• Question: How big is space

    Asked by chloe1998 to Damien, Rachael, Simon, Suzi, Tim on 18 Jun 2011. This question was also asked by ellapowerxxx.
    • Photo: Suzi Gage

      Suzi Gage answered on 13 Jun 2011:

      Hi @chloe1998
      This is a tough question, I am a scientist interested in the brain, rather than outer space, so I don’t know much about this, but I’ll have a go!
      It is thought that even if our Universe has an outer edge, space itself is infinite (which means it goes on forever). Because light takes time to travel to us, we can only see a certain distance out in to outer space, 13.7 billion light years, which sounds like a time, but is also a distance. It’s hard to make it clear how far that is, but it’s a LONG WAY! This is the edge of our Universe.

      So we can’t be sure what’s beyond this point, as the light from anything that may be out there hasn’t reached us yet. But there’s no reason to be sure there isn’t anything further away than that.

      Hope this answers your question!

    • Photo: Damien Hall

      Damien Hall answered on 18 Jun 2011:

      You might be interested as well in how we know it’s 13.7 billion light years to the edge of our Universe! I think it’s because we know that the Universe is still getting bigger – we can see that because telescope images show that stars and other objects in space are getting further away from each other, if you compare a picture taken some time ago with one taken recently. So we can measure the speed at which these space objects are moving, and then work it backwards to a point where they must have all been together – that was the Big Bang. Doing that, we can work out that the Big Bang was 13.7 billion years ago.

      So the Universe is more than 13.7 billion light years across (more, because we’re not at the edge ourselves), and it’s getting bigger!

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