Because instead of a CRT and its associated electronics, they featured a spinning disk with a spiral pattern of holes. These mechanical TV systems were quickly superseded in the 1930s by all ...

The convection created helps to keep the disc spinning," the post said. Flowing water is also an important part of the equation, the park said in the post. "Areas where water accelerates ...

Researchers believe ice discs spin because of temperature changes in the water, creating a vortex underneath. The movement chips away the edges, creating its circular shape. The large rotating ...