ASTRO 1 Lecture Notes - Lecture 8: Coulomb Barrier, Hydrostatic Equilibrium
Document Summary
Bottom pressure is greater: this also makes it so the sun does not collapse on itself, hydrostatic equilibrium: when things are balances (using pressure) Energy conservation: if we push on a gas to compress it, it will heat up because we"ve done work on it. Think of a bike pump: a gas must do work on its surroundings in order to expand, so it will cool down. What keeps the sun hot over billions of years: the sun"s energy is produced by hydrogen fusion: 4 hydrogen nuclei 1 helium nucleus + energy. Hydrogen fusion in the sun usually takes place in a sequence of steps called the proton-proton chain. Each of these steps releases energy that heats the sun and gives it its luminosity. As 2 protons get closer, it gets harder to bring them together: this is called the coulomb barrier. After you get passed the coulomb barrier, the two protons become attracted to each other.
