If the universe is expanding it must be expanding into something what do you think it is expading into?

Question: If the universe is expanding it must be expanding into something what do you think it is expading into?
- Keywords:
  space,
  universe
Asked by Squiddy to Anna, Hayley, Iain, Rebecca on 26 Jun 2015. This question was also asked by sunish.
- Iain Bethune answered on 26 Jun 2015:
  
  Hi Squiddy, I don’t think it’s expanding into anything – the universe is all that their is! But it is expanding, which is counter-intuitive. I wrote a longer explanation in response to this question:
  
  What is beyond the universe?
  
  I hope it helps you understand!