FOM: Reply to Pratt: Einstein, determinism, uncertainty

Fri Mar 6 10:45:36 EST 1998

We are apparently using the word "determinism" in different senses.  Let me
clarify:  The less problematic form of indeterminism is the non-unique
dependence of the future on the present.  This is exemplified by a sample of
a radioactive isotope in which a COMPLETE specification of the physical state
still does not tell you when and in which atom the next decay will occur.
Although Einstein believed the universe was not indeterminate in this sense
(the "God does not play dice" quote), it could be without violating his
philosophical requirement that a physical theory be "local" and "realistic".
The Heisenberg uncertainty is the more problematic form of indeterminism--
quantum mechanics claims not only that a particle's position and momentum can't
be precisely measured simultaneously, but that they don't EXIST simultaneously.
EPR rejected this with the argument you recapitulate; but Bell showed EPR's
locality and realism assumptions were inconsistent with QM's predictions and
experiment supported QM.  Bell rejected locality and deplored the orthodox but
"unprofessional" alternative of rejecting realism.  -- Joe Shipman

More information about the FOM mailing list