Columbia Encyclopedia

(Encyclopedia) red shift or redshift, in astronomy, the systematic displacement of individual lines in the spectrum of a celestial object toward the red, or longer wavelength, end of the visible spectrum. The effect...

(Encyclopedia) precipitation, in chemistry, a process in which a solid is separated from a suspension, sol, or solution. In a suspension such as sand in water the solid spontaneously precipitates (settles out) on st...

(Encyclopedia) thrush, in medicine, infection caused by the fungus Candida albicans, manifested by white, slightly raised patches on the mucous membrane of the tongue, mouth, and throat. The mucous membrane beneath ...

(Encyclopedia) valence, combining capacity of an atom expressed as the number of single bonds the atom can form or the number of electrons an element gives up or accepts when reacting to form a compound. Atoms are c...

(Encyclopedia) Weissenburg in Bayern vīˈsənbo͝ork ĭn bīˈyərn [key] or Weissenburg, town, Bavaria, S Germany. It is a manufacturing center of Middle Franconia; products include gold and silver lace, processed...

(Encyclopedia) dimension, in mathematics, number of parameters or coordinates required locally to describe points in a mathematical object (usually geometric in character). For example, the space we inhabit is three...

(Encyclopedia) bear, large mammal of the family Ursidae in the order Carnivora, found almost exclusively in the Northern Hemisphere. Bears have large heads, bulky bodies, massive hindquarters, short, powerful limbs,...

(Encyclopedia) joint, in geology, fracture in rocks along which no appreciable movement has occurred (see fault). Nearly vertical, or sheet, joints that result from shrinkage during cooling are commonly found in ign...

(Encyclopedia) python pīˈthŏn [key], name for nonvenomous constrictor snakes of the boa family, found in the tropical regions of Africa, Asia, Australia, and the S Pacific islands. Pythons climb and swim expertly...

(Encyclopedia)  CE5 Gills of a fish: Side view (A) and ventral view (B) gills, external respiratory organs of most aquatic animals. In fishes the gills are located in gill chambers at the rear of the mouth (phary...