Chasing the Elusive Arrow of Time with Computer Algorithms

Michael Byrne in Motherboard:

What direction is time heading in at this very moment? Are you sure? Of course you are. Life is just a constant barrage of causes and effects, things happening beforeother things that, had they not occurred, would have prevented the other, subsequent things from happening. No one goes through their life thinking about this, the directionality of time, because it's beyond evidence and buried in the brain's deepest intuitions: you were born before you die and it could hardly be the other way around. Time moves forward.

As it is with really all of the mind's deepest intuitions, this directionality is not so easy. It's possible to imagine a wide variety of schemes involving information and information hiding that make time's arrow less clear. In fact, physics, at its smallest, deepest roots has really no interest in forward and backward; it could really go either way. Time, or the direction of time, arises as physics gets bigger and more complicated. Zoom way in, all the way in actually, and what you'll find is enviable oblivian: cause-effects, effect-causes, effect-effects, cause-causes. Something like that.

More here.