Discovery
The English chemist William Hyde Wollaston was in 1802 the first person to note the appearance of a number of dark features in the solar spectrum. In 1814, Fraunhofer independently rediscovered the lines and began a systematic study and careful measurement of the wavelength of these features. In all, he mapped over 570 lines, and designated the principal features with the letters A through K, and weaker lines with other letters. Modern observations of sunlight can detect many thousands of lines.
About 45 years later Kirchhoff and Bunsen noticed that several Fraunhofer lines coincide with characteristic emission lines identified in the spectra of heated elements. It was correctly deduced that dark lines in the solar spectrum are caused by absorption by chemical elements in the Solar atmosphere. Some of the observed features were identified as telluric lines originating from absorption in oxygen molecules in the Earth's atmosphere.
Read more about this topic: Fraunhofer Lines
Famous quotes containing the word discovery:
“Your discovery of the contradiction caused me the greatest surprise and, I would almost say, consternation, since it has shaken the basis on which I intended to build my arithmetic.... It is all the more serious since, with the loss of my rule V, not only the foundations of my arithmetic, but also the sole possible foundations of arithmetic seem to vanish.”
—Gottlob Frege (1848–1925)
“As the mother of a son, I do not accept that alienation from me is necessary for his discovery of himself. As a woman, I will not cooperate in demeaning womanly things so that he can be proud to be a man. I like to think the women in my son’s future are counting on me.”
—Letty Cottin Pogrebin (20th century)
“One of the laudable by-products of the Freudian quackery is the discovery that lying, in most cases, is involuntary and inevitable—that the liar can no more avoid it than he can avoid blinking his eyes when a light flashes or jumping when a bomb goes off behind him.”
—H.L. (Henry Lewis)