• Question: Is the theory of cosmic inflation (proposed by Alan Guth) is correct, and if so, what are the details of this epoch? What is the hypothetical inflaton field giving rise to inflation? If inflation happened at one point, is it self-sustaining through inflation of quantum-mechanical fluctuations, and thus ongoing in some impossibly distant place? And more interestingly it’s expanding but relative to what?

    Asked by waveicle to Adam, Geoff, Rob, Sheila, Suzie on 18 Mar 2011 in Categories: .
    • Photo: Geoff McBride

      Geoff McBride answered on 17 Mar 2011:

      Is it the luminiferous aether. Good exam question by the way.

    • Photo: Adam Tuff

      Adam Tuff answered on 18 Mar 2011:

      This still baffles everyone – at some point, something drove this incredibly rapid expansion, and at the moment nothing has been able to explain it very well – I was talking to another student yesterday about “branes” in the terms of what caused the big bang, and this apparently could drive the rapid inflation; the details of which I’m afraid I’m not an expert on!
      I don’t think space time is as simple as a flat surface so we could go ans stick a flag in a point and go “this is where the big bang happened”, because after all the big bang is thought to be an explosion of space-time itself! If you want a career in theoretical physics, this is a very much debated topic with a lot of interest!

    • Photo: Suzie Sheehy

      Suzie Sheehy answered on 18 Mar 2011:

      Hi there, thanks for your very technical question!

      I’m not a cosmologist and this might be better aimed at someone who is specialised in that field, I’m not sure my 4th year university quantum field theory and general relativity really give me the expertise needed here.. but I’ll try!

      We don’t know for now if the theory of cosmic inflation is correct or not, because we don’t have the experimental evidence, but there are good reasons to believe it is true in terms of what we know about the beginning of the universe..

      The inflationary ‘epoch’ was where the universe rapidly expanded, but when I say ‘expanded’ it wasn’t ‘into’ anything, it was the expansion of space-time itself. This is hard to visualise but if you look through some of the previous questions all of us have had a go at describing this!

      I personally haven’t worked through the maths of the theory so off the top of my head I don’t know the answer to what the inflation field is, except that it is a scalar field. You can look up what that means or ask me another question about it if you like!

      If you want to read more, there are lots of good books out there or a good article on inflation can be found here:
      http://www.lifesci.sussex.ac.uk/home/John_Gribbin/cosmo.htm

    • Photo: Sheila Kanani

      Sheila Kanani answered on 18 Mar 2011:

      Blimey I think you know more than I do on this topic, and I did it at uni. What an amazing question! 😀

    • Photo: Robert Simpson

      Robert Simpson answered on 18 Mar 2011:

      I wish I could answer your question but I just don’t know enough about it. I can say that when the Universe expands, it doesn’t expand ‘into’ anything. Rather spacetime expand is expanding. There are other questions that have been asked that deal with that point.

Comments