On 03 Dec 2017, at 18:21, [email protected] wrote:
On Sunday, December 3, 2017 at 2:07:17 PM UTC, Bruno Marchal wrote:
On 01 Dec 2017, at 00:20, [email protected] wrote:
On Thursday, November 30, 2017 at 11:16:07 PM UTC,
[email protected] wrote:
On Thursday, November 30, 2017 at 9:47:37 PM UTC, Bruce wrote:
On 30/11/2017 10:59 pm, [email protected] wrote:
On Thursday, November 30, 2017 at 11:42:51 AM UTC, Bruce wrote:
On 30/11/2017 10:32 pm, [email protected] wrote:
On Thursday, November 30, 2017 at 4:08:20 AM UTC-7, Bruce wrote:
On 30/11/2017 9:53 pm, [email protected] wrote:
On Wednesday, November 29, 2017 at 10:40:36 PM UTC, Bruce wrote:
On 30/11/2017 5:31 am, John Clark wrote:
On Tue, Nov 28, 2017 at 10:59 PM, Bruce Kellett
<[email protected]> wrote:
> I see no reason all the Everett worlds have the same
physics,
> Everettian worlds follow from assuming that the
Schrödinger equation applies everywhere without exception, so
that all physical evolution is unitary. A change in the
underlying physics -- such as a change in the value of
fundamental constants, Planck's constant or Newton's constant for
example -- would not be unitary, so cannot occur in MWI.
Why can't it be unitary?? Show me why if Newton's
constant had any value other than 6.754* 10^-11 m3 kg^−1
s^−2 the sum of all quantum probabilities would no
longer add up to exactly 1. If you can really do that then you've
just derived Newton's constant directly from
first principles and you
should but a ticket to Stockholm right now because you're
absolutely certain to win the next nobel Prize.
Although unitarity does mean that probabilities always sum to
unity, that is a consequence of unitary evolution, not a
definition of it. A unitary transformation is one that can be
reversed: so the unitary operator U can be written as exp(-iH),
for example, and the complex conjugate (or the adjoint for
hermitian operators) is the inverse transformation.
Considering the evolution of the wf, if there exists a DE that
describes the collapse process, would it necessarily be
nonlinear? Is nonlinear a problem; that is, what is the downside
to nonlinear? How would it effect the issue of hidden variables?
TIA, AG
Collapse would be non-linear and non-unitary --
intrinsically non-reversible. This is not necessarily a problem
since there are plenty of non-linearities in physics. It has
nothing to do with hidden variables.
Why would it be non linear? Brent claimed (on page 1)
Page 1 of what?
On Google it's organized as pages, now up to page 15. Go to top of
thread and read second message by Brent. AG
that if the QM could be made deterministic, say by a DE that
described collapse, it would imply awful consequences, such as
the future determining the past.
No, it wouldn't imply that.
Would making QM into a deterministic theory imply an
inconsistency in the postulates of QM? TIA, AG
QM in MWI is deterministic. Bohm's theory is deterministic, though
expressly non-local. Determinism is not really an issue. One world
theories are intrinsically random, not deterministic.
How can MWI be deterministic if it can't tell us what outcome we
will observe in this world, or any other? AG
Because MWI says that all outcomes are realized, each in a separate
world. Apparent randomness comes about because we don't know which
world we will end up in (though we actually end up in all the
worlds, so we, or our duplicates, observe all possible outcomes).
Bruce
OK. I wouldn't use "deterministic" to describe that situation, but
that's neither here nor there.
More important is Brent's reply to my question which started this
discussion thread. He stated that a deterministic ONE WORLD version
of QM would have dire effects, such as the future influencing the
past. His exact words are in the 2nd message in this discussion.
You don't seem to share this view. I know that Bohm developed a
deterministic version of QM which is expressly non-local and not
covariant. I don't think it's what Brent was referring to.
Also, I noticed that Bruno, our resident enthusiast of arithmetic
as the solution to all enigmas,
That is very elegant mathematically, but I am not necessarily
enthusiast about this, and sometimes I call Mechanism terrifying
thinking. At the first sight it entails that agonies are infinite,
as your consciousness survives in the closest environment/
computations logically possible, and there are an infinity of them.
Nothing funny there.
The point is that it is a logical consequence of what is perhaps the
oldest hypothesis in science: that life is a mechanism. Of course,
the infinite agony might end ... because things are more subtle when
doing the math, so no need to despair prematurely of mechanism
either. Computer science suggests some "jumps", which makes the
prediction there very difficult, but all in all, sometimes I wish
death is an end. That is made impossible with mechanism, as
Descartes and many others intuited correctly.
By "mechanism", I see you mean "materialism", the theory that life
and consciousness can be explained by the motion and interaction of
atoms and molecules. I see no evidence that death is not implied by
materialism. I've experienced the passing away of many, and its
permanence is very convincing. Moreover, cut a nerve and sensation
ceases; be injected with an anesthetic and one loses consciousness
in a matter of seconds. All pretty convincing that materialism is on
the right track, as opposed to speculation and fantasies about
mathematics and arithmetic. AG
?
By mechanism I mean the idea that we can survive with an artificial
*digital* brain. Precisely: that it exists a level of granularity so
that I survive, or my first person experience remains unchanged,
through a digital (physical) simulation of my brain at that level.
This is believed indeed by many materialists, but they use mechanism
to hide the mind-body problem. When, actually, Mechanism can be shown
incompatible with very weak form of materialism or physicalism.
To understand this, you need to understand a bit of computability
theory (alias Recursion Theory). Computation, simulation, emulation,
are concepts that can be defined in the arithmetical language, and the
existence of computations can be made in very small fragment of
arithmetic.
Then the problem, for the (Löbian) universal machine, which plays the
role of the believer/knower/observer, cannot made a difference from
its First Person perspective (1p view) between being supported by
arithmetic or being supported by something physical, or whatever. It
cannot know which computations support it, among the infinitely many
which exists, and eventually, the physical appearance have to be
explained in term of the observable by the machine. This gives a way
to test between mechanism and materialism (roughly speaking, because
we could also be failed by our descendent, to be logically complete).
I am the one not speculating. I assume a widespread believed
hypothesis (its contrary needs some magic).
I can prove the existence of the computations, if you are OK with
2+2=4, and, assuming that mechanism, it leads to a gigantic, highly
structured web of "dreams". Then the math confirms the intuitionist
logic for the knower, and quantum logics for observer (using only the
classical definition provided by the greeks, and defining "rational
belief" by Gödel's provability predicate.
The main advantage here is that the logic of self-reference splits
most of the logics in two, and justify why some part are not
rationally justifiable, and some parts are rationally justified.
Quanta are recovered (up to now) by a notion of first person plural
sharable qualia.
Other advantage. For the basic assumption we need only very elementary
(non Löbian, but Turing Universal) arithmetic, or anything Turing
equivalent, like any first order specification of any Turing universal
system.
Bruno
This entails also that, in physics, Everett, who used a rough
informal form of Mechanism, has done only one half of the work. It
remains to explain the wave itself phenomenologically. It is not a
matter of choice but of intellectual rigor. Invoking Primary Matter
in a mechanist metaphysics is as much wrong than invoking God in the
explanation of the existence of the universe. It just doesn't work.
It is not logically valid. That does not mean that God does not
exist, but it means that it cannot be used in explanation, nor in
moral (!). The case of Pirmary Matter is worst, it leads to
inconsistencies (with even very weak form of Mechanism).
stated that Weinberg showed that a non-linear SWE to explain
collapse would imply that the laws of thermodynamics are flawed. Is
this your understanding?
Somehow, yes. Weinberg wrote a paper(*) showing that if we assume
that the fundamental wave equation is non linear, and still getting
the QM predictions already verified, then the "parallel universes"
can interact with each others, and that this possibility entails the
need to abandon almost all of today's physics. The conclusion is
that it is foolish to try to solve the conceptual problem of QM by
searching a non linear equation in place to the usual linear one.
Even Bohm add a non linear potential, but keep the linear SWE.
Bruno
(*) I don't find my old photocopy, but I am pretty sure you will
find it (and many related papers) by searching on "weinberg's
nonlinear quantum mechanics".
TIA, AG
--
You received this message because you are subscribed to the Google
Groups "Everything List" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
http://iridia.ulb.ac.be/~marchal/
--
You received this message because you are subscribed to the Google
Groups "Everything List" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
http://iridia.ulb.ac.be/~marchal/
--
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
