AST 1001 Chapter Notes - Chapter Chapter 1 Modern View of the Universe: Ecliptic, Observable Universe, Astronomical Unit
Document Summary
Chapter 1: a modern view of the universe. 1. 2 the history of the universe: birth of the universe: began with hot and dense big bang, galaxies as cosmic recycling plants: early on only contained two chemical elements (hydrogen and helium). Summary: earth is not the center of the universe but instead is a planet orbiting a rather ordinary star in the milky way galaxy. The milky way galaxy, in turn, is one of billions of galaxies in our observable universe: cosmic distances are literally astronomical, but we can put them in perspective with the aid of scale models and other scaling techniques. Big bang and were later fused into heavier elements by massive stars. Stellar deaths released these atoms into space, where our galaxy recycled them into new stars and planets. Our solar system formed from such recycled matter some 4 billion years ago: we are latecomers on the scale of cosmic time.
