Albert Einstein (1879-1955) Germany, Switzerland, U.S.A.
Albert Einstein was probably the greatest physicist in all of history (some would say Isaac Newton shares that honor). The atomic theory achieved general acceptance only after Einstein's 1905 paper which showed that atoms' discreteness explained Brownian motion. Another famous 1905 paper introduced the famous equation E = mc2; yet Einstein published other papers that same year, two of which were more important and influential than either of the two just mentioned! No wonder that physicists speak of the Miracle Year without bothering to qualify it as Einstein's Miracle Year! (Altogether Einstein published at least 300 books or papers on physics.)
Although most famous for his Special and General Theories of Relativity, Einstein was also an early pioneer in quantum theory (although he disagreed with the usual view of the Uncertainty Principle). He received the Nobel Prize for discovering the photoelectric effect, but never received a Nobel Prize for either Theory of Relativity even though these were two of the most creative and important scientific theories ever.
Einstein certainly has the breadth, depth, and historical importance to qualify for this list; but his genius and significance were not in the field of pure mathematics. (He acknowledged his limitation, writing "I admire the elegance of your [Levi-Civita's] method of computation; it must be nice to ride through these fields upon the horse of true mathematics while the like of us have to make our way laboriously on foot.") Einstein was a mathematician, however; he pioneered the application to tensor calculus to physics and invented the "Einstein summation notation." I've chosen to include him on this list for the same reason I include Kepler: his extreme greatness overrides his focus away from math. Einstein ranks #10 on Michael Hart's famous list of the Most Influential Persons in History. Einstein once wrote "... the creative principle resides in mathematics [; thus] I hold it true that pure thought can grasp reality, as the ancients dreamed."
