Scientific American did a piece on some English professors who built one capable of hurling a small car about 10-15 years ago. (Shortly after the article appeared, the professors were hired to build a smaller one for the TV show Northern Exposure.)

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We want our children to go to the planets. Burt Rutan 6/21/04
Tuckers! Science! Automotive Oddities! Boycott Trek XI! Building my hot rod with the help of the intarwebs Those who would delay scientific progress for a little temporary prosperity shall have neither.