how did the big bang start? who discovered it?

Question: how did the big bang start? who discovered it?

Asked by sussim24 to Alexandra, Dean, Jess, Luisa, Sian on 22 Jun 2010 in Categories: General.
- Sian Foch-Gatrell answered on 21 Jun 2010:
  
  Everything that we currently know suggests that the Universe did in fact have a beginning (and before anyone religious gets upset by this statement – the beginning of a Universe does NOT contradict the possibility of a God or Gods or which ever you are inclined to believe in). The Theory of the Big Bang can actually be accreted to Edwin Hubble (the man whom which has the Hubble telescope named after him). Currently no one knows how the Big Bang started, that’s currently what the Large Hadron Collide is looking into, the Higs Boson! But basically it is thought that the Universe sprang into existence from a singularity around 13.7 billion years ago. That’s pretty much as much as I know about the Big Bang theory.
- Dean Whittaker answered on 21 Jun 2010:
  
  How it started is an interesting question – because nobody is quite sure (as far as I’m aware).
  
  The person who is attributed with the discovery is Edwin Hubble (who had the space telescope named after him). Have you ever noticed when an ambulance goes by, the tone of the siren changes as it goes past. This is because the waves are getting squashed together as it approaches you and getting stretched as it moves away (squashed waves are high pitched sounds and stretched waves are low pitched. Well what Hubble realised is that as you look out into the universe, then you get the same effect with light. Except everything is always moving away, all the waves are stretched out (which is the colour red – for light blue is like a high pitch and red a low pitch)… He did some clever maths and worked out that it must have all started at the same point and exploded outwards.
  
  What we do know is that there was a lot of energy in the big bang and that when it started there was matter and antimatter. You can create matter from energy as long as you create antimatter in equal proportions. What we don’t know is why there isn’t any antimatter left or where the energy all came from in the first place.
  
  So far using telescopes we’ve looked back (by look far away – where light has taken a long time to travel to us) to 5s after the big bang (I think, but please check that because I’m not sure).
- Jessica Housden answered on 21 Jun 2010:
  
  Well, no one actually knows 100% how it started. But, scientists are able to explain what happened and that is what is understood by the Big bang theory, the description scientifically of what happened after the Big bang. Scientists can describe the Big Bang from a very very small fraction of a second after the Big Bang started.
  
  The general theory is that everything in the Universe, all the stars, gas, planets and matter that we haven’t yet even discovered started off in a very very small space, where the laws of Physics had not even started to work properly. Then , something changed, maybe best described as similar to liquid turning into turning to gas and the Universe expanded exponentially. What was before the Big Bang? We don’t know. One thought is that the Universe expands, then contracts (Big Crunch) then expans again. But there are lots of other theories as well.
  
  Lots of scientists have developed the Big Bang theory. Lemaitre and Einstein were key to developing the idea, and observations and clever mathematics from Hubble (that objects in space were moving away from each other) and other astronomers (that the Universe is filled with a background radiation; thought to be left over from the Big Bang) helped to prove their theories right.
- Luisa Ostertag answered on 22 Jun 2010:
  
  I don’t know. Hope Dean and Jess have some ideas?!

Question: how did the big bang start? who discovered it?

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