• Question: do you believe that the theory that the universe is ever expanding is true, if so what evidence do you have to back up your answer.

    Asked by louismart to Lyn, Katy, Paul, PB, Ruth on 27 Jun 2013.
    • Photo: Paul Waines

      Paul Waines answered on 27 Jun 2013:

      Hi louismart (again)

      As I’m not a physicist, I can only go with what they say- they are so clever, I think their brains are expanding never mind the universe. I’ll try to explain…

      For years, scientists struggled to work out how big the universe was.

      Isaac Newton discovered gravity, and said that if the universe was only a certain size, then surely it shouldve collapsed onto itself by now (because of gravity). There were lots of other questions like this over centuries of astronomy!

      In 1929, a man called Edwin Hubble worked out that the universe is expanding and that the only way it hadn’t collapsed was because it was still expanding! But how, you may ask, did he do this?

      He compared the brightness of stars in several different ways, and used an awful lot of maths!!

    • Photo: Ee Lyn Lim

      Ee Lyn Lim answered on 28 Jun 2013:

      That’s a very good question, and I believe many of the world’s best physicists are asking it too!

      Personally I have no idea – this is not even regular physics – this is quantum physics, and has to do with Einstein’s relativity! I never managed to get my head around it, since my work involves mostly just cells and mice – I should really have another go at trying to understand it though!

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