The center of a black hole, where the curvature of spacetime is maximal. At the singularity, the gravitational tides diverge; no solid object can even theoretically survive hitting the singularity. Although singularities generally predict inconsistencies in theory, singularities within black holes do not necessarily imply that general relativity is incomplete so long as singularities are always surrounded by event horizons. A proper formulation of quantum gravity may well avoid the classical singularity at the centers of black holes.
spacetime has infinite curvature and matter is crushed to infinite density under the pull of infinite gravity. At a singularity, space and time cease to exist as we know them. The laws of physics as we know them break down at a singularity, so it’s not really possible to envision something with infinite density and zero volume. You might check out the web site for further information on back holes and singularities: http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/010912a.html
The singularity: an infinitely convoluted point of infinite curvature.
What happens to space and time now? Do space and time end? No one knows. Presumably the answer has something to do with a hitherto unfathomed theory of quantum gravity… maybe superstring theory? http://casa.colorado.edu/~ajsh/singularity.html
Applying the Einstein Field Equations to collapsing stars, German astrophysicist Kurt Schwarzschild deduced the critical radius for a given mass at which matter would collapse into an infinitely dense state known as a singularity. For a black hole whose mass equals 10 suns, this radius is about 30 kilometers or 19 miles, which translates into a critical circumference of 189 kilometers or 118 miles. http://archive.ncsa.uiuc.edu/Cyberia/NumRel/BlackHoleAnat.html
Penrose diagrams of a Schwarchild black hole show an additional singularity. This is said to be of a white hole, which supposedly demonstrates the opposite feature to that of a black hole. Instead of the huge attractive force of gravity, it actually repels matter. It is suggested that it is the missing link between our universe and another, releasing the matter that for us is lost into the black hole. As this phenomena has never been observed, the theory is mainly by-passed.
The bizarre nature of Einstein’s equations suggest that black holes should theoretically lead to parallel univeses, i.e. one that is seperate from our own. There may be many different ones of these, each slightly different to the one we are presently existing in. This however is still very much only a hyperthetical situation. http://www.astro.keele.ac.uk/workx/blackholes/index3.html
The Wormhole Solution
Einstein did not like the singularity in the centre of the black hole. In 1935 he and Rosen found another solution to the equations of a black hole. It is shown to the above. There is an Einstein-Rosen bridge or wormhole connecting two different regions of spacetime.
The Einstein-Rosen solution does not say anything about the relationship between the two regions of spacetime. One possibility is shown above. The black hole in some region of spacetime connects to a black hole in another region of spacetime.