To demonstrate a basic property of physics, Norwegian physicist Andreas Wahl tied himself to the side of building 45 feet off the ground.
The only thing keeping him from falling and potentially breaking a body part, or several, was a cable with a weight attached to the end.
While Wahl’s experiment seems risky, he’s actually perfectly safe. And that’s all thanks to a fundamental property of physics called centripetal force.
When Wahl’s colleagues released the weight, both he and it started to fall. Wahl fell straight under the force of gravity, but the weight, because it was placed at a distance from Wahl, traced an arc through the air, just like a swinging pendulum.
Watch the video: