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Dyson, Freeman John

(Encyclopedia)Dyson, Freeman John dīˈsən [key], 1923–2020, British-American theoretical physicist and mathematician, studied Trinity College, Cambridge (B.A., 1945) and Cornell. He did bomber operations resear...

hardening

(Encyclopedia)hardening, in metallurgy, treatment of metals to increase their resistance to penetration. A metal is harder when it has small grains, which result when the metal is cooled rapidly. Sometimes small ar...

superfluidity

(Encyclopedia)superfluidity, tendency of liquid helium below a temperature of 2.19K to flow freely, even upward, with little apparent friction. Helium becomes a liquid when it is cooled to 4.2K. Special methods...

soup

(Encyclopedia)soup, liquid food in which different kinds of solid food have been cooked, e.g., meat, fish, fowl, vegetables, cereals, or fruit. Many soups are peculiar to certain localities, e.g., the pot-au-feu of...

californium

(Encyclopedia)californium kălˈĭfôrˌnēəm [key] [from California], artificially produced, radioactive metallic chemical element; symbol Cf; at. no. 98; mass no. of most stable isotope 251; m.p. about 900℃; b...

capacitor

(Encyclopedia)capacitor or condenser, device for the storage of electric charge. Simple capacitors consist of two plates made of an electrically conducting material (e.g., a metal) and separated by a nonconducting ...

lymphatic system

(Encyclopedia)CE5 Lymphatic system lymphatic system lĭmfătˈĭk [key], network of vessels carrying lymph, or tissue-cleansing fluid, from the tissues into the veins of the circulatory system. The lymphatic sy...

lead poisoning

(Encyclopedia)lead poisoning or plumbism plŭmˈbĭzˌəm [key], intoxication of the system by organic compounds containing lead. These enter the body by respiration (of dust, fumes, or sprays) or by ingestion of f...

sleep

(Encyclopedia)sleep, resting state in which an individual becomes relatively quiescent and relatively unaware of the environment. During sleep, which is in part a period of rest and relaxation, most physiological f...

Afghanistan War

(Encyclopedia)Afghanistan War, 1978–92, conflict between anti-Communist Muslim Afghan guerrillas (mujahidin) and Afghan government and Soviet forces. The conflict had its origins in the 1978 coup that overthrew A...