Time’s arrow is due to that the macroscopic observers keep losing the microscopic information about the physical systems.

For simplicity, we consider only classical systems now.

Microscopically, there is no time arrow, because for any two times, t1 and t2, their states have one-one correspondence. In other words, once we know the exact state of a physical system at time t1, we also know the exact state of the system at time t2, and vice versa.

This feature of time may be corresponding to a NDE feature that a dying person moving towards the end of the white tunnel will feel that all the past, present, and future collapse to one point. Some people call that point “the Eternal Now”.

— Me@2013-08-26 6:12 PM

2013.09.02 Monday (c) All rights reserved by ACHK