Columbia Encyclopedia

Search results

331 results found

nitrogen cycle

(Encyclopedia)CE5 Nitrogen cycle nitrogen cycle, the continuous flow of nitrogen through the biosphere by the processes of nitrogen fixation, ammonification (decay), nitrification, and denitrification. Nitrogen...

aerodynamics

(Encyclopedia)aerodynamics, study of gases in motion. As the principal application of aerodynamics is the design of aircraft, air is the gas with which the science is most concerned. Although aerodynamics is primar...

Blake, William

(Encyclopedia)Blake, William, 1757–1827, English poet and artist, b. London. Although he exerted a great influence on English romanticism, Blake defies characterization by school, movement, or even period. At the...

climate

(Encyclopedia)climate, average condition of the atmosphere near the earth's surface over a long period of time, taking into account temperature, precipitation (see rain), humidity, wind, barometric pressure, and ot...

balloon

(Encyclopedia)balloon, lighter-than-air craft without a propulsion system, lifted by inflation of one or more containers with a gas lighter than air or with heated air. During flight, altitude may be gained by disc...

oxygen

(Encyclopedia)oxygen, gaseous chemical element; symbol O; at. no. 8; interval in which at. wt. ranges 15.99903–15.99977; m.p. −218.4℃; b.p. −182.962℃; density 1.429 grams per liter at STP; valence −2. T...

jet propulsion

(Encyclopedia)CE5 Types of jet engines: In the propeller-driven turbine a stream of high-velocity gases provides the power to drive the turbine and turn the propeller. In the jet-driven turbine the stream of gas...

ammonia

(Encyclopedia)ammonia, chemical compound, NH3, colorless gas that is about one half as dense as air at ordinary temperatures and pressures. It has a characteristic pungent, penetrating odor. Ammonia forms a minute ...

Byron, George Gordon Noel Byron, 6th Baron

(Encyclopedia)Byron, George Gordon Noel Byron, 6th Baron bīˈrən [key], 1788–1824, English poet and satirist. Ranked with Shelley and Keats as one of the great Romantic poets, Byron became famous throughout E...

volcano

(Encyclopedia)volcano, vents or fissures in the earth's crust through which gases, molten rock, or lava, and solid fragments are discharged. Their study is called volcanology. The term volcano is commonly applied b...