Text Size

Stardrive


Let n1 = n2 = n equal intensity at both the transmitter A and receiver B slits.
The overlap nonlocal modulation control parameter from the over-complete Glauber laser states is
(A1|A2) ~ exp{ - n[(1  - e^i(@1 - @2)]} + exp{ - n[(1  - e^-i(@1 - @2)]}
& = @1 - @2
(A1|A2) ~ exp{ - n[(1  - cos& - isin&)} + exp{ - n[(1  - cos& + isin&)}
~ e^-n(1 - cos&){e^insin& + e-insin&}
(A1|A2) ~ 2cos(nsin&)e^-n(1 - cos&)
Obviously, we need to exploit the periodicity in (A1|A2) and the exponential works against us except when cos & ~ +1 where the exponential periodically peaks at 1. That is the relative phase & at each of the screens must be an integer multiple of 2pi i.e. constructive interference peaks.
Note that when & = 0, (A1|A2)  ~ 2, which is a fortunate result independent of n when we switch off the transmitter Heisenberg microscope.

For the fringe spacings see http://en.wikipedia.org/wiki/Double-slit_experiment

See also the pdf uploaded today June 30, 2011 to physics section of the library below.



typo correction missing i in the exponential
On Jun 29, 2011, at 8:50 PM, JACK SARFATTI wrote:


Therefore, the complex number control parameter at A

(A1|A2) ~ exp{ - (1/2)[(n1) + (n2)  - 2(n1n2)^1/2e^i(@1 - @2)]} =/= 0

Therefore, the fringe visibility at the receiver B screen at points x' can be computed from the local cross terms

(A1|A2)(B1|x')(x'|B2) + cc


Let n1 = n2 = n equal intensity at the transmitter A slits.

(A1|A2) ~ exp{ - n[(1  - e^i(@1 - @2)]} + exp{ - n[(1  - e^-i(@1 - @2)]}


& = @1 - @2

(A1|A2) ~ exp{ - n[(1  - cos& - isin&)} + exp{ - n[(1  - cos& + isin&)}

~ e^-n(1 - cos&){e^insin& + e-insin&}

~ e^-n(1 - cos&)2cos(nsin&)

as n increases we want & approaching zero to prevent the receiver interference terms from getting too small.

~ 2e^-n&^2/2cos(n&)

Jun 30

On Jun 29, 2011, at 8:28 PM, nick herbert wrote:

Why are you bringing up "Glauber states", Jack?
Just to muddy the waters?

Of course, making imperfect non-strong measurements muddies the waters.

A Glauber state possesses an indefinite photon number.

All entangled states that we know of are Fock states
with a definite photon number.


Really Nick? I think I read there are now entangled laser beams.

In any case, that there may be entangled laser beams does not violate quantum theory as far as I know.

If that could be done, it seems to show a flaw in Stapp's proof and in all the no-cloning no entanglement signaling proofs.

That is, all those proofs at the basis of the black hole information dispute, quantum cryptography etc would be thrown in doubt.

How does this entangled macro-quantum coherent state violate orthodox quantum theory?

|z1)|z'2') + |z2)|z'1')

where

z = sqrt(n)e^i@

So, Nick you agree that orthonormality of the states that are traced over is needed for no-signalling?

Hey Nick what about this?


Laser beams are entangled in space - physicsworld.com
physicsworld.com/cws/article/news/35171 - Cached
Jul 29, 2008 – Breakthrough could allow optical measurements to beat the 'diffraction limit'
?
[PDF] Femtosecond laser–pumped source of entangled photons for quantum ...
www.ece.rochester.edu/source/Roman.../Pan_SPIE_Prague_07.pdf
File Format: PDF/Adobe Acrobat - Quick View
by D Pan - Related articles
We present an experimental setup for generation of entangled-photon pairs via spontaneous parametric down-conversion, based on the femtosecond-pulsed laser. ...
Entangled entanglement in Raman lasers | Eur. Phys. J. D
epjd.edpsciences.org/articles/epjd/abs/2011/05/d09661/d09661.html
Feb 4, 2011 – European Physical Journal D, Molecular, Optical and Plasma Physics, EPJ D.
Demonstrating various quantum effects with two entangled laser beams
arxiv.org › quant-ph - Cached
by B Hage - 2011 - Related articles
Mar 22, 2011 – Abstract: We report on the preparation of entangled two mode squeezed states of yet unseen quality. Based on a measurement of the covariance ...
Quantum-beat lasers as bright sources of entangled sub-Poissonian ...
link.aps.org/doi/10.1103/PhysRevA.78.045801
by X Hu - 2008 - Cited by 14 - Related articles
Oct 8, 2008 – We show that a quantum-beat system with incoherent pump or coherent driving produces an entangled sub-shot-noise laser that operates well ...
LEDs may put lasers out of quantum computing business
arstechnica.com/.../leds-may-put-lasers-out-of-quantum-computing-... - Cached
Jun 10, 2010 – To generate entangled pairs of photons, researchers often use a process called parametric down-conversion. A laser sends its light at a ...
Quantum Entangled Power Distribution
lofi.forum.physorg.com › Physics › Physics General - Cached
4 posts - 2 authors - Last post: Jul 18, 2007
... of almost unlimited power when blended with quantum entangled power ... quantumentangling to power source that powers the lasers with ...
LIGHT-EMITTING DIODES: LED source emits entangled photon pairs ...
www.optoiq.com/index/display/.../laser...9/.../light-emitting-diodes.html
Sep 1, 2010 – This is the first demonstration of a solid-state, electrically driven device consisting of a quantum dot embedded in a semiconductor LED ...
Demonstrating hybrid quantum effects with two entangled laser beams
www.opticsinfobase.org › Conference Papers › EQEC › 2011 › EA
by B Hage - 2011
May 22, 2011 – Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings ...
Spooky Atomic Clocks - NASA Science
science.nasa.gov › ... › Science@NASA Headline News › 2004 - Cached
Apr 6, 2011 – In this laser experiment entangled photons are teleported from one place to another. NASA uses atomic clocks for spacecraft navigation. ...

A hidden flaw in Henry Stapp's no EPR signal proof and all other proofs? Is the no cloning an arbitrary quantum theorem wrong? See the pdf just uploaded in Library Resources under Physics. Think for yourself if you can do elementary algebra and have taken courses in advanced physics in a good college or university.


On Jun 29, 2011, at 3:01 PM, Ruth Elinor Kastner wrote:


Jack: I remember discussing this with John Cramer a few years ago. I found a reference (by Shih et al as I recall) saying that you cannot get an interference pattern without coincidence of the two photons -- this what Cramer refers to not seeing in the Dopfer thesis. Without coincidence you just get noise. I think this is the reason it might be impossible to get signalling. If one is able to improve the resolution of the down-conversion process so that you can see the interference pattern independently, then  my understanding is that you lose the EPR correlation.  Apologies if someone has already mentioned this and I missed it.
Ruth


Yes, that is the standard argument I am very familiar with. However, now Cramer recently claims he can get the interference pattern without the coincidence circuit because of advances in EPR sources. According to a document that Russell Targ sent me, Cramer now claims that, with the proper source of EPR pairs switching off the coincidence circuit is only a 15% reduction in receiver fringe visibility if the Heisenberg microscope is switched off at the transmitter. This clearly violates Stapp's et-al's general proof to the contrary within OQT.


I claim I have carried out Stapp's linear unitary partial trace of the EPR pair reduced density matrix proof in this particular situation in David Kaiser's Fig 9.1 of The Hippies Who Saved Physics:



And that the implicit assumption in his general partial trace of the EPR pair density matrix proof in the situation of Fig 9.1 is my


                                                        (A1|A2) = 0

i.e. orthogonality of the slit states on the transmitter side. So that is the issue here.

 

(There is a glitch in the Joomla program that screws up the equations. I am trying to fix it.)

 

 

Where is the precise error in my algebraic analysis of Kaiser's Fig 9.1 above?
________________________________________
From: Jack Sarfatti [sarfatti@pacbell.net]
Sent: Wednesday, June 29, 2011 4:11 PM
To: art wagner
Subject: Re: Quantum Mechanics 1: The No-FTL signalling theorem


The paper looks good. However my algebra is very simple. The issue is whether it contains an obvious contradiction with OQT? Even a smart undergrad physics major should be able to point out the error if indeed there is one.


I claim (A1|A2) = 0


Is necessary to get no signal in that instance for Kaiser's Fig 9.1. So far neither Henry nor any other quantum mechanic has actually addressed the relevant point.


On Jun 29, 2011, at 12:58 PM, art wagner > wrote:


Could the viewpoint espoused by this paper on the nature of the wavefunction be of any use here?  [I do realize you're using bra-ket forms] - http://arxiv.org/ftp/arxiv/papers/1001/1001.5085.pdf
________________________________
Date: Wed, 29 Jun 2011 12:44:58 -0700
From: sarfatti@pacbell.net
Subject: Re: Quantum Mechanics 1: The No-FTL signalling theorem
Henry
I certainly agree that changing the statistical rules of OQT will allow signal nonlocality as in Antony Valentini's papers that are clearly sufficient, but is it necessary? John Cramer has recently suggest it is not necessary.


At this point I am playing Devil's Advocate. I expect my algebra has an error, but I have not been able to get you to really address that particular alleged counter example to your general proof. My model is essentially similar to John Cramer's variation on the Dopfur experiment.
I wrote several lines of algebra. Which ones do you disagree with as a description of Kaiser's Fig 9.1.
:-)
________________________________
From: Henry P. Stapp >;
To: JACK SARFATTI >;
Subject: Quantum Mechanics 1: The No-FTL signalling theorem
Sent: Wed, Jun 29, 2011 5:18:04 PM
Since you seem to be contemplating producing faster-than-light signalling by merely choosing unusual experiments conditions, but not changing the basic statistical rules of orthodox QM, and seem to have doubts the correctness of the No-FTL-Signalling Theorem, it might be instructive to look again at the usual derivation.
The basic interpretive rule of OQM is that the probability that a measurement associated with a projection operator P will give the positive outcome "Yes" is

The basic interpretive rule of OQM is that the probability that a measurement associated with a projection operator P will give the
positive outcome "Yes" is

(P)= Trace P rho/Trace rho

and that this "Yes" response to the probing action will reduce the
prior state rho to (P rho P)/trace P rho P.

The probability of the negative response "No" is

(P') = Trace P' rho/ Trace rho,     with P'= (I-P).

Thus the probability of "Yes" plus the probability of "No" is

(Trace P rho/Trace rho)+ (Trace (I-P) rho/Trace rho)

=Trace (P + I - P)/Trace rho

= 1.

If Q is a projection operator whose support is spacelike
separated from the support of P, so that QP=PQ,
then the probability of "Yes" for Q and "Yes" for P is

(QP) = Trace QP rho/Trace rho

and the probability for "Yes" for Q and "No" for P is

(QP') = Trace Q(I-P) rho/ Trace rho.

Hence the probability of Yes for Q if the outcome of the mearurement
of P is unknown is

(QP) + (QP')

which is just

(Q):

This does not depend upon which measurement P was performed in the
faraway region: different choices of P produce no effect on the
probability of the outcome of the measurement in the region
associated with Q.

I do not see how this result can be rationally challenged,
given the standard rules of OQT.

Given any finite set of kets {|A1), |A2), ... , |AN)}
orthogonal or not, any non zero ket
|X) = c1|A1) + c2|A2) + ... CN|AN),
with complex coefficients Ci,
gives a projection operator

P= |X)(X|/(X|X)

(PP= P)

I do not see how anyone can rationally challenge these
conclusions, given the rules of OQT. They imply that,
given the rules of OQT, the probabilities of outcomes
on either side of Sarfatti's (or anyone's) experiment cannot
depend on which experiment is performed in the faraway other
region: a sender cannot, by his free choosings of which measurement
P to perform in L, send a message to a colleague that is observing the outcome of a measurement of Q in a region R that is spacelike separated from L: no matter what Q is measured in L, the  outcome

predicted by OQT will be independent of which P the "sender" chooses.
Thus sending a FTL signal requires no mere clever choices of complex
measurements P and Q: it requires also a violation of the laws of OQT.
I have no doubt that this very simple, but extremely important, fact was known to the founders of quantum theory.

 

odd glitch fixed


I am playing Devil's Advocate here just in case John Cramer's variation on the Dopfur experiment is correct and Henry's et-al's general no-signal proofs in OQT have a hidden flaw in them like John von Neumann's wrong proof against hidden variables.
My starting equation is


<x,x'|A,B> = <x|A1><x'|B2'> + e^i@(y)<x|A2><x'|B1'>    (3)


the first term on the RHS is the sum of all Feynman histories where particle A of the entangled pair passes through slit 1 and lands on a point x on the screen AND particle B passes through slit 2' on the other side landing on the other screen at x'. The particles are emitted back to back. The random phase factor includes scatterers in the Heisenberg microscope and possible environmental decoherence.  I suppress the unitary time translation operators or the Feynman propagators depending on which formalism one would use in detail. x includes the time of arrival. This is an important detail.
when the multiple integral with respect to y and x of


<A2|x,y><y,x|A1> = 0  (2)


this assumes that the integrals are taken at fixed times - that is a problem here because the alternative paths for a given single particle in an entangled pair will have different arrival times at the screen if they start with the same speed. Of course there will be an uncertainty in initial speeds as well. So the integrals for orthogonality only select the alternative histories for the same transit time from source to different points on the screen.


Of course in a real experiment one pair at a time, waiting for a build up of a pattern, this condition of same transit time is violated. So this is a conceptual problem. There is a similar problem for intense beams. And, of course, laser beam eigenstates are over-complete Glauber states and not mutually orthogonal for different Feynman histories.
I think you get effective nonunitarity if you integrate over the screen for different arrival times from the emission source!


In any case it seems obvious to me that the fringe pattern on the receiver side depends on the density matrix partial trace over the transmitter screen that is terms like


  <A2|A1><B1'|x'><x'|B2'>   (7)


Therefore, the key factor needed for no-signaling is the effective orthogonality condition

<A2|A1> = 0



This is what Henry Stapp and I are currently arguing about.
So far Henry is invoking general ideas without specifically looking at my modeling of this device.
I could be wrong of course and probably am.
Jun 28


Subject: Re: Henry (Stapp) where is the error in my "proof" about entanglement signaling?



On Jun 27, 2011, at 6:06 PM, Henry P. Stapp wrote:

On Mon, 27 Jun 2011, JACK SARFATTI wrote:

On Jun 27, 2011, at 12:49 PM, Henry P. Stapp wrote:



On Sat, 25 Jun 2011, JACK SARFATTI wrote:

On Jun 25, 2011, HENRY STAPP wrote:


To accommodate the Bem results, or otherwise allow for violations of the
no-FTL-signally theorem one must violate the basic rules of contemporary quantum mechanics, not merely set up clever experiments.


I agree with Henry on this. Indeed my Journal of Cosmology paper (April 2011 Vol 14 - Penrose-Hameroff ed) agrees with this. So if Henry wants to say that

<A1|A2> =/= 0 violates OQT so be it.

However, it appears that we can do that in the lab with modern techniques.

HPS:

I am not saying that <A1|A2> =/= 0 violates OQT!
Just the opposite!


Well in that case what do you disagree with in my description of the double two slit experiment?


HPS: If you happen to have a standard double slit experiment then in this case you happen to have a condition <A1|A2>=0,


But that is not the gedankenexperiment. The one I am modeling with the algebra is David Kaiser's Fig 9.1 So, the issue is what specific algebra in my model do you think is in error?
I think I have followed your general proof in this particular instance. However, in order to get no FTL signal I need <A1|A2> = 0 in the case that the Heisenberg microscope is switched off on the transmitter side. In OCT this condition is satisfied I think. However, with new techniques of weak and partial measurements and perhaps with entangled laser beams this may not be so. We also have John Cramer's variation on the Dopfur experiment which is functionally equivalent to mine. Now both Cramer and I may be in error here of course. The issue is where is the error in my algebra?

HPS but that fact does does not enter into my proof of the No-FTL-Signalling theorem, which goes through just as well, and unaltered, for the case <A1|A2> =/= 0. In order to make the predictions in R to depend on which choice of experiment performed in L you must deviate from the statistical rules of OQT, no matter whether <A1|A2> is zero or not. My proof that the orthodox rules lead to the No-FTL-signalling property does not fail, or need to be changed in any way, if <A1|A2> =/= 0. The proof holds equally well in this case: it does not involve any condition <A1|A2>=0 in the first place, even though that condition does happen to be satisfied in the simpest case of a true double slit experiment.

Your statements create the impression that you thought that by going to the case <A1|A2>=/=0 you could evade my proof of NO FTL signalling.
For reasons given, that is not the case.

JS: I suspect I am in error, but I can't find it in my algebra for Fig 9.1. For same reason I suspect that Cramer's experiment will not work, though he makes a plausible argument.

Do you disagree with my statement that terms like


<A2|A1><B1'|x'><x'|B2'>  (7)

suffice for a local interference pattern on the receiver side provided that

<A2|A1> =/= 0 ?

In case the readers do not have easy access to the original argument I repeat it here

On Jun 25, 2011, at 10:02 AM, JACK SARFATTI wrote:

Let y be the support of the test particles that scatter the electron in the Heisenberg microscope on the transmitter side. Do not confuse y with x the position of the massive electron part of an entangled pair of electrons. Orthogonality of the transmitter slit states

<A2|A1> = 0  (1)


is only true for a reliable strong measurement of which way the transmitter electron A goes OR if no strong which-way measurement is even attempted. That is when the multiple integral with respect to y and x of

<A2|x,y><y,x|A1> = 0  (2)

This is not the case in an unreliable partial and/or weak which-way measurement where the effective measurement operator is not Hermitian.

e.g. in some weak measurements the effective measurement operator has an imaginary part.


The EPR pair interferometers have the entangled state for slits (1,2) & (1',2') at positions on screens x & x' for photons A & B in the same individual pair

<x,x'|A,B> = <x|A1><x'|B2'> + e^i@(y)<x|A2><x'|B1'>     (3)

where @(y) is a stochastic phase whose degree of randomness is controlled by tuning the efficiency of the slit detector on the transmitter side.

Now the no-signal theorem in this case is trivial as shown by Henry Stapp.

Form the Born probability. Ignore @ for now. It's not important for this part of the argument.

P(x,x') ~ |<x,x'|A,B> |^2  (4)

What is important are the cross terms, e.g.

<A2|x><x|A1><B1'|x'><x'|B2'>  (5)

Integrate over the transmitter positions x and also the scatterers y if the Heisenberg microscope is switched on at the transmitter and assume completeness of the eigenstates for the transmitter electron of the entangled pair |x>

i.e. integral of the projection operator

|x><x| = 1   (6)

Therefore the net result of this partial trace is

<A2|A1><B1'|x'><x'|B2'>  (7)

The usual assumption is that the A slit bras and kets are orthogonal i.e.

<A2|A1> = 0  (8)

In that case there is never a LOCAL interference pattern on EITHER side under any conditions.




I am pointing out that neither the condition <A1|A2>=0,
nor any analog of such a condition, enters into my
general proof of the No-FTL signalling theorem.

OK, but what is wrong with my above model of the above experiment in David Kaiser's Fig 9.1?

It seems to me that in that particular model you must demand

<A2|A1> = 0

The proof that I gave earlier of the No-FTL-signalling theorem does not bring in any condition <A1|A2> = 0,
and it applies perfectly well, without comment, to the
case at hand where <A1|A2>=/= 0.

It applies perfectly well to the case where the projection
operator representing the answer "yes" to the experimenter's
probing question is P = |X><X|/<X|X> with
|X> = a|A1> + b|A2>, with a and b any complex numbers not
both zero.

I do not know where the condidtion <A1|A2> =0 that
Sarfatti mentions came from. It certainly does not
enter into my general argument, and emphatically not in
the case that Sarfatti is considering, in which
<A1|A2> =/= 0. The given proof of the theorem
goes through, provided only that the statistical
rules of OQT are maintained.

The theorem states that if the statistical rules
of OQT are valid, then the probabilities of the various
possible outcomes of an experiment performed in a spacetime
region R cannot depend upon which experiment is randomly chosen
and performed in a spacetime region L if R lies outside the
forward lightcone of region L, even though the OUTCOMES of
the experiments in the two regions may be intricately correlated,
due to interactions that occurred in the past.


On Jun 27, 2011, at 12:49 PM, Henry P. Stapp wrote:
On Sat, 25 Jun 2011, JACK SARFATTI wrote:
See Fig 9.1 in David Kaiser's book How the Hippies Saved Physics to follow the equations below.
On Jun 25, 2011, HENRY STAPP wrote:
To accommodate the Bem results, or otherwise allow for violations of the
no-FTL-signally theorem one must violate the basic rules of contemporary quantum mechanics,
not merely set up clever experiments.

I agree with Henry on this. Indeed my Journal of Cosmology paper (April 2011 Vol 14 - Penrose-Hameroff ed)
agrees with this. So if Henry wants to say that
=/= 0 violates OQT so be it.
However, it appears that we can do that in the lab with modern techniques.
HPS:
I am not saying that =/= 0 violates OQT!
Just the opposite!

Well in that case what do you disagree with in my description of the double two slit experiment?
Do you disagree with my statement that terms like
  (7)
suffice for a local interference pattern on the receiver side provided that
=/= 0 ?
In case the readers do not have easy access to the original argument I repeat it here
On Jun 25, 2011, at 10:02 AM, JACK SARFATTI wrote:
Let y be the support of the test particles that scatter the electron in the Heisenberg microscope on the transmitter side. Do not confuse y with x the position of the massive electron part of an entangled pair of electrons. Orthogonality of the transmitter slit states
= 0  (1)
is only true for a reliable strong measurement of which way the transmitter electron A goes OR if no strong which-way measurement is even attempted. That is when the multiple integral with respect to y and x of
= 0  (2)
This is not the case in an unreliable partial and/or weak which-way measurement where the effective measurement operator is not Hermitian.
e.g. in some weak measurements the effective measurement operator has an imaginary part.
The EPR pair interferometers have the entangled state for slits (1,2) & (1',2') at positions on screens x & x' for electrons A & B in the same individual pair
= + e^i@(y)     (3)
where @(y) is a stochastic phase whose degree of randomness is controlled by tuning the efficiency of the slit detector on the transmitter side.
Now the no-signal theorem in this case is trivial as shown by Henry Stapp.
Form the Born probability. Ignore @ for now. It's not important for this part of the argument.
P(x,x') ~ | |^2  (4)
What is important are the cross terms, e.g.
  (5)
Integrate over the transmitter positions x and also the scatterers y if the Heisenberg microscope is switched on at the transmitter and assume completeness of the eigenstates for the transmitter electron of the entangled pair |x>
i.e. integral of the projection operator
|x> Therefore the net result of this partial trace is
  (7)
The usual assumption is that the A slit bras and kets are orthogonal i.e.
= 0  (8)
In that case there is never a LOCAL interference pattern on EITHER side under any conditions.
HPS:
I am pointing out that neither the condition =0,
nor any analog of such a condition, enters into my
general proof of the No-FTL signalling theorem.

OK, but what is wrong with my above model of the above experiment in David Kaiser's Fig 9.1?
It seems to me that in that particular model you must demand
= 0
HPS:
The proof that I gave earlier of the No-FTL-signalling theorem does not bring in any condition = 0,
and it applies perfectly well, without comment, to the
case at hand where =/= 0.
It applies perfectly well to the case where the projection
operator representing the answer "yes" to the experimenter's
probing question is P = |X> with
|X> = a|A1> + b|A2>, with a and b any complex numbers not
both zero.
I do not know where the condition =0 that
Sarfatti mentions came from. It certainly does not
enter into my general argument, and emphatically not in
the case that Sarfatti is considering, in which
=/= 0. The given proof of the theorem
goes through, provided only that the statistical
rules of OQT are maintained.
The theorem states that if the statistical rules
of OQT are valid, then the probabilities of the various
possible outcomes of an experiment performed in a spacetime
region R cannot depend upon which experiment is randomly chosen
and performed in a spacetime region L if R lies outside the
forward lightcone of region L, even though the OUTCOMES of
the experiments in the two regions may be intricately correlated,
due to interactions that occurred in the past.


On Jun 21, 2011, at 2:42 PM, Ruth Elinor Kastner wrote:

  Just a note to say that I agree with much of what Prof. Stapp says here regarding the need to question a 'block world'-type view, and note that my 'possibilist' development of Cramer's Transactional Interpretation ("PTI") makes use of a sub-empirical domain that seems to me very similar to his 'process time'. My book for CUP on PTI is underway and will present these ideas in detail. Due to time constraints I did not quite get to this in my AAAS talk.

best
Ruth
________________________________________
From: Henry P. Stapp [hpstapp@lbl.gov]
Sent: Tuesday, June 21, 2011 5:18 PM
To: JACK SARFATTI

Subject: Re: Retrodiction yes, retrocausation no

From Henry Stapp:

Because my comments at the recent AAAS meeting were mentioned, I would
like to give a fuller account of what I said, or at  least tried to
say, and my opinion on the significance of the Bem results---
assumed for present purposes to be veridical and reproducible.

In the first place, the Aharonov papers do not change standard
(orthodox) QM by "one iota", in the sense that the predictions of
results of observations on the post-selected subsets are precisely
the predictions obtained by application of the standard rules. That
is why there is no doubt or question about what the predictions are.
And there should be no surprise that the predictions are confirmed by
the observations: that matching is merely confirmation of the standard
rules of QM, applied to the specified empirical conditions.

Jack: Exactly, the practical advantage is psychological leading to weak and partial measurement methods good for extracting weak signals in strong noise. Techniques that might have been discovered by orthodox thinkers. but allegedly were not.

The second key point is that the results reported by Bem are
inconsistent with the standard rules of orthodox QM. That is because
the Bem results essentially allow the transmission of a "signal"
(a message created by the sender) backwards in time.

Yes, this is signal nonlocality! This is what we were looking for as described in David Kaiser's book How The Hippies Saved Physics. The New York Times Book Review (June 19, 2011) is hostile to the book and grossly inaccurate about the physics. Peter Woit's review in American Scientist is much more balanced and accurate. - Jack

The idea of making changes that act "backward in time" needs to be
clarified, since it is, in a sense, incompatible within the ordinary
common sense idea of time. Yet the empirical results arising
from the Wheeler delayed choice experiments seem, in some sense, to
be saying that choices made now are affecting what happened in the past.
This backward-in-time aspect of QM is compactly captured by the
assertion made in the recent book "The Grand Design" by Hawking and
Mlodinow "We create history by our observations, history does not
create us". (p.140)

How can one make rationally coherent good sense out of this
peculiar feature of QM?

The way I do this is to introduce the concept of "process time",
which is a "time" that is different from the "Einstein time" that
is joined to physically described space to give Einstein space-time.
(See my chapter in "Physics and the Ultimate Significance of Time" SUNY,
1986, Ed. David Ray Griffiths. Three physicists, D. Bohm, I. Prigogine and
I presented our ideas about time.)

Jack: Since entropy is technically imaginary action, e.g,. Hawking's rotation to imaginary time relates quantum field theory to statistical mechanics with a change of space dimension. So would a complex time do what Henry wants? Of course the signature changes. No light cones in imaginary time, so no causal constraints either?

In relativistic quantum field theory (Tomonaga/Schwinger) the quantum
state collapses not on an advancing sequence of constant time surfaces
t(i):t(i+1)>t(i); but rather on an advancing sequence of space-like
surfaces sigma(i): for each i, every point on sigma(i) is spacelike
displaced from every other point on sigma(i), and every point on
sigma(i+1) either coincides with a point on sigma(i), or lies in the open
future lightcone of some points on sigma(i).

At each surface sigma(i) a projection operator P(i), or its complement
P'(i)=(I-P(i)), acts to reduce the quantum state to some part of its
former self.

For each sigma(i) there is a "block universe" defined by extending the
quantum state on sigma(i) both forward and backward in time via the
unitary time evolution operator generated by the Schroedinger equation.
Let the index i that labels the sigma(i) be called "process time".
Then for each instant i of process time, a new history is defined by
the backward-in-time evolution from the newly created state on
sigma(i). All predictions about the future are "as if" the future
state is the smooth continuation from the newly created past.
This newly created past is the "effective past", in the sense that
the future predictions are given by taking this newly created past to be
the past.

In orthodox QM each instant of process time corresponds to an
"observation": the collapse at process time i reduces the former
quantum state to the part of itself compatible with the increased
knowledge generated by the new observation.

The actual physical universe is generated by the always-forward-moving
creative pocess---in the sense that the sequence of surfaces sigma(i)
advances into the future, even though there is an associated set
of revised "histories".

This is all just standard quantum mechanics, elaborated for clarity.

The element of "randomness" enters Copenhagen/vonNeumann QM in the
following way:

Each "observation" must be preceded first by a choice on the part of
the observer of what aspect of nature he or she wants to probe.
The outcome "yes" of the probing action must be a recognizable
empirical experience. The "probability" that nature will return the answer
"yes" is specified by quantum theory. The probability of "No" is the
complement: Prob(Yes)+Prob(No)=1.

It is a fundamental theorem of QM that IF the standard orthodox
statistical rules governing nature's choice of reply are strictly
adhered to, then no "message" (information transfer containing
info controlled by the sender) can be sent faster-than-light
or backward-in-time: I cannot receive "now" information controlled
by the "freely chosen" actions of a sender acting in my future, in any
frame: "messages" can be sent only into the forward light-cone;
"normal statistics entails normal causation!"

Jack: According to this rule, John Cramer's recent modification of the Dopfur experiment throwing out the coincidence circuit must fail.

Given the powerful evidence for the validity of the
orthodox rules, not only from the thousands of standard pertinent
experiments performed during the past century, but also for the
strange predictions for post-selection and partial measurements described
at this AAAS conference, it is reasonable to try retain the orthodox
rules, insofar as is possible, and not try to start from scratch, as
was recommended by some speakers.

The simplest way to get the Bem results within the general framework of
orthodox QM is to allow a slight biasing of the orthodox statistical
rules: a biasing of nature's choices that works to  enhance the
maintainance of life of biological systems.

We know already from EPR-type phenomena that nature's choices "here" must
have some sort of pertinent access to faraway information: nature's choice
at some moment i in process time may have access to the corresponding
block universe, which represents weighted potentialities for the future,
as they exist at that particular moment i in process time.

Of course, this notion that nature's choices are biased in favor
of biology is absolutely opposed to the concepts of classical physics,
where everything---except the initial state of the universe---is
controlled by purely local mechanical process. This idea that nature
creates the initial state, but thereafter maintains a strictly
hands-off stance, is carried over to QM by the orthodox statistical
rule, which is completely determined by purely physical considerations.
But the Bem experiment, by indicating a possible bio-enhancing bias,
may be an empirical indication that the classical-physics notion of a
hands-off basically passive nature may be incorrect!

Of course, this conclusion tends to move science in a direction
somewhat concordant with some religions, but that fact is not a proper
scientific reason to reject it: the motivation here is strictly
to save the principles of orthodox QM, in the face of data that,
if bona fide, seem to entail a need to revise in some way the
strictly orthodox theory. And the simplest revision is to back
away from the notion that nature, after creating the physical universe,
simply lets it run on automatic. That idea is certainly very agreeable
to mathematical physicists, but is hardly the only way that nature could
behave. We may need to tailor the existing theory to accomodate the data,
not confine the acceptable data to those that fit the existing (subject to
modification) theory!

That, in brief, is the message that I tried to convey at the AAAS meeting!

Jack: Indeed you did and if you look at B.J. Carr's 2008 review paper you will see I have been arguing very much the same position based on the prior reports of Libet, Radin, Bierman, Puthoff & Targ. Now Bem's data seem to put the last nail in the applicability of Orthodox Quantum Mechanics for living matter.

Can Psychical Research Bridge the Gulf Between Matter and Mind? Bernard Carr Proceedings of the Society for Psychical Research, Vol 59 Part 221 June 2008 describes my ideas on signal nonlocality violating quantum theory in living matter as well as Brian Josephson's.

see also

Subquantum Information and Computation
Antony Valentini
(Submitted on 11 Mar 2002 (v1), last revised 12 Apr 2002 (this version, v2))
It is argued that immense physical resources - for nonlocal communication, espionage, and exponentially-fast computation - are hidden from us by quantum noise, and that this noise is not fundamental but merely a property of an equilibrium state in which the universe happens to be at the present time. It is suggested that 'non-quantum' or nonequilibrium matter might exist today in the form of relic particles from the early universe. We describe how such matter could be detected and put to practical use. Nonequilibrium matter could be used to send instantaneous signals, to violate the uncertainty principle, to distinguish non-orthogonal quantum states without disturbing them, to eavesdrop on quantum key distribution, and to outpace quantum computation (solving NP-complete problems in polynomial time).
http://arxiv.org/abs/quant-ph/0203049
---------------------------------------------------------------


On Sat, 18 Jun 2011, JACK SARFATTI wrote:


On Jun 18, 2011, at 5:00 PM, Michael Nauenberg wrote:

I couldn't attend your  San Diego meeting,  but I had sent a
message to Daniel, summarized below,  which I had hoped he would share with you

Michael

Subject:  Retrodiction yes, retrocausation no.

Dear Daniel,

I won't be able to attend your meeting, but I had a brief
e-mail exchange with Jeff. The best way to summarize my disagreement with
the article of Aharanov et al. is
that standard quantum mechanics is consistent with
"retrodiction", but not with  "retrocausation". For a consistent post-selection of states
in the future, prior  statistical predictions of quantum mechanics are properly
given by "conditional" probability relations.
But the Aharanov et al. claim in Physics Today that imposing such future boundary conditions,i.e.
retrocausation, does not change  quantum mechanics
by "one iota", is not valid.

I hope these comments are helpful.

Regards, Michael

I do agree that it's retro-causal signal nonlocality that is the real revolution in physics as given by Daryl Bem's paper throwing the last nail in the coffin of signal locality. That means a violation of Orthodox Quantum Theory OQT in living systems. Henry Stapp made this clear in his talk. I have been saying for a long time what Henry now says. On the other hand, both weak measurement and Elitzur's partial measurements lead to useful technology that almost certainly would not have been thought of in the OQT way of thinking.

So if you like

retrodiction = weak retrocausality

the real beef however is

signal nonlocality ---> decodable messages received before they are sent, but only if in fact nothing prevents them from being sent in a globally consistent loop.

"A beautiful theory is murdered by an ugly fact." Richard Feynman

OQT = beautiful theory

Bem's experiments = ugly fact

(also of course Libet, Schmidt, Radin, Bierman ...)