This device is a radiometer that is powered by light striking the surface of the leaves on the spindle inside. The light causes the black surfaces of the panels to heat up to a higher temperature than the white surfaces. Air molecules inside the partially evacuated sphere are heated more by the black panels and "KICK" off the surface with a higher momentum than those molecules striking the white surface. The difference in the force of the "Kick" causes the spindle to rotate. It is NOT powered by the momentum of the light photons as many people mistakenly believe.

Pira DCS # 4D20.10

Radiometer   Light Source   Steel Pole
Cenco Black Table Clamp