Optics Highlights

I. Ancient History


  The history of optics and optical devices begins in ancient Greece; the comic writer Aristophanes wrote about reflecting the sun’s rays. Democritus and Aristotle speculated about the nature of vision. The story of Archimedes focusing the sun’s rays to win a battle for Syracuse in 213 BC is only a legend, reported centuries later, but in the Roman Empire, the philosopher, statesman and tragedian, Seneca noted the magnification of objects seen through water-filled transparent vessels, and his friend, the Emperor Nero may have been the first to use a monocle, employing an emerald lens to view events in the coliseum. The Alexandrian astronomer and mathematician, Ptolemy measured the refractive effects of water and discussed the refractive effects of the atmosphere. At the beginning of the second millennium, the remarkable Persian, Alhazan, solved problems of reflection and refraction, and was the first to explain that vision was the result of light coming from an object into the eye..
  Aristophanes (450? - 388? BC) the Rabelaisan writer of early Greek comedy, lived during the turbulent period of the Peloponnesian War. His comedies are filled with course, outspoken abuse and satire of prominent individuals. In Clouds, an attack on the educational theories of the radical intellectual Sophists, a character reflects the sun’s rays to secretly melt an I.O.U. (written on a wax tablet). Aristophane’s plays are still being produced after 2,500 years, the most popular being Lysistrata, a comedy in which the women of Greece unite in a sex-strike to force their husbands to agree to peace.
Democritus (460 - 370 BC) is known only by the surviving fragments of his works; he is said to have been a wealthy citizen of Thrace (modern Bulgaria,for the most part). His place in the history of Physics rests upon his conceptions of the Void and of eternal, indivisible, infinitesimal atoms. He made the first attempt to explain perception and color; his theory was that sensation was caused by the size and shape of atoms, and that color was due to such properties as the roughness of the constituent atoms.
Aristotle (384 -322 BC) was a son of the Macedonian court physician. He was sent to Athens to study, later founded a school of philosophy there, and for a while was tutor to Alexander the Great. When his works were translated into Latin during the 12th and 13th centuries, they exerted a profound influence on European thought. Aristotle was concerned by questions of perception, and rejected the Euclidian theory that vision was solely due to rays emanating from the eyes and "touching" the object.
Archimedes (290? - 212? BC), the great mathematician and inventor of the ancient world, was born and spent most of his life in Syracuse, the great city/state of Sicily. He was on close terms with the king, and participated actively in the defense of the city against the Romans, inventing and building war machines. He was killed when the city was finally taken and sacked. Archimedes was very much involved in catoptrics (reflections from surfaces) and in refraction, but his writings in this field are lost, and his mathematics papers were not translated into Latin until the 16th and 17th centuries; their appearance had a significant effect upon the development of mathematics.
Lucius Annaeus Seneca (4 BC - 65 AD) managed to survive 69 years in the midst of the intrigue and murder at the center of Roman imperial power. Nearly killed by Caligula, exiled for adultery by Claudius, tutor and favorite of Nero, he was finally ordered to commit suicide after being implicated in a plot against his former student. His writings include a number of philosophical works (he was a Stoic) and a series of revenge tragedies. His place here is due to the fact that he noted and wrote about the magnifying effects of liquids in transparent vessels.
Nero (Nero Claudius Caesar Augustus Germanicus) (37 - 68) became Emporer of Rome at the age of 17 as the result of successful series of poisonings by his mother, Agrippina. His subsequent megalomaniac artistic pretensions, extravagances and misrule led to his eventual overthrow, death, and traditional infamous reputation. His place in a history of optics is due to the circumstance that he used an emerald (the first monocle) while watching combats in the arena.
Ptolemy (Claudius Ptolemaeus) (!27 - 145) propounded the heliocentric system which prevailed for the next 1400 years. Nothing is known about his life and he has no biography. Only one of the five volumes he wrote on optics has survived. He dealt with refraction and obtained the small angle approximation to Snell’s law, concluding that the ratio of the angles of incident and refracted light were constant.. He also discussed the refraction of starlight by the atmosphere but held to the theory that vision is due to rays emitted from the eye touching the object .
Alhazan (Abu Ali Hasan Ibn al-Haitham) (965 - 1040) was one of the most famous of the Arab scholars and those of his 200 works which were translated had great influence when they became available in medieval Europe. He was born in Basra, traveled widely, and lived in Egypt. It is said that when he could not satisfy the Caliph’s request that he find a way to control the Nile floods he feigned madness until the Caliph died. His work in optics included research on reflections from spherical and parabolic mirrors. He disproved Ptolemy’s law of refraction and disagreed with his theory of vision. He also discussed atmospheric refraction, explained the increase in apparent size of the sun and moon near the horizon, and attempted to measure the height of the atmosphere.
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