AST 341 Lecture Notes - Lecture 22: Antiparticle, Stephen Hawking, Accretion Disk

• School: Stony Brook University
• Department: Astronomy
• Course: AST 341
• Professor: Rosalba Perna

Document Summary

We have discussed how the degeneracy pressure of neutrons can hold the neutron star against gravity only up to a mass m 2 3m for the ns. For larger masses, no other known force is able to halt the gravitational collapse, and a new type of compact object is formed: a black hole. The description of a black hold, in fact the very concept of such an object, is entirely based on the theory of general relativity. However, some ideas on this topic were already present in the nineteenth century. The physicist pierre laplace asked the following question: He naively used the equation 1 esc = (gm m)/r to nd the radius at which vesc = c. this gives r = (2gm )/c2. If an object of mass m has a radius smaller than this value, then not even light would be able to escape.