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Home > Dictionary of Science Quotations > Scientist Names Index F > Jean-Bernard-Lιon Foucault Quotes

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Jean-Bernard-Lιon Foucault
(18 Sep 1819 - 11 Feb 1868)

French physicist.


Science Quotes by Jean-Bernard-Lιon Foucault (2 quotes)

Science gains from it [the pendulum] more than one can expect. With its huge dimensions, the apparatus presents qualities that one would try in vain to communicate by constructing it on a small [scale], no matter how carefully. Already the regularity of its motion promises the most conclusive results. One collects numbers that, compared with the predictions of theory, permit one to appreciate how far the true pendulum approximates or differs from the abstract system called 'the simple pendulum'.
— Jean-Bernard-Lιon Foucault
'Demonstration Experimentale du Movement de Rotation de la Terre', 31 May 1851. In C. M. Gariel and J. Bertrand (eds.), Recueil des Travaux Scientifiques de Lion Foucault (1878), Vol. 2, 527. Trans. Harold Burstyn.
Science quotes on:  |  Experiment (543)  |  Pendulum (13)

The observations, so numerous and so important, of the pendulum as object are especially relevant to the length of its oscillations. Those that I propose to make known to the [Paris] Academy [of Sciences] are principally addressed to the direction of the plane of its oscillation, which, moving gradually from east to west, provides evidence to the senses of the diurnal movement of the terrestrial globe.
— Jean-Bernard-Lιon Foucault
'Demonstration Physique du Mouvement de Rotation de la Terre', 3 Feb 1851. In C. M. Gariel and J. Bertrand (eds.), Recueil des Travaux Scientifiques de Lion Foucault (1878), Vol. 2, 378. Trans. Harold Burstyn.
Science quotes on:  |  Earth (487)  |  Pendulum (13)



Quotes by others about Jean-Bernard-Lιon Foucault (1)

The velocity of light is one of the most important of the fundamental constants of Nature. Its measurement by Foucault and Fizeau gave as the result a speed greater in air than in water, thus deciding in favor of the undulatory and against the corpuscular theory. Again, the comparison of the electrostatic and the electromagnetic units gives as an experimental result a value remarkably close to the velocity of light–a result which justified Maxwell in concluding that light is the propagation of an electromagnetic disturbance. Finally, the principle of relativity gives the velocity of light a still greater importance, since one of its fundamental postulates is the constancy of this velocity under all possible conditions.
Studies in Optics (1927), 120.
Science quotes on:  |  Air (151)  |  Conclusion (120)  |  Condition (119)  |  Constancy (4)  |  Constant (40)  |  Corpuscle (8)  |  Electromagnetic (2)  |  Electrostatic (4)  |  Experiment (543)  |  Fundamental (122)  |  Importance (183)  |  James Clerk Maxwell (75)  |  Measurement (148)  |  Postulate (23)  |  Principle (228)  |  Propagation (9)  |  Relativity (50)  |  Result (250)  |  Speed Of Light (11)  |  Theory (582)  |  Unit (25)  |  Water (244)  |  Wave (55)


See also:
  • 18 Sep - short biography, births, deaths and events on date of Foucault's birth.
  • More for Jean-Bernard-Lιon Foucault on Today in Science History page.
  • Pendulum: Leon Foucault and the Triumph of Science, by Amir D. Aczel. - book suggestion.

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