Tue, 30 Nov 1999 00:37:09 +0100
Stephen Paul King wrote:
> I believe that the grandfather paradox is
> unsound since it tacitly implies the ability to violate the second law,
> e.g. it would be possible to create a Maxwell Daemon in the form of a
> computer program that, given the information representing the exact
> future states of the hot and cold "sources" of an adiabatic engine and
> controlling the "valve" connecting the two, that it could generate more
> work that would be possible otherwise; it would be at least 100%
> efficient! So this implies a strong but subtle connection between the
> thermodynamics and computational pictures of q-jumps between
> superpositions of "macroscopically equivalent" spacetimes.
This discussion harks back to Boltzmann H-theorem, which played a
crucial role in the development of black body theory and hence in the
birth of quantum theory. We all know that Planck's radiation law is
obtained maximizing the entropy of the radiation's energy spectra.
Continuous spectra yield the Jeans-Raleigh law. Discrete spectra yield
Planck's law. Discrete spectra however refer to possible energy
measurements. Planck's law is the result of entropy maximization on the
set of possible energy measurements under the assumption that the
resonators absorb and emit energy continuously.
Continuos process, discrete measurement, entropy maximized on the set of
This striking inconsistency, which was recognized immediately by
Einstein, is at the core of the wave-particle dualism. It also tells
something about the relationship between observer and second principle.
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