AS101 Lecture Notes - Lecture 9: Orion Arm, Perseus Arm, Cosmological Constant
Document Summary
Inflationary theory predicts irregularities (and their size) in the cmb. 1 degree diameter irregularities most common - size predicted by inflationary theory for flat universe. If open universe - irregularities would be smaller. A possible form of dark energy that can change in strength as the. Dark matter needs to be cold: likely cosmological constant (not changing) (but quintessence is not quite ruled out) Universe began with big bank 13. 8 billion years ago. Shortly after big bang, had inflationary period. Universe is expanding at an accelerating rate. Currently composed of about 5% normal matter, 27% dark matter, 65% dark energy. Solar system - a solar system is a star and all of the objects that travel around it - planets, moons, asteroids, comets, and meteoroids. Our sun and solar system in the "orion spur" of the milky way. Originally believed to be in a spur, but later believed to be a branch of perseus arm.
