Columbia Encyclopedia

Search results

500 results found

Beach, Moses Yale

(Encyclopedia)Beach, Moses Yale, 1800–1868, American journalist, b. Wallingford, Conn. As a young man he invented a rag-cutting machine and a gunpowder engine. In 1838 he bought the New York Sun from his brother-...

eclipse

(Encyclopedia)CE5 A. Lunar eclipse B. Solar eclipse eclipse ēklĭpsˈ, ĭ– [key] [Gr.,=failing], in astronomy, partial or total obscuring of one celestial body by the shadow of another. Best known are the lu...

limb darkening

(Encyclopedia)limb darkening: see sun.

Tropic of Cancer

(Encyclopedia)Tropic of Cancer, parallel of latitude at 23°30′ north of the equator; it is the northern boundary of the tropics. This parallel marks the farthest point north at which the sun can be seen directly...

solar constant

(Encyclopedia)solar constant, the average amount of radiant energy received by the earth's atmosphere from the sun; its value is about 2 calories per min incident on each square centimeter of the upper atmosphere. ...

Aristarchus of Samos

(Encyclopedia)Aristarchus of Samos ărˌĭstärˈkəs, sāˈmŏs [key], fl. c.310 b.c.–c.230 b.c., Greek astronomer and mathematician of the Alexandrian school. He is said to have been the first to propose a heli...

corona, in astronomy

(Encyclopedia)corona, luminous envelope surrounding the sun, outside the chromosphere. Its density is less than one billionth that of the earth's atmosphere. The corona is visible only at the time of totality durin...

rainbow

(Encyclopedia)rainbow, arc showing the colors of the spectrum, violet inside and red outside, which appears when the sun shines through water droplets. It often appears while the sun is shining after a brief thunde...

coronagraph

(Encyclopedia)coronagraph kərōˈnəgrăfˌ [key], device invented by the French astronomer B. Lyot (1931) for the purpose of observing the corona of the sun and solar prominences occurring in the chromosphere. Be...

photosphere

(Encyclopedia)photosphere, luminous, apparently opaque layer of gases that forms the visible surface of the sun or any other star. The photosphere lies between the dense interior gases and the more attenuated gases...