• Question: Is time travel possible?

    Asked by Najibah :) to Anna, George, Jodi, Rob, Stefan on 12 Nov 2014.
    • Photo: Rob Appleyard

      Rob Appleyard answered on 12 Nov 2014:

      Travelling forwards in time is easy. We’re all doing it right now. Backwards time travel, on the other hand, almost certainly isn’t.

      There’s an old problem – what happens if you go back in time and shoot your own grandparent? Maybe you’d stop existing? But if you stopped existing, then there would be nobody to shoot your grandfather, so your grandfather would never be shot, so you would exist!

    • Photo: Stefan Lines

      Stefan Lines answered on 12 Nov 2014:

      Hi Najibah. I don’t think it is possible to travel back in time, and even if it was possible in a very limited way (such as the hypothesised Tachyon particle) – as Rob mentioned, there would be the issue of violations of causality, i.e. Kill your parents, you cease to exist! Have you seen that Simpsons episode where Homer uses the toaster to travel back in time? That’s a good enough reason not to even think about doing it, even if we could!

    • Photo: Jodi Schneider

      Jodi Schneider answered on 13 Nov 2014:

      No, but I love reading about it. The Doomsday Book by Connie Willis is a great example (careful or you’ll wind up in the Black Plague!)

    • Photo: George Ryall

      George Ryall answered on 14 Nov 2014:

      As the others have said, the big issue is causality – by travelling back in time you could change your own future – stopping yourself travelling back in time, creating a paradox.

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