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.
Whether they're sorting out scrap metal or helping us unlock the secrets of the universe, electromagnets are pretty nifty devices. What's so great about magnetism on demand? We'll electrify you with the details in these videos.
Who made it possible to light up your home at night? Thomas Edison, right? Yes, but without the work of Nikola Tesla, we would be living in a different world.