what happened during the big bang(what caused it)?

Question: what happened during the big bang(what caused it)?
- Keywords:
  bang,
  big,
  big bang,
  theory
Asked by nevie to rhysphillips on 17 Jun 2011.
- Rhys Phillips answered on 17 Jun 2011:
  
  It was probably caused by the universe getting bigger and bigger and changing temperature very quickly.

Question: what happened during the big bang(what caused it)?