How Lengths Contract Through Movement

The notion in regard to contraction was initially submitted by a somewhat unheard of Irish physicist, George Francis FitzGerald. FitzGerald shared his idea in a brief communication to the American Journal Science in 1891, ten years after Michelson’s first documented result, furthermore he proposed a cause.


I propose that virtually the only theory that is able to resolve this “conflict” is that the length of form changes, conforming as they are moving through the ether or even across it, by an amount depending on the square of the ratio of their accelerations to that of light. We understand that energy forces are impacted by the motion of the energized bodies relative to the ether, furthermore it appears to be a not improbable supposition that the molecular forces are undoubtedly influenced by the motion, and that the proportions of a body alters as a result.

While FitzGerald described the ether, which was thought to be the carrier for light waves at the time, the objective viewpoint holds with or without the ether. Somewhat later his somewhat timid suggestion that molecular forces are actually altered by motion was actually repeated and honed by the most recognized physicist of the time.

Although FitzGerald was actually little known outside Ireland, the Dutch scientist Hendrik Lorentz was certainly identified as the greatest physicist since Maxwell. In 1902 he and Pieter Zeeman received the second Nobel Prize ever awarded for identifying the “Zeeman effect” that resulted in the discovery of electron spin (Chapter 6). Einstein described Lorentz “the most well-rounded and harmonious personality he had met in his entire life” (P1982, p. 169). Upon Lorentz’s passing, Europe’s greatest physicists attended the funeral and three minutes of silence were actually observed throughout Holland.

Lorentz had actually not seen FitzGerald’s study, yet he too recognized that Michelson’s strange result could make sense in the event that the apparatus contracted along the direction of motion. He went further than FitzGerald; he did the calculation (not an easy one) using Maxwell’s equations. When he found that the theoretical contraction accurately compensated for the extra traveling distance, this was surely one of the great “Eureka” moments in physics, equal to those of Newton and Einstein.