The Dancing Disc

A Coin that Spins and Spins and Spins

Kit for a large Leonhard Euler commemorative medal: complete with mirror platform on which it dances like a spinning top with increasing speed for up to 1 1/2 minutes.
Who hasn't experienced this? If you spin an upright coin, it rotates faster and faster until it comes to a sudden halt with a crash.

Thanks to its optimised properties, the AstroMedia Dancing Disc spins particularly long and noisily (Video). This kit for a dancing disc is a tribute to the brilliant mathematician Leonhard Euler and is dedicated to his memory. He was the first to describe the spinning process in several mathematical formulas, now known as Euler's Equations.

The Dancing Disc is significantly larger and heavier than an ordinary coin. In addition, the side edges of the disc have been optimised in such a way that frictional losses are particularly low. That is why it rotates all the longer and more impressively. With a bit of practice you can make the disc oscillate for over 2 minutes. The kit includes a round mirror, which is slightly concave and thus makes sure the stainless steel disk does not move too far from the centre during its dance.

The Principle

Give the dancing disc a good twist. Due to its weight, it leans a little more with each turn, becoming faster and louder at the same time. To put it simply, the disc gains the energy it needs for the ever-accelerating dance as its centre of gravity approaches the base: At the beginning it is erect, and the power required for this is stored in the disc as potential energy. This is released when the disc tilts and is converted into rotational kinetic energy.