[Fis] Reply to Igor and Aleks

Dear Michel,
If you'll permit, I'll include two replies in this one message.

Dear Igor and colleagues,
I agree with you that information concerns a violation of uniformity,
though I would refine the idea, perhaps, to improbability. Which, I
think, would align the notion with what von Neumann and Shannon taught.
I hope I�m starting to understand what you mean by tokenization. I read
it as those variables which can be used to specify particular physical
configurations. Like the various words one might choose to convey the
meaning of a sentence. In physics, I interpret your idea as the
variables we use to stipulate the configuration of physical objects. In
thermodynamics, position, energy, and momentum, say. Now, I�d expand the
list with the time variable also.
So, the entropy of an ideal gas, for example, is a function of the range
of position and momentum values available to each molecule. Using
position and velocity as �tokens� would, as I understand it, imply a
relatively high information content for a crystal, not the opposite,
Since the position and velocity of those molecules is restricted. I
suppose it would be possible to convey information by establishing that
we�ll choose dark chocolate for dessert if there is a molecule at (or
within a limited range of) a certain location relative to the corner of
the crystal; and choose milk chocolate otherwise. It�s like placing a
mark at a specific location on a blank sheet of paper. The gas molecules
don�t carry such information, do they?
Cordially,
Michael

Dear Aleks,

Thanks. I agree with you about the importance of changes over time in
concepts like �dog� and such, and also think the question whether
physical constants and physical laws are time invariant is a crucial
one. I believe that cosmologists and other scientists have investigated
the question and actually done some measurements. If I recall, changes
in certain physical constants, for example, would mean evolution to a
very different physical universe than the one we observe now. Likewise
for changes in certain physical laws. General relativity, I believe,
teaches that space itself is not invariant, but has actually expanded
since the time of the big bang, and is shaped by the massive bodies in
the universe.
Specifically, the Szilard engine apparatus records a series of
information bits, just like a computer, though here one uses L and R,
rather than the 1, 0 symbols usual in computing. (Charles Bennett, and
others, have used the Szilard engine as their model of a computer memory
register.) A certain kind of measurement during the engine cycle allows
it to do macroscopic work, just as a gasoline engine can do work. The
bits written to the engine apparatus by measurement are always randomly
distributed, say, (R,L,L,R,L,R,......) and measurements occur
sequentially, after a certain average time interval, Delta-t. So, the
question is, where is the new information to run the engine, if the
memory register always shows a different, but random, distribution of R
and L? The answer is this: after the particular measurement which
permits engine operation, the register repeats the same sequence of R
and L, then repeats it again, and again, etc.
I interpret this as a time signal. At any instant in time, there is
nothing to distinguish one register output from another, but when the
sequence is repeated, in time, the engine operator recognizes an
improbable occurrence in time which actually indicates the operating
fluid of the engine is compressed to a particular side of each cylinder,
and can now do macroscopic work. I think this improbable occurrence in
time indicates an entropy decrease. Does anyone else buy that argument?
Or not?
Thanks,
Michael

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Received on Thu Apr 8 07:23:22 2004