Discovery
The discovery of UV radiation was associated with the observation that silver salts darkened when exposed to sunlight. In 1801, the German physicist Johann Wilhelm Ritter made the hallmark observation that invisible rays just beyond the violet end of the visible spectrum darkened silver chloride-soaked paper more quickly than violet light itself. He called them "oxidizing rays" to emphasize chemical reactivity and to distinguish them from "heat rays," discovered the previous year at the other end of the visible spectrum. The simpler term "chemical rays" was adopted shortly thereafter, and it remained popular throughout the 19th century. The terms chemical and heat rays were eventually dropped in favour of ultraviolet and infrared radiation, respectively.
The discovery of the ultraviolet radiation below 200 nm, named vacuum ultraviolet because it is strongly absorbed by air, was made in 1893 by the German physicist Victor Schumann.
Read more about this topic: Ultraviolet
Famous quotes containing the word discovery:
“The new supplants the old. Yet men’s minds are stuffed with outworn bunk. Educating the young in the latest findings of authorities and scholars in the social sciences is important. It is equally important to devise ways and means for aiding the middle-aged and old to reexamine hang-over unscientific doctrines and ideas in the light of recent discovery and research.”
—Mary Barnett Gilson (1877–?)
“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)