The way I like to think of it, and I'm not sure how valid my thoughts are... I think about what you would experience as an observer in a ship traveling faster a

The way I like to think of it, and I'm not sure how valid my thoughts are... I think about what you would experience as an observer in a ship traveling faster and faster. If the ship had a window to look out, you wouldn't really be noticing anything happen to time, you'd be seeing the universe get squished, with everything getting closer and closer to you. If you managed to actually achieve the speed of light, the universe would be completely flat. Everything would be contained in a single plane perpendicular to your direction of travel. So now, what would it mean if you went even faster? The universe would no longer be flat, but would be achieving a negative size. What that really means is not clear to me, but I suppose it's here where the traveling back in time starts to make sense mathematically.