Electric ball in children's museums that makes hair fly on end?

Question

Can anyone tell me what it's called? and a little about how it works?

Answer 1

It's called a van deGraff generator.  There is a lot of information, pictures, and videos, on the internet.

Answer 2

van de Graaff generator. Essentially there is a moving belt inside which generates huge amounts of static electricity using friction. It can build up millions of volts in this way (curiously, this is not dangerous since there is so little actual charge present). When you touch the ball, electricity is transferred to your body and into your hairs. When they acquire charge, they repel each other, which is why they stand on end.

Answer 3

The contraption is called a Van der Graaf Generator. It's basically a device that creates static electricity by rubbing a metal brush against rubber surgical tubing that's made into a belt. This rubbing generates an excess positive charge that is collected into a container, usually a metal sphere.  When you go near it (let's say you use your index finger), the excess charge can "jump" from the sphere into and thereby zap you. When you touch the sphere, the excess positive charges are going to you. Some of these charges will go into and around your hair...like charges repel, thus you hair will push away from each other and create the standing hair effect.