Lorentz-Fitzgerald contraction. Artwork showing a sequence of tennis balls moving at different speeds, demonstrating the change in measured length (L*) from rest length (L) with velocities (v) close to that of the speed of light (c). At zero velocity, L=L* (left), while at the speed of light (right), L* tends towards zero. This change (along with time dilation) was explained in the Special Theory of Relativity developed by the Swiss-German physicist Albert Einstein (1905), but was first proposed by the Irish and French physicists George FitzGerald (1889) and Hendrik Lorentz (1892). The effect has been observed in particle physics experiments.