Euler's Disk

A hypnotic display of light and sound that spins science into art. The 3" diameter chrome-plated steel disk will spin faster and louder the longer it rotates. Just give it a spin and gravity does the rest. Includes Disk, 9" concave mirror base and 9 pieces of holographic, magnetized foil. 6 disks included per pack.

What is it? 
Euler's Disk is a chrome plated steel disk the is 1/2 inch thick and 3 inches wide.  One edge is carefully machined to a smooth radius.  Use any combination of the nine magnetized pieces of holographic foil to make a variety of brilliant surface designs.  A concave mirror base provides a setting the the disk to spin on like a coin...  a coin that doesn't seem like it will ever stop.

The action of the disk is "spolling" which means rolling and spinning.  Hold the disk upright, slightly angled onto it's rolling edge and give it an easy twist.  That's all there is to it.  A spolling Euler's Disk produces a captivating sonic hum and a magical holographic display. 

The scientific principles involve energy.  When Euler's disk is spun, it contains both potential and kinetic energy.  Theoretically speaking, the disk would spoll (spin and roll) forever if it were not for friction and vibration.