Talk:Many-worlds interpretation/Archive 3

message: I don't find this article at all accessable.  It strikes me more as an entry for an advanced science textbook than one for an encyclopedia.
--shockeroo 00:04, 05 Jun 2006 (GMT)
I agree.  We're trying to make it more accessible without losing the more technical stuff; it's better than it used to be.  Have patience. --Michael C Price 07:27, 5 June 2006 (UTC)
thread_title:  Accessability & Ease of Understanding 

message: The advantages of MWI section says:
While MWI does not quite generate the kinds of worlds necessary to justify the anthropic principle, it is a step on the way to Stephen Hawking's No Boundary Proposal and Max Tegmark's All Universe Hypothesis which do justify the anthropic principle[citation needed].
The No Boundary Proposal is just a conjecture about the initial conditions; I don't see the connection with MW, except insofar as it stems from quantum cosmology.  Perhaps the latter should be stated as a benefit of MW instead.  If no citation appears shortly I'll change the text to reflect this.--Michael C Price 07:27, 5 June 2006 (UTC)
replies: text: Done. --Michael C Price 10:23, 5 June 2006 (UTC)
thread_title:  Uncited no boundary claim 

message: "The relative-state interpretation makes two assumptions. The first is that the wavefunction is not simply a description of the object's state, but that it actually is entirely equivalent to the object, a claim it has in common with some other interpretations. The second is that observation or measurement has no special role, unlike in the Copenhagen interpretation which considers the wavefunction collapse as a special kind of event which occurs as a result of observation."
This seems to be at odds with the statement "Each subsequent binary measurement (that is interaction with a system M) causes a similar split in the history tree. "
If a split is caused BY the measurement, then observation does in fact still play a special role.  Multiplying outcomes, instead of collapsing them.
I'd appreciate any comments on my stupidity in this matter.
: Good observation.  Observation plays no special role in the sense that the kind of state transformation needed to describe it is not different from the transformations that describe reversible time evolution.--CSTAR 15:43, 11 June 2006 (UTC)
replies: text:  Yes, any thermodynamically irreversible interaction with the environment causes a similar Everett-world splitting.  The mechanism of the splitting is decoherence.--Michael C Price 11:02, 12 June 2006 (UTC)
thread_title:  observation has no role? 

message: "Classical physics is physics based on principles developed before the rise of quantum theory, usually including the special theory of relativity and general theory of relativity." --Wikipedia
When I referred to "classical physics" before, Lethe said there was no such thing, he said the term "classical physics" had no meaning.  tsk, tsk, tsk.
Michael D. Wolok 09:18, 18 June 2006 (UTC)
replies: text: BTW Michael, I've left some advice for you, a few hours ago, on your talk page.  I hope you find it helpful.  Regards, --Michael C Price 09:46, 18 June 2006 (UTC)
replies: text: I have never claimed that classical physics does not exist, nor do I know what a claim like that would even mean. -lethe talk [ +] 09:48, 18 June 2006 (UTC)
thread_title:  Didn't Lethe deny the existence of "classical physics": 

message: I am a bit concerned about the state of the article, so I've rewritten the early sections.  If no one objects then I'll paste it over the article (and delete from here).  Here it is:
:: It generally looks fine by me. I may have some quibbles here and there. --CSTAR 14:12, 19 June 2006 (UTC)
replies: text:  Done!  --Michael C. Price talk 15:20, 19 June 2006 (UTC)
thread_title:  Intro and first 2 sections reworked? 

message: I think Price's intro section (first paragraph) is a marked improvement on what is currently in the article, and I move that it be adopted.  Some copyediting and wording revisions suggested themselves to me, should I edit the version as it sits on the talk page, or wait for it to go into the article?  Anyway, about the rest, could you maybe highlight some of the changes?  I am having a hard time picking out what changes have been made to the last section for example.  Though of course this means that the revision must be conservative about keeping the work of others which is presently in the article, so I support that. -lethe talk [ +] 14:33, 19 June 2006 (UTC)
replies: text: Thanks for both votes, OK I'll copy it into the article when I've finished this message, that way any minor changes (get ready CSTAR, Lethe!) can go in straight.  It should also enable folks to do a diff on it.  You right, though, I didn't change last section that much, although I felt it does duplicate the wavefunction collapse article a bit.  Not sure what to do about that, though.  --Michael C. Price talk 15:11, 19 June 2006 (UTC)
replies: text: At the last second I decided to short the title of section 2.  Every thing as it was here (about to be deleted).  --Michael C. Price talk 15:19, 19 June 2006 (UTC)
thread_title:  comments to Price's new version 

message: It is not the custom of nature to do things just once.  From what we are able to observe, nature is fond of repeating the same thing over and over again with minor and major variation.  Near infinite variation of a theme is nature's way.  It is much more likely our universe is just one snowflake among countless others that have fallen and will fall, than the only snowflake to ever exist.  If science has taught us anything, it has taught us that we are not special.  Our planet is not the only planet.  It is not at the center of the universe.   Our star is not the only star.  And it is not at the center of the universe.  Our galaxy is not the only galaxy.  And our galaxy is not at the center of the universe.  It would indeed be remarkable if our universe was the only universe, and the centerpiece of all creation.  
: True, a persuasive argument, but outside the scope of quantum theory and therefore MWI.  However well within the scope of the multiverse -- you could mention it there.  --Michael C. Price talk 17:42, 19 June 2006 (UTC)
thread_title:  It is not the nature of nature to do things just once. 

message: To assume good faith is a fundamental principle on Wikipedia. As we allow anyone to edit, it follows that we assume that most people who work on the project are trying to help it, not hurt it. If this weren't true, a project like Wikipedia would be doomed from the beginning.
So, when you can reasonably assume that something is a well-intentioned error, correct it without just reverting it or labeling it as vandalism.
Especially, remember to be patient with newcomers, who will be unfamiliar with Wikipedia's culture and rules. Correcting a newly added sentence that you know to be wrong is also much better than simply deleting it. You should not act like their mistake was deliberate. Correct, but don't scold.
Avoidance The best way to resolve a dispute is to avoid it in the first place.
Be respectful to others and their points of view. This means primarily: Do not simply revert changes in a dispute. When someone makes an edit you consider biased or inaccurate, improve the edit, rather than reverting it. Provide a good edit summary when making significant changes that other users might object to.
:You might like to learn about another policy we have.  It's called assume good faith, and one might argue that you are violating it now.  Nevertheless, I'm happy to see that you're raising your complaints here on the talk page where the dispute is, instead of spreading it across hundreds of users' talk pages. -lethe talk [ +] 19:30, 19 June 2006 (UTC)
replies: text: I disagree with your assessment of the situation. -lethe talk [ +] 02:45, 20 June 2006 (UTC)

text: Well let me be more explicit: you have grossly misinterpreted your own understanding of the MWI, my own position about MWI, the other editors' consensus about your additions.  You have made wild and far-flung false accusations about me and others while continually asserting your own benevolence, you have disrupted Wikipedia process, and you have caused dismay to many friendly people around here.  I for one can say I am near my wit's end.  Please start assuming good faith, and please be more civil, and please calm down. -lethe talk [ +] 14:13, 20 June 2006 (UTC)
thread_title:  Lethe violates all these Wikipedia rules 

message: If ten thousand monkeys, typed ten-thousand words per second for ten-thousand years, and produced Wikipedia, I wouldn't be a bit surprised.  
That's a joke.  
Michael D. Wolok 20:56, 19 June 2006 (UTC)
thread_title:  If ten thousand monkeys . . .  

message: Lethe wrote: 
> For one thing, the claim that all physics is deterministic is incorrect. 
I said all physics aside from the Copenhagen Interpretation of quantum mechanics is determinstic.  If I am mistaken please correct me, and I will learn something.  Roger Penrose and many other famous physicists seem to agree with me.  I am struggling to understand why you say I am mistaken.  You said I was patently in error before concerning statements I made that renown physicist Max Tegmark explicitly agreed with me on. I know you think you are infallible, but maybe, just maybe consider the possibility you could be wrong again.
Please, let's consider my addition and object to it on a sentence by sentence basis. If I am wrong, and you are right, I will have no problem modifying my addition or retracting it in its entirety if necessary.  Let's discuss it.  
Michael D. Wolok 03:07, 20 June 2006 (UTC)
replies: text: I have said this before, but I will repeat myself for you: statistical mechanics is another nondeterministic theory.  So not all physics outside of Copenhagen is deterministic. -lethe talk [ +] 03:18, 20 June 2006 (UTC)

text: Einstein knew very well about the nondeterminism of statistical mechanics.  He wrote a seminal paper on Brownian motion in 1905.  The reason Einstein objected to quantum mechanics but not statistical mechanics is that statistical mechanics was never put forth as a fundamental theory.  It's easy to imagine that a deterministic fundamental theory might lead to a nondeterministic phenomenological theory through the law of large numbers, and that was the expectation until the advent of quantum mechanics.  Quantum mechanics was then, and is still today, thought to be a fundamental description.  Thus if quantum mechanics is nondeterministic, then God plays dice, while the nondeterminism of statistical mechanics does not have anything to do with God's gaming habits.  This is an interesting topic to discuss, but does not belong in this article.  The upshot remains this: there is physics outside of Copenhagen which is nondeterministic. -lethe talk [ +] 03:40, 20 June 2006 (UTC)

text: The reason we are having this debate is because you want the sentence "Quantum mechanics becomes a deterministic theory making it more compatible with [..] all other physics theory to date which are all deterministic".  I see no way to make this sentence into something meaningful.  It's not correct as it stands, because there are other nondeterministic theories.  Would you prefer to compare quantum mechanics only to other fundamental theories?  Because quantum mechanics is the only fundamental theory we have.  I'm not focusing on semantics just to annoy you; the fact that other theories are nondeterministic seems to me a fatal flaw for this sentence, and the fact that these other theories are not fundamental (which doesn't really mean anything anyway) does not save it. -lethe talk [ +] 04:39, 20 June 2006 (UTC)

text: This may have been an advantage historically; when we have to compare quantum mechanics' validity as a fundamental theory to those which preceded it (Newton's gravitation, Maxwell's electromagnetism).  But this is of historical interest only.  No one today believes that Newton's gravitation or Maxwell's electromagnetism is a fundamental theory, any more than they do classical statistical mechanics.  So what exactly is it that you want to say?  That this could have been counted as an advantage for MWI in 1915 if MWI had been invented then?  Well that's just silly.  Today, the only candidates we have for fundamental theories are quantum theories.  Also, I'm not sure if the designation "fundamental" has any meaning on other than an esthetic level, so the whole point may be purely philosophical.  -lethe talk [ +] 11:27, 20 June 2006 (UTC)
thread_title:  Lethe wrote: For one thing, the claim that all physics is deterministic is incorrect.  

message: Regarding Price's recent edit: While I agree that MWI is more streamlined, and that this is an attractive feature, I'm a little queasy about citing Ockham's razor.  Ockham's razor is the the reason quoted by opponents of MWI most often, in my experience, and it somehow feels like we're co-opting our critics' arguments, trying to pull the rug out from under them.  Do we intend to have a "criticisms of MWI" section somewhere?  Mention of Ockham in that section would satisfy me.  Simply removing the citation to Ockham, but keeping the rest of the sentence might also satisfy me.  I wonder what others think. -lethe talk [ +] 11:17, 20 June 2006 (UTC)
replies: text: I was thinking of adding a criticisms section, and you're right a different form of Ockhamn's razor (cheap on axioms, expensive with universes) would appear there as well.  --Michael C. Price talk 11:31, 20 June 2006 (UTC)
thread_title:  Ockham's razor 

message: I have filed an RfC about M. Wolok.  Any interested parties are invited to comment.  Some of the events occurring on this talk page are mentioned. -lethe talk [ +] 14:25, 21 June 2006 (UTC)
replies: text: In the interests of accuracy (& possibly pedantry) I should point out that I did not agree "to discuss line by line why the additions are unsuitable" but rather I only discussed them as so far as to make a point -- which meant on some issues (such as verifiability) that I did not get past the first sentence.  To analyse further would have been repetitve.  --Michael C. Price talk 16:28, 21 June 2006 (UTC)

text: I don't think Michael Wolok was being sarcastic and condescending past the first 2 or 3 sentences in his response to my writing suggestions.  I suggest you delete the rest.  Should you also mention my suggesion for a non-technical MWI guide, since it can be interpreted as a sort of mediation offer?  --Michael C. Price talk 16:52, 21 June 2006 (UTC)
replies: text: If you feel that my assessment was overly harsh or otherwise inaccurate, or would like to mention your other olive branch attempts with Wolok, please add a statement to the RfC.  After this week's continued assaults from that quarter, I have become quite frustrated.  I don't think I've ever lost my cool on Wikipedia the way I did here.  -lethe talk [ +] 19:08, 21 June 2006 (UTC)
thread_title:  Wolok RfC 

message: It seems an age ago I said:
: My understanding is that Einstein merely disliked CI's indeterminism, but that his fundamental objection was to having the role of observation hard-wired into the physics, instead of emerging from the physics.  In a letter to Schrodinger I believe, although I'd have to check.  But Einstein died before Everett published so how he would have reacted to MWI is conjectural.--Michael C Price 09:30, 25 May 2006 (UTC)
replies: text: "Whether you can observe a thing or not depends on the theory which you use. It is the theory which decides what can be observed." Albert Einstein to Werner Heisenberg, objecting to placing observables at the heart of the new quantum mechanics, during Heisenberg's 1926 lecture at Berlin; related by Heisenberg in 1968, quoted by Abdus Salam, Unification of Fundamental Forces, Cambridge University Press (1990) , pp 98-101
--Michael C. Price talk 23:05, 23 June 2006 (UTC)
thread_title:  Einstein on observation 

message: Is the many-worlds interepretation really saying that there are infinite universes branching off from this one? How does this solve the deterministic probelms of quantum physics? And second of all, is there actually any proof for the idea of paralell universes? Is this the same as multiverse theory? I noticed in the multiverse theory article that there are many critiques of it. How come this version is so popular? It sounds like pure junk science to me.
:Quick explanation: MWI accepts the reality of multiple outcomes at all levels (gluons to galaxies), not just at the microscopic level.  The big picture, with all multiple outcomes, is determinate.  The proof of MWI is that all other interpretations are garbage for one reason or another.  The multiverse is more philosophical, less grounded in empiricism than the MWI.  It is popular for the reasons outlined in the last two (or possibly three) sentences.  Please specify which part sounds like junk.  --Michael C. Price talk 00:03, 9 August 2006 (UTC)
replies: text: Complete garbage: you did want a quick explanation, right?  Branching is a consequence of thermodynamics, not sentience.  :-)  --Michael C. Price talk 00:05, 9 August 2006 (UTC)

text: The BBC account is mixing up MWI, the multiverse and M-theory -- so it really is pretty confused.  To answer an earlier point, yes MWI implies branching timelines or histories (although whether a truely infnite number or just very, very large is debatable).  I'm glad you're asking these questions -- it makes me realise how deficient the MWI wikipedia article is.  This is slightly egotistical of me, but your might find this Everett FAQ useful.  --Michael C. Price talk 00:34, 9 August 2006 (UTC)

text: The colliding thing comes from M- or string theory or some TOE -- not relevant to MWI, which is purely a nonrelativistic quantum effect.  Yes to your molecular level question.  Most parallel universes in MWI will be very very different from ours -- but there're an infinite, or near infinite, number of them in total , so even a relativity small number of "near" neighbours is still a very very large number.  By the SciAm guy I take it you mean Max Tegmark -- he knows what he's taking about -- but he covers the multiverse more, which is a much more general concept than just MWI.  Yes and yes to your final sentence. --Michael C. Price talk 00:51, 9 August 2006 (UTC)

text: As I said, the collison thing has nothing to do with MWI.  More to do with the ekpyrotic or Brane cosmology if you want a link (neither of which if true would have any impact on MWI).  Perhaps I see where you're coming from with the branching thing -- universes which branch off are almost identical but as time passes they diverge more and more.  So ones that diverged from "ours" a nanosecond ago are pretty similar, whereas ones that diverged a billion years ago are very very different.  You're are right that "we're just one of the many branches of an original universe" (except that if eternal inflation is correct there may be no "original".... but I don't really want to go there).  As for "And do our copies in the other branching universes have sentience as we do, or what?", well if they don't it would violate one or two rather fundamental scientific principles and imply vitalism -- which is not mainstream.  BTW you have hit the nail on the head with your question about how to make branching precise -- since it is based on quantum thermodynamics it is inherently fuzzy -- but thermodynamics admits to no easy explanation, so that's another topic I don't want to discuss here (my FAQ covers it to some extent) --Michael C. Price talk 01:20, 9 August 2006 (UTC)

text: As I said earlier, MWI is the outcome or consequence of non-relativistic quantum mechanics and is really quite agnostic on cosmological questions about the big bang and such like.  All events are handled within MWI, big bang or no big bang.  (BTW eternal inflation does talk about eternal inflation -- eventually.)  I'm a bit worried about your question "Or is this the original universe that all the other divergent timelines branched off of?": there is no "original universe" in this sense around today, any more than any of your cells are the original fertilised ovum.  The timelines/histories/worlds/universes split or divide or branch or fork.  I'm turning in for now, so read the links and we'll resume later.  --Michael C. Price talk 02:02, 9 August 2006 (UTC)

text: The millimetres things is a reference to the conjectured dimensions of the "bulk" at brane cosmology (an unproven hypothesis, hence Tegmark's vagueness) but more importantly has nothing to do with MWI.  On the "original universe" point did my "ovum" analogy help?  --Michael C. Price talk 09:08, 9 August 2006 (UTC)
replies: text: BTW, good luck with the physics professor approach -- my guess is they'll have to be real friendly to answer coherently.  And I do appreciate your questions because, as I said, they make me realise the deficiencies in the article.  --Michael C. Price talk 09:22, 9 August 2006 (UTC)

text: They all branch endlessly. Each universe is equally real, although some occur "more often" than others (in a way that relates to probability). --Michael C. Price talk 10:58, 9 August 2006 (UTC)

text: No, a universe splits or branches.  This splitting is not instaneous either but spreads causally.  See Schrodinger's cat.  First the radioactive atom splits, then the cat, then the external observer etc etc. --Michael C. Price talk 10:58, 9 August 2006 (UTC)

text: No, see above.  --Michael C. Price talk 10:58, 9 August 2006 (UTC)

text: Exactly so.  --Michael C. Price talk 10:58, 9 August 2006 (UTC)

text: Unsure.  See previous responses.  --Michael C. Price talk 10:58, 9 August 2006 (UTC)

text: No, not at all.  Observational cosmology is not a finished science (and how could it be?), that's all.  Don't confuse statements of observational incompleteness for deficiencies in a theory. --Michael C. Price talk 11:08, 9 August 2006 (UTC)

text: No, see my FAQ.  --Michael C. Price talk 11:08, 9 August 2006 (UTC)

text: Q24 Does many-worlds allow free-will? --Michael C. Price talk 01:10, 20 September 2006 (UTC)
thread_title:  Could someone give a quick explanation 

message: Reading the Cat articles makes it clear why I never heard any serious discussion of "Interpretation of QM" while I was in school or doing basic research (in junior positions) at great research centers.  It was all perfectly clear to him in 1935, except that he didn't know how to answer the EPR paradox, which was contrived to be contra-intuitive.  The discoverers of QM already knew what they were doing, just as Einstain did about relativity.  It is just that it takes a century for these things to filter down.
I repeat here that the main difficulties seem to arise when people re-phase what they have read or heard in ordinary language.  Since QM cannot be expressed in ordinary language, this is like the game of "telephone", in which people sitting around a table each whisper what they heard from the person on the other side.  It is worse because the fact that QM disagrees with ordinary language systematically favors more classical views.  If you go back to someone like Schrödinger (or Weinberg) who knows QM well, the picture is much clearer.
I admit that when I first came to Wikipedia I did not realize that people with the standing of Roger Penrose had questions about basic QM.  However I still believe that worrying about these things is (professioanally) a minority point of view.  As far as I am concerned, it was all settled in 1935, except that the "many worlds" predication for EPR experiments had not yet been confirmed.  (As a result of this, Schrödinger suggests and argues against hidden variables ideas that have now been ruled out, as explanations, by experiment.)    David R. Ingham 04:24, 9 September 2006 (UTC)
thread_title:  Schrödinger 

message: The following edit requires a less telegraphic style:
:It resembles a return to the concepts of the 1935 Schrödinger's cat article.
The intent of this statement (I believe) is to that the state of the cat (before it is observed) is a quantum superposition of two histories. This requires more elaboration and probably shouldn't be in the intro. 
BTW, there are several more "animal friendly versions" of Schroedinger's cat.  One due to Henry Stapp (somebody climbs up or down some steps based on an experiment's outcome) and another due to Peter Forrest who uses some kind of stuffed animal in place of a real cat. --CSTAR 16:41, 10 September 2006 (UTC)
replies: text: I've removed the statement: it's opaque and implies that Schrodinger had some sympathy with MWI.  I don't believe that any of the founding fathers of QM ever expressed any such view, perhaps because they were too old or dead by 1957.  --Michael C. Price talk 01:16, 20 September 2006 (UTC)
thread_title:  Recent edit on Schrödinger's cat article