Many congratulations to Fabrice Bellard, the French computer scientist who has calculated the value of pi to a jaw-dropping 2.7 trillion decimal places. This is a new record, which took 131 days of computation time and checking. And all of this without supercomputers - he performed his calculations on a trusty desktop PC. The previous record (a mere 2.8 trillion places) was set last August by a team from the University of Tsukuba in Japan.

This area of work, the ability to calculate irrational numbers to ever-increasing accuracy, has become known as 'arbitrary precision arithmetic'. In itself, it seems unlikely that such an accurate value for pi will prove useful in any practical context. But the constant is often used in testing computers and software algorithms. And Monsieur Bellard's techniques, which he claims were 20 times faster than those used by the Japanese team, will contribute to further advances, and may even be used in other areas of mathematics and computer science.

We love this story because it highlights the fact that ordinary mathematicians can still make significant, ground-breaking contributions to mathematics.

Now, I wonder whether Monsieur Bellard can recite the value of pi he has calculated. Then I would be really impressed.