NOW YOU KNOW

You’ve probably seen lasers used to make spectacular light shows in the sky at evening events. Lasers also are used to cut and weld metal, read price codes, even repair damaged eyes. But just what is a laser? It’s a machine that makes a very narrow, powerful beam of light. Some beams are so thin, they can drill 200 holes on a spot the size of a capital “O” on this page. Their most common use, though, is to record music, movies, computer data and other materials on special discs.

Source: World Book Encyclopedia

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