Uploaded on Oct 18, 2010
According to Susskind, if Hawking's ideas were correct then it would infect all physics; there would no longer be any direct link between cause and effect. Physics would become impotent.
Since that meeting the "information paradox" has come to be seen as one of the most fundamental and most difficult problems in physics.
Arguments effectively boiled down into two camps. On the one side, Susskind and those who believed that Hawking was wrong and that information could not be lost - and on the other, Hawking and those who believed that physics would have to be re-written to take into account the uncertainty about information that Hawking had uncovered.
For 20 years, arguments raged. No side was willing to admit defeat... until a paper emerged written by a brilliant young Argentinean mathematician known as Juan Maldacena.
This paper claimed to be a rigorous mathematical explanation of what happened to information in black holes - and it showed that information was not lost. Hawking, it seemed, was on the losing side. But Hawking was not convinced.
Hawking set to work with a young research student, Christophe Galfard, to try to pick apart the Maldacena paper.
They thought they could use the same mathematical techniques employed by Maldacena to prove that information was in fact lost. But after two years' work, they still could not prove their thesis.
Then disaster struck, Stephen Hawking was taken ill with pneumonia and rushed to hospital; doctors feared for his life.
Hawking was kept in hospital for over three months. But whilst others fussed over his health, Hawking was thinking. Finally, on what many feared might be his death bed, he thought he'd come across what had eluded him for the past 30 years - a solution to the information paradox.