Sailboat sailing upstream with no wind
December 13, 2018 9:10 AM Subscribe
A few years ago, I had my mind blown by the Blackbird land yacht, which was able to "sail" directly downwind faster than the wind using only wind power. At first glance it appears to violate some law of physics, but in the end it turns out that it doesn't; energy is ultimately being provided by the wind, just in a way that you wouldn't expect it to be able to. I have now encountered a new aerodynamics brain twister. Artemis Racing, a perennial America's Cup contender, have said that it is possible to build a sailboat which can sail upstream in a river even if there's no wind, using the "apparent wind" created by the... uh... by the river water pushing the boat downstream, I guess? Maybe? Could someone explain how this might work in a way that I might be able to understand?