Photograph by Justin Mullins - Beauty (Euler's Identity) - 1998
The British philosopher, logician and mathematician Bertrand Russell wrote in his Autobiography: ""It seems to me now that mathematics is capable of an artistic excellence as great as that of any music, perhaps greater; not because the pleasure it gives (although very pure) is comparable, either in intensity or in the number of people who feel it, to that of music, but because it gives in absolute perfection that combination, characteristic of great art, of godlike freedom, with the sense of inevitable destiny; because, in fact, it constructs an ideal world where everything is perfect but true."
According to Justin Mullins, an artist whose exhibition "Mathematical Photography" (snapshots of the most beautiful and the ugliest mathematical equations) opens today in London, what mathematicians traditionally call beauty is not visual but a conceptual elegance - for example, an equation that uses few assumptions or gives an original insight.
His supreme example of mathematical beauty is Euler's Identity. Discovered by the 18th century Swiss mathematician Leonhard Euler, it links the the fields of geometry, the study of space, and algebra, the study of structure and quantity.
His favourite, though, is the mathematical snapshot of "romance" which he gave to his partner, Sandra, which describes a phenomenon called quantum entanglement, discovered by Albert Einstein. It shows how two sub-atomic particles can be "linked in a very deep and fundamental way even though they may be separated by the width of the universe", said Mullins. True love in an equation. "She's now my wife so obviously it worked."