Albert Einstein (1879-1955), German-born physicist. Famous for his theories of relativity, Einstein has become a cultural icon, his name synonymous with genius. In 1905, whilst working as a patent clerk, he wrote four papers, including one on special relativity. From this the idea of a space-time continuum followed and is represented here as space warped into the shape of an hourglass (at right). His paper on general relativity followed in 1916, which theorized that gravitational acceleration can be described by the curvature of space and time. His theories replaced the previously unchallenged Newtonian system, and as such have shaped modern physics.