GG101 Chapter Notes - Chapter 2: Outgoing Longwave Radiation, Orbit, Sphericity
Document Summary
Milky way galaxy: a flattened, disk-shaped mass estimated to contain nearly 400b stars and spiral arms. We are located within the orion arm. A black hole called sagittarius sits in the middle. The solar system condensed from a large, slowly rotating and collapsing cloud of dust and gas called a nebula. Gravity is the mutual attracting force exerted by the mass of an object upon all other objects, was the key force in this condensing solar nebula. The early protosun grew in mass at the centre, drawing orward more matter, which solidified into planets: there are approximately 250 planets outside of the milky way. Plantenesimal hypothesis/dust-cloud hypothesis: explains how suns condense from nebular clouds with planetesimals forming in orbits about the central mass. The speed of light is 300,000 kps: light year: how fast light travels in one year"s time.
