ASTR 1013 Lecture Notes - Lecture 1: Astronomical Unit, Solar System
Document Summary
+astronomical unit (au)= mean earth to sun distance= 1. 5x10^8. +light year (ly)= distance light travels in one year. +parsec (pc)= distance at which 1 au subtends 1/3600 degrees= 3. 3ly. +typical distance between 2 stars ~ (about) 1ly. +clusters of clusters of galaxies and empty voids between~10^8 ly. +speed of stars around center of galaxy, or galaxies within a galaxy cluster~10^2km/sec. +science: the hunt for deeper understanding of, and new knowledge about the physical universe. +newton"s formulas are great for low speed and low mass, general relativity is for high speed high mass. +astronomy"s distinction: studies conditions that don"t exist on earth.
