|Subject: Counter example to the quantum inequality
Date: Thu, 02 Sep 2004 16:47:12 +0300
From: Dimi Chakalov <email@example.com>
To: Serguei Krasnikov <Gennady.Krasnikov@pobox.spbu.ru>
RE: Serguei Krasnikov, Counter example to the quantum
inequality, gr-qc/0409007 v1, http://xxx.lanl.gov/abs/gr-qc/0409007
May I ask you to help me understand your recent paper, gr-qc/0409007 v1. Please correct me if I'm wrong.
You derive a quantum inequality to fields in curved spacetime, and show that (quote from the abstract) "actually the quantum inequality does not hold even in a simplest case of a free field in the two-dimensional de Sitter space. Which suggests that there is no grounds today to regard those wormholes and warp drives as 'unphysical'."
You pick up a geodesic segment y that belongs to region W (dark gray) of the de Sitter space (light gray, Fig. 1), and place there an observer whose world line is y .
All this pertains to (gr-qc/0409007
v1, p. 4) "a massless conformal scalar field in the conformal vacuum state
associated with the metric (2). Its renormalized stress-energy tensor in
W is readily found by formula (6.136) of "
Then you wrote (p. 4):
ET = [XXX] (t_1 - t_0),
which obviously -- just by picking sufficiently small e and t_0 -- can be made arbitrarily large in contradiction with (1a)."
I cannot understand the meaning of (t_1 - t_0).
Is this a *time interval* "measured" in a *curved spacetime* inhabited by quantum fields?
If I guess right, please note that the very notion of 'time interval' requires the putative global mode of spacetime,
Secondly, we still don't know -- or do we? -- the exact nature of those suspected "complications that quantum physics is likely to introduce to the question of geodesic behavior" (C. Misner et al., Gravitation, 1973, p. 480). I think the issue is open,
And thirdly, what hides these catastrophic 'negative energy densities' so that we're alive and well to discuss them? You can make them *arbitrarily* large on paper, and I wonder what is the mechanism restricting the production of *actual* negative energy densities,
I hope you and your colleagues will help.
Sorry for my speculations, I know that I sound like the old Tanzanian saying,
Note: The issue of negative energy densities is crucial to the engineering applications of PHI, and I seriously doubt that Serguei Krasnikov or any of his colleagues would reply. If my guess is wrong and I receive some substantial information, I won't post it here. This is a rule which I've never broken. People usually reply by quoting from their published papers, which is, in my opinion, redundant and accumulates a lot of junk in this web site. Sorry about that.
Many years ago, back in the past century, I asked Marc G. Millis by email if he would be interested in my experience in PK, and he replied with "NO" (capital letters, single line). I think it was a bit harsh reply, but perhaps he was optimistic about NASA Breakthrough Propulsion Physics (BPP) Project. Let's see what has happened with the first BPP Challenge: propulsion without propellant. The latest document is NASA TM-2004-213082, dated May 2004: "Although many approaches were found to be dead-ends, more remain unresolved and further possibilities remain unexplored. At this stage, the work is embryonic and faces challenges typical of any new, emerging area."
Never say "NO", Marc. Keep your mind
open to all possibilities.
Subject: Negative energy densities:
Where are they?
Dear Dr. Fewster,
Regarding your recent gr-qc/0409043 v1, I wonder what is hiding these 'negative energy densities'.
If I have a cancer tumor, it doesn't matter if it would be a small one bounded by some "cancer inequality" or a huge one, as suggested by Dr. Krasnikov. Soon or later I'll be dead.
What is the "mechanism restricting the production of negative energy densities, their magnitudes, durations, or interactions with other matter" (A. Helfer, Operational Energy Conditions, gr-qc/9709047)?
If this mechanism is still unknown, perhaps we need new physics. My tentative answer to the question in the subject line begins with a simple experiment, which you and your colleagues can perform with your brain,
It's safe, but UNspeakable,
Briefly, my suggestion for the cancellation of the negative energy densities is to "elevate" them outside 4-D spacetime. General example dealing with the so-called dark energy at
If you dislike the phrase "outside 4-D spacetime", please recall the unsolved problems of 'quantum state' and its "collapse": where was this 'quantum state' before it popped up in the 4-D spacetime? All we can say, after Max Born, is about some probability for occurrence, and nothing about its relativistic status. Hence I believe we need new physics.
Your insights and those from your colleagues will be highly appreciated, and will be kept strictly private.
P.S. Another example: Daniele Colosi and Carlo Rovelli talked recently about "globally defined n-particle Fock states" (Global particles, local particles, gr-qc/0409054), and posed the following question (p. 16): "Can we view QFT, in general, as a theory of particles? Can we think that reality is made by elementary objects - the particles - whose interactions are described by QFT? We think that our results suggest that the answer is partially a yes and partially a no."
Which is, in German, 'Jain',
"Cramer refers to the future-directed [psi]-wave as an "offer wave" (OW). This wave continues on until it interacts with an absorber, which absorbs the wave and in response emits a "confirmation wave" (CW) also having two components, both advanced and retarded. Offer waves and confirmation waves extending forward in time beyond the absorber and backward in time beyond the emitter are exactly out of phase. If the absorberís returned confirmation wave is equal in amplitude to the offer wave, the "pre-emission" waves and the "post-absorption" wave mutually cancel; the only nonzero field that remains is on the worldline connecting the source and the absorber, where a retarded OW and an advanced CW "overlap." The final amplitude of this standing wave is [psi]*[psi] , which reflects the Born probability in an elegant manner."
But "before" we get to the Born probability in such an elegant manner, we're dealing with the global mode of spacetime. Another way to explain it is with Yakir Aharonov's interpretation of QM. Hence we never observe real negative energy densities, causal paradoxes, time travel and closed time curves, naked singularities & black holes, etc., as I tried to suggest on December 3, 2002.
Now, all we have to do is to "upgrade" Einstein's GR with two virtual worlds constituting the putative global mode of spacetime, in which we could have the preliminary talk between matter and geometry. We need to discover the "mysterious time" of Bill Unruh as a substitute for Cramer's "pseudo time", and to solve the puzzle of 3-D space in GR. Then perhaps we will understand the nature of the energy-components of the gravitational field, and why we should be able to make them zero, as stressed by Hermann Weyl back in 1922. Are they zero indeed? The answer is, again, 'Jain'.
I'll soon write a brief
note on the issue raised by H. Weyl, from my
perspective. Meanwhile take a look at Carl Hoefer's paper "Energy Conservation
in GTR", Stud. Hist. Phil. Mod. Phys. 31(2), 187 (2000); see pp.
193-195, pdf file available from here.
Subject: Re: Counter
example to the quantum inequality
I read the second edition of your
"Counter example to a quantum inequality", and was very surprised to see
that Christopher Fewster's
You didn't even mention the colossal
puzzle with those negative energy
As acknowledged by Tom Roman (gr-qc/0409090,
ref.  in your
Perhaps you can help Tom Roman,
If you can't, what is the reason for all these speculations?
Perhaps it will be a good idea if you address the crux of the puzzle, and not dance around it like a cat around a hot pot of milk.
You wrote: "I wish to thank the members of the Friemann seminar for helpful remarks."
I believe know all the members of the Friedmann seminar, particularly the leader, and am sure they can be of help.
Dear Dr. Krasnikov,
You wrote: "Suppose one wants to undertake a time trip. A possible strategy would be just to look for a ready-made closed timelike curve (CTC), or to wait passively until such a curve appears."
Perhaps you may wish to see
To the best of my knowledge -- please correct me if I'm wrong -- there is no intrinsic dynamics of the spacetime itself. It describes a ridiculous block universe: "nothing ever moves therein; nothing happens; nothing changes" (Bob Geroch),
This is 'not even wrong'. I will be very happy to elaborate, if necessary.
In my view, the only option that we have to correct this utterly ridiculous misconception is to introduce two modes of time, global and local, such that in the *local* mode of time we would enjoy a perfect (not FAPP) spacetime continuum.
Hence the "separation" "between" any two successive events from the *local* mode of time is ZERO, according to your tardyon wristwatch,
You have a perfect continuum in the *local* mode of time, and can never observe the "gaps" in the *global* mode of time with any inanimate measuring device.
With your brain -- maybe, but this is still an open question,
You also wrote: "I wish to thank R. R. Zapatrin for useful discussion and Starlab NV for wonderful conditions which I enjoyed while working on this paper."
I can only regret that Starlab NV filed for bankruptcy. BPP Project at NASA is short of money too,
Perhaps the solution is at the tip of your fingers.
Please write me back if you believe that I'm on a wrong track. I extend this request to all colleagues of yours included in the CC: and BCC: lists.
Thank you for your time.
Thank you, once more, for your kind reply from Tue, 6 Aug 2002 22:54:22 +0400 (MSD).
Your recent article on spacetime shortcuts, gr-qc/0207057 v2 [Ref. 3], reminds me of A. Shimony's 'peaceful co-existence of QM and STR': in both cases it is not clear to me why and how FTL signaling & closed time curve (CTC) are banned by Mother Nature,
Perhaps the crux of the puzzle is the phenomenon of transience, as explained by Shimony,
It seems to me that present-day theoretical physics does not, and can not provide room for the phenomenon of transience,
There are compelling evidence for some preferred Cosmic Background Radiation reference frame, as acknowledged by G. Smoot,
and demonstrated by R. Kühne [Refs. 4 and 5]. There are even more compelling evidence in favor of some preferred reference frame in Lorentz covariant quantum mechanics [Ref. 6]. I think all this goes back to the fundamental issue of quantum reality posed by E. Schrödinger in 1935,
May I ask a simple question.
Do you attribute a physical meaning to the quantum state, its time evolution, and localization?
I will be happy to learn the opinion of your colleagues as well.
My answer to the question is 'both yes and no' or 'Jain' (in German), since I postulate two modes of time (or rather two modes of spacetime), global and local. The remnant from the global mode of time is what causes the confusion, suggesting all kinds of pathologies such as CTC, spacetime shortcuts, and "quantum computing",
However, if we find the phenomenon of transience embedded in some 'universal time arrow', I believe it will become clear why we will never suffer from these pseudo-pathologies, and how can we explore them with our brains,
You can read this email also at
[Ref. 4] Rainer W. Kühne, General
Relativity Requires Absolute Space and Time,
[Ref. 5] Rainer W. Kühne, A Model
of Magnetic Monopoles,
[Ref. 6] J. Rembielinski and K. A. Smolinski,
Einstein-Podolsky-Rosen correlations of spin measurements in two moving
> > It looks like you think of me with stereotypes :-)
It's like the case of Max Planck:
"An important scientific innovation rarely makes its way by gradually winning over and converting its opponents: it rarely happens that Saul becomes Paul. What does happen is that its opponents gradually die out and that the growing generation is familiarized with the idea from the beginning: another instance of the fact that the future lies with youth."
My guys are probably 11 year old,
I'm almost 52, and am fine.