• Question: Is time travel possible?

    Asked by anon-267455 on 5 Nov 2020. This question was also asked by anon-267545, anon-267549.
    • Photo: Savannah Clawson

      Savannah Clawson answered on 5 Nov 2020:

      We are technically travelling through time all the time! The only thing is that we only seem to be able to travel forwards in time, i.e. days, weeks, years pass and you grow older. To travel backwards in time, we would have to be able to travel faster than the speed of light – something which we currently think is impossible. One really interesting thing about time is that it flows at a different rate depending on how fast you are moving – time actually slows down the faster you move! With our current technology, we don’t have any vehicles that can travel fast enough for this to be a noticeable effect for humans but these effects (and the effects of gravity) do have to be taken into account for precise measurements like calibrating GPS satellites.

    • Photo: Julian Onions

      Julian Onions answered on 5 Nov 2020:

      Forwards in time, yes – we can speed it up in various (rather extreme) ways. Backwards in time – most scientist agree this is probably impossible, although there have been ideas, which usually require even more extreme events – such as huge black holes spinning at nearly the speed of light and so on. Even then no one is sure if that might even be an answer.

    • Photo: Daisy Shearer

      Daisy Shearer answered on 8 Nov 2020:

      You’d probably need to be able to move really, really fast to travel back in time well beyond our current technological capabilities.
      But in terms of forward-moving time, relativity says that we can slow down time if we are moving fast or if we are in stronger gravity. For example, if you’re an astronaut on the international space station and you have a twin on Earth (for argument’s sake, you were born at the exact same time), then after a year you will be around 0.01 seconds younger than your twin! This is because of an effect called ‘gravitational time dilation’ which is related to Einstein’s theory of relativity. It’s also the reason why we think that time slows down to almost an infinite amount to an outside observer at the edge of a black hole!

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