STATIC ELECTRICITY

Charge carriers, particularly electrons, can build up, or become deficient, on things without flowing anywhere. You’ve probably experienced this when walking on a car- peted floor during the winter, or in a place where the humidity was very low. An excess or shortage of electrons is created on and in your body. You acquire a charge of static
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electricity. It’s called “static” because it doesn’t go anywhere. You don’t feel this until you touch some metallic object that is connected to earth ground or to some large fixture; but then there is a discharge, accompanied by a spark that might well startle you. It is the current, during this discharge, that causes the sensation that might make you jump. If you were to become much more charged, your hair would stand on end, because every hair would repel every other. Like charges are caused either by an excess or a de- ficiency of electrons; they repel. The spark might jump an inch, two inches, or even six inches. Then it would more than startle you; you could get hurt. This doesn’t happen with ordinary carpet and shoes, fortunately. But a device called a Van de Graaff gen- erator, found in some high school physics labs, can cause a spark this large