My earlier recommendation of book by Roland Omnes on quantum
interpretation may have been wrong -- I might have meant the book by
Max Jammer instead.
I took a look at L.S.Schulman: Times arrows & quantum measurement,
Cambridge UP 1997.
His first page (xv) says "idea first suggested by Thomas Gold 1958:
the local thermodynamic arrow of time is a consequence of the
expansion of the universe."
Page 2 he says this is "stark power of a great - nearly obvious - truth...
but others consider Gold's thesis neither obvious nor true. Moreover
despite my admiration, I find Gold's argument flawed. It is a subtle
flaw..."
By the way, I do not recall Zeh's book even broaching this whole
subject, presumably because Zeh considered it to be garbage. Zeh's
book strikes me as far superior to Schulman's but unlike Schulman does
not attempt to take a stance.
LSS claims he is going in ch4 to explain/elaborate Gold to deduce that
the cosmo-expansion and 2nd law time arrows both must be aligned. He
also claims ch6 is the "other heart of his book" and it presents his
own quantum measurement theory. ch11 overviews.
Turning to ch4 he explicitly says "Coffee cools because the quasar
3C273 grows more distant." Well, I have to congratulate LSS on his
courage -- he certainly is up front with his outrageous garbage. LSS
says he is going to impose "two time boundary conditions" which is
something that physicists almost never do and already seems extremely
suspect.
In 4.1 he says "the issue is not whether systems move from uncommon to
common states
but why uncommon came first." Well, no. In my picture, there is an
observable and unobservable part of the universe, and we must average
over the states of the latter when observing the former, and the whole
ball of wax is always in one state (and that one state cannot be said
to be "common" or not, that word has no meaning).
So LSS here does not understand the picture.
(Also in my picture it is no paradox if the universe "must have begun
in a low entropy state,"
I still am ok with high entropy in the sense that in my picture that
does not prevent entropy increase. Entropy increase is about
information transfer/swapping between the unobservable and observable
parts of the universe.)
Then LSS says Gold observed that what is key is that "the expansion
allows photons to get away." Photons that get away form part of the
unobservable part of the universe and thus can "measure" our part and
thus cause decoherence. Correct idea, but missing my picture which
notes for "gravitons," not photons, gravitons always "get away" even
in a contracting universe.
I basically agree with the Gold idea that photons by "getting away"
can cause decoherence, though... but if we live in a "turnaround to
crunch" universe, photons actually never really get away.
Gold then considers a star inside a magic insulating box. Note I too
had considered that,but making the point gravitons would pass thru the
box walls and could not be stopped even in principle. Incidentally
S.Weinberg in his GR book estimates our sun outputs about 1 megawatt
of graviton radiation continually. Gold ignores gravitons, and claims
after a long time the star in the box would lose "time's arrow."
Meaning what? It would reach thermodynamic equilibrium?
This would involve the gas of photons surrounding the star acquiring
so great entropy that the star, by emitting photons via nuclear
reactions, would no longer be raising the entropy of the whole system.
So, I agree that would happen if there were no gravitons, but SO
WHAT? This is not losing time's arrow, this is proceeding according
to the entropy arrow until a state of maximum entropy was reached.
Perfectly normal.
And incidentally in order for this to happen the photon gas
surrounding the star would need
to reach a temperature exceeding MeV certainly. In the real universe
with gravitons I
suspect the star would continue burning inside Gold's magic box until
essentially every single
hydrogen was fused, rendering the whole argument garbage.
In 4.2 Schulman says a bunch of stuff about entropy wholy unsupported
by any numerical calculation. For example, do black holes have a lot
of entropy or a little? You need to do a numerical calculation to
find out. He does not. That makes everything he says in this section
unsupported garbage. It is easy to do the calculations, in fact I
once did as an undergraduate... he just does not. The fact is black
holes are the main numerical contributor
to the entropy of the universe today, contrary to LSS's false claim
they are "minor."
So his whole picture of the universe is just wrong.
Anyhow, I've now got to the end of LSS's core chapter 4 and I find it
basically incoherent.
This cannot be taken seriously.
