The arrow of time.

Yesterday's post about time was both confusing and fascinating. Here's another fascinating thing about time: it only moves in one direction.

The arrow of time points toward entropy. Things tend to get more disorganized. That's why scrambled eggs don't seem to reassemble themselves or divers jump out of the water and land on the side of the pool completely dry.

But why does time's arrow point in one direction? I don't know. You can argue that it needs to point this way in order for there to be a cause-and-effect relationship between events and things.

Yet I heard that from a purely mathematical angle, it doesn't matter which way time flows. Physicists' calculations work both forwards and backwards.

There may be other parts of the universe where time flows backwards. Or perhaps in the vast multi-verse, there are universes that exist in which time flows backwards. We just can't see them.

I think it would be cool if, at the end of the universe, time reversed itself and ran backward until the big bang again. Then our bodies would reform and be resurrected and we'd live until we got smaller and smaller and eventually disappeared inside our mother's bellies.