From: jwill@AstraGate.net (John Michael Williams)
Subject: Re: Any ideas on measuring radiation in the home ?
Date: 12 Oct 2002 12:46:08 -0700
NNTP-Posting-Date: 12 Oct 2002 19:46:08 GMT
John Woodgate wrote in message news:...
> I read in sci.electronics.design that Dirk Bruere
> wrote (in ) about 'Any ideas on
> measuring radiation in the home ?', on Wed, 9 Oct 2002:
> >So, how does that compare to living near a HV AC powerline?
> There are MANY differences between the fields generated by an electrical
> storm (broadband, very large fluctuations) and a power line (narrow
> band; more or less continuous).
One major difference is that a lightning strike can generate
electromagnetic waves which then propagate independent of
the source. Power lines generate only virtual fields: On
each cycle, the entire field is cancelled and then is
reformed with reversed polarity.
Also, power lines are terminated at both ends and in general
radiate nothing (unlike an antenna, which is open at at least
one end). If power lines radiated their fields, they would
not carry power to the users.
> The fields from power lines DON'T occur naturally. But people have been
> living near and under power lines for around 70 years in many countries.
Yes. I agree with this. Also, I think the argument from
"evolution" is flawed in other ways: For example, humans
HAVE evolved in the presence of bacteria. Yet, many common
bacteria become harmful or deadly anyway. There is no reason
to assume that having evolved in the presence of something has
any bearing on whether it might be harmful or not.
> If there were any harmful effect, sufficient to justify all the jumping
> up and down and screaming, it would be rather easily detectable by now,
> whereas even the most prejudiced analyses show nothing definite.
It is very difficult to prove no harm, so generally it pays
to remain open to the possibility. I tend to agree with
you that power lines are harmless (unless touched!).
For example, tobacco--the tobacco companies have killed MILLIONS
of people since introducing "cigar-ettes". They gave them out
free during WW I (nothing like a good war to improve the
addiction rate). Yet, it was not suspected they were so
deadly until the lung cancer rates began climbing -- twenty or
thirty years later. Lung cancer was a rare disease before
cigarettes. It could only be caused by inhaling radioactive
dust in a uranium mine. Now that the issue has been recognized, other
cancers such as of the mouth, from chewing tobacco or smoking, and
other diseases such as arterial placque leading to hypertension,
are being discovered. The full extent of the damage to health
and longevity may never be known.
Someone 75 years old may say, "Ha Ha. I've smoked for
forty years, and it hasn't hurt me a bit." But, visit a
cemetary, someday. This is the problem: Noone can prove
anything by epidemiological statistics any better than by
One has to assume harmlessness from good understanding,
not from obviousness.
> OTOH, urban legends and scare stories are rife, many published by people
> who demonstrate clearly a total absence of understanding of the subject.
> My favourite is a claim of a 60 V/m **d.c.** electric field attributed
> to a 50 Hz mains water heater. This is a heating element, sealed in a
> steel tube, immersed in 100 L of water, in a water-tight copper casing.
> 'Oh, yes, the field disappeared when the heater was switched off.' Yes,
> and I'm the Good Fairy Sunbeam.