Mathematician George David Birkhoff (1884–1944) is best known for his work on differential equations and dynamics. His ergodic theorem gave the kinetic theory of gases a rigorous basis. He solved important problems in celestial mechanics and made contributions to the mathematical foundations of relativity theory and quantum mechanics.
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Birkhoff also had a keen interest in aesthetics—the qualities that make a painting, sculpture, musical composition, or poem pleasing to the eye, ear, or mind. He sought a formula—a mathematical measure—that would capture an object’s beauty.