Columbia Encyclopedia

Search results

500 results found

siphon

(Encyclopedia)siphon sīˈfən, –fŏn [key], tube or other enclosed conduit through which a liquid is lifted over an elevation and then emptied at a lower level. The movement of the liquid is driven primarily by ...

Guri Dam

(Encyclopedia)Guri Dam, 24,364 ft (7,426 m) long and 531 ft (162 m) high, on the Caroní River, Bolívar state, SW Venezuela. Built in phases between 1963 and 1986, the dam consists of a central concrete gravity da...

Weil, Simone

(Encyclopedia)Weil, Simone sēmônˈ vīl [key], 1909–43, French philosopher and mystic. After receiving her baccalauréat with honors at 15, she studied philosophy for four years, then entered (1928) the prestig...

standpipe

(Encyclopedia)standpipe, tank or pipe for holding water in an elevated position to create pressure in a water supply system. For a tall building, where the pressure from the mains at street level is insufficient to...

Delaware Aqueduct

(Encyclopedia)Delaware Aqueduct dĕlˈəwâr, –wər [key], SE N.Y., 85 mi (137 km) long, carrying water from the Rondout Reservoir, Sullivan co., SE into the New York City water system at the Hillview Reservoir, ...

mass, in physics

(Encyclopedia)mass, in physics, the quantity of matter in a body regardless of its volume or of any forces acting on it. The term should not be confused with weight, which is the measure of the force of gravity (se...

nastic movement

(Encyclopedia)nastic movement, in botany, the movement of plant parts in response either to certain external stimuli or to internal growth stimuli. Nastic movements, which are generally slow, can be observed by tim...

cosmology

(Encyclopedia)cosmology, area of science that aims at a comprehensive theory of the structure and evolution of the entire physical universe. The earliest pre-Ptolemaic theories assumed that the earth was the cent...

free fall

(Encyclopedia)free fall, in physics, the state of a body moving solely under the influence of gravitational forces (see gravitation). A body falling freely toward the surface of the earth undergoes an acceleration ...

equilibrium

(Encyclopedia)CE5 Equilibrium equilibrium, state of balance. When a body or a system is in equilibrium, there is no net tendency to change. In mechanics, equilibrium has to do with the forces acting on a body. ...