Columbia Encyclopedia

Search results

500 results found

dwarf planet

(Encyclopedia)dwarf planet, a nonluminous body of rock or gas that orbits the sun and has a rounded shape due to its gravity. Unlike a planet, a dwarf planet is not capable of clearing its orbit of smaller objects ...

phosphorus

(Encyclopedia)phosphorus fŏsˈfərəs [key] [Gr.,=light-bearing], nonmetallic chemical element; symbol P; at. no. 15; at. wt. 30.97376; m.p. 44.1℃; b.p. about 280℃; sp. gr. 1.82 at 20℃; valence −3, +3, or ...

competition, in biology

(Encyclopedia)competition, in biology, relationship between members of the same or different species in which individuals are adversely affected by those having the same living requirements, such as food or space. ...

Oersted, Hans Christian

(Encyclopedia)Oersted or Ørsted, Hans Christian häns krĭsˈtyän örˈstĭᵺ [key], 1777–1851, Danish physicist and chemist. He was professor at Copenhagen from 1806. His discovery (1819) that a magnetic need...

liquid

(Encyclopedia)liquid, one of the three commonly recognized states in which matter occurs, i.e., that state, as distinguished from solid and gas, in which a substance has a definite volume but no definite shape. T...

space medicine

(Encyclopedia)space medicine, study of the medical and biological effects of space travel on living organisms. The principal aim is to discover how well and for how long humans can withstand the extreme conditions ...

kinship

(Encyclopedia)kinship, relationship by blood (consanguinity) or marriage (affinity) between persons; also, in anthropology and sociology, a system of rules, based on such relationships, governing descent, inheritan...

dermatology

(Encyclopedia)dermatology dûrmətŏlˈəjē [key], branch of medicine concerned with diagnosis and treatment of diseases and disorders of the skin. Dermatologists also study the structure and function of the skin,...

kerosene

(Encyclopedia)kerosene or kerosine, colorless, thin mineral oil whose density is between 0.75 and 0.85 grams per cubic centimeter. A mixture of hydrocarbons, it is commonly obtained in the fractional distillation o...

neutrino astronomy

(Encyclopedia)neutrino astronomy, study of stars by means of their emission of neutrinos, fundamental particles that result from nuclear reactions and are emitted by stars along with light. Approximately 100 billio...