GEOL 1050 Lecture Notes - Lecture 1: 30 Foot Fall, Edwin Hubble, Redshift
Document Summary
Large solid body orbiting a star (the sun) Has cleared its neighborhood of other objects (by gravity: moon: a solid body locked in orbit around a planet, pluto is excluded because of #3, it"s too small. Two groups of planets in our solar system: terrestrial planets- small, dense rocky planets. Mercury, venus, earth, and mars: gas-giant planets- large, low-density, jupiter, saturn, uranus, and neptune. Asteroid belt is between mars and jupiter. Earth spins rapidly on an axis of rotation. Rotation is centered on polaris, the north star. Rotation proven by foucault"s pendulum (1851: pendulum swings in same plane, earth"s rotation moves the ground beneath the pendulum. Stars are immense balls of incandescent gas: light and heat derives from nuclear fusion reactions, gravity binds stars together. Our sun is one of 300 billion stars in the milky way. Speed of light is 186,000 miles/s (300,000 km/s: moon is 1. 3 light-seconds away, sun is 8. 3 light minutes away.
