So, let’s begin at the beginning…
Science YouTuber, Derek Muller, claimed he could use a wind-powered car to cruise faster than the wind while traveling directly downwind, using only the power of the wind.
Wind powered car + cruise faster than the wind + travelling directly downwind + using only the wind = you keeping up with us, yeah?
Alex Kusenko, a professor of physics at the University of California, said it would break the laws of physics. The pair bet $10,000 to find out if Muller could prove it.
The wind-powered car looks like a windmill attached to a rickety F1 racer, but it’s more complicated. The car's wheels power the turbine and the propeller spins backwards, generating thrust. Racing downwind, the propeller spins faster and so do the wheels, pushing the car faster than the initial wind speed. According to Kusenko, the greater speeds are caused by random gusts and inertia. He was willing to put $10,000 on the line if Muller could prove otherwise.
The car looks odd, we’ll admit that much. But, you have to see it in action for yourself. And better yet, understand it.
“When the speed of the car is exactly equal to the speed of the wind, it seems like the propeller can provide infinite force,” Muller said in his video, citing one of Kusenko’s biggest problems with the experiment. “This is exactly what you’d expect with any lever or pulley. If one arm of the lever is zero, then you can lift an infinite weight with any amount of force on the other side.”
Here’s the vid that got Alex the 10 grand.
As a proof of concept, Muller teamed with YouTuber Xyla Foxlin to build a model downwind cart which they ran on a treadmill. After working out some design flaws, Foxlin’s cart would always gain speed and move faster than the treadmill.
“Professor Kusenko has now conceded the bet,” Muller said on YouTube. “And he transferred $10,000 to me. I want to thank him for being a man of honor and changing his mind in light of the evidence presented.”
Muller said he plans to give the money away as part of a science communication competition.
Here's the aftermath video with some explainer bits and pieces for you physics buffs out there.
Did you love that as much as us?
Maybe you'd love some more physics style banter at www.spacesociety.com.au?