Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!lll-winken!scooter!neoucom!wtm
From: wtm@neoucom.UUCP (Bill Mayhew)
Newsgroups: sci.electronics
Subject: cows and high tension wires
Message-ID: <1845@neoucom.UUCP>
Date: 30 Nov 89 05:22:56 GMT
Sender: wfd@neoucom.UUCP
Organization: Northeastern Ohio Universities College of Medicine
Lines: 50

As part of the obligatory stuff necessary to get through undergrad
EE school, I recall taking a course named, "energy conversions,"
that dealt with giant electric motors, 100 KVa transformers and
ower transmission lines.

One of the readings was on transmission lines.  It discussed that
power disspated in the space surrounding the lines is substantial,
and field strenghths can be several hunderd volts per meter in the
close environs.  The article mentioned that cows in the vicinty of
transmission lines tend to line up with the major axis of their
bodies parallel to the tranmission line.  The feeling (literally??)
was that it was more comfortable for the cows to line up that way,
as their bodies would subtend a smaller number of isopotential
field lines, and thus the impressed voltage on the cow would be
smaller.

As far as living close to an AC transmission line goes, I'd worry
more about what unknown thing it might do to me, rather than
anything that might happen to my computer!

There have been some articles that border on pseudoscience
circulating lately that claim a correlation of cancer incidence an
living close to a large source of 60 Hz H field!  You read that
right.  The author cliamed that 60 Hz magnetic fields correlate to
incidence of lukemia.  His reasoning was that people that lived
close to the head end of a power line where the currents in the
line are higher suffered more cancers than people that lived near
the end.  What the article did not mention was if other causitive
factors such as people that live near the head end might be
exposed to higher levels of emissions from the utility or other
industry were accounted for.  The sample population was also
relatively small.

The earth's magnetic field (though virtually steady-state) can be
measured in Tesla, while the H field more than a few hundred feet
from a transmission line would be fractional Webers/m^2.  Why is a
60 Hz alternating field more deleterious than a steady state
field?...  One theory was that the alternating field disrupts RNA
durring cell division.  Why wouldn't the earth's field be a
problem?  The RNA in the cell is moving around, so it is going to
be cutting field lines of the earth's feild which are much stronger
than any field from the power lines nearby.

Perhaps, the original poster was just trying to whip up some
network fury?  It wouldn't surpirse me to see several hundred
articles on the subject.


Bill
wtm@neoucom.edu


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