LightRotor (*) provides a simple demonstration of the conversion of heat into a rotational movement i.e. kinetic energy: The air inside the rotatable cylinder is heated by the candle. This warm air has a density (remember: density is mass per volume) less than that of the surrounding cold air. So it is lighter and rising inside the cylinder. It is the same effect like a rising cork after dipping under water. The result is an ascending air flow that drives the propeller and the connected cylinder.
Beside the pure physical demonstration the LightRotor is very aesthetic device. The light of the candle shines through the transparent paper and so the rotor glows: an illuminated and rotating lampion.
The kit is shipped in a flat box and includes all parts, two candles and a construction guide with drawings describing all steps of assembling. The lampshade is made of two flat transparent paper sheets that have to be folded to a cylindrical form and connected to each other and the preassembled propeller via metal clips. All other joints are made by plugging. The kit requires no gluing and is easy to assemble within a few minutes.
Height ~33 cm.
(*) Patent pending