E&S SCI 9 Lecture Notes - Lecture 2: Parsec, Elliptical Galaxy, Observable Universe
31 May 2016
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Document Summary
2. ideas ( hypotheses ) should be rejected if constantly contradicted by observations. Hypotheses rejected by observations, but never proved by them. Cosmic web: filamentary network of galaxies that aren"t evenly distributed and instead form a web. Collisions b/t galaxies in clusters lead to destruction of disk galaxies and formations of large elliptical galaxies. The mw will eventually collide with its neighbor and form a larger galaxy. Collisions often lead to a dramatic burst of star formation because interstellar gas is compressed by the collision, and collapses on itself. Gas and dust exists within spiral galaxy, allowing for planet formations. Distance from earth to sun is one au. Diameter of planetary region of solar system is 100 au. Distance between stars is called the parsec (pc, around 3 lightyears) Distance between sun and center of milky way is about 8000 pc. Distance of milky way is roughly 50000 pc. Distance between galaxies is 1 megaparsec (10^6 parsecs)
