PHYS 037 Lecture Notes - Lecture 5: Cosmic Microwave Background, Beryllium, Microsoft Onenote
18 Oct 2016
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Document Summary
Temp of universe was low enough to forbid formation of elements heavier than. High enough to forbid electrons joining the nuclei and forming atoms. This continued until the universe was cold enough. Ejected as soon as they joined the protons. Photons no longer had the energy to kick out the electrons. When the universe reached 3740 k at 240,000 years after the bb. Rate of scatter competes with rate of expansion of the universe. Continues until the time between scatter of photons exceeds the age of the universe at that epoch. Photons can move freely and unimpeded by the matter. Matter and radiation were in equilibrium (temp was uniform) Light not impeded by atoms in universe & could escape. Universe was without any source of light & dominated by dark matter. No information can be obtained from that time since no light could escape.
