The vanes in the radiometer are alternately dark and light in color. When the light strikes these wings, it transfers heat to each one, but not in the same degree. The lighter wing reflects the rays, and the darker wing absorbs the rays. The stronger the light the more energy there is to heat up the darker side of the wing causing the wings to spin faster as the light gets brighter. It's the sphere powered by the sun.
Full color box.
This product was added to our catalog on Friday 03 January, 2014.