John William Strutt, 3rd Baron Rayleigh

John William Strutt, 3rd Baron Rayleigh, was a British physicist born 12 November 1842 into a hereditary peerage. In 1871 he published the first theoretical treatment of elastic light scattering by particles much smaller than the wavelength - Rayleigh scattering - which explained the blue of the sky. He described transverse surface waves in solids (Rayleigh waves), contributed circulation theory for aerodynamic lift, and introduced the Rayleigh number, Rayleigh flow, the Rayleigh-Taylor instability, and the stability criterion for Taylor-Couette flow. In optics he proposed a criterion for angular resolution; in thermodynamics his Rayleigh-Jeans law for black-body radiation later helped birth quantum mechanics. His 1877 textbook The Theory of Sound remains in use. In 1904 he won the Nobel Prize in Physics for discovering argon. He served as President of the Royal Society from 1905 to 1908 and as Chancellor of the University of Cambridge from 1908 until his death on 30 June 1919.