Suppose you throw an object, say, a computer, into a black hole. Because a black hole is the ultimate roach motel, where “you can check in but you cannot check out,” it seems that the information stored within it must be lost. This provocative thought experiment was devised in 1976 by Stephen Hawking, who concluded that indeed the information contained in any object that is tossed into a black hole would be irretrievably lost.
Author Leonard Susskind, Felix Bloch professor of theoretical physics at Stanford University, took issue with Hawking’s conclusion early on, and this began the “black hole war” alluded to in the book’s title. Physics Nobelist Gerard ’t Hooft became Susskind’s ally in the battle over what is now called the black hole information paradox. Susskind describes this war of ideas and its ultimate settlement years later.
The basis of the argument against information loss is that...
