Rows of computer screens. Photograph: Bernd Kammerer/AP
Dr Martin Novak of Michelfeld, Germany, has used his personal computer to calculate the world's longest prime number - a mere 10 million digits.
The optician with an amateur interest in mathematics was running the Great Internet Mersenne Prime Search (Gimps) on his home computer, a programme that harnesses the downtime of domestic machines to perform calculations. The principle, taken from the 1999 SETI@home search for aliens, is that hundreds of thousands of home computers working together can outpower even the biggest supercomputer.
Earlier this year, ClimatePrediction.net took data from its users to forecast the impact of global warming and, as Nature reports, physicists hope to enlist millions of computers to test Einstein's prediction that there are waves of gravity rippling through the cosmos. You can sign up to all of them now, though since Dr Novak has already won the $100,000 prize for the first 10 million digit prime number it will have to be purely for the love of learning.
