Ethan Hawke is best known for movies like Dead Poets Society and Before Sunrise, but one of the most overlooked roles is in a sci-fi thriller from 2014.

Time travelers might not have to worry about creating a world where their parents never met. It’s a worry of time travelers everywhere. What if they go back in time and do something terrible, like ...

Add Yahoo as a preferred source to see more of our stories on Google. A physicist has worked out the math that makes 'paradox-free' time travel plausible No one has yet managed to travel through time ...

(PhysOrg.com) -- Entropy can decrease, according to a new proposal - but the process would destroy any evidence of its existence, and erase any memory an observer might have of it. It sounds like the ...