A recent paper by Lorenzo Maccone in the Physics Review Letters has what I think is a very interesting argument about the arrow of time.
A long standing dilemma in physics is that all physical laws work the same irrespective of whether time moves forward or back. However, we only experience time moving in one direction only. Specifically, we can only observe ‘entropy’ increasing, ie you can only see an egg crack, or milk split, but will never see those phenomena reverse spontaneously. However there were no widely understood underlying theoretical basis why that should be so.
In the paper, the author argues that actions that increase entropy leave information behind, while processes that reduce entropy necessarily involve erasing information. Which means physics cannot study those processes where entropy has decreased, even if they were commonplace.