Saturday, November 6, 2010

Directly Downwind Faster Than The Wind

A recent article in Make:Online and soon to appear in Make Magazine discusses the successful attempt by Rick Cavallaro to create a wind-powered vehicle that can go faster than the wind. This "land yacht", called the Greenbird, has been verified by the North American Land Sailing Association to have run at 2.8 times the speed of the wind. They have done this with various sensors, the data for which can be found on their website.

Rick was continuing the work of Jack Goodman who released a video of his toy DDFTTW cart in 2006 and created a huge internet buzz. Unfortunately for Jack, it also created huge controversy. People issued cries of "Perpetual Motion", "fraud", "its all done with string". Physicists claimed if this video were true it would break the basic laws of physics so it is clearly a hoax. One contributor to Make Magazine tried to reproduce the results and couldn't, and therefore concluded that Jack Goodman was a fraud.

You would think that Rick's full-scale reproduction of Jack's work verified by an independent body would be enough to silence the critics, but people continue to lose their minds over the impossibility of using the wind to travel faster than the wind. The cries of perpetual motion and breaking fundamental laws of physics continue. I find the hysteria just a little bit baffling.

Understanding how DDFTTW is possible is actually fairly straightforward. Once you understand what is going on, it is clear that what is causing all the naysaying is simply a failure of imagination.