• Question: is the universe expanding?

    Asked by FelicityP to Heather, Helen, Hugh, Jane, Julian on 18 Nov 2014.
    • Photo: Julian Onions

      Julian Onions answered on 18 Nov 2014:

      Yes, the universe is expanding, in fact it’s worse than that. In the late 1990s we found out not only is it expanding, but its beginning to expand faster.
      This was discovered by looking at very distant explosions of stars, and seeing that the distance measurements didn’t all fit on a graph line as they should.
      The people who discovered this got the Nobel prize a couple of years ago for their work.

    • Photo: Heather Campbell

      Heather Campbell answered on 18 Nov 2014:

      Julians described the accelerated expansion of the Universe really well. Just to add, this is what I work on! looking for these special type of supernovae (explosions of stars) which are all about the same brightness, and using them to work out how much faster and faster things are moving away from each other. We think the acceleration is caused by some mysterious dark energy but what this is we don’t know!
      The expansion (before we new about that accelerating) was discovered by Hubble measuring that galaxies were all moving away from each other.

    • Photo: Helen Johnson

      Helen Johnson answered on 18 Nov 2014:

      Yep as Heather said, Hubble discovered that there were galaxies other than our own, and that they were all moving away from us. Wherever you are in the Universe you would see the same thing – everything moving away from you.

      You can imagine it as if you drew some points on a balloon and then blew it up – the points all get further apart! This is kind of a 2D representation of what’s happening to the Universe. There’s no one special point that everything is moving away from, it’s just all expanding and has been since the Big Bang.

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