RattleBack

It spins this way, but not that way?! The Rattleback is an insolent piece of history that will bring you hours of enjoyment.

The Rattleback’s history dates back thousands of years. In that time it has come to be known as the “Rebellious Celt” for its unorthodox and outright defiant behavior against the laws of physics. Not quite as dramatic as a 13th Century Scot wailing “Freedom!” during his execution at the hands of an oppressive king, but the Rattleback is pretty insubordinate, nonetheless.
Having been studied for over a hundred years, it has only been recently made clear exactly how the Rattleback works (long mathematical equations we won’t bother to excite you with here). Also known as a “wobble stone,” the Rattleback’s unique shape is what gives it its rebellious behavior. If spun one way, the Rattleback will rotate in a normal manner but try twirling it in the opposite direction and witness an apparent backlash against natural laws! The Rattleback becomes volatile as it starts to rattle before eventually stopping and reversing its own direction!
One of the most extraordinary physics toys ever known, the Rattleback has intrigued man throughout history. Now the time has come for you to enjoy it! Clear off some of those papers that are cluttering up your desk and make some room for the Rattleback. For the rebel in us all!