I just got done watching Stephen Hawking's Into the Universe episode 2, which is about time travel. They think that time travel into the past is most likely impossible simply because of paradoxes (go back in time, and kill yourself before you went back in time). However, tiny wormholes the size of an electron open up all the time, allowing matter to go through time. Wouldn't it still be possible to build a machine that would try and detect this electron, and kill the machine's operator before they sent it back in time? And what do you guys think might happen if a paradox like this DID occur? Please move this thread if it's in the wrong section, thanks.