On 6 January 2014 06:47, John Clark <johnkcl...@gmail.com> wrote:

> On Sun, Jan 5, 2014 at 12:20 PM, Jason Resch <jasonre...@gmail.com> wrote:
> > Bell's theorem holds only under a certain set of assumptions,
> True. As I've said many times Bell made exactly 3 assumptions:
> 1) High School algebra and trigonometry works.
> 2) Things are local.
> 3) Things are realistic.

In fact Bell made a fourth assumption, although he didn't realise he was
making it until later. Namely, he assumed that time is asymmetric (i.e.
that it's possible to tell which time direction is the past and which is
the future *at every level*). This assumption contradicts a lot of
empirical measurements at the quantum level, and as Bell later agreed (in
correspondence with Huw Price), if hsi 4th assumption is dropped (i.e. if
he assumes time symmetry *at any level*) then that will *also* lead to his
inequality being violated. So add to the list:

4) Time is asymmetric not just at the level of everyday experience, but
also at the quantum level

Dropping Bell's 4th assumption is one way to "fix" the violation of Bell's
inequality while keeping all the above assumptions. That is, assumptions
1-3 listed above can still hold IF the particles being measured are subject
to time-symmetric laws of physics.

The jury is still out on which of Bell's 4 assumptions should be dropped.
Bell himself considered time symmetry to be too weird to be the one that
should go, however a lot of experimental evidence suggests that the quantum
states used in EPR experiments do indeed operate time-symmetrically (i.e.
can be influenced by boundary conditions in both the past and the future).

Bell's 4th assumption seems to me quite a reasonable one to drop, given
that most physics contradicts it.

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