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Jean Bernard Léon Foucault (French pronunciation: [ʒɑ̃ bɛʁnaʁ leɔ̃ fuko]) (18 September 1819 – 11 February 1868) was a French physicist best known for the invention of the Foucault pendulum, a device demonstrating the effect of the Earth's rotation. He also made an early measurement of the speed of light, discovered eddy currents, and although he didn't invent it, is credited with naming the gyroscope. The Foucault crater on the Moon is named after him.Foucault was the son of a publisher in Paris, where he was born on September 18, 1819. After an education received chiefly at home, he studied medicine, which he abandoned in favour of physics due to a fear of blood.[1] He first directed his attention to the improvement of L. J. M. Daguerre's photographic processes. For three years he was experimental assistant to Alfred Donné (1801–1878) in his course of lectures on microscopic anatomy.
Polarization-diversity radar: Two theoretical studies (Scientific report/Stormy Weather Group)
With A. H. L. Fizeau he carried out a series of investigations on the intensity of the light of the sun, as compared with that of carbon in the arc lamp, and of lime in the flame of the oxyhydrogen blowpipe; on the interference of infrared radiation, and of light rays differing greatly in lengths of path; and on the chromatic polarization of light.
In 1851, he provided the first experimental demonstration of the rotation of the Earth on its axis (see diurnal motion). This was achieved by considering the rotation of the plane of oscillation of a freely suspended, long and heavy pendulum in the Panthéon in Paris. The experiment caused a sensation in both the learned and popular worlds. In the following year he used (and named) the gyroscope




as a conceptually simpler experimental proof. In 1855, he received the Copley Medal of the Royal Society for his 'very remarkable experimental researches'. Earlier in the same year he was made physicien (physicist) at the imperial observatory at Paris.

In September, 1855, he discovered that the force required for the rotation of a copper disc becomes greater when it is made to rotate with its rim between the poles of a magnet, the disc at the same time becoming heated by the eddy current or "Foucault currents" induced in the metal.


Diagram of a variant of Leon Foucault's speed of light experiment where a modern laser is the source of light.In 1857, Foucault invented the polarizer which bears his name, and in the succeeding year devised a method of testing the mirror of a reflecting telescope to determine its shape. The so-called "Foucault Test" allows the worker to tell if the mirror is perfectly spherical, or if it deviates from a sphere. Prior to Foucault's invention, testing reflecting telescope mirrors was a "hit or miss" proposition.
With Charles Wheatstone’s revolving mirror he, in 1862, determined the speed of light to be 298,000 km/s (about 185,000 mi./s) —10,000 km/s less than that obtained by previous experimenters and only 0.6% off the currently accepted value.

Albert Abraham Michelson .

Albert Abraham Michelson (December 19, 1852 – May 9, 1931) was an American physicist known for his work on the measurement of the speed of light and especially for the Michelson-Morley experiment.
Radiation in a magnetic field.A theory of the X-Rays.

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Pars pro toto is Latin for "(taking) a part for the whole"[1] where a portion of an object or concept represents the entire object or context.

When used in a context of language it means that something is named after a part of it, or after a limited characteristic, in itself not necessarily representative for the whole. For example, "glasses" is a pars pro toto name for something that consists of more than just two pieces of glass.

Pars pro toto is a common device in iconography, where a particular icon can stand for a complete set of characteristics.


The opposite of a pars pro toto is a totum pro parte, in which the whole is used to describe a part, such as Germany for West Germany or East Germany during the Cold War or America in the place of the United States of America.

A similar term, synecdoche, comes from Greek, meaning 'simultaneous understanding'.

metaphor

Sometimes, metaphor and metonymy can both be at work in the same figure of speech, or one could interpret a phrase metaphorically or metonymically. For example, the phrase "lend me your ear" could be analyzed in a number of ways. We could imagine the following interpretations:
The Symbol of the Soul Form Holderlin to Yeats: A Study in Metonymy
Analyze "ear" metonymically first — "ear" means "attention" (because we use ears to pay attention to someone's speech). Now, when we hear the phrase "lending ear (attention)", we stretch the base meaning of "lend" (to let someone borrow an object) to include the "lending" of non-material things (attention), but, beyond this slight extension of the verb, no metaphor is at work.
Imagine the whole phrase literally — imagine that the speaker literally borrows the listener's ear as a physical object (and the person's head with it). Then the speaker has temporary possession of the listener's ear, so the listener has granted the speaker temporary control over what the listener hears. We then interpret the phrase "lend me your ear" metaphorically to mean that the speaker wants the listener to grant the speaker temporary control over what the listener hears.
First, analyze the verb phrase "lend me your ear" metaphorically to mean "turn your ear in my direction," since we know that literally lending a body part is nonsensical. Then, analyze the motion of ears metonymically — we associate "turning ears" with "paying attention," which is what the speaker wants the listeners to do.
It is difficult to say which of the above analyses most closely represents the way a listener interprets the expression, and it is possible that the phrase is analysed in different ways by different listeners, or even by one and the same listener at different times. Regardless, all three analyses yield the same interpretation; thus, metaphor and metonymy, though quite different in their mechanism, can work together seamlessly. For further analysis of idioms in which metaphor and metonymy work together, including an example very similar to the one given here.

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In the theory of probability, the Glivenko–Cantelli theorem, named after Valery Ivanovich Glivenko and Francesco Paolo Cantelli, determines the asymptotic behaviour of the empirical distribution function as the number of iid observations grows. This uniform convergence of more general empirical measures becomes an important property of the Glivenko–Cantelli classes of functions or sets. The Glivenko–Cantelli classes arise in VC theory, with applications to machine learning. Applications can be found in Econometrics making use of e.g. M-estimators