Your second paragraph is simply incorrect: there is no known asymmetry in the laws of physics that might explain the arrow of time.
The laws of physics are CPT-invariant, as /u/gjm pointed out; CP symmetry is known to be broken; consequently T symmetry is also broken. The effect has been measured directly: http://physicsworld.com/cws/article/news/2012/nov/21/babar-makes-first-direct-measurement-of-time-reversal-violation.
This is not helpful for explaining the arrow of time, for reasons that Sean Carroll points out in the post I linked.
The laws of physics are CPT-invariant, as /u/gjm pointed out; CP symmetry is known to be broken; consequently T symmetry is also broken. The effect has been measured directly: http://physicsworld.com/cws/article/news/2012/nov/21/babar-makes-first-direct-measurement-of-time-reversal-violation.
This is not helpful for explaining the arrow of time, for reasons that Sean Carroll points out in the post I linked.