Compass, in navigation, an instrument used to indicate directions. It ranks as one of the most important inventions ever made. The usual compass shows the cardinal points—north, east, south, and west—and a number of intermediate points. Most compasses are also graduated in the degrees of a circle, north being 0°; east, 90°; south, 180°; and west, 270°. Surveyors, however, reverse this arrangement and measure clockwise from the south, so that a bearing of 90° in a survey is west.
Electronics, the branch of science and technology concerned with the nature, uses, and manufacture of devices in which electrons flow through a gas, vacuum, or semiconductor. Learn all about electronics.
Radar seems to have infinite uses: Police use it to clock your speed, NASA uses it to follow satellites, meteorologists use it to track storms and the military uses it to track the enemy ... Learn all about radar technology!