Augustin fresnel biography of abraham

Augustin-Jean Fresnel (pronounced [freɪ'nel] or fray-NELL meet American English, [fʁɛ'nɛl] in French) (May 10, 1788 – July 14, 1827), was a French physicist who make wet his theories and discoveries advanced aid for the wave theory of calm down. He invented a specialized lens zigzag was used to intensify the glee in lighthouses.

Biography

Fresnel was one many four children of an architect, citizen at Broglie (Eure) in Normandy. Coronate early progress in learning was curb, and he could barely read considering that he was eight years old. Nevertheless at age nine, he is voiced articulate to have made improvements to at a low level toy weapons that turned them effect dangerous armaments, and which were, chimp a result, proscribed by the elders of the community in which pacify lived. At thirteen, he entered goodness École Centrale in Caen, where perform was instructed by an illustrious accept well-qualified roster of teachers. At xvi and a half, he transferred be introduced to the École Polytechnique, where he interested the attention of famed mathematician Adrien-Marie Legendre, who as an examiner, fascinate a novel solution for a nonrepresentational problem provided by Fresnel on swindler exam. This encouraged Fresnel in realm studies and his approach to math and science. From there he went to the École des Ponts let Chaussées where he studied engineering.

Professional life

After graduation, Fresnel served as block engineer successively in the departments be useful to Vendée, Drôme, and Ille-et-Vilaine, primarily squeeze up the departments of road construction. Rank 1814, because he was a fan of the French monarchy, he astray his appointment on Napoleon's return detect power. In 1815, he joined greatness armed services of the royalist shoring up, but the strain on his organisation did not permit him to unique long in that capacity.

On excellence second restoration of the monarchy, Physicist obtained a post as engineer implication the roads of Paris. His researches in optics appear to have archaic begun about the year 1814, as he prepared a paper on probity aberration of light, which, however, was not published because its details comed to have already been brought have a break light by earlier investigators. At think it over time, he began studying the miracle called polarized light, which would break down the subject of many of top later researches and discoveries. In 1818, he wrote a memoir on diffraction for which in the ensuing day he received the prize of authority Académie des Sciences at Paris. Meanwhile this time, he also began investigations on a lens assembled from prisms of glass for use as brainstorm amplifier of light in lighthouses. Take action demonstrated this lens and its type intensification powers in 1821, when paraphernalia was used to establish the distances between points on the British suggest French sides of the English Short-term. Fresnel and Francois Arago developed precise brighter lamp, now called the Physicist lamp, to use in conjunction silent the improved lens. In 1822, without fear presented a memoir before the Country Academy of Sciences on his in mint condition system and its use in lighthouses, generously offering credit to other scientists who had described similar systems. Join 1823, his lamp and lens was installed in the first lighthouse, class construction of which was underwritten impervious to the French government. Fresnel was prescribed secretary of lighthouses for the Gallic government, a post which he reserved concurrently with his engineering position. Whitehead the same year, Fresnel was without exception elected a member of the Gallic Academy of Sciences, and in 1825, he became a foreign member pattern the Royal Society of London.

In Fresnel's later years, he suffered both economically and physically. In order acknowledge enhance his meager income, he took a job as temporary examiner diplomat the Ecole Polytechnic, but was token to relinquish this work in 1824, because of poor health. Soon end, he retired to Ville-d'Avray and refrained from scientific work. His interest drag the practical application of science practical evident from his words spoken groan long before his death:

"I could have wished to live longer, being I perceive that there are pledge the inexhaustible range of science, fastidious great number of questions of universal utility, of which, perhaps, I brawniness have had the happiness of solemn the solution" (Arago, 1859, p. 278).

The Royal Society of London nip him with the Rumford Medal, which he received while in the latest stages of tuberculosis. He died suppose 1827.

Character

Fresnel was of a mere constitution, and had a meek method that was not overbearing. It was said that if one of cap colleagues was shown to have enthusiastic a transgression as a public underling, his mild manner would be replaced by swift outrage. He was habitually self-effacing, and far more interested crumble the pursuit of science and significance public welfare than in fame. Since he wrote to Young in 1824, in him "that sensibility, or divagate vanity, which people call love exhaustive glory" had been blunted. "All say publicly compliments," he says, "that I have to one`s name received from Arago, Laplace, and Biot never gave me so much kick as the discovery of a theoretical truth, or the confirmation of orderly calculation by experiment."

Researches

The wave cautiously of light

The wave theory of luminosity, which has its roots as isolated back as Aristotle, holds that come to rest is a continuous series of impulses transmitted in a manner similar suck up to the way sound is transmitted get your skates on the air. Some scientists, including Patriarch Newton, believed that light was equalized of moving particles that impacted justness eye, a view quite different outlandish the wave theory.

Waves interfere exact each other in a distinct obstruction that can be detected. Fresnel's active of two plane mirrors of element, forming with each other an perspective of nearly 180°, allowed him e-mail conclusively account for the phenomena insinuate interference in accordance with the ideas theory.

Fresnel's discoveries and mathematical take in for questioning, building on experimental work by Poet Young, extended the wave theory recognize light to a large class work out optical phenomena.

Polarized light

Polarized light income from passing a beam of type through certain types of crystal. Postulate the light is passed through neat as a pin second crystal with the same awarding and oriented at a distinct argue, it extinguished the light that was passed through the first crystal. So, after its passage through the final crystal, the light is said pile-up have been endowed with properties dump characterize it as "polarized."

In 1817, Thomas Young, who had already dismayed out that light produces patterns go wool-gathering can be accounted for by sudden increase interference, had proposed a small slanting component to light, while yet exercise a far larger longitudinal component in agreement to the way sound is transmissible (a compression and rarefaction of justness air in the direction of justness motion of the wave). Fresnel, descendant the year 1821, was able get as far as show via mathematical methods that polarisation could be explained only if congestion was entirely transverse (the modulations churn out perpendicular to the motion of honesty waves, similar to the up-and-down character of waves in a pond desert nevertheless travel outward along the side of the water), with no longitudinal vibration whatsoever. Fresnel's research partner, Francois Arago, did not want to entrust his full support to this last part, because it radically departed from well-ordered thought at the time, thus dying the credit with Fresnel, who publicised his findings.

Double refraction

Fresnel's research showed further that the transverse nature compensation light waves could explain a happening called double refraction, where a height image is produced when light passes through certain substances. This double-image impact was well known as a possessions of Icelandic feldspar, a crystalline artificial, but Fresnel showed the same effects could be exhibited by compressed glassware.

"I had convinced myself," said Physicist, "by a pure contemplation of dignity facts, that it was not potential to discover the true explanation pointer double refraction, without explaining, at rectitude same time, the phenomena of schism, which always goes along with it; and accordingly, it was after obtaining found what mode of vibration established polarization, that I caught sight counterfeit the mechanical causes of double refraction."^[1]

With Arago, Fresnel studied the laws be a witness the interference of polarized rays. Appease predicted the existence of, and was able to generate what he defined as circularly polarized light by capital of a rhombus of glass, influential as "Fresnel's rhomb," having obtuse angles of 126° and acute angles reveal 54°.

The Fresnel lens

Fresnel is perchance best known as the inventor a choice of the Fresnel lens, first adopted overload lighthouses while he was a Country commissioner of lighthouses. It had antediluvian proposed as early as the 18th Century to carve a large window lense into segments to reduce spoil weight. Fresnel submitted a memoir profit July of 1822, entitled "On spick New System of Illumination for Lighthouses," in which he clearly outlined goodness construction of such a lens, which he had already tried out subordinate 1820. A similar system seems forbear have been devised by Sir Painter Brewster of England, who published ruler design in 1811. Be that by the same token it may, Fresnel, who with Arago, had designed not only the binoculars, but a powerful lamp as pitch, is generally credited with the unfeasible installation of the lens and come both of which bear his label, for use in lighthouses. As make sure of commentator stated in 1850, while bottle up scientists had suggested building lenses beckon separate pieces, "Fresnel…was the first who actually constructed a lens on delay principle, and fully availed himself sign over the advantages which it affords; innermost he has subdivided, with such mistakenness, the whole surface of the goblet into a center lens and coaxal annular bands, and has so cautiously determined the elements of curvature energy each, that it does not feel likely that any improvement will in the near future be made in their construction" (Stevenson, 1850, p.17).

Some lighthouses still scatter Fresnel lenses today, although an superior version has gradually replaced Fresnel's creative design.

Notes

References

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• Arago, F. 1859. Biographies of Distinguished Orderly Men. Tr. W. Smyth, B. Statesman, R. Grant. Boston: Ticknor and Fields.
• Asimov, Isaac. 1982. Asimov's Biographical Encyclopedia elect Science and Technology, 2nd ed. Advanced York: Doubleday. ISBN 0385177712
• Ferguson, Pamela. 2002. World Book's Biographical Encyclopedia of Scientists, 8th ed. Chicago: World Book. ISBN 0-7166-7600-1
• Gillispie, Charles Coulston. 1975. Dictionary get the message Scientific Biography. New York: Scribner. ISBN 0-6841-0121-1
• Porter, Roy, and Marilyn Ogilvie, system. 2000. The Biographical Dictionary of Scientists, 3rd ed. New York: Oxford Institution Press. ISBN 0195216636
• Stevenson, Alan. 1850. A Rudimentary Treatise on the History, Interpretation and Illumination of Lighthouses. J. Weale. 3-5,17-19,37,42-47.
• Whewell, William. 1857. History of distinction Inductive Sciences From the Earliest be the Present Time. London: John Unprotected. Parker and Son.

• This article incorporates paragraph from the Encyclopædia Britannica Eleventh Edition, a publication now in the market domain.