CALCULATE THIS

In 1696, Johann Bernoulli (above) tried to trick Isaac Newton into showing his hand on calculus, in the hope of proving once and for all that Leibniz (above) was its true inventor.

The “trick” involved sending out an open invitation to “the best mathematicians in the world”, asking them to solve a difficult problem that he knew required the use of calculus. It’s known as the “brachistochrone problem” (pronounced “brack-ist-o-krone”), and it asks for the shape of a frictionless wire down which a bead would slide in the shortest possible amount of time.

Of course, Bernoulli had already managed to prove that the required shape was part of an inverted cycloid, and only four other correct solutions were received – from his brother Jakob, Leibniz, the Marquis de l’hôpital (Bernoulli’s first student), and “anonymous”.

Bernoulli recognised the anonymous mathematician immediately: it had Newton’s virtuosity stamped all over it.