| Subject: The simple and obvious truth is ... ?
Date: Mon, 08 Jul 2002 17:07:30 +0100 From: Dimi Chakalov <dchakalov@surfeu.at> To: Asher Peres <peres@photon.technion.ac.il> CC: mermin@msc.cornell.edu, shimony@bu.edu, kochen@math.princeton.edu, adler@ias.edu, jbub@carnap.umd.edu,j.fearns@ic.ac.uk, jb56@cus.cam.ac.uk, c.anastopoulos@phys.uu.nl, rgrif@andrew.cmu.edu BCC: [snip] Dear Asher, I'm reading your recent quant-ph/0207020, "What's Wrong with these Observables?", which you wrote in honor of David Mermin's birthday [Ref. 1]. I was struck by the following bold statement: "The simple and obvious truth is (...)." Since you talk about *truth*, and not about your metaphysical inclinations, may I ask you to provide some statement which could make this truth falsifiable. Say, "if X turns out to be true, then I am wrong". Or "if Y turns out to be true, then I am wrong *and* Abner Shimony is right". Please put your cards on the table. Also, as you wrote in quant-ph/9711003, "Interpreting the Quantum World", http://members.aon.at/chakalov/quantum.html#Peres "(...) quantum mechanics permits the occurrence of all possible events (with definite probabilities), but in our consciousness there is only one world." Would you please reveal the simple and obvious truth behind this mystery? To be specific, let's consider the human brain (not our consciousness), since the brain is certainly a physical system. Please see: http://members.aon.at/chakalov/Adler.html#NB Regarding POVMs [Ref. 1], please see: http://members.aon.at/chakalov/Brukner.html My proposition can be read at http://members.aon.at/chakalov/Vecchi.html http://members.aon.at/chakalov/Anandan.html#NB , and my favorite interpretation of QM is explained at http://members.aon.at/chakalov/Khrennikov.html#Växjö Summary at http://members.aon.at/chakalov/dimi.html#summary I believe you will agree that it is highly frustrating to accept Niels Bohr's dictum "there is no quantum world". It makes me feel like a dumb Bulgarian cow. How do you feel about it? I do hope to hear from you. Needless to say, I enjoyed very much your article [Ref. 1]. I do hope that you will 'put your cards on the table' before its publication in "Foundations of Physics". You can read this email also at http://members.aon.at/chakalov/Peres.html With best regards, Dimi
Reference [Ref. 1] Asher Peres. What's Wrong with
these Observables? Wed, 3 Jul 2002 09:39:31 GMT,
"It is a pleasure to dedicate this article to David Mermin,
for his birthday and many more birthdays.
"I gave a talk "When is a quantum measurement?" after
which Abner Shimony came to me and said, with a big friendly smile "Asher,
you understand nothing! You speak just like Niels Bohr!" One person's insult
is another person's compliment.
"The simple and obvious truth is that quantum phenomena
*do not* occur in a Hilbert space. They occur in a laboratory. If you visit
a real laboratory, you will never find there Hermitian operators. (...)
Still, the activation of a particular detector is a macroscopic, objective
phenomenon. There is no uncertainty as to which detector actually clicked.
"Traditional concepts such as "measuring
Hermitian operators," that were borrowed or adapted from classical physics,
are not appropriate in the quantum world. In the latter, as explained above,
we have emitters and detectors, and calculations are performed by means
of POVMs.
"The KS theorem itself is not involved. Its only role is to restrict our freedom of concocting realistic non-contextual theories that would replace quantum mechanics." ====
Subject: Re: The simple and obvious truth
is ... ?
Dear Asher, In my email from Mon, 08 Jul 2002 17:07:30 +0100, I asked you to produce some statement which would make "the simple and obvious truth" falsifiable, http://members.aon.at/chakalov/Peres.html I spotted a wonderful opportunity in your recent quant-ph/0212023 [Ref. 2], Eq. 19, pp. 9-10: "This arbitrariness is a kind of gauge freedom, and can be resolved only by a complete dynamical description of the intervention process. This, however, is an arduous problem." You and Dr. Terno didn't claim that this is impossible. Just an arduous problem. On the other hand, we know that only gauge-independent quantities can qualify as observables. In short, to make "the simple and obvious truth" falsifiable, please state the conditions under which you will consider this arduous problem impossible *in principle*. I am asking you for a clear and unambiguous formulation of the conditions under which you will accept that these gauge-independent observables can not be found *in principle*. Again, please put your cards on the table. It's about time. Thank you very much in advance. You can read this email also at http://members.aon.at/chakalov/Peres.html#NB For more on this and relevant issues, please see http://members.aon.at/chakalov/Krasnikov.html#NB http://members.aon.at/chakalov/Professor_X.html
With best regards, Dimi
References [Ref. 2] Asher Peres, Daniel R. Terno.
Quantum Information and Relativity Theory. Wed, 4 Dec 2002 11:34:08 GMT,
"Contrary to the impression that may be given in elementary
courses, a wave function is not a physical object. It is only a mathematical
expression which encodes information about the potential results of our
experimental interventions. The latter are commonly called "measurements"
-- an unfortunate terminology, which gives the impression that there exists
in the real world some unknown property that we are measuring. Even the
very existence of particles depends on the context of our experiments.
In a classic article, Mott (1929) wrote "Until the final interpretation
is made, no mention should be made of the [alfa]-ray being a particle at
all." Drell (1978) provocatively asked "When is a particle?" In particular,
observers whose world lines are accelerated record different numbers of
particles (Unruh, 1976; Wald, 1994).
"A seemingly paradoxical way of presenting these results
is to ask the following naive question: suppose that Alice finds that X_z
= 1 while Bob does nothing. When does the state of Bob's particle, far
away, become the one for which X_z = -1 with certainty? Though this question
is meaningless, it has a definite answer: Bob's particle state changes
instantaneously. In which Lorentz frame is this instantaneous? In *any*
frame! Whatever frame is chosen for defining simultaneity, the experimentally
observable result is the same, as can be shown in a formal way (Peres,
2000b). Einstein himself was puzzled by what seemed to be the instantaneous
transmission of quantum information. In his autobiography, he wrote the
words "telepathically" and "spook"(Einstein, 1949).
"A physical system is called "open" when parts of the
universe are excluded from its description. In different Lorentz frames
used by observers in relative motion, different parts of the universe are
excluded. The systems considered by these observers are essentially different,
and no Lorentz transformation exists that can relate them (Peres and Terno,
2002).
"There is nothing mysterious in the transition from the
quantum world to the classical one.
"Dirac (1947) wrote "a measurement always causes the system
to jump into an eigenstate of the dynamical variable being measured." Here,
we must be careful: a quantum jump (also called collapse) is something
that happens in our description of the system, not to the system itself.
Likewise, the time dependence of the wave function does not represent the
evolution of a physical system. It only gives the evolution of probabilities
for the outcomes of potential experiments on that system (Fuchs and Peres,
2000).
"Quantum measurements are usually considered as quasi-instantaneous processes. In particular, they affect the wave function instantaneously throughout the entire configuration space. Measurements of finite duration (Peres and Wootters, 1985) make no essential difference in this respect. "Is this quasi-instantaneous change of the quantum state, caused by a local intervention of an exophysical agent, consistent with relativity theory? The answer is not obvious. "The wave function itself is not a material object forbidden to travel faster than light, but we may still ask how the dynamical evolution of an extended quantum system that undergoes several measurements in distant spacetime regions is described in different Lorentz frames. "Difficulties were pointed out long ago by Bloch (1967),
Aharonov and Albert (1981, 1984), and many others (Peres, 1995 and references
therein).
p. 9: "To become fully relativistic, the notion of intervention
requires some refinement. The precise location of an intervention, which
is important in a relativistic discussion, is the point from which classical
information is sent that may affect the input of other interventions. More
precisely, it is the earliest small region of spacetime from which classical
information could have been sent. Moreover, in the conventional presentation
of non-relativistic quantum mechanics, each intervention has a (finite)
number of outcomes, for example, this or that detector clicks. In a relativistic
treatment, the spatial separation of the detectors is essential and each
detector corresponds to a different intervention. The reason is that if
several detectors are set up so that they act at a given time in one Lorentz
frame, they would act at different times in another Lorentz frame. However,
a knowledge of the time ordering of events is essential in our dynamical
calculations, so that we want the parameters of an intervention to refer
unambiguously to only one time (indeed to only one spacetime "point").
Therefore, an intervention can involve only one detector and it can have
only two possible outcomes: either there was a "click" or there wasn't.
p. 9: "However, when we consider genuine Lorentz transformations, we have not only to Lorentz-transform the above symbols, but we are faced with a new problem: the natural way of calculating the result of a sequence of interventions, namely by considering them in chronological order, is different for different inertial frames. The issue is not only a matter of covariance of the symbols at each intervention and between consecutive interventions. There are genuinely different prescriptions for choosing the sequence of mathematical operations in our calculation. Therefore these different orderings ought to give the same set of probabilities, and this demand is not trivial. p. 9: "The evolution of the quantum state of this bipartite system appears to be genuinely different when recorded in two Lorentz frames in relative motion. The quantum states are not Lorentz-transforms of each other. Yet, all the observable results are the same. (...) [Eq. 19] p. 10: "This arbitrariness is a kind of gauge freedom,
and can be resolved only by a complete dynamical description of the intervention
process. This, however, is an arduous problem. Relativistic interactions
necessarily involve field theory, and the question is how to generalize
the quantum information tools (POVMs, completely positive maps) into objects
that are described by quantum field theories (Terno 2002a).
"The good news are that there is still plenty of work
to be done. (...) After all these problems have been solved, we'll still
have to find a theory of the quantum dynamics for the spacetime structure.
"We are grateful to numerous friends for helping us locate references. We apologize if we missed some relevant ones. Only in a few cases, the omission was intentional." ========== Subject: Re: The simple and obvious
truth is ... ?
Dear Asher, In your "Quantum Information and Relativity Theory", quant-ph/0212023, http://members.aon.at/chakalov/Peres.html#omission you and D. Terno wrote: "We are grateful to numerous friends for helping us locate references. We apologize if we missed some relevant ones. Only in a few cases, the omission was intentional." It seems to me that there are some critical omissions, intentional or not, in your quant-ph/0212023. The story goes back to your essay "Quantum Theory Needs No Interpretation" [Ref. 3], in which you used the word 'knowledge' five times, in line with Niels Bohr's dictum "There is no quantum world. There is only an abstract quantum physical description." Ten years ago, Bill Unruh [Refs. 4 and 5] stressed the problems with this interpretation of quantum theory. Nothing -- knowledge included -- can change its state instantaneously. Unless you are a ghost and do not need a brain, which I think is highly unlikely. Five years ago, David Mermin set the issue in the context of STR [Ref. 6]: the present moment 'now', in which your knowledge changes "instantaneously", cannot be identified. Given these serious omissions, intentional or not, it is hardly surprising that you have encountered insurmountable problems with reconciling QM with STR: "After all these problems have been solved, we'll still have to find a theory of the quantum dynamics for the spacetime structure", http://members.aon.at/chakalov/Peres.html#NB It seems to me that you are not 'alone in the dark', http://members.aon.at/chakalov/Kim.html http://members.aon.at/chakalov/Ashtekar.html#note The last omission which I noticed is from your 1986 article "Existence of "Free Will" as a Problem of Physics" [Ref. 7]. Again, it's about the human brain. Can I help you? See my FAQ at http://members.aon.at/chakalov/faq.html Regards, Dimi
[Ref. 3] Christopher A. Fuchs and Asher Peres. Quantum Theory Needs No "Interpretation", Physics Today, 51(3), 70-71 (2000). "Collapse is something that happens in our description
of the system, not to the system itself. Likewise, the time dependence
of the wavefunction does not represent the evolution of a physical system.
It only gives the evolution of our probabilities for the outcomes of potential
experiments on that system. This is the only meaning of the wavefunction.
"Also, it is not yet understood how to combine quantum
mechanics with gravitation, and there may well be important insight to
be gleaned there."
[Ref. 4] Bill Unruh. The Reality and Measurement
of the Wavefunction.
"On the other hand if the wave function is simply a tool
by which we encode our knowledge into the theory, the change of the wavefunction
under a change in knowledge is perfectly rational. It leaves one, however
with uncomfortable questions about how knowledge differs from other physical
processes."
[Ref. 5] Bill Unruh. Time, Gravity, and
Quantum Mechanics.
"The controversy about the nature of knowledge is probably
even deeper than controversy about the nature of measurement."
[Ref. 6] N. David Mermin. What Is Quantum
Mechanics Trying to Tell Us?
"The notion of now -- the present moment -- is immediately
evident to consciousness as a special moment of time (or a brief interval
-- of order perhaps a few tenths of a second). It seems highly plausible
to me that your now overlaps with my now or, if you are very far away from
me, with a region space-like separated from my now. On the other hand,
I can conceive of it not working this way -- that your now is two weeks
behind or fifteen minutes ahead of my now. In that case when we have a
conversation each of us is talking to a mindless hulk. (...) Physics has
nothing to do with such notions. It knows nothing of now and deals only
with correlations between one time and another. The point on my world-line
corresponding to now, obvious as it is to me, cannot be identified in any
terms known to today's physics."
[Ref. 7] Asher Peres. Existence of "Free Will" as a Problem of Physics, Found. Phys. 16(6) 573 (1986), p. 580 "One may speculate whether, in a complete description of the whole Universe, including our brains, determinism would be restored."
Note: See the recent paper by Asher Peres, "Einstein, Podolsky, Rosen, and Shannon", quant-ph/0310010, v1 of 2 October 2003: Jim Cushing: "I mentioned to Peres that his position appeared to be an instrumentalist one. He replied with no apparent discomfort that others had told him that before."
Asher Peres: "Jim had asked me that question with
the same tone as if he were asking whether I was a cannibal. "Quantum states are not physical objects: they exist only in our imagination." Asher Peres is certainly not a cannibal, but does he have a human brain? Does he know that the present moment 'now', which his colleague David Mermin uses without hesitation, refers to their joint knowledge that will not evaporate but will remain invariant in any reference frame? Is he aware of the fact that his brain does keep a Lorentz-invariant representation of his knowledge, or else he would not be able to remember anything? Has he ever read anything about the human brain? One thing for sure: if he is a human being, he would have to use his brain. Everything in the brain does have neurophysiological representation, human imagination included. These brain states are physical stuff and they certainly comply with the theory of relativity. Nothing -- I mean, nothing -- in the brain can change "suddenly" or "instantaneously". That's what ghosts are all about. I believe each and every cannibal would understand this. But not Asher. No, he is not a cannibal.
===== Subject: No, Asher Peres is
not a cannibal
Subject: An utterly serious error 3. Then the beautiful phrase 'until then'
refers to t_c - t_e > 0 . ========== Note added on October 14, 2003: I haven't yet heard from Prof. Alwyn van der Merwe. Perhaps it is still not entirely clear why I am sharply against Asher Peres' interpretation of quantum states as something that exists "only in our imagination" (cf. above). What is 'imagination'? Go to some New Age store, buy one of those magic crystal balls, and focus your attention right in the center. If you do this exercise for a couple of hours, seven days a week, chances are that some day you will "see" some possible outcomes from physical observations upon some quantum system, but all these predictions will be strictly in your imagination. These are not physical objects, as Asher rightly stressed above. They certainly have neurophysiological basis, only we cannot, and do not, use crystal balls in quantum physics. I sincerely hope that Alwyn van der Merwe and his colleagues from the Editorial Board of Foundations of Physics will agree. However, sometimes Asher Peres uses another notion -- knowledge. In fact, he and his younger collaborator, Christopher Fuchs, used it five times in their much-debated article on the "knowledge" interpretation of QM [Ref. 3]. Fine, but then comes the next question: knowledge about what? Certainly not about some rigid reality 'out there'. This issue has been sorted out by Erwin Schrödinger in 1935. Of course, Asher does not claim that we literally create physical reality by some "sudden" changes of our knowledge. No. He simply bypasses this issue, by saying that QM cannot address this question, since it is outside its scope. And because it is outside QM, we should use "knowledge" without thinking what does knowledge refer to. We should not mention the fact that these "waves" of knowledge do produce physical effects such as interference pattern, as we know from the double-slit experiment, so they are certainly not confined in our brains only. Briefly, since the notion of a rigid objective reality 'out there', as known from classical physics, is not applicable to quantum physics, Asher takes 'knowledge' out of its classical context and drops it in quantum physics, but with specific limitations: it is knowledge, but not like in classical physics. What, then? No, you can't ask such question in QM. I think this is 'not even wrong'. It is like saying "this is a special energy, but don't ask what object has such energy, because we are not allowed to state such question." This too is New Age. I sincerely hope that Alwyn van der Merwe and his colleagues from the Editorial Board of Foundations of Physics will agree. My good old friend Henry Margenau preferred to talk about quantum states as Onta (Reality in Quantum Mechanics, Philosophy of Science, 16 (1949) 287-302). The best way to explain this new (to Asher Peres) notion of reality is to recall the game of twenty questions played by John Wheeler (John and Marry Gribbin, In Search of Schrödinger's Cat, Black Swan, London, 1998, p. 209): "There had been a plot not to agree on an object to be guessed, but that each person, when asked, must give a truthful answer concerning some real object that was in his mind, and which was consistent with all the answers that had gone before." With only one question left, John Wheeler guessed: "Is it a cloud?" The answer was "Yes!" The answer 'cloud' did not exist before the first question asked by John Wheeler, nor until the last question. It was created during the game context, in perfect agreement with Kochen-Specker theorem (I'm sure Asher knows it very well). But how did 'cloud' exist before the game? It had existed as Onta, says Henry Margenau. Of course, he was perfectly aware of the need for reconciling these Onta with the laws of Special Relativity, since everything we observe as 'this cloud, here-and-now' is already in full agreement with STR, being already placed in our back light cone. Henry Margenau knew that we need to work a lot before being able to even approach this highly non-trivial task, which is why he and Wolfgang Yourgrau founded Foundations of Physics. This is our gift from Henry. I sincerely hope that Alwyn van der Merwe and his colleagues from the Editorial Board of Foundations of Physics will agree. I will immediately report here any new developments around the article by Asher Peres, quant-ph/0310010. I will be delighted if he decides to change its title to "Einstein, Podolsky, Rosen, Shannon, and Margenau", and hope this time he could hardly reply with "I have no pertinent comments" (private communication, February 2000). Anyway, Henry Margenau left the spacetime six years ago, on 8 February 1997, and I was not able to tell him about my efforts to elaborate on his Onta. It is very real indeed, only UNspeakable. It could be the quantum reality 'out there'. This is a very old idea, which I was able to share with Henry back in 1990. He did like it. Very much indeed.
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