John Henry Poynting ( 9 Sep 1852 - 30 Mar 1914) British physicist who introduced a theorem (1884-85) that assigns a value to the rate of flow of electromagneticenergy known as the Poyntingvector, introduced in his paper On the Transfer of Energy in the ElectromagneticField (1884). In this he showed that the flow of energy at a point can be expressed by a simple formula in terms of the electric and magnetic forces at that point. He determined the mean density of the Earth (1891) and made a determination of the gravitational constant (1893) using accurate torsion balances. He was also the first to suggest, in 1903, the existence of the effect of radiation from the Sun that causes smaller particles in orbit about the Sun to spiral close and eventually plunge in.
Posted on: Mon, 09 Sep 2013 04:29:14 +0000
Trending Topics
Recently Viewed Topics
© 2015