A number puzzle originating in the work of self-taught maths genius Srinivasa Ramanujan nearly a century ago has been solved. The solution may one day lead to advances in particle physics and computer security. Karl Mahlburg, a graduate student at the University of Wisconsin in Madison, US, has spent a year putting together the final pieces to the puzzle, which involves understanding patterns of numbers. "I have filled notebook upon notebook with calculations and equations," says Mahlburg, who has submitted a 10-page paper of his results to the Proceedings of the National Academy of Sciences. The patterns were first discovered...