Ever rub your stocking feet along a shag carpet and then touch someone? If you have, you were producing exactly what a Van de Graaf generator does -- electricity.
A shocking stocking experience may not be as dramatic as large bolts of electricity sparkling and cracking like lightning, but the static-electricity charge built up by the friction from your socks and the rug does teach a certain respect for the power of electricity.
This is exactly what Dr. Robert J. Van de Graaff, a former Massachusetts Institute of Technology physicist and the man for whom the Van de Graaff generator is named, wanted to do with his invention: teach respect for electricity. Dr. Van de Graaff also used his invention to study the way atoms are made up.
The electrical charge, which is another way of saying the electricity present around a Van de Graff generator, is caused by a series of felt or rubber belts rubbing against each other in much the same way that socks rub against the carpet on the floor.
This machine can illustrate much basic knowledge about electricity and how it is used in our daily lives. The original model is now on working display at the Museum of Science in Boston, Mass. The machine is over 37 feet tall and the sparks of electricity that bolt out from it are as long as 15 feet.
Much smaller Van de Graaff generators are often used in junior and senior high school science classrooms. If you were to approach the generator while it was in operation, the hair in your head and arms would stand on end.
We often take electricity for granted. Just turning on the television, making toast for breakfast in the morning, or having a light to read by at night all depend on our use of electricity. Thanks to Dr. Van de Graaff, we have a better understanding and control of the power of electricity.