John William Strutt, 3rd Baron Rayleigh

John William Strutt, third Baron Rayleigh, was one of the most versatile British physical scientists between roughly 1850 and 1930. Born at Langford Grove, near Maldon in Essex, in 1842, he died at Witham, in the same county, in 1919. His work spanned almost every branch of physics, and he also ventured into other disciplines, which places him in the tradition of Helmholtz.

He was educated at the University of Cambridge, where he held the Cavendish Professorship of Experimental Physics from 1879 to 1884. Between 1887 and 1905 he was Professor of Natural Philosophy at the Royal Institution in London and, in 1905, he presided over the Royal Society. Together with William Ramsay he received the Nobel Prize for the discovery of argon.

His most celebrated work in acoustics, Theory of Sound, written over roughly five years between 1877 and 1878, is a standard reference work, often regarded as the bible of acoustics. In this field he extended Helmholtz's theory of resonators, refined the corrections for resonance tubes, and theoretically explained the heat-maintained vibrations in tubes, an effect known as the Rijke tube. He also studied singing and sensitive flames, and attributed the whispering-gallery effect of St Paul's Cathedral to the slight inward inclination of its walls. His collected papers, numbering more than four hundred, were published in 1922.