Veritasium takes into the weird nuances of rotation. “Rotation,” you might be saying to yourself. “Isn’t that just a thing spinning around?” Well, no. There’s a lot more to it, and it lies in the linkage between what Soviet cosmonaut Vladimir Dzhanibekov noticed about a wingnut in 1985 and a paper published 10 years later in the Journal of Dynamics and Differential Equations which explores what happens when you flip a tennis racket into the air–which, it turns out, is quite a bit.