 it reads as it passes next to a coordinate clock that
reads t1, and the time T2 it reads as it passes next to another coordinate
clock that reads t2, and then you can just define the average rate over
that interval as [T2 - T1]/[t2 - t1], and if the difference between T2 and
T1 approaches 0 this approaches the *instantaneous* rate at T1).

Therefore I don't see any reason to accept your criticism in this
paragraph. If you disagree, which I'm sure you will, then explain why this
concept of inertial time is not frame independent and valid. Perhaps a
clear example would help?

If you disagree with my statement above that different frames can disagree
on the amount that a clock slowed down (or sped up) after a given proper
acceleration, I can give you a numerical example.

Another way to approach this is do you deny that if we drop a coordinate
grid on an area of EMPTY space that the coordinate clocks at the grid
intersections all run at the same rate? And if not, why?

Are you talking about an inertial coordinate grid of rigid rulers, or an
arbitrary non-inertial coordinate grid where we can imagine different grid
points connected by rubbery rulers that can stretch and compress over time?
In the simpler case of an inertial grid, obviously all inertial coordinate
clocks tick at the same rate relative to any other inertial coordinate
system, though not necessarily relative to an arbitrary non-inertial
system. And the clocks of an arbitrary non-inertial coordinate system need
not tick at a constant rate relative to inertial systems.

And don't start making up other frames on me here. Just compare the proper
times of those ```

### Re: Block Universes

```On Thu, Feb 27, 2014 at 4:05 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

Remember we are talking ONLY about PROPER TIMES, or actual ages. These DO
NOT HAVE any MEANING IN OTHER FRAMES than that of the actual frame of the
observer in question.

No, you couldn't be more wrong about that last statement. Any physics
textbook will tell you that the proper time between two events on a
worldline is a frame-independent quantity that can be calculated in ANY
frame, in fact this is one of the most important frame-independent
quantities in both special and general relativity (for example, in general
relativity the curvature of spacetime is defined in terms of the metric
which gives proper time along all possible timelike worldlines in the
spacetime, and proper distance along all possible spacelike worldlines).

A simple example: say in Alice's rest frame, there are two markers at rest
in this frame 20 light-years apart, and Bob moves inertially from one
marker to the other a velocity of 0.8c in this frame. What is the proper
time on Bob's worldline between passing the first marker and passing the
second? In Alice's frame we could calculate this by first noting it should
take 20/0.8 = 25 years of coordinate time in this frame for Bob to get from
one to the other, and then the time dilation equation tells us that if he's
moving at 0.8c his clock should be slowed by a factor of sqrt(1 - 0.8^2) =
0.6 in this frame, so Bob's own clock should tick forward by 25*0.6 = 15
years between passing the first marker and the second. That is BOB'S PROPER
TIME, AS CALCULATED IN ALICE'S REST FRAME.

You could of course calculate the proper time in Bob's rest frame too. In
this case, you have to take into account length contraction--the markers
are moving at 0.8c relative to Bob's frame, so if the distance between them
was 20 light-years in their own rest frame, in Bob's frame the distance
between them is shortened by a factor of sqrt(1 - 0.8^2) = 0.6, so in Bob's
frame the second marker is 20*0.6 = 12 light-years away at the moment he is
passing the first marker. Thus, if the second marker is moving towards him
at 0.8c, it will take 12/0.8 = 15 years of coordinate time in this frame to
reach him after the first marker passed him. And since he is at rest in
this frame, his clock ticks at the same rate as coordinate time, so his
clock should also tick foward by 15 years between passing the first marker
and passing the second. That is BOB's PROPER TIME, AS CALCULATED IN BOB'S
REST FRAME, and you can see that we get exactly the same answer as when we
calculated his proper time using Alice's rest frame.

After looking over this example, please tell me if you AGREE or DISAGREE
that in relativity the proper time between two specific events on a
worldline can be calculated using any frame we wish (in the manner above),
and we'll always get the same answer regardless of what frame we use.

So your comments that an observer's age will be measured differently in
other frames, while obviously true, is NOT the observer's PROPER AGE or
PROPER TIME. Every observer has one and only one proper age, that is his
proper age to himself, NOT to anyone else, not in any other frame.

Every observer has a proper age at any specific event on their worldine,
like the event of Bob passing one of the markers in my example above. But
this proper age is not associated with any particular frame, it's a
frame-independent quantity that can be calculated in whatever frame you
wish, and no matter what frame you use to perform the calculations you'll
always get exactly the same answer.

different in different frames. Of course they can be but that is NOT PROPER
ACTUAL AGE.

But you are not pointing to a specific event on his worldline and asking
his proper age at that point, you are asking what his age *would* have been
if he hadn't accelerated. This involves looking at TWO worldlines--one of
the actual person who had done some acceleration, and another hypothetical
worldline he would have had if he had not accelerated (this need not be
purely hypothetical, you could imagine he had a twin who was moving
alongside him before he accelerated, but continued to move inertially when
he accelerated). And you're asking which event on the second inertial
worldline lines up with some specific event on the worldline that
experienced acceleration (like the event of his accelerometer first showing
that he has stopped accelerating and is experiencing 0 G-force once again).
It's impossible to answer that question in relativity without picking a
specific frame with a specific definition of simultaneity, which allows us
to match up the event on the non-inertial worldline with some specific
event on the inertial worldline, and then calculate the age on the inertial
worldline at that event.

So I have to disregard all those comments because they don't apply to
PROPER TIMES OR ACTUAL ```

### Re: Block Universes

```On Thu, Feb 27, 2014 at 4:49 PM, Jesse Mazer laserma...@gmail.com wrote:

A simple example: say in Alice's rest frame, there are two markers at rest
in this frame 20 light-years apart, and Bob moves inertially from one
marker to the other a velocity of 0.8c in this frame. What is the proper
time on Bob's worldline between passing the first marker and passing the
second? In Alice's frame we could calculate this by first noting it should
take 20/0.8 = 25 years of coordinate time in this frame for Bob to get from
one to the other, and then the time dilation equation tells us that if he's
moving at 0.8c his clock should be slowed by a factor of sqrt(1 - 0.8^2) =
0.6 in this frame, so Bob's own clock should tick forward by 25*0.6 = 15
years between passing the first marker and the second. That is BOB'S PROPER
TIME, AS CALCULATED IN ALICE'S REST FRAME.

You could of course calculate the proper time in Bob's rest frame too. In
this case, you have to take into account length contraction--the markers
are moving at 0.8c relative to Bob's frame, so if the distance between them
was 20 light-years in their own rest frame, in Bob's frame the distance
between them is shortened by a factor of sqrt(1 - 0.8^2) = 0.6, so in Bob's
frame the second marker is 20*0.6 = 12 light-years away at the moment he is
passing the first marker. Thus, if the second marker is moving towards him
at 0.8c, it will take 12/0.8 = 15 years of coordinate time in this frame to
reach him after the first marker passed him. And since he is at rest in
this frame, his clock ticks at the same rate as coordinate time, so his
clock should also tick foward by 15 years between passing the first marker
and passing the second. That is BOB's PROPER TIME, AS CALCULATED IN BOB'S
REST FRAME, and you can see that we get exactly the same answer as when we
calculated his proper time using Alice's rest frame.

Incidentally, for two events E1 and E2 on the worldline of an inertial
clock (like the events of Bob passing each marker), there is also a simple
formula for calculating the proper time the clock ticks between those
events, using the coordinates of any frame you like. That is:

(proper time between E1 and E2)^2 = (coordinate time between E1 and E2)^2 -
(1/c^2)*(coordinate distance between E1 and E2)^2

Or using more common notation,

dtau^2 = dt^2 - (1/c^2)*dx^2

If you use units where c = 1, like years for time and light-years for
distance, this reduces to:

dtau^2 = dt^2 - dx^2

For example, in Alice's frame we have dt = 25 years, and dx = 20
light-years, so dtau^2 = 25^2 - 20^2 = 625 - 400 = 225, so dtau is the
square root of 225, or 15. Likewise, in Bob's frame we have dt = 15 years
(which you could derive using the Lorentz transformation if you knew the
coordinates of passing each marker in Alice's frame), and dx = 0, which
again gives dtau^2 = 225 and therefore dtau = 15.

This formula is the spacetime analogue of the Pythagorean formula in
Euclidean geometry, which tells you that if you have a line segment that
has some length ds that you want to calculate, then if you use any
cartesian coordinate system to define the x and y coordinates of its
endpoints, so you can find dx and dy between the endpoints, then ds^2 =
dx^2 + dy^2. Just as the length of a line segment will have an answer that
is the same regardless of how you orient your Cartesian coordinate axes (dx
and dy may change depending on the axes, but ds will always be the same),
so the proper time between two events on a worldline has an answer that is
the same regardless of what inertial frame you use (dx and dt can vary, but
dtau will always be the same)--both are coordinate-independent quantities,
and both are understood to reflect the geometry of the space/spacetime in
which they are defined.

Jesse

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### Re: Block Universes

```On Thu, Feb 27, 2014 at 6:43 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

My understanding of the first part of your reply is though proper time is
ONLY one's reading of one's own clock (as I stated) it IS possible for
any other observer to calculate that proper time and always come up with
the same answer. Is that correct?

For a given clock C, it is possible for any observer to calculate the
proper time between events ON C'S OWN WORLDLINE, and everyone will get the
same answer (it is frame-invariant). But what is NOT frame-invariant is the
answer to a question like what is the proper time on that distant clock
RIGHT NOW, at the same moment that my own clock shows some specific time
T--in that case you aren't talking about a specific event on C's
event of your clock showing time T), and asking which event on C's
worldline is simultaneous with that. Since simultaneity is frame-dependent
in relativity, there is no frame-invariant answer to this second type of
question.

If so that's precisely what I've been claiming all along! That it's always
possible for any observer to calculate any other observer's PROPER TIME.
Why did I get the strong impression you were claiming that wasn't so from
your previous replies? That is precisely the whole crux of my case, and
precisely what I've been claiming

In my view that is exactly what is necessary to establish a 1:1
correlation between proper times. If everyone can always calculate
everyone's proper times including their own in an UNAMBIGUOUS INVARIANT WAY
then why isn't it possible to establish a 1:1 correlation between them?
Please give me a clear and simple proof that it's not

By unambiguous invariant way, which of these do you mean?

1. If they all agree to use a particular reference frame to define
frame-dependent things like simultaneity and velocity, then they can agree
on which proper times on each worldline are simultaneous, giving a 1:1
correlation.

2. They have a way to define a 1:1 correlation between proper times that
does NOT depend on agreeing to use any particular reference frame.

Please tell me whether you would select 1 or 2 (or some third option that
is somehow different than either one).

I'm not sure whether it's necessarily relevant here but note that the
event markers that define proper ages are already actual physical
worldline event points defined by the earth's orbit and rotation.

But we have been discussing scenarios involving observers zipping around in
space, so events on Earth would not be at the same point in spacetime as
events on their own worldlines.

So the very definition of a proper age is already IN TERMS OF worldline
markers. We don't have to specify new markers to make things work. Proper
time is ALREADY NECESSARILY defined in terms of event markers such as
physical clock ticks. We don't need any new ones.

I agree that clock ticks can count as markers, but sometimes you're
dealing with problems where you want to calculate what a clock reading at a
point on some observer's worldline will be without knowing it in advance.
If you have a network of coordinate clocks, you can also use readings on
coordinate clocks at the moment the traveling observer passes right next to
them as event markers, and ask questions like what is this observer's
proper time at a coordinate time of t, i.e. at the moment the coordinate
clock he's right next to at that moment reads t.

Do you also agree that proper time RATES are calculable by other observers
and invarian? Not just the times, but the rates as well?

No, there is no frame-invariant notion of clock rate in relativity. The
only way to talk about rates is to look at the rate a clock is ticking
relative to coordinate time in some coordinate system, and obviously this
can differ from one coordinate system to another.

Jesse

On Thursday, February 27, 2014 4:49:17 PM UTC-5, jessem wrote:

On Thu, Feb 27, 2014 at 4:05 PM, Edgar L. Owen edga...@att.net wrote:

Jesse,

Remember we are talking ONLY about PROPER TIMES, or actual ages. These DO
NOT HAVE any MEANING IN OTHER FRAMES than that of the actual frame of the
observer in question.

No, you couldn't be more wrong about that last statement. Any physics
textbook will tell you that the proper time between two events on a
worldline is a frame-independent quantity that can be calculated in ANY
frame, in fact this is one of the most important frame-independent
quantities in both special and general relativity (for example, in general
relativity the curvature of spacetime is defined in terms of the metric
which gives proper time along all possible timelike worldlines in the
spacetime, and proper distance along all possible spacelike worldlines).

A simple example: say in Alice's rest frame, there are two markers at
rest in this frame 20 light-years apart, and Bob moves inertially from one
marker ```

### Re: Block Universes

```On Wed, Feb 26, 2014 at 2:31 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

You continue to quibble over terminology to avoid engaging the real
issues. Of course by 'view' I DO mean the actual equations in terms of a
coordinate system with origin at a particular observer. There is OF COURSE
a single set of equations that describes that view.

There are a single set of equations for any particular coordinate system,
but my point is that for non-inertial observers or observers in curved
spacetime, talking about an observer's view is ill-defined because there
is no convention about which coordinate system to label as the view of a
given observer. Even if you specify that you want a coordinate system with
origin at a particular observer, there are an infinite number of DIFFERENT
non-inertial coordinate systems you could come up with that would have the
property that the observer is always at the origin, each with a different
question from my last post, which you didn't answer:

'--If you don't disagree with the statement above, do you disagree with my
statement that there's no specific coordinate system that is understood by
physicists to represent a particular observer's view or perspective in
general relativity, so that if you just talk about equations used by
observer A without specifying a coordinate system, physicists wouldn't know

Could you please just just quote my questions and answer them specifically
in turn, as I always do with yours, rather than just sort of summarizing
what you think my main points are and addressing them in a broad manner?

Yes, of course the OBSERVABLES are based on some coordinate system, but
you can't seem to get it through your head that any observer A who observes
another observer B can also know the equations governing how that observer
B observes A himself.

I'm not sure which question you are responding to here, you say next
question but it seems like this is actually a response to my FIRST
question (with no response given to any of the others), namely:

'--Do you disagree that equations that observer A uses to calculate the
observables of any other observer B are always based on A using some
particular coordinate system? (if so, can you give an example of an
equation that could be used to make such a calculation which would not
depend on any specific coordinate system, but which would still be
observer-dependent in some sense, so it would still be meaningful to
identify this equation specifically with observer A?) '

You didn't really respond to any of the subsequent three questions with
dashes before them, as far as I can see, although you did respond to the
question in my last paragraph. Can you please go back and respond to the
middle 3 questions?

Do you deny that?

I deny that there is any single set of equations governing how observer B
observes A himself, if B is not an inertial observer in flat spacetime. If
he's not, then as I said, there's no convention in relativity that says
that any particular coordinate system should be interpreted as belonging
to B. If you specify in detail what coordinate systems you want A and B to
use to perform calculations (or if both of them are inertial in flat
spacetime, so it's taken as read that they each use their own rest frame),
then of course A can figure out what B would calculate and B could figure
out what A would calculate.

Also, do you understand that even for inertial observers, the idea that an
observer's own rest frame can be labeled his view or taken to describe
his observations is PURELY A MATTER OF CONVENTION, not something that is
forced on us by the laws of nature? Physicists just don't want to have to
write out in the observer's comoving inertial frame all the time, so they
just adopt a linguistic convention that lets them write simpler things like
from this observer's perspective or in his frame as a shorthand for the
observer's comoving inertial frame. Physically there is no reason an
observer can't assign coordinates to events using rulers and clocks that
are moving relative to himself though, lots of real-world experiments
involve measuring-instruments that move relative to the people carrying out
the experiment.

I'll skip now to the point you make in your last paragraph responding to
my symmetric trip case:

Why, because the point of the symmetric trip argument is TO ESTABLISH a 1:1
correlation ONLY BETWEEN THE PROPER TIMES OF A and B, not any of the any
other coordinate systems you attempt to drag into the discussion to
obfuscate things.

It isn't a 1:1 correlation between the proper times of A and B without
qualification, it's a 1:1 correlation between the proper times of A and B
RELATIVE TO THEIR REST FRAME. If you use a different frame, there is a
different 1:1 ```

### Re: Block Universes

```On Wed, Feb 26, 2014 at 4:50 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

A symmetric trip is defined in terms of the symmetric view of two
observers A and B OF EACH OTHER IN TERMS OF THEIR OWN COMOVING COORDINATE
SYSTEMS.

If they aren't inertial observers in flat spacetime--and they can't be
inertial if they depart from one another and then reunite later--then
their own comoving coordinate systems is a COMPLETELY UNDEFINED PHRASE.
There are an infinite number of DIFFERENT non-inertial coordinate systems
you could design in which they remain fixed at the spatial origin of the
coordinate system (so each one is comoving in that sense), and there is
no convention recognized by physicists that their own comoving coordinate
system would refer to any particular one of these different possible
systems. DO YOU DISAGREE?

I have asked variants of this question several times now, once again you
seem to be back to your old habit of refusing to answer simple
agree/disagree questions I ask you, even after you have demanded that I
answer a number of yours. As I said before, this is quite rude behavior,
and if you aren't interested in civil reasoned discourse where you actually
address the other person's arguments and questions, rather than just
haranguing them with the same assertions and expressing incredulity that
they could fail to be convinced, then there's obviously no point to any
further exchanges between us.

The proper times of both twins A and B have a 1:1 correlation and are
equal at start and finish of the trip.

Although it's true in a frame-independent sense that their proper times are
equal at the end when they reunite, any 1:1 correlation of proper times
DURING the trip can only be defined relative to a particular coordinate
system, and there's no physical reason why using the system where their
velocities are symmetrical is more correct than using any other
coordinate system. As I just said in my last post:

'It isn't a 1:1 correlation between the proper times of A and B without
qualification, it's a 1:1 correlation between the proper times of A and B
RELATIVE TO THEIR REST FRAME. If you use a different frame, there is a
different 1:1 correlation between the proper times of A and B, RELATIVE TO
THAT OTHER FRAME. Nothing in the phrase 1:1 correlation between the proper
times of A and B by itself tells us what frame to use.'

Do you disagree with the above?

PROPER clocks always run at the same rate in the same relativistic
conditions.

Run at the same rate has no coordinate-independent meaning in relativity.
You won't find any relativity textbook that defines the rate of a clock
in any way except relative to a particular choice of coordinate system
(assuming we're not just talking about visual rates based on light signals).

Do you disagree that the above is true ACCORDING TO MAINSTREAM RELATIVITY
THEORY AS UNDERSTOOD BY PHYSICISTS? (if you agree, but you think that YOU
have discovered a new coordinate-independent concept of clock rate that
physicists have failed to recognize, then please specify that).

The laws of nature do not change during the trip. The relativistic
conditions of both PROPER clocks thus DO run at the same rates DURING the
trip. Forget everything else but the PROPER clocks because it's irrelevant
to the case.

Proper time deals only with clock readings at specific locally-defined
events on their worldlines (like the time on their clock at the moment they
pass next to some marker in space), there is no corresponding notion of a
coordinate-independent proper rate of a clock. Again, the rate a clock
is ticking is an INHERENTLY coordinate-dependent notion in mainstream
relativity theory.

Thus there will be a 1:1 correspondence of PROPER clock times DURING THE
TRIP.

This is NOT any SINGLE FRAME VIEW. You continue to try to analyze it from
some single frame. IT CAN'T BE DONE. This is a logical consequence of the
laws of relativity, NOT THE VIEW FROM ANY SINGLE FRAME.

You say logical consequence, but again it is just an assertion, not an
actual logical demonstration of HOW the laws of relativity lead to this
conclusion.

If you can't even get this simple fact I see no reason to proceed. It
seems to me that your stated agenda of not accepting p-time prevents you
from thinking objectively here.

No mainstream physicist would agree with this simple fact, and that has
nothing to do with whether they prefer block time or presentism or have no
opinion on the matter. They all recognize that clock rates, and
correspondences between proper times of clocks separated in space, are
inherently frame-dependent.

In any case, a simple way to proceed would involve just doing me the
courtesy of answering my questions, so we can better pinpoint the first
point on which we are in disagreement, and see if this is a matter of
disagreeing about how things work in mainstream relativity theory (in which
case I can look for references to support my claims, and we ```

### Re: Block Universes

```On Wed, Feb 26, 2014 at 6:46 PM, Edgar L. Owen edgaro...@att.net wrote:

Jesse,

O, for God's sakes. Just take a SINGLE INERTIAL coordinate system centered
at some point in deep space from which they both depart, travel
symmetrically away from RELATIVE TO THAT SINGLE COORDINATE SYSTEM and then

The whole trip is symmetric, the twins' proper times will be in a 1:1
correlation at all times from beginning to end. Both twins agree their
proper clocks run at the exact same rates, not because they observe them
but because they understand relativity.

Do you agree? Of course not

I agree that there is a 1:1 correlation between their proper times RELATIVE
TO THAT INERTIAL COORDINATE SYSTEM (in this case, the correlation is such
that a given proper time time T of one is correlated with the SAME proper
time T of the other, according to that coordinate system's definition of
simultaneity). Likewise, their proper clocks run at the exact same rates
RELATIVE TO THAT INERTIAL COORDINATE SYSTEM (i.e. both have the same
function for proper time as a function of coordinate time). But so what?
Their proper times have a different 1:1 correlation relative to some other
inertial coordinate system (in which the proper time T for one is
correlated with a DIFFERENT proper time T' for the other--this is still a
1:1 correlation in the sense that a specific proper time for one is
correlated to a specific proper time of the other), and their proper clocks
run at different rates relative to this other coordinate system (they have
different functions for proper time as a function of coordinate time). So
this is of no help in deciding which of the VARIOUS possible 1:1
correlations in their proper times represent the proper times that share
the same frame-independent present moment, even if such a thing exists
(as you know I am skeptical about such a thing, but I don't totally rule it
out as a possibility).

Please tell me if you agree or disagree that all statements about 1:1
correlations of proper times and ratios of rates only have meaning
RELATIVE TO SOME COORDINATE SYSTEM (in mainstream relativity theory anyway,
leaving aside ideas which aren't part of relativity like p-time), and that
all inertial coordinate systems are considered equally valid in special
relativity.

If you continue to ask me Do you agree? type questions while ignoring the
similar questions I ask you, I guess I'll have to take that as a sign of
contempt, in which case as I said I won't be responding to further posts of
yours. Any response is better than just completely ignoring questions, even
if it's something like I find your questions ambiguous or you've asked
too many questions and I don't have time for them all right now, please
narrow it down to one per post.

Jesse

Nevertheless, it's correct and the rest of what I said follows...

Edgar

On Wednesday, February 26, 2014 3:40:36 PM UTC-5, jessem wrote:

On Wed, Feb 26, 2014 at 2:31 PM, Edgar L. Owen edga...@att.net wrote:

Jesse,

You continue to quibble over terminology to avoid engaging the real
issues. Of course by 'view' I DO mean the actual equations in terms of a
coordinate system with origin at a particular observer. There is OF COURSE
a single set of equations that describes that view.

There are a single set of equations for any particular coordinate system,
but my point is that for non-inertial observers or observers in curved
spacetime, talking about an observer's view is ill-defined because there
is no convention about which coordinate system to label as the view of a
given observer. Even if you specify that you want a coordinate system with
origin at a particular observer, there are an infinite number of DIFFERENT
non-inertial coordinate systems you could come up with that would have the
property that the observer is always at the origin, each with a different
question from my last post, which you didn't answer:

'--If you don't disagree with the statement above, do you disagree with
my statement that there's no specific coordinate system that is understood
by physicists to represent a particular observer's view or perspective
in general relativity, so that if you just talk about equations used by
observer A without specifying a coordinate system, physicists wouldn't know

specifically in turn, as I always do with yours, rather than just sort of
summarizing what you think my main points are and addressing them in a