PHYS 180 Lecture Notes - Lecture 7: Escape Velocity, Event Horizon, Square Root
Document Summary
The velocity you need to escape the gravitational field of a mass. If the mass gets large enough the escape velocity = speed of light. As we increase the amount of mass, the hole becomes deeper. Black hole: too deep, nothing can climb out of it. First prposed in the 1783 by john michell. Based on the idea of escape velocity. Predicted a way of finding them: look for a star orbiting a dark place. In 1916 karl sh again proposed the idea of black holes. The event horizon is also known as the sh radius. Not until 1967 did the idea really catch on. You can define a radius that is associatd with a black hole: event horizon. Black holes have collapsed down in a point. The radius is when light has become trapped. The mass in a black hole has collapsed to an infinitely small size a singularity.
