In 1954, Charles Townes invented the laser's microwave cousin, the maser. The next logical step was to extend the same physical principles to the shorter wavelengths of light, but the idea did not catch fire until October 1957, when Townes asked Gordon Gould about Gould's research on using light to excite thallium atoms. Each took the idea and ran with it. The independent-minded Gould sought the fortune of an independent inventor; the professorial...