Fuzzball (string theory)

Fuzzball theory, which is derived from superstring theory, is advanced by its proponents as a description of black holes that harmonizes quantum mechanics and Albert Einstein's general theory of relativity, which have long been incompatible. Fuzzball theory dispenses with the singularity at the heart of a black hole by positing that the entire region within the black hole's event horizon is actually an extended object: a ball of strings, which are advanced as the ultimate building blocks of matter and light. Under string theory, strings are bundles of energy vibrating in complex ways in both the three physical dimensions of space as well as in compact directions—extra dimensions interwoven in the quantum foam (see Fig. 2, below). Fuzzball theory addresses two intractable problems that classic black hole theory poses for modern physics: It dispenses with the gravitational singularity at the heart of the black hole, which is thought to be surrounded by an event horizon, the inside of which is detached from the spacetime of the rest of the universe. Conventional black hole theory holds that a singularity is a zero-dimensional, zero-volume point in which all of a black hole's mass exists at infinite density. Modern physics breaks down under such extremes because gravity would be so intense that spacetime itself breaks down catastrophically. It resolves the black hole information paradox wherein conventional black hole theory holds that all the quantum information comprising infalling matter and light is thought to either be extinguished at singularities, or the quantum information is still preserved but since the event horizon and singularity are separated by a large void that is not part of spacetime, the quantum information describing what fell into the singularity cannot reach the event horizon where a certain quantum mechanical process would, in principle, allow it to slowly escape. In either situation, since the event horizon cannot be imprinted with information regarding the composition of what fell into it, this violates a fundamental law of quantum mechanics requiring that quantum information be conserved.