I read the Grandfather Paradox link that buen posted and correct me if I'm wrong here, but I think I see a flaw. Assuming that there is only one time line, some time in the future someone travels back in time, then kills their grandfather. Ok. Now that person will never be born. However the single time line can surely remain, however now the time traveller never existed. Any takers?
What if you went back in time and just before you killed him, your grandfather stole the time machine? He went forward in time to just before you had the time machine. He then killed you. You would not have gone back in time so he could steal the time machine....and so on and so on (continue for as long as you like).
No that was nonsense on American television, showing a woman talking while holding her ear. Some wag decided she was using a mobile phone. Can't have been a very good signal back in 1920!
Yes, that was a bit silly. There was also one with a guy that looked to be dressed in 90's gear though the photo was taken in the 20's or something. Does anyone have an actual opinion on my flaw theory other than jake?