🚀 go-pugleaf

Good ole' 92223.112308MRG3 writes:

An analysis of the physical description of Sarfatti's spin-flip mechanism.
I know this is redundant and obvious to almost anyone who has taken
the usual first year quantum courses, but I just had to...

Abstract: I show that the proposed description of the spin-
flip device can either be local or unitary, but assuming both
leads to a contradiction.  Hence, if the description is the
"correct" quantum mechanical one it is the nonlocal nature of
the spin-flip which gives rise to FTL communication, NOT
quantum entanglement.

Evolution in quantum mechanics is given by unitary
transformations on the hilbert space of vectors associated
with the possible state of the system.  

[Excellent intro to quantum theory omitted]

The transition in question is
(|v1>|v2> +|h1>|h2>)/sqrt2 -> (|v1>e^(i phi) +
|h1>)|v2>/sqrt2
It is elementary to show that this is norm preserving in that
the initial state has the same norm as the final state (and
is equal to one) so that probability is conserved.  

-----
Okay, maybe this is a case of a typo but yet again I have to note that
this transformation is NOT unitary, since the h2 that appears on the
left side is simply MISSING from the right side.  A transformation that
is not 1-1 cannot be unitary.

It seems, by the way, that Sarfatti knows his transformation is unitary
and couldn't care less:

In article <BssCHF.JxB@well.sf.ca.us> sarfatti@well.sf.ca.us (Jack Sarfatti) writes:

>to Mike Gallis MRG3@PSUVM.PSU.EDU
>EXORCISING THE UNITARITY DEMON
>
>#1 your argument [ |v> - |h>]/sqrt2 -> 0 does not describe the behavior of
>my
>device. I showed that earlier.
>
>#2 The mistake you keep making is to take a fragmentary view. You keep
>saying that the matrix is not unitary. So what! I am using both Feynman
>rules
>from preparation to irreversible detections and this process is not unitary.
>If you
>want to describe the total behavior of my device then of course the matrix
>from
>start to finish is not unitary because of measurements!
>
>Feynman gives us two rules to do standard quantum mechanics. The first rule
>corresponds to your much beloved unitary evolution but you forget that
>unitary
>evolution is only true between preparation and detection. Feynman's unitary
>rule is:
>Unitary rule: Add amplitudes before squaring for indistinguishable
>histories.
>
>Feynman's non-unitary measurement rule is:
>
>Measurement rule: Square amplitudes before adding for distinguishable
>histories.
>
>Why do you, and others for that matter, have such tunnel vision and exclude
>the detection processes?
>
>#3 It is not good enough to present irrelevant formal arguments that the
>matrix
>is not unitary. It is not supposed to be unitary since I have a complete
>solution
>of the problem including the irreversible measurements at the four
>detectors.

Well, you can call what you are doing "standard quantum mechanics" and
cite Feynman if you like, but the nonunitarity of your process goes
against what I'd call "standard quantum mechanics" and a clear symptom
of that fact is that you claim that you can get faster-than-light
communication!  I would urge you to stop arguing and build a device
which does this feat you claim it can do.  If you can do it and others
can repeat the experiment, you'll be famous.  If you can't do it... I
won't be surprised.