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Paphlagonia

(Encyclopedia)Paphlagonia păfˌləgōˈnēə [key], ancient country of N Asia Minor, between Bithynia and Pontus on the Black Sea coast, in modern Turkey. A mountainous district with the Halys as its chief river, ...

ratio

(Encyclopedia)ratio. The ratio of two quantities expressed in terms of the same unit is the fraction that has the first quantity as numerator and the second as denominator. For example, if in a group of 100 people ...

power, in physics

(Encyclopedia)power, in physics, time rate of doing work or of producing or expending energy. The unit of power based on the English units of measurement is the horsepower, devised for describing mechanical power b...

Huggins, Sir William

(Encyclopedia)Huggins, Sir William, 1824–1910, English astronomer. Using a spectroscope, he began to study the chemical constitution of stars from the observatory attached to his home in Tulse Hill, London. He pr...

Ghez, Andrea Mia

(Encyclopedia)Ghez, Andrea Mia, 1965–, American astrophysicist, b. New York City, Ph.D. California Institute of Technology, 1992. She has been on the faculty at the Univ. of California, Los Angeles, since 1994. G...

Lacaille, Nicolas Louis de

(Encyclopedia)Lacaille, Nicolas Louis de nēkôläˈ lwē də läkäˈyə [key], 1713–62, French astronomer. As a result of his success in making meridional measurements in France under the patronage of the duke ...

Cannon, Annie Jump

(Encyclopedia)Cannon, Annie Jump, 1863–1941, American astronomer, b. Dover, Del. In 1897 she became an assistant in the Harvard College Observatory, where (1911–38) she was astronomer and curator of astronomica...

Wood, Robert Williams

(Encyclopedia)Wood, Robert Williams, 1868–1955, American physicist, b. Concord, Mass., grad. Harvard (B.A., 1891). After studying abroad he became associated with Johns Hopkins as professor of experimental physic...

Ptolemy

(Encyclopedia)Ptolemy (Claudius Ptolemaeus), fl. 2d cent. a.d., celebrated Greco-Egyptian mathematician, astronomer, and geographer. He made his observations in Alexandria and was the last great astronomer of ancie...

Cockrell, Francis Marion

(Encyclopedia)Cockrell, Francis Marion kŏkˈrəl [key], 1834–1915, Confederate general and U.S. senator, b. Johnson co., Mo. Enlisting as a private with Confederate forces in the Civil War, he became a brigadier...