- #1
vzn
- 17
- 0
hi all in another recent thread there was an epic battle between
a local realist & a qm formalist. good theatre. but a stalemate in
the end.
I would like to post just a few key recent refs I was reminded of by that
thread, which might be useful for anyone interested in the area. from
your pt of view, either the LHV position is increasingly untenable for
anyone other than fanatics. or, another idea-- there is only a very
narrow slice of LHV theories remaining that have not been ruled out so far,
which have to have a higher degree of sophistication than some of the
"toy models" considered by bell.
more discussion on the "qm2" mailing list
http://groups.yahoo.com/group/qm2/
a. phd & nobel prize winner t'hooft is working on LHVs somewhat
recently which can be found in this paper. the idea is to use a set
of simple harmonic oscillators as the hidden systems. this would tend
to refute the idea that there is no point in working on LHVs, that the
whole matter is closed, that there is no possibility, etc. some other
researchers are already building on it
How Does God Play Dice? (Pre-)Determinism at the Planck Scale
http://www.arxiv.org/abs/hep-th/0104219
b. I think bell came up with a wonderful analysis of this problem but
in my opinion his form of the LHV is too strict. (or equivalently, you
can see it as ruling out all but a very restricted class of LHVs, which
have not been explored too much). let's look at the probability
distribution of the single hidden variable as we rotate analyzers in the
bell experiment. bells proof assumes this distribution does not change
as their difference angle changes. reasonable for a toy LHV model.
however there do exist LHV models such that the lambda probability
distribution can change as the analyzers change. the details are subtle
but mostly unexplored. therefore it makes a lot of sense to look
at LHV theories that are maximally compatible with the predictions of QM.
c. a very neat experiment purports to do a "efficient detection" of
a bell experiment for the 1st time. published in nature.
"experimental violation of a bells inequality with efficient detection"
by rowe et al, 2001. link to the paper & my analysis of this here.
http://groups.yahoo.com/group/qm2/message/9730
basically I agree its a
beautiful tour-de-force qm experiment which measures what it
purports to measure, but from the pt of view of bell rigor, the experiment
is very much lacking in rigor. the authors trapped two ions in an
atom trap. but the bell experiment consisted of a single laser and single
detector for BOTH ARMs of the experiment, which are traditionally at
least spatially separated!
d. it seems to me the ultimate hidden variable in QM is simply
"phi", the phase angle in the wavefn. it appears EVERYWHERE in
qm derivations yet the theory denies that it can be measured. suppose
there were some new theory that proposed that phi could somehow
be measured via some clever advancements (theoretical/experimental).
phi is clearly a hidden variable in QM--therefore "HVs" cannot
be so controversial. the major problem is figuring out how
to make a theory in which you have "locality", LHV.
a local realist & a qm formalist. good theatre. but a stalemate in
the end.
I would like to post just a few key recent refs I was reminded of by that
thread, which might be useful for anyone interested in the area. from
your pt of view, either the LHV position is increasingly untenable for
anyone other than fanatics. or, another idea-- there is only a very
narrow slice of LHV theories remaining that have not been ruled out so far,
which have to have a higher degree of sophistication than some of the
"toy models" considered by bell.
more discussion on the "qm2" mailing list
http://groups.yahoo.com/group/qm2/
a. phd & nobel prize winner t'hooft is working on LHVs somewhat
recently which can be found in this paper. the idea is to use a set
of simple harmonic oscillators as the hidden systems. this would tend
to refute the idea that there is no point in working on LHVs, that the
whole matter is closed, that there is no possibility, etc. some other
researchers are already building on it
How Does God Play Dice? (Pre-)Determinism at the Planck Scale
http://www.arxiv.org/abs/hep-th/0104219
b. I think bell came up with a wonderful analysis of this problem but
in my opinion his form of the LHV is too strict. (or equivalently, you
can see it as ruling out all but a very restricted class of LHVs, which
have not been explored too much). let's look at the probability
distribution of the single hidden variable as we rotate analyzers in the
bell experiment. bells proof assumes this distribution does not change
as their difference angle changes. reasonable for a toy LHV model.
however there do exist LHV models such that the lambda probability
distribution can change as the analyzers change. the details are subtle
but mostly unexplored. therefore it makes a lot of sense to look
at LHV theories that are maximally compatible with the predictions of QM.
c. a very neat experiment purports to do a "efficient detection" of
a bell experiment for the 1st time. published in nature.
"experimental violation of a bells inequality with efficient detection"
by rowe et al, 2001. link to the paper & my analysis of this here.
http://groups.yahoo.com/group/qm2/message/9730
basically I agree its a
beautiful tour-de-force qm experiment which measures what it
purports to measure, but from the pt of view of bell rigor, the experiment
is very much lacking in rigor. the authors trapped two ions in an
atom trap. but the bell experiment consisted of a single laser and single
detector for BOTH ARMs of the experiment, which are traditionally at
least spatially separated!
d. it seems to me the ultimate hidden variable in QM is simply
"phi", the phase angle in the wavefn. it appears EVERYWHERE in
qm derivations yet the theory denies that it can be measured. suppose
there were some new theory that proposed that phi could somehow
be measured via some clever advancements (theoretical/experimental).
phi is clearly a hidden variable in QM--therefore "HVs" cannot
be so controversial. the major problem is figuring out how
to make a theory in which you have "locality", LHV.