BLACK HOLE     B lack holes  are some of the most interesting pathologies in space and time delivered by Einstein's general theory of relativity. They form when matter collapses gravitationally onto itself, such as when massive stars burn out. They are a region of space where the gravitational pull is so strong that nothing--not even light--can escape. Hence John Wheeler called them "black holes." There is more. They incorporate singularities in spacetime structure: points where Einstein's theory breaks down, since the curvature of spacetime becomes infinite. And they can supply bridges to new universes.  S uch a star may become a white dwarf or a neutron star, but if the  star  is sufficiently massive then it may continue shrinking eventually to the size of a tiny atom, known as a gravitational singularity. A  black hole refers to the region in space in which the singularity’s gravitational force is so strong that not even light can escape its pull.          ...
    THE THEORY  OF        EVERYTHING      THE ORIGINE AND FATE OF THE UNIVERSE   SPECIAL EDITION   THE THEORY OF EVERYTHING   THE ORIGIN AND FATE OF THE UNIVERSE     STEPHEN W. HAWKING   CONTENTS   Introduction.     FIRST LECTURE   IDEAS ABOUT THE UNIVERSE..     SECOND LECTURE   THE EXPANDING UNIVERSE.     THIRD LECTURE   BLACK HOLES....     FOURTH LECTURE   BLACK HOLES AIN'T SO BLACK     FIFTH LECTURE   THE ORIGIN AND FATE OF THE UNIVERSE     SIXTH LECTURE   THE DIRECTION OF TIME     SEVENTH LECTURE   THE   THEORY OF EVERYTHING.     INTRODUCTION   In this series of lectures I shall try to give an outline of what we think is the history of the universe from the   Bigbang      to black holes. In the first lecture I shall briefly review past ideas about the universe     and how we got to our present picture. One might call this the history   of the universe.      In the second lecture I shall describe how both Newt...