Foucaultn.
/fuːˈkəʊ/, U.S. /fuˈkoʊ/ Used attributively and in the possessive to designate experiments or discoveries made by Foucault, or apparatus designed by him. Foucault current n. an eddy current. Foucault method n. (also Foucault knife-edge method, Foucault test) a method of testing lenses and mirrors for surface irregularities. Foucault pendulum n. (also Foucault's pendulum) a pendulum designed to demonstrate the rotation of the earth by the rotation of its plane of oscillation. Foucault prism n. a polarizing prism resembling a Nicol prism but having the two halves separated by a film of air.
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the world > the earth > earth sciences > geography > map-making > map > [noun] > other representations
georama1823
moving map1830
Foucault pendulum1852
the world > physical sensation > sight and vision > optical instruments > instruments to refract, etc., light > [noun] > prism
prism1612
Nicol prism1838
Foucault prism1882
biprism1884
Fresnel biprism1890
Porro prism1909
pentaprism1937
the world > physical sensation > sight and vision > optical skills and techniques > [noun] > other techniques
collimation1687
autocollimation1870
neutralization1897
microprojection1904
Foucault method1923
orthostereoscopy1928
phase contrast1934
the world > matter > physics > electromagnetic radiation > electricity > electric current > flow of electricity > [noun] > eddy current
Foucault current1953
1852 London, Edinb., & Dublin Philos. Mag. 4th Ser. 3 331 (heading) A mathematical theory of M. Foucault's pendulum experiment.
1863 E. Atkinson tr. A. Ganot Elem. Treat. Physics 632 Foucault's experiment.—This consists in projecting on a screen the image of the charcoal points produced in the camera obscura at the moment at which the elctric light is formed.
1882 L. Wright Light xi. 251 A large Foucault prism is only about one-fourth the cost of a Nicol of the same aperture.
1883 E. Atkinson tr. A. Ganot Elem. Treat. Physics (ed. 11) 869 The currents..produced in solid conductors and which are converted into heat, are often spoken of as Foucault currents.
1887 T. C. Mendenhall Cent. of Electr. 189 Foucault's first automatic regulator.
1892 G. F. Barker Physics 835 Foucault's interrupter..consists of an arm supported on a vertical spring, carrying an armature at one end and a vertical platinum contact-point at the other.
1902 Encycl. Brit. XXIX. 195/1 Foucault's gyroscope.
1906 A. Russell Altern. Curr. II. 326 Foucault's disc.
1923 R. Glazebrook Dict. Appl. Physics IV. 329/1 For the investigation of spherical aberration errors Foucault's original knife-edge method is still frequently employed.
1929 Encycl. Brit. IX. 551/1 Eddy or ‘Foucault currents’ induced in a copper disc moving in a strong magnetic field.
1930 L. C. Martin Introd. Appl. Optics I. 204 In case a prism is wanted for purposes of ultra-violet polarimetry, the Foucault type..is employed.
1930 L. C. Martin Introd. Appl. Optics I. 257 (caption) The Foucault knife-edge test.
1931 Discovery May 164/1 A knowledge of the rotation of our world might be gained by such means as the Foucault pendulum or the gyro-compass.
1952 F. Twyman Prism & Lens Making (ed. 2) xi. 373 Correcting mirrors by local polishing with the help of the Foucault test.
1953 P. Kemp Alternating Current Electr. Engin. (ed. 8) x. 96 These e.m.f.s..set up local circulating currents known as Foucault or Eddy Currents and give rise to a loss of power.
1966 McGraw-Hill Encycl. Sci. & Technol. (rev. ed.) IX. 618 A Foucault pendulum is a spherical pendulum suspended so that its plane of oscillation is free to rotate.
This entry has not yet been fully updated (first published 1933; most recently modified version published online March 2022).
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