ERS111H5S Lecture Notes - Lecture 2: Big Bang, Protostar, Shap
Document Summary
The universe is all the space and all the matter and energy within it. The big bang theory says that all matter and energy--everything that now constitutes the packed into an infinitesimally small point. The universe is still and will forever be expanding. If it is still expanding, that means that it was really small, and it"s according to the big bang was a really small point. 13. 7 billion years ago, the whole universe was smaller than an atom. It was a dense, very small point that was very hot and full of energy. Then an "explosion" happened producing irregular distribution of hydrogen, helium and. As the universe continued to expand and cool further, atoms and molecules slowed down patchy clouds called nebulae. All we have of the big bang are echoes and waves of the radiation that it made.
