There is so much to be said about the dangers of time travel, but the going-back-in-time-and-accidentally-killing-your-grandfather is not one of them. If you kill your grandfather, you will not be born, so you will not be able to kill him. Unless you open a parallel time stream, which is a completely different matter. No, the danger with modern day time travel is that you might fuck up your calculations, and get fucked in return.
|Photos from Hustler|