In "Discovering new primes" in issue No 1 we introduced PASS Maths readers to GIMPS, the Great Internet Mersenne Prime Search. Well, on Sunday 24th August 1997 they did it again.

Gordon Spence, an IT Manager from Hampshire beat the previous record and found the largest known prime number: 2 raised to the power of 2,976,221 minus 1, beating the previous record by a large margin.

Although Spence's prime is the 36th Mersenne prime to be found it is not necessarily the 36th one in sequence. There are many smaller Mersenne numbers still to be tested representing thousands of years of computing time on an ordinary desktop PC.

The reason for GIMPS' success is that there are thousands of participants all over the world checking the numbers on their PCs, and they're still looking for more. Taking part couldn't be easier and who knows? You might just end up in the record books.

- GIMPS
- The Great Internet Mersenne Prime Search.