The history of technology is full of breakthroughs in one field that wound up working wonders in a related one. The 300B vacuum tube, introduced by Western Electric in 1937 to amplify telephone signals, found a far more enduring use as a high-fidelity audio amplifier. The atomic clocks first used in the 1960’s by the U.S. military to track Sputnik and later to validate Albert Einstein’s relativity theories are now the basis of Global Positioning System. And of course, the magnetron, invented in the 1920’s at General Electric and used in radars during World War II, later found itself repurposed as the basis for the microwave oven.

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