[net.physics] The Revenge of Probabilism in QM

torek@umich.UUCP (Paul V. Torek ) (01/28/86)

Quoted without permission from Nicholas Maxwell, "Are Probabilism and
Special Relativity Incompatible?" *Philosophy of Science* 52 (1985) 23-43,
esp. pp. 36-40 [Answer to title question:  yes, and Maxwell favors 
probabilism]:

"... This [Maxwell's] approach requires that precise, microrealistic,
quantum conditions be specified for propensities to be `actualised' --
for probabilistic events to occur in quantum systems even in the absence
of measurement.  My proposed solution to this key problem is that 
probabilistic `actualizations' occur whenever, as a result of potential
particle creation or annihilation, a composite quantum system evolves
into a superposition of two states with rest masses that differ by
[delta]m.  [Sorry folks, I don't have a delta on my keyboard--pt] 
Reinterpreting the time/energy uncertainty relations, I suggest that
such a superposition persists only for a time [delta]t = h / [delta]m c**2,
and then jumps to one or the other rest mass state.  All quantum
measurements can, I argue, be interpreted as special cases of this kind
of probabilistic occurrence (see Maxwell 1976a, 1982).
:

torek@umich.UUCP (Paul V. Torek ) (01/28/86)

	"... This `propensiton' version of QT can in principle reproduce
all the empirical success of orthodox QT. ... [but/and] propensiton QT
differs empirically from orthodox QT, in principle and perhaps in practice.
This is because of the fact that propensiton QT asserts that probabilistic
events occur even in the absence of measurement, whereas orthodox QT denies
this.  In particular, the two versions of QT ought to be empirically 
distinguishable by means of experiments performed on decaying systems, such
as radioactive nuclei, of the kind discussed by Fonda et. al. (1978). ...
The two version of QT predict the same rate of decay, in the absence of
measurement, if and only if the decay rate is exponential.  For short and
long times, QT predicts departure from exponential rates of decay (in the
absence of measurement).  Thus there is here a basis -- certainly in
principle, and perhaps in practice -- for crucial experiments designed to
decide between orthodox and propensiton versions of QT.  (For further
details concerning the points of this paragraph, see Maxwell 1976a,
1982, 1984, chap. 10; and Fonda et. al. 1978.)"

Fonda, L.; Ghirardi, G. C.; and Rimini, A. (1978) "Decay theory of unstable
	quantum systems", *Reports on Progress in Physics* 41: 587-631.
Maxwell, N. (1976a), "Towards a Micro Realistic Version of Quantum Mechanics",
	*Foundations of Physics* 6: 275-92, 661-76.
----------. (1982), "Instead of Particles and Fields: A Micro Realistic
	Quantum `Smearon' Theory", *Foundations of Physics* 12: 607-31.
----------. (1984), *From Knowledge to Wisdom*.  Oxford: Basil Blackwell.

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