You are the world's cleverest man. You have solved one of maths' most intractable problems. Do you a) accept a $1m reward, or b) reject the money, barricade yourself inside your flat and refuse to answer the door? The answer, if you are the reclusive Russian genius Grigory Perelman, is b).
The Clay Mathematics Institute in Cambridge, Massachusetts, last week honoured Perelman for his solution to a problem posed almost a century ago by French mathematician Henri Poincaré. The theorem – known as Poincaré's conjecture – involves the deep structure of three-dimensional shapes. It is one of seven elusive challenges set by the institute, each carrying a $1m reward. It took the world's leading mathematicians several years to verify that Perelman had definitively solved the problem in a paper published in 2002.
Perelman, however, doesn't want the cash. This latest snub follows his refusal in 2006 to collect the maths equivalent of an Oscar, the Fields Medal. Perelman is currently jobless and lives with his mother and sister in a small flat in St Petersburg. (He has his own spartan one-bedroom flat, allegedly full of cockroaches, but rarely uses it.)