I won’t do a direct copypasta, since you can just read it from the link there. But the basic thing is, if you go back in time, no matter how small an event you change, it will result in drastic differences in the progression of future events.
Since I love to overthink things, I had already thought of this problem. But never wrote it down, or even expanded on the basic thought. But now somebody was nice enough to do all the work for me. That was good of him.
Also, his idea of ‘changes propogate at the speed of time” is sort of like the mechanics of the upcoming game Achron, which I was already looking forward to.