rattleback

This makes the rattleback a physical curiosity that has excited human imagination since prehistorical times.

A rattleback is a semi-ellipsoidal top which will rotate on its axis in a preferred direction.

"Spin reversal of the rattleback: Theory and experiment."

The amplified mode will differ depending on the spin direction, which explains the rattleback's asymmetrical behavior.

"How things work: The rattleback revisited."

"Realistic mathematical modeling of the rattleback."

Replies: The toy, sometimes called a "rattleback," is said by highfalutin types to exhibit "vibration-rotation coupling."

If anyone cannot find it, or would like references for more accurate, mathematical analyses of the rattleback, just drop me an e-mail and I will provide them.

One plastic rattleback made and sold by Charles W. Sherburne is described as 12 inches in length.

Caughey, T.K. "A mathematical model of the rattleback."

Moreover, for most rattlebacks the motion will happen when the rattleback is spun in one direction, but not when spun in the other.

"The Amateur Scientist: The mysterious 'rattleback': A stone that spins in one direction and then reverses."

This book also has crude analyses of tops, including the flipping tippe top, boomerangs, martial arts, and other popular topics that usually interest those intrigued by the rattleback.

Other ways to add motion to a rattleback include tapping by pressing down momentarily on either of its ends, and rocking by pressing down repeatedly on either of its ends.

When the rattleback is spun in the "stable direction", also known as the weak reversal direction, friction and damping often slow the rattleback to a stop before the rolling instability has time to fully build.

While rattleback artifacts are described as stone with various measurements, most which are sold currently as novelty puzzles and toys are described as plastic with measurements of 3.75 inches long x 0.75 inches wide x 0.4375 inches high.

When there is an asymmetry in the mass distribution with respect to the plane formed by the pitching and the vertical axes, a coupling of these two instabilities arises; one can imagine how the asymmetry in mass will deviate the rattleback when pitching, which will create some rolling.