Intuitively, there just shouldn’t be any way for something wind-powered to move directly downwind faster than the wind itself. It’s impossible: Release a balloon, and the wind blows the balloon as fast as the wind is moving, and that’s as fast as any wind-powered object can go, before the wind. Sure, sailboats can win a race against the balloon by moving diagonally across the wind, but moving in a straight line down a 10 kph wind, and the balloon moves at 10 kph. End of story.
Or, start of story.
Rick Cavallaro and John Borton have built a cart that moves 2.86 times the speed of the wind, moving straight downwind. That may seem impossible, but after a year of tinkering and some financial assistance from Google and Joby Energy, they did it. Don’t believe me? Check out the video. Keep a weather eye out for the green flag at 0:35. Notice how it’s blowing the exact opposite direction of the orange wind socks on the cart? That’s because the cart is going faster than the wind.
How is it possible?