PRODUCT DESCRIPTION

3.5" Diameter Purple Sphere on Clear Braided Stem. The radiometer, also known as a light windmill, is an instructive physical object which actually demonstrates a scientific theory, namely, converting light into energy. This theory shows how the radiometer converts light into energy. The radiometer will spin 2000 revolutions per minute in warm light, such as sunlight and well lit rooms. They will not spin using fluorescent lights. These radiometers are truly one of a kind. Invented in 1873 by Sir William Crookes, the radiometer, also known as the light mill or solar engine, consists of a glass bulb with a partial vacuum. Inside are four vanes which are mounted on a spindle. The vanes rotate when exposed to a warm light. More intense light increases the rotations, up to 2,000 per minute. Hand blown in Germany, these radiometers are available in a variety of designs with color stems and spheres to please the most sophisticated taste.

FEATURES

More intense light increases the rotations, up to 2,000 per minute.
Inside are four vanes which are mounted on a spindle.
Size 3.5 Diameter.
Great Gift Idea.
Color Puprle.

Wood Designs 60500 Kindergarten Blocks - 24 Shapes, 183 Pieces, 9.5" Height, 9.5" Width, 12" Length