About time: Why does time's arrow fly only one way?

[David Morris]

http://www.newscientist.com/article/mg21128330.500-about-time-why-does-times-arrow-fly-only-one-way.html

Even though entropy increase is a statistical, and not fundamental,
phenomenon, it is enough to give rise to a powerful pillar of physics:
the second law of thermodynamics. According to the second law, the
entropy of the universe can never decrease. And there, you might
think, lies the key to time's arrow - the steady march from low
entropy to high is what we perceive as the passage from the past to
the future.

If only it were so easy. Unfortunately the second law does not really
explain the arrow of time. It merely says that high entropy states are
more likely than low entropy ones. Time does not enter the picture,
meaning that the world 5 minutes from now is likely to have higher
entropy and so should the world 5 minutes ago.

The only way to explain the arrow of time, then, is to assume that the
universe just happened to start out in an extremely unlikely low
entropy state. If it had not, time would have become stuck and nothing
interesting, like us, would ever have happened. "Time's arrow depends
on the fact that the universe started up in a very peculiar state,"
says physicist Carlo Rovelli of the Centre for Theoretical Physics in
Marseilles, France. "Had it started up in a random state, there would
be nothing to distinguish the future from the past."