(1899 - 1977)
Mathematician and Physicist. He was a professor at the Massachusetts Institute of Technology. He studied relativity with Albert Einstein and electromagnetic theory with Max Planck. In 1946 he returned to Mexico and founded the Instituto Nacional de Energia Nuclear.
He was a pioneer in the field of cosmic-ray physics, and an advocate for the peaceful uses of atomic energy. He was president of the Latin American Council on Cosmic Rays, and represented Mexico in conferences of the United Nations Atomic Energy Council.