[extropy-chat] Note on "Random (effects without a cause)" comment

[scerir]

From: "John K Clark"
> I don't see the advantage of bringing back determinism
> to Physics if the price you must pay is something
> as un-testable as non locality.

I agree.

> People say Einstein didn't like non-determinism
> but what he REALLY didn't like is non-locality,
> the idea that you can't understand anything until
> you understand everything.

I agree again. Einstein had (1927) his own hidden 
variable model, very detailed too. But he refused 
to publish it because he soon realized it was 
deterministic but, of course, non-local.

> > QM allows, or implies, FTL signals.

> Bullshit. We know for a fact that you can change
> things at a distance much faster than light,
> it has been demonstrated in the lab, but they
> are NOT signals, you can not use the phenomena
> to transmit information.

The so called non-locality of QM (and of Nature)
is not true non-locality because it does not 
allow FTL (human) signals. It is non-separability. 
We agree on this.

What I have said is that - as shown by Bell in a paper,
and he also made several numerical simulations at CERN,
then by Eberhard, and many others - a deterministic
theory reproducing the results of (the indeterministic)
QM would imply the possibility of sending FTL (human)
signals. Signals, not mere 'influences'. [*]

s.


[*] 

It is possible to prove that. The following
maybe helps, but it is not a formal proof. 

Bell's condition (violated by QM) is:

p[A,B,lambda](x,y|i,j) = p[A,lambda](x|i) p[B,lambda](y|j)

the joint probability of outcomes x and y, for measurements
of observables i and j, in the A and B wings, is equal
to the product of the the separate probabilities. 'Lambda'
are hidden variables.

The condition above is equivalent (after Jarrett) 
to the conjunction of the following two double 
independent conditions:

Separability condition
p[A,lambda] (x|i,j,y) = p[A,lambda] (x|i,j)
p[B,lambda] (y|i,j,x) = P[B,lambda] (y|i,j)

Locality condition
p[A,lambda] (x|i,j) = p[A,lambda] (x|i)
p[B,lambda] (y|i,j) = p[B,lambda] (y|j)

The separability condition is violated by QM
and by experiments.

A deterministic theory reproducing all the results
of QM does violate Bell's condition. So it does 
violate the separability condition or the locality 
condition.

But a deterministic theory reproducing all the results
of QM cannot violate the separability condition.
Because if (see the right hand of sep. cond.) 
the specification of lambda, i, j, determines completely 
the outcomes x, y, then any additional conditioning on
x or y (see the left hand of sep. cond.) is superfluous, 
having x and y just one value allowed (so they
cannot affect the probability) which (in such 
a deterministic theory) can take just values 0 or 1. 

Hence a deterministic theory reproducing all the results
of QM does violate the locality condition. Such a
violation implies FTL signals.