| Subject: Omissions in
arXiv:0801.0688v2
[quant-ph] Date: Mon, 7 Jan 2008 09:27:38 +0200 From: Dimi Chakalov <dchakalov@gmail.com> To: hartle@physics.ucsb.edu Jim: I believe the publication year of ref. [43] is 1996. To identity other omissions in your latest paper, and reply to my email messages sent since January 1997 (regarding gr-qc/9701022), check out http://www.god-does-not-play-dice.net/Professor_X.html#Bayes Dimi ====================== Dear Professor Hartle, I'm reading your latest article, entitled: "The Physics of ‘Now’" [Ref. 1]. I still cannot find any references to brain neurophysiology. Perhaps you might be interested to see http://members.aon.at/chakalov/Beauregard.html#note For professional advice, may I suggest you to contact Prof. Phillip A. Sharp or any member of his Lab. I hope my email sent in the past three years has been safely received. In case you're still interested in quantum gravity, see http://members.aon.at/chakalov/Harada.html Yours faithfully, Dimi Chakalov
http://members.aon.at/chakalov/faq.html Pritie amzanig huh?
Reference [Ref. 1] James B. Hartle, The Physics of ‘Now’, gr-qc/0403001 v1, March 2, 2004 "Past, present, and future are not properties of four-dimensional
spacetime. Rather, they are properties of a specific class of subsystems
of the universe that can usefully be called information gathering and utilizing
systems (IGUSes) [1]. The term is broad enough to include both single representatives
of biological species that have evolved naturally and mechanical robots
that were constructed artificially. It includes human beings both individually
and collectively as members of groups, cultures, and civilizations.
Footnote 1: "This paper does not aim to discuss or resolve
any of the philosophical debates on the nature of time.
"When the register P_n is erased, the robot has 'forgotten'
its contents. The present extends over a finite interval [tau] (footnote
6).
"The robot has conscious focus on the present, but only access to the past through the records that are inputs to the unconscious computation of its schema. The robot can thus be said to ‘experience’ the present and ‘remember’ the past. The ‘flow of time’ is the movement of information into the register of conscious focus and out again. Prediction requires computation -- either conscious or unconscious -- from memories of the present and past acquired by observation and is thus distinct from remembering. "The subjective past, present, and future, the flow of
time, and the distinction between predicting and remembering are represented
concretely and physically in the structure and function of the model robot.
We now proceed to describe this structure and function in four-dimensional
terms."
"He is grateful to Terry Sejnowski and Roger Shepard for
information about the literature in psychology that bears on the subject
of this paper. Special thanks are due to Roger Shepard for an extended
correspondence on these issues."
===== Subject: Re: Request for paper
Dear Dr. Meinel, Thank you for sending me your review of Hartle's book. You wrote: "The book closes with a careful treatment of gravitational wave emission by weak, nonrelativistic sources (chapter 23) and nonrotating relativistic stars (chapter 24)." I may be wrong, but I can't remember seeing any reference to Hermann Weyl's paper on the problems with the linearized approximation of Einstein's GR; please see a translation of "How far can one get with a linear field theory of gravitation in flat space-time?" Amer. J. Math. 66 (1944) 591, http://xxx.lanl.gov/abs/physics/0407134 You also wrote: "The clear physical presentation is reminiscent of the Landau/Lifshitz style." I guess you imply L.D. Landau and E.M. Lifshits, "The Classical Theory of Field", Pergamon Press, Oxford, 1985. But see Leopold Infeld and Jerzy Plebanski ("Motion and Relativity", Pergamon Press, Oxford, 1960, Chap.. VI), who argued that "it is hardly possible to connect any physical meaning with the flux of energy and momentum tensor defined with the help of the pseudo-energy-momentum tensor. Indeed, the radiation can be annihilated by a proper choice of the coordinate system. On the other hand, if we use a coordinate system in which the flux of energy may exist, then it can be made whatever we like by the addition of proper harmonic functions (...)." Again, I may be wrong, but I can't remember any statement in Hartle's book in the following format: 'if A is true, then GR waves cannot be detected in principle'. That's Landau/Lifshitz style IMHO. I'm writing this because I am afraid that Hartle's book will attract a great number of students, researchers and lecturers in physics, who are not aware of the 1944 paper by Hermann Weyl mentioned above. Unless I've missed something in Hartle's book, please don't feel obliged to reply. Best regards, Dimi Chakalov
============ Subject: Spacetime alternatives for
non-relativistic QT?
Dear Drs. Bosse and Hartle, May I ask a question. In your recent "Representations of Spacetime Alternatives and Their Classical Limits", quant-ph/0503182 v1, you wrote (p. 1): "Spacetime alternatives may permit more realistic descriptions of measurements. No realistic measurement occurs exactly at one moment in time. Finally, spacetime alternatives may be essential for a quantum theory of gravity, where there is no definite notion of spacetime geometry to supply meaning to "at a moment of time" [2]." Then in Sec. VIII Conclusion, you wrote (p. 11): "This
paper has explored the classical (~h --> 0) limit of quantum operators
representing spacetime alternatives in the context of non-relativistic
I wonder how your ideas on spacetime alternatives would evolve if you consider the issue of Lorentz-invariant nonlocality, http://www.God-does-not-play-dice.net/Tresser.html#collapse It seems to me that simple considerations such as ~h --> 0 cannot explain the transition from quantum to classical regime, and back. I think the rule ~h --> 0 tallies to Murphy's Law No. 15: "Complex problems have simple, easy-to-understand wrong answers." Looking forward to hearing from you, Sincerely yours, D. Chakalov
John S. Bell
Note: On Thursday,
April 7th, at 10.40, Jim Hartle will deliver a talk, entitled: "The
Classical Behavior of Quantum Universes", at Geometry and Physics
after 100 Years of Einstein's Relativity, 10 Years Albert Einstein
Institute, April 5 - 8, 2005, Max Planck Institute for Gravitational Physics
This conference is 'by invitation only', which is why he will have no problems with scoffing at Einstein by talking about "a quantum universe characterized fundamentally by chance, fluctuation and indeterminism". How would he do that? Quote again from his abstract: "Two ingredients are essential: First, coarse graining is needed for the decoherence of alternate histories of geometry and coarse graining beyond that is needed to resist the noise that mechanisms of decoherence produce." Sounds like a lot of "coarse graining", but I wasn't invited. If Einsteins was alive, I suppose he would kindly ask Jim Hartle to explain how his computer works, as a "decoherent" quantum system. Read all about it here. More about Jim Hartle here.
What was Murphy's Law No. 15?
D. Chakalov
===== Subject: Geometry
and Physics after 100 Years of Einstein's Relativity
Dear Colleagues, I mentioned your forthcoming conference at http://www.God-does-not-play-dice.net/Hartle.html#note Sincerely, Dimi Chakalov
Six comments on
James B. Hartle's "Generalizing Quantum Mechanics for Quantum Spacetime",
gr-qc/0602013 v1; 31 pages,
4 figures, contribution to the 23rd Solvay Conference The Quantum Structure
of Space and Time
I will quote from the recent manuscript by James B. Hartle (JBH), accentuating some portions from his text. JBH, p. 1: "Quantum mechanics can be applied to spacetime provided that the usual textbook formulation of quantum theory is suitably generalized." Comment 1: The usual textbook formulation of QM may be very misleading, however. See Ashtekar & Schilling here. JBH, ibid.: "A generalization is necessary because, in one way or another, the usual formulations rely on a fixed spacetime geometry to define states on spacelike surfaces and the time in which they evolve unitarily one surface to another. But in a quantum theory of gravity, spacetime geometry is generally fluctuating and without definite value. The usual formulations are emergent from a more general perspective when geometry is approximately classical and can supply the requisite fixed notions of space and time." Comment 2: Once we lose completely the classical time in which physical states "evolve unitarily one surface to another", it is not at all clear how we could recover it "approximately", along with the alleged unitary dynamics. Once we lose the latter, there is no way back. If Jim Hartle knows how to "approximately" recover the world of tables and chairs, he should provide a testable prediction from his theory, for example, a calculation of the error in that recovery. JBH, p. 4: "... there is no evidence that all the phenomena we do see, from the smallest scales to the largest of the universe, cannot be described in quantum mechanical terms and explained by quantum mechanical laws." Comment 3: Untrue. The
crucial evidence is right above JBH's neck.
More here. JBH, p. 6: "The Schrödinger equation (3.1) assumes a fixed notion of time." Comment 4: Here Jim Hartle hit the nail on the head. That "sharp time" is a staggering anomaly, as stressed by Erwin Schrödinger in "Die gegenwärtige Situation in der Quantenmechanik" seventy years ago; reference here. See also my White Paper here. If we use that "fixed notion of time", we utterly abuse QM. The "fixed notion of time" corresponds to 'classical reality out there'. There are no time operators in QM, and we should be fully aware of the fact that we literally filter the quantum reality through the "fixed notion of time" in STR. There is no other way for Jim Hartle to proceed, however, since probabilities can be normalized at a fixed instant only (Ashtekar, 1993). Probabilities cannot be normalized as 'probabilities in time' [Refs. 1 and 2]. Briefly, the normalization problem shows up in all efforts to comply with the fundamental fact that quantum reality does not exist 'out there', as we know since 1935. If we want to address properly the nature of quantum reality, we need a new notion of spacetime. To begin with, we need a theory with "explicit (but unmeasureable) time", as suggested by Bill Unruh. JBH, p. 21: "10 Emergence of Signature "Classical spacetime has Lorentz
signature. At each point it is possible to
Comment 5: The underlying reality not committed to the Lorentz signature can be seen below, from (Tegmark, 1997).
Perhaps we don't need "all possible
signatures" but the signature of the intact quantum world
in which two virtual worlds with inverted spacetime basis, material and
tachyonic, can co-exist. This is potential reality on null
hypersurfaces.
JBH, p. 22: "Traveler, there are no paths, paths are made by walking." Comment 6: There are no pre-determined paths; I fully agree. In a background-free quantum gravity, paths are being created dynamically, in line with the ontological principle of relational reality. There is no unitary dynamics here, of course. Perhaps Jim Hartle will disagree on all accounts (see also his GR textbook), but let's face it: we have just one notion of time, from our wristwatch. This kind of time breaks down in both QM (see Comment 4) and GR. More facts here. It's a pity Jim Hartle insists on
those "information gathering and utilizing systems" [M. Gell-Mann and J.
Hartle, Phys. Rev. D 47, 3345 (1993)], but he at least
can gather
information from his dedicated web page. Not that he would reply. Never
did so far, and probably never will. That's unitary dynamics for sure. D. Chakalov References [Ref. 1] J. Oppenheim, B. Reznik, and W.G. Unruh, When does a Measurement or Event Occur? quant-ph/9805064 v2, p. 4: "The norm can even be zero or infinite.
One can try to normalize the probabilities, but the normalization is different
for each state [psi] , and one needs to know the state [psi]
at all times before the normalization can be done. (...) Furthermore, it
can be shown [6] that
formally, an operator which measures the time of the occurrence of an event
cannot exist."
[Ref. 2] J. Oppenheim, B. Reznik, and W.G. Unruh, Time as an Observable, quant-ph/9807058 v2, pp. 4-5: "This normalization can only be done
if one knows the state [psi](x, t) at all times t (infinitely far in the
past and future). (...) However, this continuous measurement procedure
has it’s own difficulty, and also emphasizes the problem with the previous
probability distribution. Namely, that the probability to find a particle
at t = T is generally not independent of the probability to find
the particle at some other time t = T'."
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