Image credit: FasterThanTheWind.org
I am not sure if this one is awesome, pointless, or a bit of both.
It turns out that there is a huge debate in certain circles as to whether it is possible to create a purely wind-powered vehicle that can travel directly downwind, faster than the wind itself. But while some eminent people are claiming it is impossible, others are busy making it happen. And they have video to prove it.
The project is being run by aerodynamicist and avid kite surfer Rick Cavallaro, with the help of some friends, and some fat funding from Joby Energy and Google. Apparently having built a scale model that proved it was possible, and having been met not with contrition from former skeptics, but derision, Rick decided to vindicate his claims on a larger scale.
Now I can't blame the skeptics. I'll be the first to admit that I am no genius when it comes to physics. But if somebody asked me if it was possible to create a car powered by nothing but wind, and then travel directly into a headwind [CORRECTION: We are talking about travelling downwind - i.e. with the wind. As I say - I am no expert...], at speeds faster than the wind itself, my response would probably be "of course not." I am not alone. Richard Jenkins, who himself smashed the world land land speed record for wind powered vehicles, was skeptical too. But, as he writes over at Zerocarbonista (which of course is curated by Dale Vince, creator of a 100mph electric sports car that may or may not be wind-powered depending on your perspective), his skepticism about the Faster Than The Wind project rapidly turned to admiration. In a post entitled Another Kind of Wind-Powered Car, he lays out the narrative of his conversion:
"My heart is split between belittling idiots, and saluting eccentrics, and this downwind quest lay somewhere in the middle. These loonies were pursuing a pointless goal, doomed to failure, but there was some genuine merit in the myth and their enthusiasm. [...] A few months later they were claiming success and if it was not for another great friend, Bob Dill, advising that they were actually correct, I would have discarded their claim as an April fool. [...] Not content, I had to witness this myself. When I heard it was on for the official record at El Mirage, I jumped on a plane and went to check it out. The video speaks for itself. These guys are not idiots, but sincere, genuine, technical people who took a myth and made it real. It works. It starts from rest, trundles to true wind speed, then powers to a multiple of about 3 times the true wind speed."
Wired has an interesting piece on the Blackbird Project, explaining how the whole thing is possible. I must confess that I don't really understand the explanation about lack of relative wind:
""If you're on a bike and you're going downwind, you don't feel any wind anymore at all," he said. "You lose the power of the wind when you reach the wind speed, because there is no relative wind at that point."
But with the help of some illuminating comments in the forum, I do think I am beginning to understand how the vehicle works. Just as a yacht might tack across the wind, the airfoils on the vehicle are "running across the wind just as the airfoils of the sailboat are. Unlike the sailboat however, the sails on the vehicle are free to take a different path through the air than the chassis takes, while the hull of the sailboat is required to travel with the sail."
It's hard to argue that something is impossible when someone has been videoed doing it.
Now just what do we do with this information?