ASTR 001 Lecture Notes - Lecture 17: Escape Velocity, Event Horizon, Schwarzschild Radius
Document Summary
Consider a mass m with radius r. the escape velocity for an object on the surface of that mass is. Suppose you took an object of mass m, and concentrated it so much that the escape velocity from its surface was c. the radius of a mass so concentrated is called the schwarzschild radius (rsch) of that object. The escape velocity at radius r sch is then the speed of light, c. but suppose you squeezed the mass more, so that you could get closer to its center than rsch. You would find that the escape velocity was greater than c. not even light could escape if it were closer than rsch! An object smaller than its own value of rsch could emit no light; light could not escape from it. U(cid:272)h a(cid:374) o(cid:271)je(cid:272)t (cid:449)ould (cid:271)e a (cid:862)(cid:271)la(cid:272)k hole(cid:863) i(cid:374) spa(cid:272)e. A (cid:271)la(cid:272)k hole"s (cid:373)ass stro(cid:374)gly (cid:449)arps spa(cid:272)e a(cid:374)d ti(cid:373)e i(cid:374) (cid:448)i(cid:272)i(cid:374)ity of e(cid:448)e(cid:374)t horizo(cid:374)
