Development
Doppler first proposed the effect in 1842 in his treatise "Über das farbige Licht der Doppelsterne und einiger anderer Gestirne des Himmels" (On the coloured light of the binary stars and some other stars of the heavens). The hypothesis was tested for sound waves by Buys Ballot in 1845. He confirmed that the sound's pitch was higher than the emitted frequency when the sound source approached him, and lower than the emitted frequency when the sound source receded from him. Hippolyte Fizeau discovered independently the same phenomenon on electromagnetic waves in 1848 (in France, the effect is sometimes called "l'effet Doppler-Fizeau" but that name was not adopted by the rest of the world as Fizeau's discovery was three years after Doppler's). In Britain, John Scott Russell made an experimental study of the Doppler effect (1848).
Read more about this topic: Doppler Effect
Famous quotes containing the word development:
“Every new development for the last three centuries has brought men closer to a state of affairs in which absolutely nothing would be recognized in the whole world as possessing a claim to obedience except the authority of the State. The majority of people in Europe obey nothing else.”
—Simone Weil (1909–1943)
“To be sure, we have inherited abilities, but our development we owe to thousands of influences coming from the world around us from which we appropriate what we can and what is suitable to us.”
—Johann Wolfgang Von Goethe (1749–1832)
“They [women] can use their abilities to support each other, even as they develop more effective and appropriate ways of dealing with power.... Women do not need to diminish other women ... [they] need the power to advance their own development, but they do not “need” the power to limit the development of others.”
—Jean Baker Miller (20th century)