The Microwave

You might remember the heroic role that newly-invented radar played in the Second World War. People hailed it then as "Our Miracle Ally". But even in its earliest years, as it was helping win the war, radar proved to be more than an expert enemy locator. Radar technicians, doodling away in their idle moments, found that they could focus a radar beam on a marshmallow and toast it. They also popped popcorn with it. Such was the beginning of microwave cooking. The very same energy that warned the British of the German Luftwaffe invasion and that policemen employ to pinch speeding motorists, is what many of us now have in our kitchens. It's the same as what carries long distance phone calls and cablevision. Hitler's army had its own version of radar, using radio waves. But the trouble with radio waves is that their long wavelength requires a large, cumbersome antenna to focus them into a narrow radar beam. The British showed that microwaves, with their short waveleng...