Sunday, January 27, 2008

Going with the Flow

Think back to your high school physics classes and all those diagrams of atoms with electrons spinning around a nucleus. (They’re the drawings that looked like really small solar systems.) Basically, electrons spin around because the protons in the atom’s nucleus carry a positive charge (+) that repels the electrons’ negative charge (–). If enough of the electrons decide to move on, preferably in a more or less uniform stream, we end up with usable electricity.
Electricity comes in several flavors, but the two we’re most familiar with are …
➤ Static electricity, in which the electric charges are stationary.
➤ Dynamic electricity, in which the electric charges are moving in a current.
When you were younger, the main value of static electricity was using it to shock unsuspecting siblings and cousins after you had walked across a carpet. If you didn’t do this when you were a kid, you can always try it at your next holiday dinner. Cats also are good targets, but their revenge usually is a messier affair. Why does the shock occur? Because some electrons like to travel, and they aren’t the most stable subatomic particles. When you walk across a carpet (some are worse than others), you pick up some of these hitchhiking electrons while leaving some of your own positive charges. They have to go somewhere, and your sibling’s finger or a doorknob makes a dandy conductor. If you touch a door frame, nothing happens because wood is a good insulator. That is, it does not allow electrons to easily move through it.
Static electricity is simply an imbalance of positive and negative charges. When you get zapped, you’re just the accountant trying to balance these charges. One place you don’t want to balance these charges, by the way, is with your computer, so you can either …
➤ Touch your metal desk chair before turning on your computer to get rid of any pesky electrons that could affect your computer.
➤ Apply anti-static spray periodically to your carpet so it will have a more positive charge and be less likely to give up its electrons. Static electricity may be annoying, but dynamic electricity is another story altogether.

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