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Fresnel's legacy is the more remarkable in view of his lifelong battle with [[tuberculosis]], to which he succumbed at the age of 39. Although he did not become a public celebrity in his short lifetime, he lived just long enough to receive due recognition from his peers, including (on his deathbed) the [[Rumford Medal]] of the [[Royal Society of London]], and his name recurs frequently in the modern terminology of optics and waves.
Inevitably, after the wave theory of light was subsumed by [[James Clerk Maxwell|Maxwell]]'s [[electromagnetism|electromagnetic]] theory in the 1860s and '70s, the magnitude of Fresnel's contribution was somewhat obscured. In the period between Fresnel's unification of physical optics and Maxwell's wider unification, a contemporary authority, Professor [[Humphrey Lloyd (physicist)|Humphrey Lloyd]], described Fresnel's transverse-wave theory as "the noblest fabric which has ever adorned the ___domain of physical science, Newton's system of the universe alone excepted."{{r|lloyd-1841}}<br style="margin-bottom: 1ex;" />
== Early life ==
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=== Polarization ===
=== Partial reflection ===
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=== Reception ===
== Lighthouses and the Fresnel lens ==
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=== Later developments ===
Production of one-piece stepped lenses (roughly as envisaged by Buffon) eventually became profitable. By the 1870s, in the
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== Honors ==
[[File:Bust of Augustin Fresnel by David d'Angers-MnM 41 OA 256 D-IMG 8741.jpg|thumb
In 1823, Fresnel was unanimously elected a member of the [[French Academy of Sciences|Académie des Sciences]].{{r|brock-1909}}{{r|chisholm-1911-fresnel}} In 1824<ref>Levitt, 2013, p.{{hsp}}77.</ref> he was made a ''chevalier de la Légion d'honneur'' (Knight of the [[Legion of Honour]]).{{r|academie}} Meanwhile in Britain, the wave theory was yet to take hold; late in 1824, Fresnel wrote to Thomas Young, saying in part:<blockquote>I am far from denying the value that I attach to the praise of English scholars, or pretending that they would not have flattered me agreeably. But for a long time this sensibility, or vanity, which is called the love of glory, has been much blunted in me: I work far less to capture the public's votes than to obtain an inner approbation which has always been the sweetest reward of my efforts. Doubtless I have often needed the sting of vanity to excite me to pursue my researches in moments of disgust or discouragement; but all the compliments I received from MM. Arago, Laplace, and Biot never gave me as much pleasure as the discovery of a theoretical truth and the confirmation of my calculations by experiment.<ref>Fresnel to Young, 26 November 1824, in Young, 1855, pp.{{nnbsp}}402–3</ref></blockquote>But the "praise of English scholars" soon followed. On 9 June 1825, Fresnel was made a Foreign Member of the [[Royal Society|Royal Society of London]].{{r|royalS-2007}} In 1827{{r|chisholm-1911-fresnel|rines-1919}} he was awarded the Society's [[Rumford Medal]] for the year 1824, "For
The monument to Fresnel at his birthplace (see [[#Early life|above]]) was dedicated on 14 September 1884 with a speech by {{nowrap|[[Jules Jamin]]}}, permanent secretary of the Académie des Sciences.{{r|academie|jamin-1884}} "{{smaller|FRESNEL}}" is among the [[List of the 72 names on the Eiffel Tower|72 names embossed on the Eiffel Tower]] (on the south-east side, fourth from the left). In the 19th century, as every lighthouse in France acquired a Fresnel lens, every one acquired a bust of Fresnel, seemingly watching over the coastline that he had made safer.<ref>Levitt, 2013, p.{{hsp}}233</ref>
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Fresnel's health, which had always been poor, deteriorated in the winter of 1822-3, increasing the urgency of his original research, and causing him to turn down an invitation from Thomas Young to write an article on double refraction for the ''[[Encyclopædia Britannica]]''. In the spring he recovered enough, in his own view, to supervise the installation at Cordouan. Soon afterwards, it became clear that his condition was [[tuberculosis]].<ref>Levitt, 2013, pp.{{nnbsp}}75–6,{{nnbsp}}97</ref>
In 1824 he was told that if he wanted to live longer, he needed to scale back his activities. Perceiving his lighthouse work to be his most important duty, he resigned from the École Polytechnique. His last note to the Académie, read on 13 June 1825, described the first [[radiometer]] and attributed the observed repulsive force to a temperature difference.{{r|boutry-1948|p=601–2}} In 1826 he found time to answer some queries from the British astronomer [[John Herschel]] for an article on light, which was eventually published in the ''[[Encyclopædia Metropolitana]]''.<
Fresnel's cough worsened in the winter of 1826-7. In the spring, being too ill to return to Mathieu, he was carried to [[Ville-d'Avray]], 12km west of Paris, where he was joined by his mother. On 6 July, Arago arrived to deliver the Rumford Medal. Sensing Arago's distress, Fresnel whispered that "the most beautiful crown means little, when it is laid on the grave of a friend." Fresnel did not have the strength to reply to the Royal Society. He died eight days later, on [[Bastille Day]].<ref>Levitt, 2013, p.{{hsp}}98.</ref>{{r|boutry-1948|p=602}}
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== Posthumous publications ==
== Unfinished business ==
=== Ether models ===
=== Conical refraction ===
== Legacy ==
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[[File:Cordouan6.jpg|thumb|The lantern room of the [[Cordouan Lighthouse]], in which the first Fresnel lens entered service in 1823. The current fixed catadioptric "beehive" lens replaced Fresnel's original rotating lens in 1854.{{r|pharedeC}}]]
With a century after Fresnel's initial proposal, more than 10,000 lights with Fresnel lenses marked coastlines around the world.<ref>Levitt, 2013, p.{{hsp}}19.</ref> The numbers of lives saved can only be guessed at. Concerning the other benefits, the science historian Theresa H. Levitt has remarked:{{quote|Everywhere I looked, the story repeated itself. The moment a Fresnel lens appeared at a ___location was the moment that region becamed linked into the world economy.<ref>Levitt, 2013, p.{{hsp}}8.</ref>}}
In the history of physical optics, Fresnel's successful revival of the wave theory seems to identify him as the pivotal figure between Newton, who held that light consisted of corpuscles, and [[James Clerk Maxwell|Maxwell]], who established that light waves are electromagnetic. Whereas [[Albert Einstein|Einstein]] described Maxwell's work as "the most profound and the most fruitful that physics has experienced since the time of Newton,"{{r|jamesCMF}} commentators of the era between Fresnel and Maxwell made similarly strong statements about Fresnel:
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