Astronomy 2022A/B Lecture Notes - Lecture 3: Schwarzschild Radius, Event Horizon, Escape Velocity

• School: Western University
• Department: Astronomy
• Course: Astronomy 2022A/B
• Professor: Chris Racknor

Document Summary

Lecture 3 the geometry of the universe. How much matter is in the universe affects whether it will expand forever or recollapse (indications show expansion) Gr means that mass will cause space to curve near it. How to tell flat space from curved space. We can add up the angles of a triangle on the paper. On a flat paper, they must always add to 180 degrees not always 180 on curved space. Draw a circle - on a flat piece of paper, there is a fixed relationship between a circle"s radius and its circumference (c = 2pir) On a sphere, the circumference of a circle will be smaller than it would be on a flat piece of paper (c does not = 2pir) A universe with negative curvature would have triangles whose angles added up to < 180 degrees. Infinite plane with no edge/center that stretches on forever.