Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: PETER POULDING on 09/09/2011 01:01:02
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PETER POULDING asked the Naked Scientists:
We are constantly being told that the universe began with the big bang.
If this is true, where did the ingredients come from to cause the bang.
Peter Poulding
What do you think?
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The only "ingredient", as far as I know, was energy...
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Not even necessarily energy! Some models of the universe have the net energy of the universe as zero. The big bang is a big mystery and we are slowly developing models that seem to fit the evidence closer and closer to time = 0 but we are still a long way off. Very soon after the big bang the rules of the universe were not what they are now - the four forces were unified, the energy was unbelievable high and particles might have been unrecognizable; it is beyond us both theoretically and experimentally - but watch this space
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As imatfaal says some models have the net energy of the Universe as zero. Positive energy + negative energy (gravity) =zero. That's not the same as there being no energy needed for the creation. Initially, it took energy to create mass and hence gravity.
Where did the ingredient(s) come from. No one knows for sure but we think the uncertainty of the quantum vacuum.
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The basic ingredients are energy AND momentum in particular angular momentum. That is, the particles are always moving the massless ones always at the speed of light and the massive ones dependant on the prevailing temperature.
When particles are created in interactions, they are always created in pairs with opposite spins (angular momentum) there is a slight imbalance in this associated with B mesons and this is why there is some matter in the universe after the universe got cool enough for particles and antiparticles to annihilate (rather than just create more particles).
Models of the big bang don't talk much about the particle creation phase of the early stages of the big bang because in general one needs some particles and extremely high temperatures (LHC temperatures) to create lots more particles. Pure energy beams do not create particles. so it seems likely that there must always have been some "seed" particles about or maybe they just always exist in the QM vacuum.
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Maybe energy density like shortly after the BigBang is needed for photons to create particles.
About the imbalance in B mesons spins, it is certainly not a definitive explanation, i have big doubts...