Time's arrow

As we prepare to lurch into 2009, Roger Ebert has posted a review of The Curious Case of Benjamin Button which makes some interesting comments (with his usual wit) about the importance of the "arrow of time" in a film narrative, and how logically perverse and alien Button's life becomes as a result.

From physics, it seems that the only aspect of the universe which is asymmetric (and in fact antisymmetric) with respect to time is the entropy of a closed system (such as the universe): it must always increase during any process. I half-remember something from "A Brief History of Time" on that subject (I read it about half a decade ago). The key point is that very concept of time is an artefact of our existence as chemical beings, driven inexorably by thermodynamics. Ebert's review doesn't go into these sorts of technicalities, but it makes me wonder about the psychology of life (would we even call it life?) without a sense of time. It would be as staggeringly alien as the planet at the centre of Stanislaw Lem's "Solaris", I suspect.