Theoretical physicist Erwin Schrödinger is best known for his thought experiment known as “Schrödinger’s cat,” in which a cat hidden in a box may be simultaneously alive and dead. A lesser-known corollary, “Schrödinger’s wheel,” postulates that two cats sleeping unobserved in a box may begin rotating clockwise.

sleeping kittens, by bjimmy934, licensed under CC BY 2.0