Astronomy 1021 Lecture : Stellar Remnants

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Chris Racknor

Document Summary

On earth, escape velocity is 11. 3 km/s to escape earth s gravity, that s the minimum speed. Suppose earth were much more massive while keeping its size, then gravity would be stronger, therefore escape velocity would be higher. Black hole s escape velocity is higher than the speed of light, therefore nothing can escape the black hole (since nothing can go faster than c) Black because no light can escape hence the compact object itself is invisible. Hole because a black hole really is like a hole in the observable universe. If you enter a black hole, you leave the region of the universe that we can observe with a telescope, and you can never return. Some aspects about black holes are counterintuitive, and difficult to grasp and moreover, a lot of weird things happen around black holes. A black hole is not like an interstellar vacuum cleaner.