Nerdy Thought for the day

As I understand it, there is corollary relationship between gravity and time. Time moves slower in a gravity well. (See that episode of Stargate) So theoretically the Earth could be sucked into a black hole, and it we're just in really big time dilation field.

While I'm on the subject of temporal physics we learned from television, who first thought that if you went back in time and touched your temporal duplicate you'd erase yourself, and why doesn't someone "out of phase" fall through the floor?