Astronomy 1021 Lecture Notes - Lecture 2: Accretion Disk, Cosmic Distance Ladder, White Dwarf
23 Mar 2016
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Document Summary
No hair theorem: the only distinguishing features of a black hole are mass, spin and charge, falling into a black hole is a one way trip. It is much more likely that someone traveling the galaxy will collide with a star than a black hole because black holes are so small! The density of a black hole the mass of the sun is so much larger than the sun that the gravitational acceleration is huge at its surface , the event horizon. Like bowling balls in a rubber sheet, mass distorts the geometry of space- time. Einstein: objects always travel in the straightest possible paths, but mass changes what a straight path means. Event horizon: surface (spherical for a non- spinning black hole) Schwarzschild circumference (sc): describes the size of the event horizon: for a black hole mass in solar masses, the sc is 19 km, 3msun bh has a 3x19= 51km sc.
