Electricity

ELECTRICITY

One of the basic particles that make up matter is the electron, and under certain conditions the electrons in something will generate a charge of energy we call electricity. This form of energy is all, around us, both man-made (what comes out of the wall outlets) and in nature (lightning, or the shock you get after you shuffle across a carpet and touch a doorknob). We use electricity for a variety of tasks, from powering our labor-saving appliances to keeping unwanted intruders out of a given area with electrified fencing, from lighting our cities and running our trains to helping cure people who are sick in the head. But wherever electricity is used, there must be a conductor to carry the charge.

( Note: The following is satire. Do not try this. It would be dangerous.)

Here is a fascinating experiment you can perform to investigate various electrical conductors. Take an old lamp, and with either wire cutters or a good pair of scissors, snip off the cord near the base of the lamp. You will now just have a cord, at one end of which is the plug. Separate the leads from the other end of the cord and strip off about an inch of insulation, leaving about an inch of bare wire exposed for each of the two leads.

You are now equipped to observe the conductive properties of various household things. Simply insert the plug into the wall outlet and, holding a lead in each hand, touch the exposed wires together. The wire is a good conductor, and the current will flow very powerfully through it and blow the fuse for that outlet. This is because there is nothing to “slow the current down and use it up,” or, as scientists say, “provide resistance” to the current. Whenever we use electricity, we do so by providing resistance in the circuit, and sending the current through other devices that then make use of our wonderful friend.

Wait until the fuse is replaced, and then touch the leads to the sofa. Nothing happens. This is because the sofa is a poor conductor, or a good insulator. Try this with several different objects: see how the metal leg of a table will conduct the current well, as will your sister’s arm or a common nail. But a glass will not, nor will your baseball glove, a freshly-baked cake, or a broom. You will soon see that the best conductors of electricity are some metals (especially iron and copper) and water. Your sister’s arm is, too.

Strangely enough, the earth itself can be a good conductor. Try this: fasten the leads of the wire to the metal shaft of a long ice pick or a screwdriver. (Be sure the pick or the screwdriver have insulating handles of wood or plastic, though. A good scientist does his best not to kill himself when investigating electricity.) Then either by using an especially long lamp cord or with an extension cord, arrange it so that you can go outside with the pick and still be able to plug in the wire. When this is ready, break off one of the prongs from the plug on the wire or the extension, so that only one remains. Plug this one prong into the wall. Then – and you may want to summon several of your friends for this special demonstration – jam the pick or screwdriver blade into the earth. What will happen? How about this: all the worms in about a thirty-yard radius will soon come wriggling up out of the ground into view, writhing and squirming. The earth has completed the circuit, absorbing the current from the wall and “grounding” it. I haven’t the faintest idea why the worms come popping up, but it’s a hell of a thing.

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