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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...

Lübeck

(Encyclopedia)Lübeck lüˈbĕk [key], city (1994 pop. 217,270), Schleswig-Holstein, central Germany, on the Trave River near its mouth on the Baltic Sea. It is a major port and a commercial and industrial center; ...

Rumsfeld, Donald Henry

(Encyclopedia)Rumsfeld, Donald Henry, 1932–2021, American government official, b. Chicago, Princeton Univ. (B.A., 1954). After graduating college, Rumsfeld enliste...

work

(Encyclopedia)work, in physics and mechanics, transfer of energy by a force acting to displace a body. Work is equal to the product of the force and the distance through which it produces movement. Although both fo...

stimulant

(Encyclopedia)stimulant, any substance that causes an increase in activity in various parts of the nervous system or directly increases muscle activity. Cerebral, or psychic, stimulants act on the central nervous s...

electroencephalography

(Encyclopedia)electroencephalography əlĕkˌtrōĕnsĕfˌəlŏgˈrafē [key], science of recording and analyzing the electrical activity of the brain. Electrodes, placed on or just under the scalp, are linked to a...

Diadochi

(Encyclopedia)Diadochi dīădˈəkī [key] [Gr.,=successors], the Macedonian generals and administrators who succeeded Alexander the Great. Alexander's empire, the largest that the world had known to that time, was...

Edison, Thomas Alva

(Encyclopedia)Edison, Thomas Alva, 1847–1931, American inventor, b. Milan, Ohio. A genius in the practical application of scientific principles, Edison was one of the greatest and most productive inventors of his...

distillation

(Encyclopedia)distillation, process used to separate the substances composing a mixture. It involves a change of state, as of liquid to gas, and subsequent condensation. The process was probably first used in the p...

Drusus

(Encyclopedia)Drusus dro͞oˈsəs [key], Roman family of the gens Livius. An early distinguished member was Marcus Livius Drusus, d. 109? b.c., tribune of the people (122) with Caius Sempronius Gracchus (see under ...