🚀 go-pugleaf

orville%weyrich@uunet.uu.net (Orville R. Weyrich) writes:
>In article <1992Nov3.021632.22139@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>>                          EM field strength falls off with the square of
>>the distance from the source. So the power lines, being much further away,
>>produce much weaker fields in your home than the fields generated by the 
>>wiring and devices inside your home. A hair dryer held next to your head
>>generates a field 100,000 times stronger in your body than a distribution 
>>line a 100 feet away, buried or not.

>AH-HA! a use for my physics course in electromagnetics! :-)

>What you say is true for point sources [EM field inversely proportional
>to the square of the distance]. But power lines are DEFINITELY NOT
>point sources. For all practical purposes, they are "line sources"
>and their field strength ins inversely proportional to the distance. Hence
>the field strength is considerably stronger than that predicted by the
>inverse square.

Orville is spot on here; but a major point is that power lines and wires are
radiating continually, whereas that hair dryer is on only a tiny fraction of
the time. If you sleep with an electric blanket[1], it will give by far the
largest dose of EM radiation over a lifetime because it's so close and it's
on for so long.

(Also, Gary's calculation is incorrect: 100 squared is 10 000, not 100 000).

regs,
Graham

1. Studies have shown a link between extended exposure to EM radiation (at
   levels experienced from an electric blanket) and a reduction in production
   of a body chemical which is suspected of being a cancer inhibitor.
   I wouldn't sleep with an electric blanket on if I were you.