Walter Lewin is a physics professor that seems to love his job.
Physics is known to be a rather difficult subject to learn, so the man lectures in ways that get the class involved more than usual.
And in this instance, he showed that he was willing to put his life on the line for this subject.
While explaining how kinetic energy and gravity work, the professor used a wrecking ball model to demonstrate how the two ideas work together.
Lewin stated that if he stood up against a wall and released the wrecking ball right from where his position was, then the ball would swing back only to stop right in front of his face, based on how kinetic energy works.
If his theory was off, even by a little, it meant he would get hit in the face. He had enough faith in his theory that he was willing to do this.
And after a very suspenseful swing, it turns out that he was right.
The ball stopped just short of his face—he not only taught his students a lesson in kinetic energy but was able to leave with his face intact as well.
As amazing as this demonstration was, you shouldn’t try this on your own.