🚀 go-pugleaf

In article <654@pbhyc.UUCP> djo@pbhyc.UUCP (Dan'l Oakes) writes:
>In article <19045@ucbvax.BERKELEY.EDU> kube@cogsci.berkeley.edu.UUCP (Paul Kube) writes:
>
>>As it turns out, relative frequencies of outcomes observed in certain
>>experiments violate the inequality.  This prima facie shows that
>>either there are superluminal signals or there's a strange
>>indefiniteness to particle state (coincidentally of the type required
>>by a noninstrumentalist interpretation of QM).  
>
>Or that QM is simply inadequate.  You've thrown that possibility out the
>window unexamined.

This shows you haven't understood what I've been saying.  That's easy enough
to do, so I'll try again:

I've been mainly interested in discussing the implications of Bell's
inequalities.  Far from neglecting the possibility that QM is "simply
inadequate", the inequalities *assume* that it is: one of the
assumptions in their derivation entails that there are hidden variables
not countenanced by QM.  And the other assumptions are pretty
innocent: that there are no superluminal signals, that probability
theory is consistent; stuff like that.  Now do the experiments; alas,
the inequalilties are violated.  So it would seem (assuming the
experiments aren't cooked) that either there are superluminal signals,
or that there are no hidden variables, or that probability theory is
inconsistent.  All this without assuming QM is true.

(So far I can't see much mathematical arrogance in the argument, no
overinterpretation of the formalism.  But again, if you can point to
some reason for supposing this application of probability theory is
infelicitous, do so.)

So, no dependence on QM so far.  But there are implications for the
interpretation of QM.  It has always been tempting to interpret QM
instrumentally.  I take it that you also want to interpret QM
instrumentally; your reason seems to be that it's incredibly arrogant
to do otherwise, no matter how well confirmed QM is.  A more common
reason to opt for the instrumental interpretation is that a realistic
interpretation requires giving up some cherished conceptual
underpinnings of understanding and explanation, viz. determinism and
definiteness; these are retained on the hidden-variable
interpretation.  The importance of the tests of Bell's inequalities is
that they apparently remove this reason for wanting an instrumental
interpretation of QM, because they show you can't get determinism and
definiteness anyway (except at the cost of doing without special
relativity).  Of course you are still free to opt for an instrumental
interpretation, though, again, it would be nice to hear arguments for
it (hint: look in Bas C. van Fraasen, _The Scientific Image_).  God
knows there's too much wrong with QM for it to be right...

I will now stop repeating myself.

>To say that the mathematics is "inadequate" is not equal to saying that
>it "fails to correspond to reality."  Newtonian physics corresponds to
>reality, within its limits.  When applied to relativistic speeds, masses,
>etc., however, Newtonian physics becomes inadequate.

In what sense does it become inadequate in relativistic applications other
than failing to correspond to reality there?

>I suggest that something similar is taking place here:  that QM corresponds
>to reality, within its limits; but that, just as the level of interpretation
>and observation once showed Newtonian physics inadequate, so now QM is proving
>inadequate under certain conditions.

What conditions are these?  Its observational adequacy remains unchallenged.
If you mean its adequacy for generating understandable explanations---well,
the Bell's experiments seem to show we may have to do without that from
any observationally adequate theory.

--Paul kube@berkeley.edu, ...!ucbvax!kube