Experience this sphere powered by solar energy-the Tedco Solar Radiometer.

The vanes in the Radiometer are alternately dark and light in color.

When light strikes these vanes, it transfers heat to each one - but not at the same degree.

The lighter vane reflects the rays and the darker vane absorbs the rays. The stronger the light, the more solar energy there is entering the Solar Radiometer, causing its vanes to spin faster.