An Etymological Dictionary of Astronomy and Astrophysics

An experiment first carried out in 1903 to reveal the absolute motion of the Earth with respect to the → ether. The experiment consists of detecting a torque on a charged parallel-plate → capacitor that was suspended so that its plates were vertical. Since the Earth moves around the Sun, the moving charges were expected to produce magnetic fields, and the resulting torque should tend to turn the capacitor bringing its plates parallel to its velocity. No such effect was observed, and
the absence of the torque supports the theory of → special relativity.

See also: Named after Frederick T. Trouton (1863-1922) and Henry R. Noble; → experiment.