John Henry Poynting

John Henry Poynting (1852 to 1914) was an English physicist and Fellow of the Royal Society who became the first professor of physics at Mason Science College in 1880 and stayed on when it grew into the University of Birmingham. Born at a Unitarian parsonage in Eccles, Lancashire, he studied at Owens College and at the University of Cambridge, and worked in the Cavendish Laboratory under James Clerk Maxwell. His 1884 work gave the Poynting vector, which describes the direction and size of electromagnetic energy flow. He measured Newton's gravitational constant by a new method in 1893 and in 1903 recognised that sunlight pulls small particles toward the Sun, the Poynting-Robertson effect. With J. J. Thomson he wrote a long-lived multi-volume physics textbook.