Some further thoughts on the strangeness of quantum strangeness follow.
Quantum entanglement, coordination of values at a distance, and
quantum erasure are a well known concepts. However, the other sides
of these coins are not generally recognized. The other side of
quantum entanglement I defined as FTL statistical “discorrelation” here:
http://www.mtaonline.net/~hheffner/BellEPR.pdf
The existence of quantum erasure or "history history erasure" implies
the existence of an effect I described and named here as "quantum
waveform resurrection":
http://mtaonline.net/~hheffner/FTL-down.pdf
The conservation of energy and momentum as well as the locality of
energy and momentum are important issues with regard to the FTL by
down-converting experiment proposed above.
First, the locality issue. It is generally thought the quantum
wavefunction can not transport either energy, momentum, or
information. Perhaps this notion is partially based on the fact that
instantaneous action at a distance by a momentum possessing entity
implies the use of an infinite force to get the entity to move
infinitely fast. Otherwise, we must accept the potential of
instantaneous projection at a distance of energy and thus mass, matter.
Information must ultimately reside in a physical form to exist or be
utilized in a given location. The transfer of information is thus
inherently the transfer of an energy and/or momentum state change at
a remote location. If Alice is to transfer information to Bob then
she must ultimately change the momentum or energy states of matter at
Bob's end. This transfer, the change of momentum or energy states at
Bob's end, by a quantum wavefunction not carrying any energy or
momentum, can only happen if (a) the influence of the quantum
waveform at Bob's end does not directly (or at least detectably)
affect either energy or momentum anywhere at Bob's end and thus (b)
the accomplishment of any state state change made is made using
energy or momentum supplied entirely by Bob.
The assumption of the locality of energy and momentum then appears to
allow one to "prove" the impossibility of the proposed information
transfer via the collapse or resurrection of the quantum waveform,
especially via the method of quantum history erasure shown in Fig. 1
below. By the assumption of no energy or momentum transfer, it is
provable that nothing Alice can do at her end of the experiment as
diagramed in Fig. 2 can possibly affect what Bob sees, unless somehow
Bob supplies the energy or momentum so that he can do so. Since Bob
supplies no energy or momentum to the light interference pattern at
his end, it can thus be "proved" that pattern can not be changed
immediately by anything Alice does, assuming Alice is far enough
away. Under the assumptions, it can be proved that the light pattern
Bob observes can never be changed because Bob has no means to provide
the energy or momentum required for it to change. This is
independent of the fact he can't know when to take action based on
Alice's actions of which he is unaware.
Kim et al have showed that the pattern created by sub-populations of
photons can indeed be changed via history erasure or scrambling.
When this happens, the pattern created by the remaining population of
photons at Bob's end, the photons with histories not erased, must
also change, otherwise a detectable change in the overall pattern
results. A change in overall pattern can result in energy or
momentum transfer, state changes in localities, sensors, in Bob's
domain. A change in beam intensity at a specific spot where the
interference pattern is projected, especially an alternating change
in intensity, results in changes in both the energy and momentum
being transferred to that spot. If Bob cannot receive any useful
information from Alice it must be true that the momentum and energy
transferred to *every* spot in Bob's pattern detection surface must
be unchanged at all times.
The assumptions certainly do seem to fall down when applied to the
sub-populations of photons, the momenta of which are statistically
affected on a one-by-one basis. Much more thought on these issues is
required.
Now brief consideration of *overall* energy conservation.
To review, Fig. 1 shows how an idler from one beam can be (was) mixed
into another idler beam, scrambled, so as to lose its history.
Full Mirror
R1--->-------------\
|
| Half Mirror
L1---->------------\----------------------DL
|
|
DR
Fig. 1 - Alice's which-path scrambler
The fact that detector DR and DL can not determine whether an idler
came from R1 or L1 in Fig. 1 *erases its history* and permits the
corresponding signal photon to experience the quantum wavefunction
for interference. DL detects half its particles from R1 and half from
L1, as does detector DR. When the corresponding signal photon
pattern is tallied for all the photons detected by DL and DR, an
interference pattern is observed. The history of *every* photon
passing through the scrambler thus must be erased, even those which
pass straight through the half-mirror, i.e. Alice's beam splitter.
The scrambler in Fig. 1 can be repeated in series if necessary to
compensate for imperfect beam splitting ratios, imperfect beam
overlap, and other problems.
Now, looking at this not from a one-photon-at-a-time perspective, but
merely from a coherent wave perspective, consider what happens if we
can arbitrarily adjust the path length of R1 as compared to L1 before
the beams are merged, and thus adjust the phase relationship of the
two beams before they are merged. This creates some interesting
questions. For example, if the two beams are 180 degrees out of
phase, then no beams can emerge for detection at DR or DL? To
conserve energy, they must be reflected back to their source. If the
photons (light waves) are not reflected back to their source, but
rather they cancel, then energy is not conserved at Alice's end?
However, the reflection back seems a bit paradoxical in that in one-
photon-at-a-time mode there is nothing to reflect the individual
photons back to their source. Is it possible the phase relationship
involved in the history erasure affects or enables an amount of
energy or momentum available for transfer to Bob?
In any event, it seems that the phase relationship established in
Fig. 1 might be critical to the transfer of information. It
certainly is true that if photons are somehow completely dissolved by
Alice then this is a good reason for the histories to dissolve as
well. If Alice can dissolve photons, then overall conservation of
energy requires that energy to materialize somewhere else, and it
would seem entangled photons at Bob's location might be the only
viable candidate.
In any event, if information can be transferred it appears a means
for energy transfer, however small, might be involved.
I have to wonder if, in the actual Kim experiment, light reflected at
Alice's scrambler somehow makes it over to Bob's location and thereby
affects the interference pattern detected. The Alice and Bob parts
of the Kim experiment are not located far from each other.
Now having some fun on the purely speculative side:
FTL modulation of an interference pattern, if possible, has potential
military applications beyond FTL communications. FTL communications
in the proposed manner might be of very limited immediate practical
use given the technical and economic complications, despite the
momentous scientific impact. An important potential is that it may
be possible to cut scanning lidar signal delays in half. This would
be accomplished by broadcasting using phased arrays, the interference
pattern of which is modulated by quantum wavefunction collapse/
resurrection means. The location of a target then does not require
two-way travel delays for the detection signal, only the delay for
the return signal. A lateral (side moving) equivalent to doppler
capabilities is then possible. Lateral velocity could be sensed by
the amplitude oscillation pattern of the returning signal. A change
in scan based on received signals does not then have to wait for the
new scan pulses to arrive at the target to obtain a modified reflection.
Don't ask me what any of this means. I wrote most of it some years
ago and my memory is just not that good. 8^)
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
