St. John’s College High School science teacher David Hovan is using basketball to teach his students the laws of physics, and it made him a YouTube celebrity.

“The video was taken last spring by a student who has since graduated, and it’s gone viral,” Hovan explained, of the video that got him noticed. “The concept that I’m demonstrating is called angular momentum, and it really just comes down to rotation physics.”

See, it’s just that simple.

Hovan uses a pen to balance the spinning ball, and can grade papers while the ball continues to rotate. The Harlem Globetrotters, kings of perpetually spinning basketballs, caught wind of the video and paid a visit to Hoven’s physics class. Check out the video below: