• Question: if the universe is expaniding all the time, what is it expanding into?

    Asked by hollylewisdavies to Laura, Lily, Mark, Paul, Sarah on 24 Jun 2010 in Categories: .
    • Photo: Lily Asquith

      Lily Asquith answered on 21 Jun 2010:

      It is not expanding into anything- there is nothing outside the universe for it to expand into.

      The universe is all the stuff, but also all of space and time.

      It is the most difficult thing I have ever attempted to get my head round. We misuse the word `nothing’. Often we say that nothing is empty space, but empty space is not nothing. It is still space. It exists. Time passes for it. Matter can exists in it. It has coordinates.

    • Photo: Mark Roberts

      Mark Roberts answered on 21 Jun 2010:

      Space? Seriously I’m not an astronomer – this is more a qu for Paul

    • Photo: Laura Maliszewski

      Laura Maliszewski answered on 21 Jun 2010:

      Wow, that is a really excellent question but I have no idea what the answer might be. Maybe one of our physicists or astronomers can help out on this one.

    • Photo: Paul Roche

      Paul Roche answered on 22 Jun 2010:

      I’m afraid the answer to this is not very satisfying – astronomers will usually tell you that it is not “expanding into” anything, it is stretching (expanding) space as it goes…

      We think the Universe (i.e. everything) was created in the Big Bang, ~14 billion years ago, and that it has been expanding ever since then. The problem is, the words we use in everyday life, and our experiences, are not very good as comparisons with this sort of very complicated science – I usually get asked this question, and also “what was there before the Big Bang?, and there is no simple answer unfortunately.

      But as “the Universe” is everything, it cannot be expanding “into” anything – as it already contains EVERYTHING – does that make sense? All it can do is stretch/smear-out what it is, as it expands.

      Sorry, this is a hugely complicated question!

    • Photo: Sarah Bardsley

      Sarah Bardsley answered on 24 Jun 2010:

      If I knew that I would be a very famous scientist! We just don’t know. Here are a couple of theories;
      1. If the universe is infinite (never ending) then the answer is it isn’t expanding into anything
      2. If the universe is finite (having bounds) then the answer is there might be something its expanding it to but we don’t know what it is.

      Many great minds have pondered this question. Perhaps one day we’ll get an answer!

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