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field, in physics

(Encyclopedia)field, in physics, region throughout which a force may be exerted; examples are the gravitational, electric, and magnetic fields that surround, respectively, masses, electric charges, and magnets. The...

larva, in zoology

(Encyclopedia)larva, independent, immature animal that undergoes a profound change, or metamorphosis, to assume the typical adult form. Larvae occur in almost all of the animal phyla; because most are tiny or micro...

Ganymede, in astronomy

(Encyclopedia)Ganymede gănˈēmēdˌ [key], in astronomy, one of the moons, or natural satellites, of Jupiter; the largest natural satellite in the solar system, it is larger than the planet Mercury. ...

category, in philosophy

(Encyclopedia)category, philosophical term that literally means predication or assertion. It was first used by Aristotle, whose 10 categories formed a list of all the ways in which assertions can be made of a subje...

tenure, in education

(Encyclopedia)tenure, in education, a guarantee of the permanence of a college or university teacher's position, awarded upon successful completion of a probationary period, usually seven years. Tenure is designed ...

proof, in mathematics

(Encyclopedia)proof, in mathematics, finite sequence of propositions each of which is either an axiom or follows from preceding propositions by one of the rules of logical inference (see symbolic logic). Mathematic...

archangel, in religion

(Encyclopedia)archangel ärkˈānjəl [key], chief angel. They are four to seven in number. Sometimes specific functions are ascribed to them. The four best known in Christian tradition are Michael, Gabriel, Raphae...

bias, in electricity

(Encyclopedia)bias, a voltage, current, or other input applied to a device or system as a reference or to set its conditions of operation. A bias is usually steady but may vary with time, usually within a fixed and...

rye, in botany

(Encyclopedia)rye, cereal grain of the family Poaceae (grass family). The grain, Secale cereale, is important chiefly in Central and N Europe. It seems to have been domesticated later than wheat and other staple gr...

cypress, in botany

(Encyclopedia)cypress, common name for members of the Cupressaceae, a widely distributed family of coniferous shrubs and trees, several yielding valuable timber. The major genera are Juniperus (juniper), Thuja (arb...