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smart weapon

(Encyclopedia)smart weapon, missile or steerable bomb equipped with a laser, television, or satellite guidance system. Smart weapons, which use guidance systems that rely on external assistance, are distinguished f...

ray, in zoology

(Encyclopedia)ray, extremely flat-bodied cartilaginous marine fish, related to the shark. The pectoral fins of most rays are developed into broad, flat, winglike appendages, attached all along the sides of the head...

radar

(Encyclopedia)radar, system or technique for detecting the position, movement, and nature of a remote object by means of radio waves reflected from its surface. Although most radar units use microwave frequencies, ...

matter

(Encyclopedia)matter, anything that has mass and occupies space. Matter is sometimes called koinomatter (Gr. koinos=common) to distinguish it from antimatter, or matter composed of antiparticles. The atomic th...

Dick, Philip K.

(Encyclopedia)Dick, Philip K. (Philip Kindred Dick), 1928–82, American science-fiction writer, b. Chicago. Dick often wrote of the psychological states of individuals caught in altered realities where the everyda...

edema

(Encyclopedia)edema ĭdēˈmə [key], abnormal accumulation of fluid in the body tissues or in the body cavities causing swelling or distention of the affected parts. Edema of the ankles and lower legs (in ambulato...

Aldus Manutius

(Encyclopedia)Aldus Manutius älˈdō mäno͞oˈtsyō [key], 1450–1515, Venetian printer. He was educated as a humanistic scholar and became tutor to several of the great ducal families. One of them, the Pio fami...

Clarke, Arthur C.

(Encyclopedia)Clarke, Arthur C. (Sir Arthur Charles Clarke), 1917–2008, British science fiction writer. During World War II he served as a radar instructor and aviator in the Royal Air Force. After the war he obt...

anxiety

(Encyclopedia)anxiety, anticipatory tension or vague dread persisting in the absence of a specific threat. In contrast to fear, which is a realistic reaction to actual danger, anxiety is generally related to an unc...

histology

(Encyclopedia)histology hĭstŏlˈəjē [key], study of the groups of specialized cells called tissues that are found in most multicellular plants and animals. Histologists study the organization of tissues at all ...