Beginning of Essay
Black Hole, a theoretical concept in the study of gravitation. The gravitational field of a black hole, which is an extremely dense body, is so strong that, if the body is large enough, nothing, including electromagnetic radiation, can escape from its vicinity. ....

Middle of Essay
.... the ergosphere. According to general relativity, gravitation severely modifies space and time near a black hole. As the horizon is approached from outside, time slows down relative to that of distant observers, stopping completely on the horizon. Once a body has contracted within its Schwarzschild radius, it would theoretically collapse to a singularity—that is, a dimensionless object of infinite density. Formation Black holes may form during the course of stellar evolution. As nuclear fuels are exhausted in the core of a star, the pressure associated with their heat is no longer available to resist contraction of the core to e ....