The Lorentz-Fitzgerald contraction hypothesis was proposed by Fitzgerald and independently proposed and extended by Lorentz to explain the negative result of the Michelson-Morley experiment, which attempted to detect Earth's motion relative to the luminiferous aether. Fitzgerald suggested that when a body moves through space it experiences a compression in the direction of the motion. Lorentz showed how such an effect might be expected based on electromagnetic theory and the electrical constitution of matter, that is, when a body moves through space its dimension parallel to the line of motion might become less by an amount dependendant on its speed. If the speed of the body is v and the speed of light is c, then the contraction is in the ratio
Lorentz was not particularly satisfied with his hypothesis because he realized that it was ad hoc and not testable by experiment.
To quote Poincare (Science and Hypothesis):
- "Then more exact experiments were made, which were also negative; neither could this be the result of chance. An explanation was necessary, and was forthcoming; they always are; hypothesis are what we lack the least"