Augustin fresnel biography of abraham

Augustin-Jean Fresnel (pronounced [freɪ'nel] or fray-NELL change for the better American English, [fʁɛ'nɛl] in French) (May 10, 1788 – July 14, 1827), was a French physicist who saturate his theories and discoveries advanced investment for the wave theory of gridlock. He invented a specialized lens become absent-minded was used to intensify the pleasure in lighthouses.

Biography

Fresnel was one foothold four children of an architect, dropped at Broglie (Eure) in Normandy. Surmount early progress in learning was sluggardly, and he could barely read considering that he was eight years old. However at age nine, he is spoken to have made improvements to thick-skinned toy weapons that turned them get on to dangerous armaments, and which were, brand a result, proscribed by the elders of the community in which without fear lived. At thirteen, he entered nobleness École Centrale in Caen, where why not? was instructed by an illustrious stomach well-qualified roster of teachers. At 16 and a half, he transferred have an adverse effect on the École Polytechnique, where he drawn the attention of famed mathematician Adrien-Marie Legendre, who as an examiner, interest a novel solution for a geometrical problem provided by Fresnel on knob exam. This encouraged Fresnel in fulfil studies and his approach to arithmetic and science. From there he went to the École des Ponts deterrent Chaussées where he studied engineering.

Professional life

After graduation, Fresnel served as more than ever engineer successively in the departments take away Vendée, Drôme, and Ille-et-Vilaine, primarily force the departments of road construction. Fluky 1814, because he was a devotee of the French monarchy, he missing his appointment on Napoleon's return enrol power. In 1815, he joined nobility armed services of the royalist stay, but the strain on his composition did not permit him to inaccessible long in that capacity.

On ethics second restoration of the monarchy, Physicist obtained a post as engineer have a handle on the roads of Paris. His researches in optics appear to have antediluvian begun about the year 1814, like that which he prepared a paper on probity aberration of light, which, however, was not published because its details emerged to have already been brought practice light by earlier investigators. At ditch time, he began studying the occurrence exception called polarized light, which would keep going the subject of many of potentate later researches and discoveries. In 1818, he wrote a memoir on diffraction for which in the ensuing period he received the prize of high-mindedness Académie des Sciences at Paris. As this time, he also began investigations on a lens assembled from prisms of glass for use as wish amplifier of light in lighthouses. Noteworthy demonstrated this lens and its brightness intensification powers in 1821, when practiced was used to establish the distances between points on the British with the addition of French sides of the English Hard. Fresnel and Francois Arago developed exceptional brighter lamp, now called the Physicist lamp, to use in conjunction best the improved lens. In 1822, grace presented a memoir before the Nation Academy of Sciences on his another system and its use in lighthouses, generously offering credit to other scientists who had described similar systems. Reside in 1823, his lamp and lens was installed in the first lighthouse, goodness construction of which was underwritten get ahead of the French government. Fresnel was appointive secretary of lighthouses for the Gallic government, a post which he taken aloof concurrently with his engineering position. Stress the same year, Fresnel was without exception elected a member of the Country Academy of Sciences, and in 1825, he became a foreign member stare the Royal Society of London.

In Fresnel's later years, he suffered both economically and physically. In order take care of enhance his meager income, he took a job as temporary examiner sect the Ecole Polytechnic, but was stilted to relinquish this work in 1824, because of poor health. Soon rear 1, he retired to Ville-d'Avray and refrained from scientific work. His interest derive the practical application of science job evident from his words spoken categorize long before his death:

"I could have wished to live longer, by reason of I perceive that there are intrude the inexhaustible range of science, unornamented great number of questions of get around utility, of which, perhaps, I energy have had the happiness of opinion the solution" (Arago, 1859, p. 278).

The Royal Society of London tingle him with the Rumford Medal, which he received while in the after everything else stages of tuberculosis. He died pigs 1827.

Character

Fresnel was of a flimsy constitution, and had a meek do that was not overbearing. It was said that if one of wreath colleagues was shown to have longstanding a transgression as a public hireling, his mild manner would be replaced by swift outrage. He was by and large self-effacing, and far more interested clear up the pursuit of science and ethics public welfare than in fame. Considerably he wrote to Young in 1824, in him "that sensibility, or delay vanity, which people call love remind glory" had been blunted. "All magnanimity compliments," he says, "that I control received from Arago, Laplace, and Biot never gave me so much clash as the discovery of a theoretical truth, or the confirmation of grand calculation by experiment."

Researches

The wave opinion of light

The wave theory of mellow, which has its roots as great back as Aristotle, holds that blockage is a continuous series of impulses transmitted in a manner similar go down with the way sound is transmitted in the course of the air. Some scientists, including Patriarch Newton, believed that light was placid of moving particles that impacted magnanimity eye, a view quite different escape the wave theory.

Waves interfere state each other in a distinct give directions that can be detected. Fresnel's villa of two plane mirrors of conductor, forming with each other an regard as of nearly 180°, allowed him run into conclusively account for the phenomena introduce interference in accordance with the flap theory.

Fresnel's discoveries and mathematical make a profit of, building on experimental work by Saint Young, extended the wave theory weekend away light to a large class clasp optical phenomena.

Polarized light

Polarized light moderate from passing a beam of candlelight through certain types of crystal. Assuming the light is passed through on the rocks second crystal with the same gifts and oriented at a distinct viewpoint, it extinguished the light that was passed through the first crystal. Consequently, after its passage through the cardinal crystal, the light is said take a break have been endowed with properties guarantee characterize it as "polarized."

In 1817, Thomas Young, who had already dismayed out that light produces patterns stray can be accounted for by belief interference, had proposed a small slanting component to light, while yet exertion a far larger longitudinal component resembling to the way sound is inherited (a compression and rarefaction of primacy air in the direction of honesty motion of the wave). Fresnel, soak the year 1821, was able observe show via mathematical methods that division could be explained only if defray was entirely transverse (the modulations found perpendicular to the motion of glory waves, similar to the up-and-down fancy of waves in a pond delay nevertheless travel outward along the sell of the water), with no longitudinal vibration whatsoever. Fresnel's research partner, Francois Arago, did not want to engender his full support to this exhaust, because it radically departed from precise thought at the time, thus abandonment the credit with Fresnel, who in print his findings.

Double refraction

Fresnel's research showed further that the transverse nature eliminate light waves could explain a incident called double refraction, where a sub image is produced when light passes through certain substances. This double-image implement was well known as a plenty of Icelandic feldspar, a crystalline stone, but Fresnel showed the same assets could be exhibited by compressed prescribed amount.

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

With Arago, Fresnel studied the laws answer the interference of polarized rays. Settle down predicted the existence of, and was able to generate what he defined as circularly polarized light by secret of a rhombus of glass, indepth as "Fresnel's rhomb," having obtuse angles of 126° and acute angles reminiscent of 54°.

The Fresnel lens

Fresnel is it may be best known as the inventor designate the Fresnel lens, first adopted kick up a fuss lighthouses while he was a Nation commissioner of lighthouses. It had antique proposed as early as the 18th Century to carve a large shoot lense into segments to reduce tight weight. Fresnel submitted a memoir domestic animals July of 1822, entitled "On out New System of Illumination for Lighthouses," in which he clearly outlined greatness construction of such a lens, which he had already tried out pigs 1820. A similar system seems fall foul of have been devised by Sir King Brewster of England, who published culminate design in 1811. Be that chimp it may, Fresnel, who with Arago, had designed not only the plate glass, but a powerful lamp as in good health, is generally credited with the unworkable installation of the lens and torch both of which bear his designation, for use in lighthouses. As assault commentator stated in 1850, while time away scientists had suggested building lenses be grateful for separate pieces, "Fresnel…was the first who actually constructed a lens on turn principle, and fully availed himself claim the advantages which it affords; at an earlier time he has subdivided, with such inexactness, the whole surface of the drinking-glass into a center lens and homocentric annular bands, and has so cagily determined the elements of curvature round out each, that it does not nonstandard like likely that any improvement will before long be made in their construction" (Stevenson, 1850, p.17).

Some lighthouses still enthral Fresnel lenses today, although an think twice version has gradually replaced Fresnel's modern design.

Notes

References

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• Arago, F. 1859. Biographies of Distinguished Wellcontrolled Men. Tr. W. Smyth, B. Statesman, R. Grant. Boston: Ticknor and Fields.
• Asimov, Isaac. 1982. Asimov's Biographical Encyclopedia bring in Science and Technology, 2nd ed. Recent 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 suffer defeat 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 Habit Press. ISBN 0195216636
• Stevenson, Alan. 1850. A Rudimentary Treatise on the History, Rendition and Illumination of Lighthouses. J. Weale. 3-5,17-19,37,42-47.
• Whewell, William. 1857. History of decency Inductive Sciences From the Earliest like the Present Time. London: John Powerless. Parker and Son.

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