Science: Laser Magic

Ever since lasers—a word and an instrument stemming from Light Amplification by Stimulated Emission of Radiation—were first perfected, their fierce, pure gleam has been one of the most revolutionary tools of advancing science. By stimulating the atoms of a synthetic ruby with brief bursts from a powerful strobe lamp, scientists demonstrated that they could produce spurts of "coherent" light —pure red light that is all of the same wavelength, all polarized in the same direction, and all traveling in phase in almost perfectly parallel beams. Such light can be focused so sharply...