1892-1965

English physicist who was awarded the 1947 Nobel Prize for Physics for investigations of the ionosphere. His experiments on radio waves confirmed the existence of the Heaviside-Kennelly or E-layer originally proposed to explain Marconi's 1901 transatlantic radio transmission. In the first ever radio distance measurement, Appleton determined the layer's height to be approximately 100 km (62 miles). Further research revealed another layer above this—the Appleton or F-layer. Appleton's discoveries made possible many later advances in radio, shortwave, and radar.