• Question: Is it possible to time travel?

    Asked by rachel14 to Cathal, Ciara, Emma, Michael, Sive on 15 Nov 2013.
    • Photo: Michael Nolan

      Michael Nolan answered on 15 Nov 2013:

      Hi Rachel,

      Relativity does not allow backwards time travel but forward time travel is in principle allowed. I think though you might have to break the speed of light to do so and that’s not easy…

      However, given the first point above, you could never come back, so nobody would know for sure if you travelled forward in time.
      Backwards time travel would also create the possibility that you could kill your parents – but then if they were killed by you, how could you be born to kill them. The Universe does not like paradoxes so the laws of physics tend to preclude such possibilities.

      Interestingly at the level of atoms loving about, whether you look at atoms moving forward in time time or backwards in time, it does not matter! For us there is a distinction.

      One way to travel back in time is with Hubble – when Hubble sees 10 billion year old galaxies or pulsars it is travelling back that far as the light from those galaxies took 10 billion years to get to Hubble, so you see the galaxy as it was 10 billion years ago.

      Finally, that still doesnt stop me enjoying Dr. Who 🙂

      M

    • Photo: Sive Finlay

      Sive Finlay answered on 19 Nov 2013:

      Hi Rachel,
      Just to add that from a slightly different point of view another way of time traveling is to look back into past environment of the Earth. We can use ice cores and studies of rock formations to build up a picture of the climatic and environmental conditions of our planet millions of years ago. With the help of computer simulations and a bit of imagination I guess that counts as time travel back to the age of the dinosaurs and beyond 🙂
      Sive

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