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Internet, the

(Encyclopedia)Internet, the, international computer network linking together thousands of individual networks at military and government agencies, educational institutions, nonprofit organizations, industrial and f...

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...

tennis

(Encyclopedia)CE5 Tennis court tennis, game played indoors or outdoors by two players (singles) or four players (doubles) on a level court. In 1900 the international team competition known as the Davis Cup t...

vector

(Encyclopedia)vector, quantity having both magnitude and direction; it may be represented by a directed line segment. Many physical quantities are vectors, e.g., force, velocity, and momentum. Thus, in specifying a...

magnetism

(Encyclopedia)CE5 Lines of induction around a single bar magnet and between opposite poles of different magnets magnetism, force of attraction or repulsion between various substances, especially those made of i...

stellar evolution

(Encyclopedia)CE5 The above Hertzsprung-Russell (H-R) diagram shows the track of stellar evolution for a typical star. After spending much of its life evolving toward or along the main sequence, the star becomes...

physics

(Encyclopedia)physics, branch of science traditionally defined as the study of matter, energy, and the relation between them; it was called natural philosophy until the late 19th cent. and is still known by this na...

marijuana

(Encyclopedia)marijuana or marihuana, drug obtained from the flowering tops, stems, and leaves of the hemp plant, Cannabis sativa (see hemp) or C. indica; the latter species can withstand colder climates. It is one...

Maya, indigenous people of Mexico and Central America

(Encyclopedia)Maya mīˈə, Span. mäˈyä [key], indigenous people of S Mexico and Central America, occupying an area comprising the Yucatán peninsula and much of the present state of Chiapas in Mexico, Guatemala...

nucleus, in physics

(Encyclopedia)nucleus, in physics, the extremely dense central core of an atom. Following the discovery of radioactivity by A. H. Becquerel in 1896, Ernest Rutherford identified two types of radiation given off b...