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• TWIK
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  Hey,
  I've read the article and I'm a little disappointed about it. At my high school (in the Netherlands) the children who are in their first year (about 100 each year) make a little cart that rides against the wind, called a "TWIK" (tegen de wind in karretje; against the wind cart). First one of our teachers didn't believe it would work so he made a bet with some students... and he lost so he had to give them chocolate or something. But what my point is: it IS possible to make a cart like this, over 100 children a year make it at our school. Even better: everyone can order these TWIKS from www.opitec.com, a big postal order company in Europe, so I suppose there must be thousands of people making them. There is an instruction for making one at http://www.uk.opitec.com/cgi/ITANZBD%20%20%20%20%20%20%20142832023106?P_L=E&P_S=E&P_V=504376825-&P_PGM=&P_1=101773&P_2=H&P_3=&P_4=&P_5=&P_6=&P_M=
  I made one myself with a four-wheel drive using a elastic bend between the axles.
  Have a good time making your own "TWIK"
  Greatings from Holland,
  Daniël

  Posted by Daniël-Linschoten on November 27, 2007 at 05:51:10 Pacific Time

• still waiting
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  I have reviewed the impressive array of cart designs in the video referenced by the previous message. Unfortunately only two are depicted in free motion: Mr. Goodman's original version (which does not show a clear view of the space in front of his cart, thus failing to eliminate the possibility that someone may have been towing it on a piece of fishing line) and a very short clip right at the end, which appears to be genuine but does not give any indication of wind direction or speed, so that there is no way of knowing if the cart exceeds the speed of the wind.
  
  In this forum and in others hosted by Make I have explained repeatedly why a treadmill demonstration does not satisfy my original requirement. The cart should be on a level surface, experiencing a steady tailwind; it should accelerate up to the speed of the wind and should then exceed the speed of the wind. This is what Mr. Goodman claimed to have achieved. For reasons stated in my original article, I believe it is impossible.
  
  Note that any video should show the space around the cart to eliminate any suspicion of fakery. It's especially difficult to overcome this suspicion in a treadmill test, since a thin piece of thread could easily be held by someone off-camera.
  
  A huge amount of time and effort has gone into building some very nice cart designs. Why is no one willing to expend the small amount of additional effort to make a video that shows what Mr. Goodman's video claims to have shown? Why hasn't Mr. Goodman remade his own video showing his cart in a way that removes all suspicion?
  
  I have also proposed a variant of the Goodman experiment for those who have complained that they don't have access to a flat, level, smooth surface outdoors, on a day when a steady wind is blowing. In an indoor area where there is no movement of air, steer or tether a cart so that it will run in a circle. Use a hand-held electric fan pointed from behind the cart, and follow the cart with the fan. Scatter small styrofoam fragments during this test to show that the cart begins by moving more slowly than the air from the fan and eventually moves faster than the air from the fan. Note that if the cart can do this, logically it should continue moving forever, even when the fan is taken away. Does no one else find this a little implausible?
  
  In the absence of such a fair demonstration, I tend to believe that the well intentioned and sincere people who are trying to replicate the Goodman video are influenced by a certain amount of wishful thinking.
  
  --Charles

  Posted by charlesplatt on November 30, 2008 at 05:44:18 Pacific Time

• 
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  I believe the following document clearly explains how this sort of device can move faster than the wind. I believe it also describes a machine that travels DDFTTW without any moving parts.
  
  http://www.greglondon.com/tumbleweed/
  
  There's a lot of mumbo jumbo going on around this thing. Once you understand it, it's about as interesting as a block and tackle. It helps if someone could explain it that simply.
  
  

  Posted by GregLondon on December 06, 2008 at 02:32:12 Pacific Time

• Success at El Mirage - DDWFTTW
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  http://www.fasterthanthewind.org photos, videos, etc

  Posted by DavidGlover on July 08, 2010 at 12:08:09 Pacific Time