Physicists and astronomers

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Eddington, Arthur 1882-1944
Early work on Relativity. Astrophysics. The internal composition of stars. Led an expedition to Africa in 1919 to measure the deflection of starlight by the gravitational field of the Sun.

Edison, Thomas Alva 1847-1931
Born in the U.S.A. Invented the evacuated light bulb (1879) and the gramophone. Street lighting in New York in 1882.

Einstein, Albert 1879-1955
German-Swiss Physicist. Later a naturalised American. Developed the theories of Special and General relativity. Proposed his photoelectric equation based on the quantum theory in 1905 and was awarded the Nobel Prize for Physics for this in 1921. Proposed the idea of stimulated emission that led to the development of the laser some forty years later.

Empedocles 495-435 BC
Greek philosopher. Optical tentacles theory of vision (444 BC). Proposed that all matter was composed of four elements – earth, air, fire and water.

Eratosthenes 275-194 BC
First measurement of the size of the Earth - 24000 miles. This was found in 240 BC. He found that the Sun's rays went vertically down a well at Syene (now Shahhat, Lybia) at noon in mid summer, while they made an angle of 7½^o with a vertical stick at Alexandria, 800 km to the north.

Eudoxus (Greek) 400-355 BC
Explained the motion of the planets by a set of twenty seven transparent concentric spheres centred on the Earth.