It has been 150 years since the mathematician Bernhard Riemann published the conjecture which is now one of the most important unsolved problems in mathematics. The Riemann hypothesis encapsulates humankind's attempt to understand the mysteries of the primes: why there is no apparent pattern in the way the primes are distributed on the number line. The hypothesis is one of the Clay Mathematics Institute's Millennium Prize Problems — anyone who proves (or disproves) it will receive one million dollars.

If you'd like to have a go at solving the Riemann hypothesis yourself, then learn more about it in the Plus articles A whirlpool of numbers, The prime number lottery, and The music of the primes. To find out more about the Clay Institute Millennium Prize Problems, read How maths can make you rich and famous, Part I and Part II.