Physicists have demonstrated that spinning a hard-boiled egg horizontally makes it jump into the air.
Scientists already knew that a fast-spinning egg spontaneously stands on its end. Random jitters during that process could amplify into leaps, researchers had theorized.
In some high-speed video images, hand-twirled eggs seemed to jump. But, no one knew whether those jumps were real or resulted from inadvertent upward propulsion from a spinner's hand, notes Yutaka Shimomura of Keio University in Yokohama, Japan.