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Signal Nonlocality Real or Imaginary?
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Jack Sarfatti
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PostPosted: Sat Jul 08, 2006 4:33 am    Post subject: Signal Nonlocality Real or Imaginary? Reply with quote

re: http://qedcorp.com/APS/Srikanth1.jpg I have not fully understood as
yet all of Srikanth's potent remarks below. So this is only the first
comment of an emerging sequence since the objective is mind-boggling and
will have profound technological impact if Srikanth is ultimately
correct here. Too soon for me to tell. Much of the folklore of modern
physics will collapse like a heap of wilted broccoli if Srikanth and
Cramer and Woodward and Peacock and Hepburn et-al prevail. Reality will
be like the way I pictured it in the mid-1970's brilliantly irreversibly
described by Arch-Debunker Martin Gardner in MIT Technology Review 1976
and in "Magic and Paraphysics" about me and Uri Geller. That's why I am
being careful not to jump back on my old bandwagon prematurely
especially with Sharon Weinberger's example of Carl Collins's Hafnium
Isomer trigger delusion fresh in mind. We have had enough "Imaginary
Weapons" already. ;-)

On Jul 7, 2006, at 6:43 AM, Srikanth R wrote:

"Thank you for the forwards on the articles by Prof. John Cramer, which
I read with interest. I also found Ray Jensen's article on the net."

What's the URL?

On Thu, 6 Jul 2006, Jack Sarfatti wrote:

The raw pair entangled state in the above picture is, if I am not mistaken,

(y,x|A,B) = (y|-ps)(-ps|A)(x|ps)(ps|B) + (y|-pd)(-pd|A)(x|pu)(pu|B)

+ (y|-qs)(-qs|A)(x|qs)(qs|B) + (y|-qd)(-qd|A)(x|qu)(qu|B)

The two lenses on Bob's side filter the above nonlocally entangled
SIGNAL state down to

(y,x|A,B)' = (y|-ps)(-ps|A)(x|ps)(ps|B) + (y|-qs)(-qs|A)(x|qs)(qs|B)

The issue then is whether or not (-ps|-qs) = 0 or not? If the former for
both image and focal plane choices by Alice, then the experiment will
not work without the CCC, if the latter then it will. I think that's
what Srikanth is asserting?

“Indeed. In this "four-stream" model, the condition is true to the
extent that the nonlocal correlation is tight, as manifested in the
usual two-photon interference in the CCC.”

Yes.

“Thus, I think one cannot give up (-ps|-qs) = 0 without also giving up
the observed two-particle correlations observed in the CCC.”

But if (-ps|-qs) = 0 for both Alice using image plane and Alice using
focal plane, and IF in both cases we must use

Integral |y)(y| = 1

Then Bob will never see stand-alone local fringes without the CCC ever
no matter what Alice does. In other words "signal nonlocality" does not
happen and, therefore, the perfect no-cloning theorem and black hole
complementarity is saved IF orthodox quantum theory is THE FINAL
SOLUTION for physical reality - or in Einstein's words if quantum theory
really is "complete."

The real idea here is counter-factual definiteness that what might
happen even if it doesn't would be definite if it were to happen.
Therefore, the equation of completeness

Integral |y)(y| = 1

of everything Alice might have done in all the multiple branches or
parallel classical worlds add up to what Bob actually sees locally
without the CCC. That's the basic implicit subliminal
ontological-epistemological Ansatz in the orthodox thinking I think?


“To see this, for example, let us replace Bob's optics with a lens
system like Alice's. Her detection at y selects modes |-ps) and |-pd) on
her side, and leaves Bob's field in the superposition |ps) + |pu).”

Let's see if Alice filters in focal plane at y, starting from

(y,x|A,B) = (y|-ps)(-ps|A)(x|ps)(ps|B) + (y|-pd)(-pd|A)(x|pu)(pu|B)

+ (y|-qs)(-qs|A)(x|qs)(qs|B) + (y|-qd)(-qd|A)(x|qu)(qu|B)

there is a collapse to

(y,x|A,B)" = (y|-ps)(-ps|A)(x|ps)(ps|B) + (y|-pd)(-pd|A)(x|pu)(pu|B)

Bob's filter further collapses this to

(y|-ps)(-ps|A)(x|ps)(ps|B) with a random Bohm phase factor e^i@ relative
to |qs).

Which is completely disentangled. B's state is then |ps) and there is
also |qs), so I get a random mixture of |ps) & |qs) at x without any
fringes. I don't understand how you get the coherent superposition |ps)
+ |pu) at x in the picture? It seems only |ps) & |qs) make it through
the diaphragm with the hole? So let's stop here for the moment to get
this detail straight. What am I missing here?

In any case that's only a definite y for a possible thing for Alice to
do. We still must make the Sum |y)(y| according to the conventional
wisdom that does seem to fit other experiments on nonlocal EPR
pair-correlated interferometry. Let's delay discussion of the stuff
below until we get the above stumbling point settled.

“One can then show that, if Bob measures in his image plane, his twin
photon will be found in -y (above the lens' axis, on Bob's side), in
agreement with the Dopfer experiment. But if it were the case that
(-ps|-qs) not = 0, this would mean the nonlocal correlation is not
tight, so that one sees "ray-optically" that Bob's twin photon might
also be found at y (on his side), and, for the matter, at points other
than -y, in contradiction with the observed reasonably strong
correlation in the Dopfer experiment (This analysis ignores noise,
which, unless it is conspiratorially pathological, can still be taken
care of by rewording the contradiction in terms of the visibility of the
correlations, rather than of perfect correlations).

The proposed experiment could be also described in this way. The state
of the down converted light field (apart from a normalization factor)
can be written in the entangled form:
|psi) = |-pd,pu) + |-ps,ps) + |-qd,qu) + |-qs,qs)

Because of Bob's "direction filter", the state conditioned passing
thru it, is, ignoring normalization:

|psi1) = |-ps,ps) + |-qs,qs)

If Alice does not do anything, or if she measures "position", by
detecting her photon in the image plane, Bob's state is:

rho_1 ~ |ps)(ps| + |qs)(qs|,

that is, an incoherent mixture of the two modes. Hence no double-slit
pattern fringes are found. Until this point, there are no surprises.

But if she measures "momentum", by detecting her photon in the focal
plane, following the standard procedure, her measurement P is
represented as the sum over annihilation operators for the two modes.
Apart from phase factors, it is:

P = a_(-ps) + a_(-qs)
= |vac)(-ps| + |vac)(-qs|
= |vac)((-ps| + (-qs|)

Applying this to |psi1), we find that Bob's field is left in the state:

|phi2) = |ps) + |qs),

that is, the two modes are coherently related, which is why they can
interfere and Bob can observe a fringe pattern unilaterally (even
without CCC).”

OK if you really have proved that it is important. I need to think about
this. :-)

“I think the basic idea in Jensen's experiment is the same, except
perhaps that my use of a direction filter can help boost the nonlocal
signal, and may be experimentally more convenient. But it appears that
the heart of nonlocality here is that Alice's focal plane measurement is
not complete. (Her measurement at the focal plane in the {|-qs),|-ps)}
subspace consists of only one measurement operator, namely P not = 1.)”

That is, the formal issue is Alice's cross-term integral dy(-ps|y)(y|-
qs) + cc
does it vanish or not? Does its vanishing depend on whether the integral
is done in the focal plane or the image plane on Alice's side? There
will still be NOISE A photons in states -pd & -qd, but they are no
longer effectively entangled to B photons because of the two lenses with
the pinhole screen in-between, and therefore will not affect what
happens at B when Alice decides to make an image plane measurement.

On Jul 5, 2006, at 9:59 PM, james f woodward wrote:

“OK, I'm pleased to see that you tracked down R. Srikanth as his papers on
this subject are quite illuminating (so to speak). Assuming that this
will see wider circulation, I note that those papers are available on the
arXiv server in the quant-ph files: 9904075, 0101023, and 0101022.

The configuration of the experiment in 0101023 was inspired by the
Dopfer experiment (though, not having had a look at her thesis, I cited
it indirectly through Zeilinger's Reviews of Mod. Phys. article).

[....]

First, a disclaimer: I am just an innocent bystander in this business.
That said, I note that the normal "formal" argument is pretty much what
one would expect, namely, that non-local (that is FTL) signaling is
precluded so that SRT seems to be preserved by nature by denying us FTL
communications. This notwithstanding that non-local actions that we are
denied access to are otherwise permitted (without, allegedly, violating
SRT). The formal argument is based on the analysis of two pairs of
slits and a source of entangled photons. While one might argue that the
proposed experiment (and one already done that demonstrates the
functionality of the "Heisenberg" detector used by Alice in the attached
figure) can be effectively reduced to the simple two pairs of slits of
the formal argument, I note that the proposed experiment differs in
important ways from the simple formal case. The issue then is do these
differences merit the expectation that FTL signaling might actually be
possible, the formal argument notwithstanding?

Yes, indeed. The formal argument goes thru if we allow the usual
assumptions (measurement completeness in particular, but others have
been discussed, eg., by Peacock and Hepburn).

My own understanding, outlined above, is that the reason why Jensen and
my configurations work is that Alice's focal plane measurement violates
the usual (reasonable) assumption of measurement completenesss.”


That is, you claim

Sum |y)(y| = 1 does not apply there in focal plane, but it does apply in
image plane?

“Further reasons for me to believe this is that if we give it up in
order to avert the nonlocal signalling, we also end up spoiling our
ability to explain two-particle correlations _with_ CCC.

Another reason is that I am able to interpret noncomplete measurement
simply as a sort of counterfactual suppression or augmentation of the
probabilty to generate photons (in this case, entangled photons) _within
the coherence time_ of the light source. Thus it seems to have a natural
interpretation within orthodox QM. (I could elaborate this, if required).

Jensen, Cramer, and, from his comments below, Srikanth seem to think that
the Heisenberg detector based experiment might indeed sidestep the
conditions of the formal argument and make such communications possible.
Were the transactional interpretation (TI) of QM not available to square
relativity with such seeming non-local signaling, I'd probably not count
myself among those of this view. But the TI is available, and I suspect
that apparent FTL signaling may well be possible as it would not violate
SRT.

First let me point out some interesting features of the setup in Figure
1. If you add a coincidence counting circuit CCC to the setup you get
basicly the experiment done by Dopfer mentioned by Cramer (whose thesis
he has studied).”

This is the key issue. If you add the CCC of course you will see Bob's
(B) fringe visibility controlled by Alice (A) because IN THE ABSTRACT
ORTHODOX ARGUMENT (like Fred Alan Wolf suggested) the CCC filters a
coherent sub-ensemble out of the full integrated incoherent random
ensemble - that's orthodox QM, i.e. use of the CCC projects out a single
value of the integrand (A+|x')(x'|A-)(B+|x)(x|B-) + cc rather than the
local smear which is the dx' integral of the above expression. The
orthodox prediction is that Bob will never see fringes no matter what
Alice does if the CCC is switched off. The CCC is the classical key that
allows one to extract the nonlocal quantum message.

“Another interesting point (noted by Srikanth) is that if Alice's
apparatus is deactivated and only unentangled photons from the source
pass through Bob's apparatus, Bob sees interference fringes, not a
single slit diffraction pattern. Note too that Bob's detection system
is completely passive; he merely registers whether an interference
pattern or diffraction pattern is present (or accumulates in some short
interval) on his screen.

Indeed. I think I added this note in response to an early objection to
my proposed experiment, that the diffraction caused at the hole in the
direction filter would produce an interference pattern, no matter what
Alice did. While the appearance of an interference pattern is true, it
does not invalidate my argument because one can still show that the
_visibility_ in the patterns Bob observes will mutually differ.

Ultimately, the "funny business" seems to be taking place on Alice's
side, rather than Bob's, in her focal plane measurement. The direction
filter merely helps expose it but is in principle not necessary.

The active part of the experiment is the placement of her detector by
Alice either in the focal or imaging plane (1 or 2 f distant from her
lens) of her apparatus. If the detector is in the focal plane (at the
focus) of the lens, then the entangled photons produce an interference
pattern in Bob's apparatus (along with the unentangled photons in the
system). Placement of the detector in the imaging plane, however,
produces the opposite outcome: the photons, at best, produce a
diffraction pattern in Bob's apparatus as they pass through one or the
other of his slits. So detecting a signal doesn't consist of picking out
a faint interference pattern in overwhelming noise using a coincidence
counter. It is noting the degradation of an interference pattern
assisted by a coincidence counter.”

If that works I will be amazed and happy since that is close to what I
thought would be possible somehow back in the 1970's.

“It would be great if an open-minded quantum optical experimentalist
could be interested to test the modified Dopfer experiment! As pointed
out by Prof. John, this issue may be regarded as a quantum paradox that
can be resolved via an experiment. I once talked to a researcher at
Grenoble, France, who was quite interested in testing my idea. But he
has still not reported any further progress, possibly because their
current main thrust area seems to be in condensed matter physics.

This behavior is already demonstrated in apparatus with a coincidence
counting circuit (which, if the coincidence counter is required to
discriminate changes in the interference pattern, limits signal
transmission to (= c speeds). The question is: What happens in this
system if you turn off the coincidence counting circuit? Does Bob's
fringe/blob pattern visibly (detectably) change "instantaneously" when
Alice changes the position of her detector? If the answer to this
question is "yes", then apparently FTL signaling should be possible. In
other words, does turning off the coincidence counting circuit (which
only enables one to identify and separate entangled photons from those
that are not) change the behavior of the photons in the system so that
the entangled photons in Bob's apparatus are unaffected when Alice
places her detector in the imaging plane of her Heisenberg detector?
Keep in mind that upwards of 80% of the photons in the system are
entangled, so the SNR in the fringe pattern Bob sees is not one picked
out of massive amounts of noise -- thus requiring the coincidence
counting circuit as a matter of practicality.
Obviously, neither I, nor anyone else to my knowledge, know the factual
answer to this question (yet). But I'll still put a small amount of
money on the basic behavior of the system not depending on the presence
of the coincidence counting circuit.”

That's the key issue. Lenny Susskind will bet that Bob will only see
CONDITIONAL FRINGES for a fixed y selected by the CCC because if you are
right then his whole theory of information flow through black hole
horizons collapses like wilted broccoli and Hawking caved in too quickly
at GR 17.

With best regards,
Srik.

On Mon, 3 Jul 2006 20:31:35 -0700 Jack Sarfatti (sarfatti@pacbell.net)
writes:
On Jul 3, 2006, at 11:46 AM, Srikanth R wrote:
“Hi, Dr. Jack,
Thanks for the cc. Being the said "fellow called Srikanth", the
reference to my work prompts me to pen this quick note. Wink
Your point about why nonlocal signaling is not possible via
entanglement can be paraphrased also in this standard way: if
Alice and Bob share entanglement, Alice's any local operations will not
affect Bob's reduced density operator. Ergo there is no nonlocal
signaling.”

Right, so how do Cramer and Woodward get around this barrier?

“One of the assumptions that go into showing this is the very
reasonable one that Alice's any measurement on her half of the
entanglement must be _complete_: that is, a partition of unity.”

Yes, that was in my formalism.

“It must not be non-complete. If I am right about the possibility
of nonlocal signaling, it must be because my set-up on the sender
Alice's side appears to permit a non-complete measurement, when
She detects photons at a "path singularity" (by placing her detector
At the lens focus).”


That's what I called Y in

Sum of |y)(y| = 1 + Y


Y can be negative - under-complete

or positive - over complete

like Glauber & squeezed states, i.e. ODLRO AKA macro-quantum
coherence in ground states of condensed matter systems and in vacua
of relativistic quantum fields in D + 1 space-times.

“It is still not obvious to me that this kind of peculiar non-
complete measurement is not possible. For example, in a laser
experiment conducted within the laser's coherence length, I
believe noncompleteness can be interpreted as the augmentation or
suppression of the probability to generate photons, without
violating energy conservation.”

With ODLRO there is a breakdown of Born's probability rule. The
ODLRO condensate is a source and sink of particles and the condensate
itself is emergently phase-rigid.

“I have another ground to believe such noncompleteness is not
precluded. In a recent work (quant-ph/0602114, to be updated), I
suggested that locality (or, the prohibition on nonlocal
signaling) may be a consequence of the algorithmicity of the universe, i.e.,
that physical reality is fundamentally discrete and information
theoretic, and that the laws of physics correspond to efficient
"sub-physical" algorithms in the computational complexity
theoretic sense. From this viewpoint, nonlocal signaling is prohibited
because interactions enabling it would also permit computing NP-
complete problems efficiently, something that seems unlikely from
a computation theoretic perspective.”

Well you have just proved Roger Penrose's thesis that consciousness
is non-algorithmic beyond Strong AI and that the universe has a
conscious Mind of God. I mean, the facts are that signal nonlocality
exists in living matter - many experiments show that at AAAS USD
meeting. As Fred Alan Wolf says "the vacuum thinks".
If locality is indeed a side-effect of a deeper layer of physical
reality in this way, this suggests that it may be possible to
physically realize a logic gate (if such exists) that permits
nonlocal signaling but lacks the power to make NP-complete (and
presumably harder) problems tractable. I am able to show that the
noncomplete measurement of the above type indeed fits this bill.
I want to turn what you just said topsy turvy. Smile
Thanking you,
With best regards,
Srikanth

On Mon, 3 Jul 2006, Jack Sarfatti wrote:
The usual formal argument against any such scheme of direct
entanglement communication without a supplementary classical key
to unlock the locally undecodable entangled message goes like
follows.

First consider an ordinary double slit experiment with 2 slits a
& a'. The single-quantum state of A passing the slits is then

|A) = Ca|a) + Ca'|a')

where (a|a') = 0 means integral (a|x)(x|a') = 0
x is a position on the screen beyond the 2 slits.
The fringe pattern field is ~ Ca*Ca'(a|x)(x|a') + cc
If the pair of quanta A & B is entangled that means something
Like

|A,B) = Cab|a)|b) + Ca'b'|a')|b') I

for slits a & a' and slits b & b' for A & B respectively.
Note that this is different from two local independent fringe
patterns that you can have in a NON-ENTANGLED pair state like

[Ca|a) + Ca'|a')][Cb|b) + Cb'|b')]

In this UN-ENTANGLED case the Bohm quantum potential is QUASI-
LOCAL not directly coupling the different quanta of the form QA +
QB in non-overlapping sectors of configuration space in contrast
to the ENTANGLED case where the Bohm potential is manifestly
NONLOCAL having support in overlapping sectors of configuration
space of the form QAB =/= QA + QB.

The DOUBLE NONLOCAL PAIR OF FRINGES in the ENTANGLED STATE I has
the form

Cab*Ca'b'(a|x)(x|a')(b|x')(x'|b') + cc

Therefore there is no local fringe pattern at either end no
Matter what changes are made to the apparati because e.g. the local
fringe pattern at x is the integral of the above formula over all
x'. The result is zero for one of two reasons

(b|b') =0

and

Integral of |x')(x'| = 1

Therefore, this is the general FORMAL refutation of the INFORMAL
argument below. One will locally see no fringes under all
conditions. One can see the fringes in a correlation measurement
that selects out a fixed x' (i.e. a small enough region of x'
whose influence on the phase noise at x is small). Such
correlation measurement are always retarded timelike in hindsight
inside the light cone. That is, signal nonlocality is impossible within
the rules of
orthodox micro-quantum theory. Post-quantum theory breaks these
rules but limits to them in the appropriate regime in the same
way that General Relativity limits to Special Relativity when
curvature -) 0 in a space-time region.

On Jul 3, 2006, at 12:48 AM, james f woodward wrote:
“The presence or absence of fringes in the "receiver
detector" [that is, dots (no fringes) or dashes (fringes)] is determined
completely
by the local conditions of detection of the entangled photons in the
"transmitter detector" (at either 1 or 2 focal lengths from the
lens in the system there).”

The above formal argument says this initial step is wrong. If so,
then the quanta would not be entangled to begin with contrary to
hypothesis.

“This is completely independent of the temporal ordering of the
detection of the photons by the receiver and transmitter.

The temporal ordering of photon detection in the receiver and
Transmitter can be adjusted by changing the location of the source of the
Entangled photons between the receiver and transmitter.

For example, if the source is slightly closer to the transmitter than
the receiver, the
Transmitter detector will register photons first, and the state of the
Entangled photon in the receiver slightly later will clearly be determined
by the detection conditions in the transmitter.”

That’s ordinary common sense retarded causality. Beware “common sense.”

“But as the transmitter detection conditions can be changed locally, the
receiver
detection conditions will also change almost instantaneously when the
transmitter conditions are changed. FTL signaling; but no causal paradox
(as the transmitter detector acts first).”

???

“Move the source close to the receiver, however, and the receiver
registers the conditions at the transmitter at some non-
negligible time in the future. Retro-causation, for what you see at the
receiver depends on conditions at the transmitter in the future that has
allegedly not yet happened.”

The above formal argument predicts that one will only see a
uniform smear locally under all the different conditions
described here. One will only see the fringes emerge in a correlation
analysis after the fact.

“As I commented to John when I told him of Jensen's STAIF paper
(of which there is a more complete and detailed version by a fellow named
Srikanth published several years ago that I didn't know about at the
time), this opens the possibility of testing Wheeler and Feynman's "bilking
paradox" with real hardware that has already been proven in operation (by
Dopfer, as John has remarked). Smile Real experimental tests of FTL
Signaling using this elegant technique are now possible. And the results
should be just as significant as those of Aspect, et al. My money (in
small amounts) is on FTL signaling being possible (and the TI being
correct and discriminable thereby from other interpretations of QM).”

I hope Woodward and Cramer are correct on this because it would
then show that I was essentially correct qualitatively way ahead
of my time back in the 1970's (see Martin Gardner's "Magic and
Paraphysics"), but they have to show how the above formal
refutation I give above - the standard mainstream one essentially
- is wrong somehow.
-
On Sun, 2 Jul 2006 21:17:48 -0700 Jack Sarfatti
(sarfatti@pacbell.net)
writes:
Why do you think that? I hope you are right. I have not yet
Really thought about it.

On Jul 2, 2006, at 9:03 PM, james f woodward wrote:
It should work.
On Mon, 26 Jun 2006 22:45:51 -0700 Jack Sarfatti
(sarfatti@pacbell.net)
writes:
Is anyone able to refute John Cramer's gedankenexperiment for
backwards-through-time reverse causation in which the future
creates the past? I have not had time enough yet to think hard enough about
Cramer's particular proposal in this attachment from the AAAS USD
Meeting last week.
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