• Question: why does time travel seem so silly when it is possible( travelling cloose to the speed of light slows time) and when you returned it would be in the future

    Asked by answerIs42 to Anna, Hayley, Iain, Rebecca, Sascha on 26 Jun 2015.
    • Photo: Iain Bethune

      Iain Bethune answered on 26 Jun 2015:

      Time dilation which is predicted by general relatively means that when you approach the speed of light, time appears to slow down for you as observed by outside observers. Thus if you make a trip going very fast, by the time you come back, much more time will have elapsed on the earth than what you experienced. This is a kind of time travel – but it’s only possible to time travel forwards! There are some good arguments as to why travel back in time is impossible, due to something called the ‘arrow of time’ which Stephen Hawking explains in his book ‘A brief history of time’.