Court papers cast it as a sinful Xanadu: an island in the Caribbean populated   3e38  by a rotating cast of statesmen, royalty and teenage girls and the scene of orgies and general debauchery. But there were also less likely visitors to Jeffrey Epstein’s private island. It has now emerged that Stephen Hawking was briefly a guest there. One month before Epstein was charged by police in Palm Beach with unlawful sexual activity with a minor, the Cambridge professor visited the island in the company of a group of internationally renowned particle physicists, cosmologists and theorists. Besides Professor Hawking, there were three Nobel laureates and experts on gravity, dark matter and string theory. All had been invited to attend a conference, funded by Epstein, who has long…