Question: Is time travel possible?

anon answered on 18 Jun 2014:

Sort of, in theory, but you’ll only ever be able to go forwards in time rather than backwards. I’m not an expert, but this is how I understand it:

Quantum physics says that the faster you travel, the slower time goes. So imagine if you were one of a set of twins and you set off from earth in a spaceship that went really really fast, close to the speed of light and left your twin on earth. Time for you would slow down because you were going so fast and you’d age more slowly than normal. If you went out to a distant planet and then came back to earth, the time on earth would have carried on at its normal rate so that when you landed you’d now be younger than your twin. In that respect you can think that you’ve gone forwards in time.

In reality it’d take so long to go out to a distant planet that it really wouldn’t be worth it! I think black holes might make time travel more possible, but I really can’t remember – I read a book about it once when I was doing A levels.