Albert Abraham Michelson, American physicist, c 1910.

Albert Abraham Michelson (1852-1931) studied physics at various centres in Europe before becoming Profesor of Physics at Chicago in 1892. He established that the speed of light was a fundamental constant and, in 1907, became the first American scientist to be awarded the Nobel Prize for Physics. He is chiefly remembered for the Michelson-Morley experiment (1887) which proved the non-existence of hypothetical ether and set Albert Einstein (1879-1955) on the road to formulating his theory of relativity.