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Larry Smith wrote:
Brian Greene ... argues that it is more probable that the universe was
created last
Tuesday at 1210 GMT with us and all our memories intact than that the
universe had lower entropy in the past.
That's a common misconception.
It is a mistake to think that a "complicated" state such as the
"one week ago" state must be a high-entropy state. In fact,
there are many quite-complicated states that have little or no
entropy.
For a computer simulation that quantitatively demonstrates the
difference between complexity and entropy, see
http://www.av8n.com/physics/entropy-sim.htm
If you take the present state and evolve it forward a week or
so, unpredictable thermal fluctuations will result in many
possible outcomes for the new state. There will be an ensemble
of next-week states.
The same applies in reverse: If you take the present state and
evolve it backwards for a week or so, you will get a rather
large ensemble of last-week states. The total probability,
summed over this entire ensemble, is unity. In contrast, the
probability of any one particular state (i.e. any particular
member of this ensemble) is very small. Greene mistakenly
attributed the probability of the ensemble to one of its
members.
Tangential remark: there is not much probability that any
member of the last-week ensemble, if re-evolved forward for
a week to the present day, would reproduce the present-day
state. Each of them could, but probably wouldn't.
Returning to the main point: The "Tuesday" state to which Greene
refers is _not_ a high-probability / high-entropy / high-multiplicity
situation. All evidence (experimental and theoretical) indicates
that the past had a lower entropy than the present.
Bottom line: The equations of motion do _not_ lend any support to
the idea that the universe was created with a deceptive pseudo-history.