Lord Rayleigh
1842–1919, Langford Grove, Essex, England, Terling, Essex, England
English physicist who co-discovered the gas argon through high-precision gas-density measurements, winning the 1904 Nobel Prize in Physics.
John William Strutt, 3rd Baron Rayleigh, was one of the most accomplished physicists of the Victorian era — author of the classic The Theory of Sound (1877), Cavendish professor at Cambridge (1879–1884), and thereafter a researcher at his private laboratory at Terling Place. He explained the blue colour of the sky through what is now called Rayleigh scattering, and his meticulous gas-density measurements led to the discovery of argon — the first noble gas. He served as president of the Royal Society (1905–1908) and received the 1904 Nobel Prize in Physics.
Nobel-winning work
The 1904 Nobel Prize honoured 'his investigations of the densities of the most important gases and for his discovery of argon in connection with these studies'. In the 1890s Rayleigh made weighing measurements of gases so precise that he noticed nitrogen extracted from air was consistently about one part in a thousand denser than nitrogen obtained from chemical compounds — a small anomaly he refused to dismiss and resolved to pursue to its source.
Working with the chemist William Ramsay, he removed nitrogen from air by chemical reaction and proved the residual fraction was a new, entirely inert element — in 1894 they announced the discovery of argon, the first noble gas isolated. The discovery opened a whole new column of the periodic table and demonstrated the value of taking small measurement discrepancies seriously: a seemingly negligible difference had revealed a hidden element.
Workplaces: University of Cambridge (Cavendish Laboratory)
United Kingdom