Columbia Encyclopedia

Search results

500 results found

gun control

(Encyclopedia)gun control, government limitation of the purchase and ownership of firearms. The availability of guns is controlled by nations and localities throughout the world. In the United States the “right o...

stun gun

(Encyclopedia)stun gun, hand-held electronic device that produces a high-voltage pulse that can immobilize a person for several minutes with no permanent damage in most cases. It is powered by ordinary batteries, w...

gun

(Encyclopedia)gun, in general, any weapon that discharges shot, shells, or bullets by the explosion of gunpowder or some other explosive from a straight tube. See firearm; artillery; small arms. ...

machine gun

(Encyclopedia)machine gun: see small arms.

control systems

(Encyclopedia)control systems, combinations of components (electrical, mechanical, thermal, or hydraulic) that act together to maintain actual system performance close to a desired set of performance specifications...

rent control

(Encyclopedia)rent control, in economics and law, government regulation of rent to prevent unreasonable or excessive increases. In the United States, the federal government imposed rent control (and other price con...

birth control

(Encyclopedia)birth control, practice of contraception for the purpose of limiting reproduction. Although contraceptive techniques had been known in ancient Egypt, Greece, and Rome, the modern movement for birth ...

control surface

(Encyclopedia)control surface: see airfoil.

numerical control

(Encyclopedia)numerical control: see computer-aided manufacturing. ...

air traffic control

(Encyclopedia)air traffic control, the system by which airplanes are safely routed into and out of major airports. Air traffic control in the United States is centered in a number of regional control centers that r...