Columbia Encyclopedia

Search results

500 results found

wind tunnel

(Encyclopedia)wind tunnel, apparatus for studying the interaction between a solid body and an airstream. A wind tunnel simulates the conditions of an aircraft in flight by causing a high-speed stream of air to flow...

belladonna

(Encyclopedia)belladonna bĕlədŏnˈə [key] or deadly nightshade, poisonous perennial plant, Atropa belladona, of the nightshade family. Native to Europe and now grown in the United States, the plant has reddish,...

Vasconcelos, José

(Encyclopedia)Vasconcelos, José hōsāˈ väskōnsāˈlōs [key], 1882–1959, Mexican educator and writer. He headed (1920–24) the National Univ. of Mexico and, as minister of education under Álvaro Obregón, ...

thyroxine

(Encyclopedia)thyroxine thīrŏkˈsēn [key], substance secreted by the thyroid gland. The hormone thyroxine forms by combining the amino acid tyrosine with iodine. Complexed to a protein, it is stored in the folli...

thermometer

(Encyclopedia)thermometer, instrument for measuring temperature. Galileo and Sanctorius devised thermometers consisting essentially of a bulb with a tubular projection, the open end of which was immersed in a liqui...

Radek, Karl

(Encyclopedia)Radek, Karl kärl räˈdyĭk [key], 1885–1939?, international Communist leader and journalist, b. Lviv (then in Austrian Poland); his original name was Sobelsohn. Radek participated in the 1905 revo...

bimetallism

(Encyclopedia)bimetallism bīmĕtˈəlĭzˌəm [key], in economic history, monetary system in which two commodities, usually gold and silver, were used as a standard and coined without limit at a ratio fixed by leg...

scopolamine

(Encyclopedia)scopolamine hīˈəsēnˌ, –sĭn [key], alkaloid drug obtained from plants of the nightshade family (Solanaceae), chiefly from henbane, Hyoscyamus niger. Structurally similar to the nerve substance ...

shock absorber

(Encyclopedia)shock absorber, device for reducing the effect of a sudden shock by the dissipation of the shock's energy. On an automobile, springs and shock absorbers are mounted between the wheels and the frame. W...

sunspots

(Encyclopedia)sunspots, dark, usually irregularly shaped spots on the sun's surface that are actually solar magnetic storms. The spots are darker because the temperature of the spots is lower than that of the surro...