Parallel Worlds: A Journey Through Creation, Higher Dimensions, and the Future of the Cosmos

by Michio Kaku

Now, string theorists are trying to tackle the most difficult problem in black hole physics, the “information paradox.” Hawking has argued that if you throw something into a black hole, the information it carries is lost forever, never to return again. (This would be a clever way to commit the perfect crime. A criminal could use a black hole to destroy all incriminating evidence.) From a distance, the only parameters that we can measure for a black hole are its mass, spin, and charge. No matter what you throw into a black hole, you lose all its information. (This goes by the statement that “black holes have no hair”—that is, they have lost all information, all hair, except for these three parameters.) The loss of information from our universe seems to be an inevitable consequence of Einstein’s theory, but this violates the principles of quantum mechanics, which state that information can never really be lost. Somewhere, the information must be floating in our universe, even if the original object was sent down the throat of a black hole.