Comments on Soul Physics: An argument for hidden variables

Excellent point about the SG experiment, I had for...

2010-05-17T19:44:21.517-04:00

Excellent point about the SG experiment, I had forgot to consider that. Combined with Bell's inequalities they show that no amount of variables hidden within the wave function being measured can account for the quantum indeterminacy. That, in my mind, forces the possibility that many worlds works (at least sometimes).

So it would seem that chaos can only serve to magnify the role of the external stochastic variables...

The lack of an argument for (3) leads me to believ...

2010-05-17T15:37:24.489-04:00

The lack of an argument for (3) leads me to believe that they believe it on principle. My only concern is that your counter-example won't impress someone who holds (3) on principle. Still, this is their problem, not yours.

Sure Noah -- but that's not enough to imply th...

2010-05-17T15:02:36.253-04:00

Sure Noah -- but that's not enough to imply their conclusion. I don't see how their argument can work unless they assume that if one consequence of the fundamental law is deterministic (e.g., Schrodinger evolution), then every other consequence is as well (e.g., the measurement process). And that assumption seems wrong, for the reasons I outlined above.

It looks like (3) is something you would want at f...

2010-05-17T14:58:02.802-04:00

It looks like (3) is something you would want at first glance. If you are in the business of finding fundamental physical laws then wouldn't you want to find some very basic fundamental law that governs all the physical processes?

Good -- it does seem this argument leads just as n...

2010-05-17T06:52:33.905-04:00

Good -- it does seem this argument leads just as naturally to dynamical collapse theories like GRW. Knowledge of the stochastic parameter then becomes the "missing information."

I don't quite see how quantum chaos can help though. Care to elaborate? How does this explain the indeterminism observed (say) in a Stern-Gerlach measurement?

Eh, not entirely convincing, I think. First, they ...

2010-05-17T00:06:24.780-04:00

Eh, not entirely convincing, I think. First, they fail to rule out quantum chaos as a contributor, second they fail to rule out the influence of external stochastic variables. In the first case, small imprecisions in the specification of the wave function should be magnified to make for an unpredictable outcome (at least if quantum chaos is like classical chaos, and I confess I have no idea if this is actually the case). In the second case the influences of 'external' forces is sufficient to cause indeterminacy the same way thermal noise does classically.

In either case the variables aren't so much 'hidden' as either beyond our reach or ignored out of necessity.