Léon Nicolas Brillouin (August 7, 1889 – October 4, 1969) was a French physicist. He was born in Sèvres, France. His father,
Marcel Brillouin, grandfather, Éleuthère Mascart, and great-grandfather, Charles Briot, were physicists as well. He made contributions
to quantum mechanics, radio wave propagation in the atmosphere, solid state physics, and information theory.
