re:Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-10-24 Thread Marchal Bruno
Gordon wrote:

>But you have an inconsistent idea in that on the one hand a theory which
>say that they are physical object that becoame no physical and then just
>comp pure comp.Now although I dont thing it that narrow just like the
>old Clock work view, I do think that your theory can be simpler in that
>you dont need to call eletron real or not that dont matter.Just has
>everything as it is but araise from Comp.It the same theory just dont
>have to bother with QM directly?


I don't understand.  I am saying that physics is a branch of psychology, (where
physics becomes the study of a relative measure on sharable computationnal
histories). Now we can compare that physics with empirical physics, if not
just to confirm or refute comp. But then we have to bother with QM, isn'it?
(Note that I do not extract the measure from comp but I do extract the
logic of yes-no experiments, which can be compare with some quantum
logics or algebras).

Bruno







re:Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-10-24 Thread Marchal Bruno
Saibal Mitra wrote:

>Bruno wrote:
>
>At 16:25 +0200 11/10/1996, Saibal Mitra wrote:
>
>>>You can still have realism, but it must be the >>case that at least some
>of
>>>the things we think of as ``real physical objects´´ >>like e.g. electrons
>are
>>>not real.
>
>
>>What would that mean? What would be real? >Even in my thesis, electrons
>>are supposed to have some degree of reality like >relative stability
>>as mind pattern in normal machine dreams (1->person plural histories)
>>for example.
>
>Well, his theory is rather complicated, but he starts from a deterministic
>theory formulated in terms of primordial variables, that do represent ``real
>things´´.  Although I don't think that his ideas are necessarily correct, it
>does give food for thought.




By Bell and Kochen & Specker theorems those primordial variable
should be non local and contextual, or 't Hooft should be clear about
the different (from QM) experimental predictions his theory gives.
Perhaps I miss something.
Of course you know I believe indeterminism is a consequence of
Mechanism, so 't Hooft move seems to me without clear purpose. I mean
even without QM, I expect verifiable non-locality and contextuality,
or Many-"Worlds". 





Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-10-14 Thread Bruno Marchal

At 16:25 +0200 11/10/1996, Saibal Mitra wrote:

>You can still have realism, but it must be the case that at least some of
>the things we think of as ``real physical objects´´ like e.g. electrons are
>not real.


What would that mean? What would be real? Even in my thesis, electrons
are supposed to have some degree of reality like relative stability
as mind pattern in normal machine dreams (1-person plural histories)
for example.



>
>Suppose you are a virtual person, programmed by me and living in a virtual
>environment. You do some experiments to find the laws of physics. You try to
>break up things and look what they are ``made of´´. Would you ever discover
>how the pentium processor works if you proceed this way?


With comp I will still be able to deduce the laws of physics ...
I could miss some intermediate level. This will depends of the story
through which you come to implement "me".



>
>Similarly would you ever discover anything about neurotransmitters and
>neurons while you are asleep (and dreaming about doing experiments).


I guess no. That level of description is too high.


>
>It is more likely that you would be stuck with theories that promote
>nonexisting artefacts of  the virtual world to real physical entities.


Not if I begin to suspect comp is true. I will stop to promote
anything as real physical entities, except those dream invariants
shared by all "physical" dreams.
(I recall that dream = computations "observed" from a 1-person (plural)
point of view).

Could you tell us what is considered real by Gerard 't Hooft?


Bruno




Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-10-11 Thread George Levy



Saibal Mitra wrote:

>
>Suppose you are a virtual person, programmed by me and living in a virtual
>environment. You do some experiments to find the laws of physics. You try to
>break up things and look what they are ``made of´´. Would you ever discover
>how the pentium processor works if you proceed this way?
>
Interesting problem.

I would set up experiments to test the limit of my world. I would find 
out that  I get a exception interrupt when I blow the stack, run out of 
memory or divide by zero. This information would enable me to measure 
the size of my space (memory) and the limitations of the physics 
underlying my world.

I would test the speed of each operation in my world, and find out that 
some operations such as "MOVE" and "TEST IF ZERO" are relatively  more 
or less time consuming . From this information, I would formulate 
theories on how these operations may be implemented at a higher level 
and what kind of mechanism or architecture may be responsible for such 
timing relationships. I would watch for white rabbits, which in my world 
may be unexplained events such as "INPUTS" and try to understand what 
these "INPUTS" imply and by what mechanism they may be generated.

I would generate certain events, behavior (OUTPUTS) and observe how the 
INPUTS are affected by my OUTPUTS. From this information I may infer 
that there is an intelligence lurking beyond my world and I may even 
deduce that its name is Saibal Mitra.

George





Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-10-11 Thread Saibal Mitra

You can still have realism, but it must be the case that at least some of
the things we think of as ``real physical objects´´ like e.g. electrons are
not real.

Suppose you are a virtual person, programmed by me and living in a virtual
environment. You do some experiments to find the laws of physics. You try to
break up things and look what they are ``made of´´. Would you ever discover
how the pentium processor works if you proceed this way?

Similarly would you ever discover anything about neurotransmitters and
neurons while you are asleep (and dreaming about doing experiments).

It is more likely that you would be stuck with theories that promote
nonexisting artefacts of  the virtual world to real physical entities.

Saibal




- Oorspronkelijk bericht -
Van: "Bruno Marchal" <[EMAIL PROTECTED]>
Aan: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Verzonden: donderdag 10 oktober 2002 14:55
Onderwerp: Re: Many Fermis Interpretation Paradox -- So why aren't they
here?


>
>
> If Gerard 't Hooft's  deterministic account of Quantum field
> is both realist and Lorentz invariant, it would contradict Bell's theorem
> or Kochen and Specker theorem, or GHZ (Greenberger, Horn, Zeilinger),
> ... or it would be equivalent with Everett (accepting that quantum
> contextuality + realism implies the "many-things").
>
> Bruno
>
>
> Original message by Saibal Mitra:
>
> >- Oorspronkelijk bericht -
> >Van: "Bruno Marchal" <[EMAIL PROTECTED]>
> >Aan: "Tim May" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
> >Verzonden: vrijdag 4 oktober 2002 18:13
> >Onderwerp: Re: Many Fermis Interpretation Paradox -- So why aren't they
> >here?
> >
> >
> >>  At 9:36 -0700 1/10/2002, Tim May wrote:
> >>
> >>  >MWI looks, then, like just another variant of "modal realism." To
> >>  >wit, there IS a universe in which unicorns exist, and another in
> >>  >which Germany won the Second World War, but these universes are
> >>  >forever and completely out of touch with us.
> >>
> >>  Not quite due to possible interferences. We do have empirical
evidences
> >>  for those "worlds" imo. (if only the two slits + Bell or better GHZ)
> >
> >But quantum field theory can be derived from a completely classical
> >deterministic theory. See.e.g.:
> >
> >1) Quantum Gravity as a Dissipative Deterministic System
> >
> >Class.Quant.Grav. 16 (1999) 3263-3279
> >
> >http://arxiv.org/abs/gr-qc/9903084
> >
> >
> >2) Quantum Mechanics and Determinism
> >
> >http://arxiv.org/abs/hep-th/0105105
> >
> >3) How Does God Play Dice? (Pre-)Determinism at the Planck Scale
> >
> >http://arxiv.org/abs/hep-th/0104219
>
>





Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-10-10 Thread Bruno Marchal



If Gerard 't Hooft's  deterministic account of Quantum field
is both realist and Lorentz invariant, it would contradict Bell's theorem
or Kochen and Specker theorem, or GHZ (Greenberger, Horn, Zeilinger),
... or it would be equivalent with Everett (accepting that quantum
contextuality + realism implies the "many-things").

Bruno


Original message by Saibal Mitra:

>- Oorspronkelijk bericht -
>Van: "Bruno Marchal" <[EMAIL PROTECTED]>
>Aan: "Tim May" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
>Verzonden: vrijdag 4 oktober 2002 18:13
>Onderwerp: Re: Many Fermis Interpretation Paradox -- So why aren't they
>here?
>
>
>>  At 9:36 -0700 1/10/2002, Tim May wrote:
>>
>>  >MWI looks, then, like just another variant of "modal realism." To
>>  >wit, there IS a universe in which unicorns exist, and another in
>>  >which Germany won the Second World War, but these universes are
>>  >forever and completely out of touch with us.
>>
>>  Not quite due to possible interferences. We do have empirical evidences
>>  for those "worlds" imo. (if only the two slits + Bell or better GHZ)
>
>But quantum field theory can be derived from a completely classical
>deterministic theory. See.e.g.:
>
>1) Quantum Gravity as a Dissipative Deterministic System
>
>Class.Quant.Grav. 16 (1999) 3263-3279
>
>http://arxiv.org/abs/gr-qc/9903084
>
>
>2) Quantum Mechanics and Determinism
>
>http://arxiv.org/abs/hep-th/0105105
>
>3) How Does God Play Dice? (Pre-)Determinism at the Planck Scale
>
>http://arxiv.org/abs/hep-th/0104219




Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-10-07 Thread Saibal Mitra


- Oorspronkelijk bericht -
Van: "Bruno Marchal" <[EMAIL PROTECTED]>
Aan: "Tim May" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Verzonden: vrijdag 4 oktober 2002 18:13
Onderwerp: Re: Many Fermis Interpretation Paradox -- So why aren't they
here?


> At 9:36 -0700 1/10/2002, Tim May wrote:
>
> >MWI looks, then, like just another variant of "modal realism." To
> >wit, there IS a universe in which unicorns exist, and another in
> >which Germany won the Second World War, but these universes are
> >forever and completely out of touch with us.
>
> Not quite due to possible interferences. We do have empirical evidences
> for those "worlds" imo. (if only the two slits + Bell or better GHZ)


But quantum field theory can be derived from a completely classical
deterministic theory. See.e.g.:

1) Quantum Gravity as a Dissipative Deterministic System

Class.Quant.Grav. 16 (1999) 3263-3279

http://arxiv.org/abs/gr-qc/9903084


2) Quantum Mechanics and Determinism

http://arxiv.org/abs/hep-th/0105105

3) How Does God Play Dice? (Pre-)Determinism at the Planck Scale

http://arxiv.org/abs/hep-th/0104219








Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-10-04 Thread Bruno Marchal

At 9:36 -0700 1/10/2002, Tim May wrote:

>MWI looks, then, like just another variant of "modal realism." To 
>wit, there IS a universe in which unicorns exist, and another in 
>which Germany won the Second World War, but these universes are 
>forever and completely out of touch with us.

Not quite due to possible interferences. We do have empirical evidences
for those "worlds" imo. (if only the two slits + Bell or better GHZ)





>>
>>BTW, Tim, I am discovering n-categories. Quite interesting. John Baez
>>has written good papers on that, like his categorification paper.
>>Have you read those stuff. Could be useful for the search of coherence
>>condition in "many world/observer" realities ...
>
>I've been reading Baez for a while. An excellent teacher. I hear 
>he's working on a book on n-categories. And Baez and my namesake, J. 
>Peter May--unrelated to me, are leading a consortium to research 
>n-categories more deeply. I confess that I have only vague ideas 
>what they aresort of generalizations of natural transformations, 
>I sense.




A very natural generalisation (!). Just replace the hom Sets by hom Categories.
In which you can again replace the hom sets by hom categories 
What is intriguing is the existence of coherence conditions making those
constructions apparently very genuine for many stuff from quantum 
field theories.




>(I'm still studying categories at a more basic level, having "jumped 
>ahead" to other areas, as is my wont.)
>
>His "From Categories to Feynman Diagrams" (co-authored with James 
>Dolan) and several of his related papers are good introductions.



Thanks. I didn't see this one. Very nice. http://arxiv.org/abs/math.QA/0004133



>
>Chris Isham is also very good on drawing the connections between 
>conventional quantum mechanics (i.e., stuff in the lab, not 
>necessarily quantum gravity or quantum cosmology) and category/topos 
>theory. (In particular, the collapse of the wave function and 
>measurement looks like a subobject classifier, or, put another way, 
>the usual transition from "neither true nor false" in a Heyting 
>algebra to the "one or the other" we _always_ see once there is any 
>chance to observe/measure/decide. That is, Heyting --> Boolean is 
>what the mystery of QM centers around.


Boolean or Heyting Toposes or cartesian closed categories have exponentials.
They describes subjects (first or plural). They are distributive categories.
You always seem to forget the non distributive categories (nicely introduced in
Lawvere Shanuel book), which are akin to linear and quantum logic, 
and quantum algebra.
Technically linearity seems to be a consequence of the non distributivity,
I'm not sure I really grasp the idea yet.


>
>(I am intrigued to find that Jeffrey Bub, in his "Interpreting the 
>Quantum World," 1997, makes central use of possible worlds, 
>lattices, and such. While he does not explicitly mention Heyting 
>algebras, the connection is close, and is implicit in the math. Had 
>I encountered this approach when I was studying QM, I might have 
>pursued it as a career. Instead, I was bored out of my mind solving 
>partial differential equations for wave functions inside boxes. Ugh.)
>
>I'm reading Graham Priest's "An Introduction to Non-Classical 
>Logic," 2001, which covers various modal logics, conditional logics, 
>intuitionist logic, many-valued logics, and more ("first degree 
>entailment," "relevant logic," etc.).


I should read it. One day I will make a comment about its use of Godel in his
book "In contradiction".


>
>The tableaux approach is new to me. They look like the trees of 
>Smullyan, and hence like semilattices.


I have used the smullyan trees for the G and Co. theorem provers. The tableaux
structure reflects  in some way the Kripke structure. Posets appears with
S4-like modal logic.
You should study Gentzen presentation of logic which are naturally related
to categories. An indigest but brilliant introduction to many (intuitionnist)
logics is the North-Holland logic book by Szabo: Algebra of proofs.
To bad he miss the braided monoidal categories ... For a categorician, knots
theory is a branch of logic.



>(I'm also reading Davey and Priestley's "Introduction to Lattices 
>and Order," along with parts of Birkhoff's classic, and the 
>lattice/poset approach continues to appeal to me greatly.

Nice. They have chapters on the non distributive order structures.



>It's a vantage point which makes all of this heretofore-boring-to-me 
>logic stuff look terribly interesting. I'm viewing most 
>programs/trees/refinements/tableaux as branching worlds, as possible 
>worlds (a la Kripke), to be further branched or discarded.
>
>Hence my focus on MWI and "Everything" remains more on the 
>mathematics. (I just ordered my own copy of Goldblatt's "Mathematics 
>of Modality.")
>
>"Possible worlds," something I only encountered in any form (besides 
>Borges, Everett, parallel universes sorts of references) in the past 
>several years, is 

Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-10-01 Thread Tim May


On Tuesday, October 1, 2002, at 06:37  AM, Bruno Marchal wrote:

> At 12:26 -0700 30/09/2002, Tim May wrote:
>> If the alternate universes implied by the mainstream MWI (as opposed 
>> to variants like consistent histories) are "actual" in some sense, 
>> with even the slightest chance of communication between universes, 
>> then why have we not seen solid evidence of such communication?
>
>
> I am not sure I understand why you oppose the "mainstream MWI" and the
> consistent histories (although many does that, I don't know why).
> In all case, if QM is right (independently of any interpretation), 
> parallel
> histories or parallel universes cannot communicate, they can only
> interfere(*). The same happens with comp. Probability measures are 
> global
> and depends on the whole collection of relative computational 
> histories, but
> this does not allow the transfer of one bit from one computation to
> another.

I of course was not claiming such communication (or travel, whatever) 
would be easy. Just doing a thought experiment settting some very rough 
bounds on how impossible the communication or travel would be.

One of the conclusions of "How come they're not here?" is that, in 
fact, such communication or travel is essentially impossible (else 
they'd _be_ here).

MWI looks, then, like just another variant of "modal realism." To wit, 
there IS a universe in which unicorns exist, and another in which 
Germany won the Second World War, but these universes are forever and 
completely out of touch with us.

>
> BTW, Tim, I am discovering n-categories. Quite interesting. John Baez
> has written good papers on that, like his categorification paper.
> Have you read those stuff. Could be useful for the search of coherence
> condition in "many world/observer" realities ...

I've been reading Baez for a while. An excellent teacher. I hear he's 
working on a book on n-categories. And Baez and my namesake, J. Peter 
May--unrelated to me, are leading a consortium to research n-categories 
more deeply. I confess that I have only vague ideas what they 
aresort of generalizations of natural transformations, I sense. 
(I'm still studying categories at a more basic level, having "jumped 
ahead" to other areas, as is my wont.)

His "From Categories to Feynman Diagrams" (co-authored with James 
Dolan) and several of his related papers are good introductions.

Chris Isham is also very good on drawing the connections between 
conventional quantum mechanics (i.e., stuff in the lab, not necessarily 
quantum gravity or quantum cosmology) and category/topos theory. (In 
particular, the collapse of the wave function and measurement looks 
like a subobject classifier, or, put another way, the usual transition 
from "neither true nor false" in a Heyting algebra to the "one or the 
other" we _always_ see once there is any chance to 
observe/measure/decide. That is, Heyting --> Boolean is what the 
mystery of QM centers around.

(I am intrigued to find that Jeffrey Bub, in his "Interpreting the 
Quantum World," 1997, makes central use of possible worlds, lattices, 
and such. While he does not explicitly mention Heyting algebras, the 
connection is close, and is implicit in the math. Had I encountered 
this approach when I was studying QM, I might have pursued it as a 
career. Instead, I was bored out of my mind solving partial 
differential equations for wave functions inside boxes. Ugh.)

I'm reading Graham Priest's "An Introduction to Non-Classical Logic," 
2001, which covers various modal logics, conditional logics, 
intuitionist logic, many-valued logics, and more ("first degree 
entailment," "relevant logic," etc.).

The tableaux approach is new to me. They look like the trees of 
Smullyan, and hence like semilattices. (I'm also reading Davey and 
Priestley's "Introduction to Lattices and Order," along with parts of 
Birkhoff's classic, and the lattice/poset approach continues to appeal 
to me greatly. It's a vantage point which makes all of this 
heretofore-boring-to-me logic stuff look terribly interesting. I'm 
viewing most programs/trees/refinements/tableaux as branching worlds, 
as possible worlds (a la Kripke), to be further branched or discarded.

Hence my focus on MWI and "Everything" remains more on the mathematics. 
(I just ordered my own copy of Goldblatt's "Mathematics of Modality.")

"Possible worlds," something I only encountered in any form (besides 
Borges, Everett, parallel universes sorts of references) in the past 
several years, is my real touchstone.

And, more mundanely, I think it applies to cryptography and money. I 
had a meeting/party at my house a few weeks ago with about 50 people in 
attendance (gulp!). We had a series of very short presentations. I gave 
a very rushed 10-minute introduction to intuitionistic logic, mainly 
focused on my "time as a poset, a lattice" example, citing the natural 
way in which "not-not A" is not necessarily the same as A. If the past 
of an event is A, then no

Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-10-01 Thread Bruno Marchal

At 12:26 -0700 30/09/2002, Tim May wrote:
>If the alternate universes implied by the mainstream MWI (as opposed 
>to variants like consistent histories) are "actual" in some sense, 
>with even the slightest chance of communication between universes, 
>then why have we not seen solid evidence of such communication?


I am not sure I understand why you oppose the "mainstream MWI" and the
consistent histories (although many does that, I don't know why).
In all case, if QM is right (independently of any interpretation), parallel
histories or parallel universes cannot communicate, they can only
interfere(*). The same happens with comp. Probability measures are global
and depends on the whole collection of relative computational histories, but
this does not allow the transfer of one bit from one computation to
another.

BTW, Tim, I am discovering n-categories. Quite interesting. John Baez
has written good papers on that, like his categorification paper.
Have you read those stuff. Could be useful for the search of coherence
condition in "many world/observer" realities ...

(*) Unless Plaga is right, and it exists 100% non elastic interaction,
which I doubt ...

Bruno




Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-09-30 Thread r strasser
Let's consider Tim May's question, "why have we not seen solid evidence of such communication," and Russell Standish's statement, "It could just mean that communication between the "universes" is impossible."   Now lets list the relevant constants and some interpretations of quantum theory as they could apply to the "many worlds" interpretation of quantum mechanics (Everett). 1. The theory mandates multiple states for every particle in existence. 2. The collapse model says our observations affect the outcome of experiments: it assigns a central role to consciousness. 3. Photons, electrons, and other subatomic particles are not hard and indivisible. They behave as both waves and particles. 4. Particles can appear out of nothing - a pure void - and disappear again. 5. Physicists have teleported atoms and moved them from one place to another without passing through intervening space. 6. A single particle occupies not just one position, but exists here, there, and many places in between. 7. Quantum theory must hold at every level of reality - not just the subatomic world (David Deutsch). 8. The double slit experiment offers a rare example of two overlapping realities, in which photons in one universe interfere with those in another. 9. All quantum states are equally real, and if we see only one result of an experiment, other versions of us must see all the remaining possibilities. 10. "I don't think there are any interpretations of quantum theory other than many worlds.The others deny reality." (David Deutsch).    Given the constants and some interpretations of quantum theory, I would like a wide variety of views on what's theoretically required to communicate with "many worlds," and what would present "solid evidence of such communication."   For starters, let's consider David Deutsch's conjecture: "In fact, says Deutsch, a quantum computer could in theory perform a calculation requiring more steps than there are atoms in the entire universe. To do that, the computer would have to be manipulating and storing all that information somewhere. Computation is, after all, a physical process; it uses real resources, matter and energy. But if those resources exceed the amount available in our universe, then the computer would have to be drawing on the resources of other universes. So Deutsch feels that if such a computer is built, the case for many worlds will be compelling."   -Bob Strasser    - Original Message - From: Russell Standish Sent: Monday, September 30, 2002 6:49 PM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Re: Many Fermis Interpretation Paradox -- So why aren't they here?  It could just mean that communication between the "universes" isimpossible. Which is not surprising, really, as the division between"universes" in the MWI is what allows conscious thought to exist.It is perhaps of more interest to other multi-universe scenarios thatare independent of the anthropic principle - I'm thinking here ofSmolin's black hole universes, and also patches that lie outside ourlightcone, which is almost the same thing. There is a "cosmiccensorship conjecture", that singularities can never be naked. Perhapsthe Fermi "Where are they argument" almost proves the case.CheersTim May wrote:> > If the alternate universes implied by the mainstream MWI (as opposed to > variants like consistent histories) are "actual" in some sense, with > even the slightest chance of communication between universes, then why > have we not seen solid evidence of such communication?> > Amongst the universes, many ("many" is a huge number, obviously)  of > them will be way ahead of us. Some will have had galactic civilizations > for a billion years. Some will be versions of Earth except that the > Egyptians pioneered electronics and hence the world is a few thousand > years "ahead" of our world...even assuming time is commensurate with > ours.> > And so on. You can all imagine the rich possibilities.> > If these universes are even remotely able to affect each other, through > perhaps enormously advanced technology, then the vast number of such > possible worlds would suggest that at least some of them have figured > out how to do so.> > And yet they aren't here. No visitors from alternate universes. No > signals sent in, a la Benford's "Timescape."> > Perhaps we don't know how to listen. Perhaps there are so many possible > universes to potentially visit that we just haven't been gotten to yet. > Perhaps in a multiverse of so many possibilities, ours is just not an > interesting destination. Maybe there's a kind of MWI censorship going > on: since we are still debating the validity of MWI, we obviously 

Re: Many Fermis Interpretation Paradox -- So why aren't they here?

2002-09-30 Thread Russell Standish

It could just mean that communication between the "universes" is
impossible. Which is not surprising, really, as the division between
"universes" in the MWI is what allows conscious thought to exist.

It is perhaps of more interest to other multi-universe scenarios that
are independent of the anthropic principle - I'm thinking here of
Smolin's black hole universes, and also patches that lie outside our
lightcone, which is almost the same thing. There is a "cosmic
censorship conjecture", that singularities can never be naked. Perhaps
the Fermi "Where are they argument" almost proves the case.

Cheers

Tim May wrote:
> 
> If the alternate universes implied by the mainstream MWI (as opposed to 
> variants like consistent histories) are "actual" in some sense, with 
> even the slightest chance of communication between universes, then why 
> have we not seen solid evidence of such communication?
> 
> Amongst the universes, many ("many" is a huge number, obviously)  of 
> them will be way ahead of us. Some will have had galactic civilizations 
> for a billion years. Some will be versions of Earth except that the 
> Egyptians pioneered electronics and hence the world is a few thousand 
> years "ahead" of our world...even assuming time is commensurate with 
> ours.
> 
> And so on. You can all imagine the rich possibilities.
> 
> If these universes are even remotely able to affect each other, through 
> perhaps enormously advanced technology, then the vast number of such 
> possible worlds would suggest that at least some of them have figured 
> out how to do so.
> 
> And yet they aren't here. No visitors from alternate universes. No 
> signals sent in, a la Benford's "Timescape."
> 
> Perhaps we don't know how to listen. Perhaps there are so many possible 
> universes to potentially visit that we just haven't been gotten to yet. 
> Perhaps in a multiverse of so many possibilities, ours is just not an 
> interesting destination. Maybe there's a kind of MWI censorship going 
> on: since we are still debating the validity of MWI, we obviously are 
> in a universe where MWI has not been proved through such a visit.
> 
> (There are many divergent series here, making even crude estimates 
> difficult and probably worthless.)
> 
> Hmmm
> 
> 
> --Tim May Prime, resident of Earth Prime
> 




A/Prof Russell Standish  Director
High Performance Computing Support Unit, Phone 9385 6967, 8308 3119 (mobile)
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Many Fermis Interpretation Paradox -- So why aren't they here?

2002-09-30 Thread Tim May

If the alternate universes implied by the mainstream MWI (as opposed to 
variants like consistent histories) are "actual" in some sense, with 
even the slightest chance of communication between universes, then why 
have we not seen solid evidence of such communication?

Amongst the universes, many ("many" is a huge number, obviously)  of 
them will be way ahead of us. Some will have had galactic civilizations 
for a billion years. Some will be versions of Earth except that the 
Egyptians pioneered electronics and hence the world is a few thousand 
years "ahead" of our world...even assuming time is commensurate with 
ours.

And so on. You can all imagine the rich possibilities.

If these universes are even remotely able to affect each other, through 
perhaps enormously advanced technology, then the vast number of such 
possible worlds would suggest that at least some of them have figured 
out how to do so.

And yet they aren't here. No visitors from alternate universes. No 
signals sent in, a la Benford's "Timescape."

Perhaps we don't know how to listen. Perhaps there are so many possible 
universes to potentially visit that we just haven't been gotten to yet. 
Perhaps in a multiverse of so many possibilities, ours is just not an 
interesting destination. Maybe there's a kind of MWI censorship going 
on: since we are still debating the validity of MWI, we obviously are 
in a universe where MWI has not been proved through such a visit.

(There are many divergent series here, making even crude estimates 
difficult and probably worthless.)

Hmmm


--Tim May Prime, resident of Earth Prime