© NASA | JPL-Caltech
Artist's concept of a supermassive black hole.
Artist's concept of a supermassive black hole.
A black hole possesses a gravitational field so powerful that not even light can escape. A black hole generally forms after a star dies in a titanic explosion known as a supernova, which crushes the remaining core into dense lumps.
A maddening enigma called a singularity -- a region of infinite density -- lies at the heart of each black hole, according to general relativity, the modern theory of gravity. The infinite nature of singularities means that space and time as we know them cease to exist there.
Scientists have long sought ways to avoid the complete breakdown of all the known laws of physics brought on by singularities. Now researchers suggest the centers of black holes may not hold singularities after all.
These new findings are based on loop quantum gravity, one of the leading theories seeking to unite quantum mechanics and general relativity into a single theory that can explain all the forces of the universe. In loop quantum gravity, the four dimensions of spacetime are composed of networks of intersecting loops - ripples of the gravitational field.
The researchers applied loop quantum gravity theory to the simplest model of black hole - a spherical, uncharged, non-rotating body known as a Schwarzschild black hole.
Comment: Update June 3, 2013: The original video published with this article was a brief excerpt from a Weather Channel TV program on solar tornadoes speculating about what it might be like if one of these were to take place on Earth. Since there is no evidence that such a thing has ever happened, we decided instead to replace it with the above explanatory content on the real and documented solar tornadoes.