Born in Ulm, Württemberg (now Germany), Einstein was a theoretical physicist who initiated a scientific revolution with his theory of general relativity. Challenging classical mechanics and its basis in Newtonian science, Einstein replaced the Euclidean model of geometry with four-dimensional spacetime and, from the axiom of the absolute speed of light, logically deduced the relativity of time. Subsequent to the advent of relativity theory, there is no longer any absolute temporal metric for defining the real. Einstein published two seminal papers, “Zur Elektrodynamik bewegter Körper” (1905; “The Special Theory of Relativity”) and “Die Grundlage der allgemeinen Relativitätstheorie” (1916; “The General Theory of Relativity”), and in 1921 was awarded the Nobel Prize in Physics. His name and iconic visage have become synonymous with modern science, leaving an ineradicable imprint on 20th-century culture far beyond the enclaves of scientific research, a status partly achieved by his willingness to popularize his work. Einstein made lasting contributions to gravitational field theory, astrophysics and quantum mechanics, and much fame has accrued around his groundbreaking formula E = mc², with its articulation of mass-energy equivalence. But it is with the theory and concept of time-relativity that Einstein’s thought crosses over into cultural and aesthetic modernism.