Which universe are we in? (tossing tennis balls into spinning props)

[Tim May]

On Tuesday, July 16, 2002, at 10:39  AM, Peter Fairbrother wrote:
>
> Oh dear. QM does rule out internal states.
>
> I didn't think I would have to explain why I capitalised "Bell", but 
> perhaps
> it was a bit too subtle. Google "Bell" and "inequalities", and go from
> there.

I disagree. Bell's Inequality is not dependent on QM...it's a 
mathematical statement about the outcomes of measurements where 
stochastic processes play a role. The fact that QM is strongly believed 
to involve stochastic processes is why Bell's inequality shows up 
prominently in QM. However, we cannot then use B.I. to prove things 
about QM.

A more persuasive proof of why hidden variables are not viable in QM is 
the work done on extending some theorems about Hilbert spaces. Namely, 
Gleason's theorem from the mid-50s, later extended by Kochen and Specker 
in the 1960s. The Kochen-Specker Theorem is accepted as the "no go" 
proof that hidden variables is not viable.

>
> The uncertainty principle was generally considered to rule out internal
> states long before Bell, though. Since around 1930, I think. Whether 
> QM/the
> uncertainty principle is wrong is a different question.

Until K-S and related proofs, Bohm's internal states model (hidden 
variables) was not considered to be ruled out.

I recommend a recent book, "Interpreting the Quantum World," by Jeffrey 
Bub, 1997. He summarizes the various interpretations of quantum reality 
and explains the K-S theorem reasonably well. The Asher Peres book on QM 
is also good.

But, as I said, I accidentally beamed the message into this world. Those 
interested in discussing quantum reality and things like that should 
look into lists oriented in this direction. I don't think most list 
members here have the interest or the background, so discussions would 
be swamped by failures to communicate, abuses of language, and tangent 
rays.

--Tim May
"They played all kinds of games, kept the House in session all night, 
and it was a very complicated bill. Maybe a handful of staffers actually 
read it, but the bill definitely was not available to members before the 
vote." --Rep. Ron Paul, TX, on how few Congresscritters saw the 
USA-PATRIOT Bill before voting overwhelmingly to impose a police state