What’s the most interesting questions you have ever been asked, and what was the answer?

Question: What's the most interesting questions you have ever been asked, and what was the answer?

Asked by eleanorbeedles to Sarah, Paul, Mark, Lily, Laura on 24 Jun 2010 in Categories: About.
- Mark Roberts answered on 21 Jun 2010:
  
  Most interesting qu was when someone asked me about how a bacterium called Bdellovibrio works – it’s a really cool bacterium and infects and ‘eats’ other bacteria like E. coli!
  
  The answer was to do with how it swam using a little whip like propeller – but it’s really interesting and may provide a new way to control pathogenic bacteria by using a bacteria to fight the bacteria!
- Lily Asquith answered on 21 Jun 2010:
  
  My daughter asked me
  
  “How do we know that the universe is getting bigger and it’s not just that all the stuff inside it is getting smaller”
  
  I haven’t given her a proper answer yet. She only ever asks me physics questions when she is in trouble, to distract me. It always works.
- Laura Maliszewski answered on 22 Jun 2010:
  
  My favorite IAS so far is this: http://ias.im/16.8227
- Paul Roche answered on 22 Jun 2010:
  
  “Who would win in a fight, an Oompah Loompah or Richard Hammond?” – I still haven’t solved that one yet….
- Sarah Bardsley answered on 24 Jun 2010:
  
  This. And this.

Question: What's the most interesting questions you have ever been asked, and what was the answer?