Harry Bateman FRS (29 May 1882 – 21 January 1946) was an English mathematician. The differential equations of mathematical physics fascinated him. With Ebenezer Cunningham, he expanded the views of spacetime symmetry of Lorentz and Poincare to a more expansive conformal group of spacetime leaving Maxwell's equations invariant. Moving to the U.S.A., and obtaining a Ph.D. in geometry with Frank Morley, he became a professor of mathematics at California Institute of Technology. There he taught fluid dynamics to students going into aerodynamics with Theodore von Karman. Bateman made a broad survey of applied differential equations in his Gibbs Lecture in 1943 titled "The control of an elastic fluid".