Nick Herbert's refutation below is specious, he needs to address himself specifically to mathematical model

|z)'s are Glauber states

Sanders's state at the outputs of the Kerr-Mach-Zehnder interferometer has the general form (I have changed notation conventions slightly)

|a',b') = |z1a')|z2b') + |z3a')|z4b')

The projection operator is

rhoa'b' = |a',b')(b',a'| = |z1a')|z2b')(b'2z|(a'1z| + |z3a')|z4b')(b'4z|(a'3z| + |z1a')|z2b')(b'4z|(a'3z| + |z3a')|z4b')(b'2z|(a'1z|

The partial trace over a' consists of 8 terms of which there are only 2 in the orthodox quantum orthogonal base case. The 6 anomalous terms are the entanglement signal evading Stapp's proof.

Tra'{rhoa'b'} = (a'1z|rhoa'b'|z1a') + (a'3z|rhoa'b'|z3a')

= |z2b')(b'2z| + + |z4b')(b'4z| + (a'3z|z1a')|z2b')(b'2z|(a'1z|z3a') + (a'1z|z3a')|z4b')(b'4z|(a'3z|z1a')

+ |z2b')(b'4z|(a'3z| z1a') + (a'z3|z1a')|z2b')(b'4z| + (a'1z|z3a')|z4b')(b'2z| + |z4b')(b'2z|(a'1z|z3a')

the first two terms are what you get in Stapp's proof, i.e. no local fringes for momentum correlations and no controllable polarizations for spin experiments like Aspect's.

Let x be the position of a photon detector at a place where the two components of the b' beam overlap. The nonlocally controllable fringe pattern is simply

(x|Tra'{rhoa'b'}|x)

That is, Nick needs to show

1) mathematical errors

2) errors in my physical interpretation of the meanings of the symbols - especially the last line

local fringe pattern for the superposed b' alternatives = (x|Tra'{rhoa'b'}|x)

any good experimentalist in quantum optics can design a suitable system to test this - that's not my job here.

Clauser could easily do it, or Aspect for example. Note also

Nonlocal Effects of Partial Measurements and Quantum Erasure

Avshalom C. Elitzur, Shahar Dolev

(Submitted on 18 Dec 2000)

Partial measurement turns the initial superposition not into a definite outcome but into a greater probability for it. The probability can approach 100%, yet the measurement can undergo complete quantum erasure. In the EPR setting, we prove that i) every partial measurement nonlocally creates the same partial change in the distant particle; and ii) every erasure inflicts the same erasure on the distant particle's state. This enables an EPR experiment where the nonlocal effect does not vanish after a single measurement but keeps "traveling" back and forth between particles. We study an experiment in which two distant particles are subjected to interferometry with a partial "which path" measurement. Such a measurement causes a variable amount of correlation between the particles. A new inequality is formulated for same-angle polarizations, extending Bell's inequality for different angles. The resulting nonlocality proof is highly visualizable, as it rests entirely on the interference effect. Partial measurement also gives rise to a new form of entanglement, where the particles manifest correlations of multiple polarization directions. Another novelty in that the measurement to be erased is fully observable, in contrast to prevailing erasure techniques where it can never be observed. Some profound conceptual implications of our experiment are briefly pointed out.

On Jul 9, 2011, at 10:31 AM, JACK SARFATTI wrote:

OK here is an attempt by Nick.

It's wrong in my opinion. Nick is taking an all or nothing approach.

It's plausible that there is plenty of room to have partially distinguishable Glauber states with a detectable entanglement signal.

The point is no one seems to have noticed this obvious formal loop hole in the class of "Stapp proofs".

Nick's attitude is let's not even investigate this possibility.

On Jul 9, 2011, at 2:09 AM, Nick Herbert wrote:

Plan for a refutation of an ill-formed FTL scheme:

1. Note that the putative FTL effect works

only because of the non=orthogonality of the alpha and beta states.

If the FTL effect exists,

it occurs only where alpha and beta overlap.

2. But if Bob's received signal depends on his ability to distinguish

alpha photons from beta photons, then this ability will disappear

in the region where alpha and beta distributions overlap.

3. Thus the very region where we might expect FTL effects to occur.

happens to coincide with the region in which Bob cannot distinguish a "1" bit from a "0" bit.

When and if Jack comes up with a specific design for his FTL Sarfatti EGO machine,

I humbly suggest this as a fruitful direction for him to look for its possible refutation.

Category: MyBlog

Published on Saturday, 09 July 2011 11:22