Impossible Objects - Stubborn Turtles

Stubborn Turtles
Designer:Vladimir Krasnoukhov & Anatoli Kalinin
Craftsman:Anatoli Nevrov & Valeria Mamedova
Category:Impossible Objects

A clever variation of the Aboriginal Rattleback seen recently in Nature Company, Natural Wonders, and many other specialty stores. When spun in the direction the turtles are facing (counter-clockwise in the photograph), it will spin until it runs out of energy. When spun the other way, it will stop and reverse direction. The rattleback depends upon the center of gravity of the rounded bottom being off-center. The turtles can be rotated the opposite direction and they still stubbornly insist on spinning in the direction they are facing (clockwise, after being rotated).