My question is on the assumption that there is nothing in laws of nature that says if gravity had time reversal then nothing would appear odd. The example professor Feynman gave was a system with objects rotating due to gravitational attraction that rotated in a clockwise manner with normal forward time would be allowed rotate counterclockwise with time reversed and nothing in the laws would forbid that. Thus, it was concluded from this example that gravity can and does allow time reversal. My question on this is what about the case of a blackhole's event horizon which would appear to be a one way journey? Thus does a blackhole (which is due to gravity) negate this assumption whereby gravity is no longer thought to obey time reversal (since nothing can return from an event horizon)?