BillyB Frequent Poster
Joined: 27 Jul 2005 Posts: 60 Location: Lexington, KY, USA
|
Posted: Wed Aug 10, 2005 3:37 pm Post subject: Static discharge |
|
|
This phenomenon is called triboelectric charging.
The prefix "tribo" (pronounced TRY-bo) means "rubbing." When certain pairs of unlike materials, such as wool and hard shoe-sole leather, rub together, one material gives up some of its electrons to the other material. The separation of charge can create a strong electric field.
Here on Earth, the air around us and the clothes we wear usually have enough humidity to be decent electrical conductors, so any charges separated by walking or rubbing have a ready path to ground. Electrons bleed off into the ground instead of accumulating on your body.
But when air and materials are extraordinarily dry, such as on a dry winter's day, they are excellent insulators, so there is no ready pathway to ground. Your body can accumulate negative charges, possibly up to an amazing 20 thousand volts. If you touch a conductor, such as a metal doorknob, then--ZAP!--all the accumulated electrons discharge at once.
Source:
http://science.nasa.gov/headlines/y2005/10aug_crackling.htm?list188991 |
|