However, the hypothesis of ether was also not free from difficulties. Soon the question arose as to what was the effect of the motion of bodies through all-pervading ether. For if the ether was a luminiferous medium behaving like an elastic solid, there should be some effect of it on the planets travelling through it at immense speed in their orbital motion and also on the light waves propagating through it. In an attempt to measure the velocity of the earth through the 'ether', by measuring the effect which such a velocity would have upon the velocity of light, two American physicists, A.A. Michelson and E.W. Morley performed a classic experiment in Cleveland in the year 1881. In this experiment, light-rays were used to detect the effect of earth's motion on the ether, and thus prove its real existence.