About two weeks ago it was announced that a U.S. grad student, Clay Moulton, won second place in a "Greener Gadgets Conference" competition for inventing a floor lamp powered by gravity.
The concept was that a person would place a weight (about ten pounds) at the top of a four-foot column. Over the course of the next four hours, the weight would descend down the column, causing a rotor to spin that would produce a gentle light (about the strength of a 40 watt bulb).
Moulton's concept generated a lot of interest on blogs, but also a lot of skepticism. People who crunched the numbers insisted the thing could never work. It was outputting way more energy than was being put into it. But it seemed as if Moulton had actually built a prototype, and it did work -- and he had won an award for it. So the skeptics were kept at bay.
The skeptics were right. The thing would never work. Moulton has now admitted he hadn't built a prototype. It was just pie-in-the-sky theorizing. It would only work if super-efficient LEDs were invented at some point in the future. Or if you used a ten-ton weight. Moulton has offered to concede the second place prize.
The Gravity Lamp seems typical of so many of the inventions you read about that promise to save the world's energy problems. Somehow they never pan out. (via core77.com)