PHYS 180 Study Guide - Final Guide: Electron Degeneracy Pressure, White Dwarf, Empty Spaces
Document Summary
Cosmology: a branch of astrophysics, a study of the universe as a whole, the composition, what inhabits it, its history, where its going. No matter where oyu look, any line of sight will hit a tree trunk. That is because it is so big there are trees everywhere, you can"t see through it. Emptiness is not an option: hubble telescope image: most of it is dark, we should see something like one giant star but we don"t. Possible solutions to the paradox: the universe is actually finite. So a universe that is finite is inherently stable. So you have to have something holding the universe up on the weight of its own gravity: there could be things between stars and us that are absorbing light. We know that that exists, like dust, which absorbs light and blocks the light from things coming behind it: we know in physics that everything radiates at some wavelength.
