Quote:
Originally Posted by arsbadmojo
That's true about fluorescent tubes glowing under the wires. They'll also hum like crazy in fog or light rain.
Check this out.
How far away? 100 feet? Check me if I'm wrong, but doesn't the strength of the field drop exponentially with distance? At 100 feet you're probably down to background levels as far as health goes, but still an eyesore. |
As a physics grad student, I can easily correct this one. They do not drop off exponentially. The EM fields of a long, straight wire fall as 1/(distance) and those of two nearby wires carrying electrical current in opposite directions as 1/(distance)^2. Energy density (which is proportional to the square of field strength) for two opposing wires falls as 1/(distance)^4. The latter describes power lines well - one carrying current to the house(s), the other carrying current back from it(them).
Twice as far means field strength drops to 1/4 of the value, and energy density to 1/16 of the value.
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