Re: Naive Realism and QM
Hi Serafino, Thanks for your pointers. You obvious know your physics quite well and I think you got my point precisely! Godfrey Kurtz (New Brunswick, NJ) -Original Message- From: scerir [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Sat, 20 Aug 2005 19:22:10 +0200 Subject: Re: Naive Realism and QM Godfrey: There is no energy flux directly associated with wave-functions (like with electomagnetic or mechanical waves) but is a probability density and a probability flux associated with the square of linear functionals of the wave-function. [Scerir] The question, at this point, should be: probability of what? [GK] Exactly! [Scerir] Because, leaving aside those who think (Weinberg, Dyson, etc.) that only fields exist and are real, there are at least a couple of solutions. There are physicists (followers of Bohr [1], more or less) who think [2][3][4] that quantum physics is about 'correlations without correlata', or about 'fotuitousness and clicks'. There are physicists (followers of Einstein, and his idea of Gespensterfeld, etc.) like Born [5], Fock [6], Barut [7], etc., who think that a 'probability' wave, even in 3n-dimensional space, is a real thing, much more than a mathematical tool, and who also think that physics is not just about apparata, or clicks. s. [GK] Maybe I would not divide things exactly that way but, yes, that is basically the choices you have! Either you keep looking for an ultimate ontological category on which quantum information is predicated, or you try and build some understanding of probability as a material of sorts (that was not Bohr, but actually Schrodinger and Madelung on the latter side.) There are however some possible ontological grey areas between these two positions that can be explored and Heiseinberg tried that at some point. Bohr's position (the infamous Copnehagen Interpretations) was a bit more complicated than what the sentence you quote expresses, I would say, so it is hard to know where to place him... -Godfrey [1[ Niels Bohr: 'However, since the discovery of the quantum of action, we know that the classical ideal cannot be attained in the description of atomic phenomena. In particular, any attempt at an ordering in space-time leads to a break in the causal chain, since such an attempt is bound up with an essential exchange of momentum and energy between the individuals and the measuring rods and clocks used for observation; and just this exchange cannot be taken into account if the measuring instruments are to fulfil their purpose. Conversely, any conclusion, based in an unambiguous manner upon the strict conservation of energy and momentum, with regard to the dynamical behaviour of the individual units obviously necessitates a complete renunciation of following their course in space and time.' [2] Carlo Rovelli Relational Quantum Mechanics http://www.arxiv.org/abs/quant-ph/9609002 [3] David Mermin What is quantum mechanics trying to tell us? http://www.arxiv.org/abs/quant-ph/9801057 [4] Aage Bohr http://www.physicstoday.org/vol-57/iss-10/p15.html [5] Max Born: 'Quite generally, how could we rely on probability predictions if by this notion we do not refer to something real and objective?' [6] V.A.Fock 'Disskussija S Nilsom Borom', in 'Voprosy Filosofii', 1964 (a memorandum, about the interpretation of QM and the meaning of wavefunction, he gave to Bohr, in Copenhagen, 1957, who read it and changed his mind about several points, but not all). [7] A.O.Barut http://streaming.ictp.trieste.it/preprints/P/87/157.pdf Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.
Re: What Theories Explain vs. What Explains Theories
Hi Lee, I am not sure this is the reply you mentioned in the previous post. If so I guess you decided to make it public. That is alright with me too. Godfrey Kurtz (New Brunswick, NJ) -Original Message- From: Lee Corbin [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Sat, 20 Aug 2005 12:40:40 -0700 Subject: What Theories Explain vs. What Explains Theories Godfrey writes Yes we cannot explain QM by classical physics but NEITHER can we explain from QM the classical world we know and love with its well defined and assigned elements of (naive) physical reality that you so much cherish, I am afraid! If we did there would not be no Measurement Problem, no spooky long-distance correlations, no zombie Schrodinger Cat's around to haunt us... Quantum mechanics' greatest successes have included explanations for what you cite. That is why QM is accepted. My point is that it does NOT include explanations for any of the items I cite and that is why I cite them and that is why they are called problems. We are using the term *explain* in different ways. Look, would you have disagreed (were you living in 1800) with the Marquis Pierre Simon de LaPlace when he would assert that Newton's theory of gravity explained all celestial movements? I guess so! YOU probably would have said, Mais non, it does not explain how an influence can instantaneously reach out through space. It does not even explain what gravity *is*! (And by the way, no fair using Mercury's orbit, the details of which were not discovered at that time.) LaPlace would have looked down his nose at you and replied that the *theory* explains the movements, you fool. C'est facile de voir that you, Monsieur, wish to know what explains the theory. I have no need of your hypothesis, or of you. So likewise, I will say to you, we cannot explain quantum mechanics, but QUANTUM MECHANICS DELIVERS AN UNPRECEDENTED FIFTEEN DECIMAL PLACES OF ACCURACY and so explains incredibly perfectly the result of our laboratory experiments! [GK] Far from me to disagree with you, or Laplace! QM produces indeed the most impressive numerical predictions of any theory ever conceived by humans! [LC] YOU seem to want an explanation of (or a satisfactory interpretation of) the *theory*. The theory does not provide that! No theory--- not Newton's, not Einstein's, and not QM, can do that, can explain *itself*. [GK] Not exactly, and I have not expressed such demands of QM in any of my statements. What I stated, and you have not denied that yet, is that QM does not give me or you a picture (much less an explanation) of the world as we know it, with somewhat reliable objects placed at definite position at definite times. This is a fact, not a demand on my part on the theory. Most people who feel unhappy about this state-of-affairs don't blame it on the theory (as they did 3 generations ago) but blame it on themselves or on us, humans, who have not interpreted the theory correctly yet. From Bruno's message I take it that you subscribe to the Everett Interpretation which indeed avoids some of these problems but has some more of its own and surely does a number on your naive reality! What is it then: many worlds or one? Many worlds of course. Have you or have you not read Fabric of Reality by David Deutsch? [GK] Oh yes. But I am not a convert. [LC] As for a number on my naive reality... For Christ's sake, I give up with you. You are hopeless. You are probably one of those people who calls fascist everyone who has political disagreements with you, whether or not they themselves adopt the term. [GK] (...I'll pass on this one!) [LC] I give up. I hereby grant permission for the incredible Godfrey Kurt Lee to call me a naive realist --- but him only! Nobody else better try it! Lee [GK] Wow!! Actually my name is Godfrey Kurtz. Lee is a bad nickname that I had to use to get a username from AOL. No pun intended. (I hesitate to call you anything, at this stage! ) P.S. I will reply to the rest of your post when I am less exercised :-) [GK] Now that Bruno promoted me to a machine I feel like telling you, like good all HAL 5000: Why don't you take a pill and lay down? (:-) Get well soon, Godfrey Check Out the new free AIM(R) Mail -- 2 GB of storage and industry-leading spam and email virus protection.
Re: subjective reality
Hi Bruno, Not quite there yet, but making progress Godfrey Kurtz (New Brunswick, NJ) -Original Message- From: Bruno Marchal [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Sent: Sat, 20 Aug 2005 19:44:44 +0200 Subject: Re: subjective reality Le 19-août-05, à 18:13, [EMAIL PROTECTED] a écrit : [GK] I would like to leave copies out of the YD because I think those would actually invalidate the premise. If you ran into a copy of yourself in the street you may suspect that something is amiss in your world! [BM] OK if it is a temporary interdiction. The YD will entail that we are duplicable in a weak sense (which does not contravene the no-cloning theorem (but here I anticipate the reasoning)). You pretend YD is false, show the proof. [GK] By now you should have understood that I will not be taunted, so no use in trying. I do not pretend anything. What I have told you and maintain is that I can sketch an argument that shows that your YD is incompatible with QM being the correct physics of the world and I will do so as soon as you admit that this will invalidate ALL your thesis (not just the part of it you feel like conceding). This was my proposal all along and I have not changed it. So there is no point in challenging me in these terms. I made clear already. [GK] What I propose to do is to show you that your premise, YD, is false. That allows me to dismiss anything you say based on that premise. Of course. But of course, everything I say from CT and AR alone will survive. I hope you see this clearly. [GK] If you claim that you derive the whole of physics (including QM) from CT and AR alone there is no point in my showing you that physics invalidates YD! Is there? You would know that already, or you could derive it independently! Whether I am right or wrong would be completely indiferent to you. Why would you even consider my argument? That is actually not general at all but extremely specific. From here on I will make no comment on any sentence you preface with But from COMP (or YD) I can prove that... . Nothing personal, please understand. [BM] Sure. Except that in a second round (the interview of the lobian machine) I translate comp in arithmetic, and I extract *a* physics from that COMP. To understand that translation YD is very useful, but no more. Then if the physics that is extracted from the arithmetical COMP corresponds to the empirical physics, your proof of the falsity of the YD would show that a falsity has helped in discovering the origin of the physical laws. Funny but not entirely impossible. Except that, without wanting to discourage you in advance, it is very hard for me to believe you have find a proof or an argument showing comp is wrong. But that makes me just more curious. [GK] OK. Let me ask you this than and maybe help you avoid any more painful contortions: can you even imagine a situation in which you could be proven wrong? (Please remember how many times you have underscored that COMP is verifiable!) (skipped) I take it like that. You are telling me you are platonist the week and not platonist the week-end? Or ditto means you agree with *me*, I guess. [GK] I agree with you but I am a platonist 24/7 (=full-time)! [GK] In that case enjoy the prize! If you derived the laws of physics from CT and AR alone you surely deserve the recognition you will enjoy because that is a remarkable accomplishment! Congratulations! But there is a derivation of a physics from CT and AR. Just to understand *that* intuitively you need YD. I have done two things the universal dovetailer argument (UDA) which shows that YD + CT + AR entails that physics emerges necessary from a web of machine dreams (say, dream being entirely defined in term of computer science or number theory). But then in the second part, called sometime the arithmetical universal dovetailer argument (AUDA), or more simply the interview of the lobian machine, I translate (UDA) in arithmetic (because comp makes it possible and necessary). YD disappears or is translated in arithmetic (by Godel-like devices). The derivation of physics is purely mathematical of course, I am not a magician extracting the galaxies from someone saying yes to a doctor. It looks like it disappoints you, but there is two parts in my work: UDA: an argument that YD + CT + AR implies physics is necessarily a branch of computer science. AUDA: a translation of the argument in arithmetic, with the (modest) result that the logic of the observable proposition is given by the composition of three mathematical transformations operating on a well-known modal logic (G). And it already looks enough like some quantum logics to encourage further research. Alas the math are not easy and not well known. [GK] This hardly sounds like a derivation to me. But if your first statement above (UDA) is
Re: subjective reality
On Sun, Aug 21, 2005 at 06:21:13PM -0400, [EMAIL PROTECTED] wrote: I agree with you but I am a platonist 24/7 (=full-time)! 24/7 = 3.4285714... Why is this full time? Its a little bigger than Pi (so a little bigger than a half a turn), maybe a bit more in the state of Indiana (see http://en.wikipedia.org/wiki/Pi). I'm jesting with you of course - you must mean 24 (hours) x 7 (days) (per week), but I ask you, why do you confuse division and multiplication? Cheers -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 pgpVYnUUAqwzv.pgp Description: PGP signature
Re: Naive Realism and QM
Russell Standish wrote: On Wed, Aug 17, 2005 at 04:30:21PM -0700, Lee Corbin wrote: Your point about the squared modulus is well taken. Just why *probabilities* emerge from squared amplitudes, I couldn't tell you. I'm not sure that anyone knows---as I recall, many this is related to the basis problem of the MWI (though Deutsch and others say that decoherence takes care of everything, though). Lee This is simply the Born rule - I give a derivation of the Born rule in my paper Why Occam's Razor. Some other people on this list have asserted prior derivations of the Born rule also, which wouldn't overly surprise me as its not that mysterious. Cheers I've haven't read your derivation, but I've read quant-ph/0505059 by VAn Esch which is a proof that the Born Rule is independent of Everett's MWI and cannot be derived from it. How do you avoid Van Esch's counter example. Brent Meeker
Re: Naive Realism and QM
On Sun, Aug 21, 2005 at 06:12:54PM -0700, Brent Meeker wrote:
I've haven't read your derivation, but I've read quant-ph/0505059 by VAn
Esch which is a proof that the Born Rule is independent of Everett's MWI
and cannot be derived from it.
How do you avoid Van Esch's counter example.
Brent Meeker
I'm not sure its that relevant - I don't derive the Born rule from
Everett MWI per se, but rather from assumption that 1st person
experience should appear as the result of an evolutionary process. I
actually use Lewontin's criteria for evolution - I have an improved
explanation of this in appendix B of my draft book, although
technically it is identical to the FoPL paper.
Another way of viewing this topic is that the Multiverse (or MWI) is a
3rd person description, whereas the Born rule is a 1st person
property. So it is not surprising that the two are independent.
Looking at the paper, Esch proposes an alternative projection postulate
that weights all possible alternatives equally, ie it is equivalent to
the usual PP provided that the state vector is restricted to the set
of vectors \psi such that
\psi|P_i|\psi = 1/n_\psi or 0.
Let \psi' = \sum_i P_i\phi, for any vector \phi, and let
\psi=\psi'/\sqrt{\psi',\psi}, so this set if not empty.
This is a kind of all or nothing approach to \psi - \psi contains only
information about whether x_i is possible, or impossible, but doesn't
contain any shades of gray. It is saying, in other words, that White
Rabbit universes are just as likely as well ordered one - something
that contradicts the previous section on the white rabbit problem.
Instead, I assume that \psi does contain information about the
liklihood of each branch, and once you compute what this is, the usual
Born rule follows.
Cheers
--
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is of type application/pgp-signature. Don't worry, it is not a
virus. It is an electronic signature, that may be used to verify this
email came from me if you have PGP or GPG installed. Otherwise, you
may safely ignore this attachment.
A/Prof Russell Standish Phone 8308 3119 (mobile)
Mathematics0425 253119 ()
UNSW SYDNEY 2052 [EMAIL PROTECTED]
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International prefix +612, Interstate prefix 02
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Re: Naive Realism and QM
Russell Standish wrote:
On Sun, Aug 21, 2005 at 06:12:54PM -0700, Brent Meeker wrote:
I've haven't read your derivation, but I've read quant-ph/0505059 by VAn
Esch which is a proof that the Born Rule is independent of Everett's MWI
and cannot be derived from it.
How do you avoid Van Esch's counter example.
Brent Meeker
I'm not sure its that relevant - I don't derive the Born rule from
Everett MWI per se, but rather from assumption that 1st person
experience should appear as the result of an evolutionary process. I
actually use Lewontin's criteria for evolution - I have an improved
explanation of this in appendix B of my draft book, although
technically it is identical to the FoPL paper.
Another way of viewing this topic is that the Multiverse (or MWI) is a
3rd person description, whereas the Born rule is a 1st person
property. So it is not surprising that the two are independent.
Looking at the paper, Esch proposes an alternative projection postulate
that weights all possible alternatives equally, ie it is equivalent to
the usual PP provided that the state vector is restricted to the set
of vectors \psi such that
\psi|P_i|\psi = 1/n_\psi or 0.
Let \psi' = \sum_i P_i\phi, for any vector \phi, and let
\psi=\psi'/\sqrt{\psi',\psi}, so this set if not empty.
This is a kind of all or nothing approach to \psi - \psi contains only
information about whether x_i is possible, or impossible, but doesn't
contain any shades of gray. It is saying, in other words, that White
Rabbit universes are just as likely as well ordered one - something
that contradicts the previous section on the white rabbit problem.
Instead, I assume that \psi does contain information about the
liklihood of each branch,
That would be one form of the additional postulate which Van Esch says is
necessary to derive the Born Rule - so there is no conflict with his result.
Brent Meeker
