Poynting, John Henry

Poynting, John Henry, 1852–1914, British physicist. He was educated at Liverpool and Cambridge and was professor of physics at the Univ. of Birmingham for most of his life. He is best known for the Poynting vector, which gives the direction and magnitude of the propagation of electromagnetic radiation in space, and for his determination of the gravitational constant by use of an ordinary balance. He also did research in experimental physics and in various areas of physical chemistry (e.g., on phase changes and osmotic pressure).