Columbia Encyclopedia

(Encyclopedia)  CE5 Equatorial coordinate system equatorial coordinate system, the most commonly used astronomical coordinate system for indicating the positions of stars or other celestial objects on the celesti...

(Encyclopedia) ecliptic ēklĭpˈtĭk, ĭ– [key], the great circle on the celestial sphere that lies in the plane of the earth's orbit (called the plane of the ecliptic). Because of the earth's yearly revolution a...

(Encyclopedia) solstice sŏlˈstĭs [key] [Lat.,=sun stands still], in astronomy, either of the two points on the ecliptic that lie midway between the equinoxes (separated from them by an angular distance of 90°). ...

(Encyclopedia) Federation of the Emirates of the South: see South Arabia, Federation of. ...

(Encyclopedia) Emirates of the South, Federation of the: see South Arabia, Federation of. ...

(Encyclopedia)  Text1 of the Constitution of the United States Preamble Article I Article II Article III Article IV Article V Article VI Article VII Amendment I Amendment II Am...

(Encyclopedia) perturbation pŭrˌtərbāˈshən [key], in astronomy and physics, small force or other influence that modifies the otherwise simple motion of some object. The term is also used for the effect produce...

(Encyclopedia) aurora borealis ôstrāˈlĭs [key], luminous display of various forms and colors seen in the night sky. The aurora borealis of the Northern Hemisphere is often called the northern lights, and the aur...

(Encyclopedia) Fathers of the Church, collective name for the Christian writers of early times whose work is considered generally orthodox. A convenient definition includes all such writers up to and including St. G...

(Encyclopedia) Acts of the Apostles, book of the New Testament. It is the only 1st-century account of the expansion of Christianity in its earliest period. It was written in Greek anonymously as early as c.a.d. 65, ...