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From: Frank Reed (no email)
Date: Sat Jun 19 2004 - 16:26:26 EDT
Jared S wrote:
"If we lose the magnetic field, we'll lose our entire "shielding" and we'll
be so badly zapped by all kinds of energy that the GPS will be the least of
anyone's concerns. With all the money you save not buying sextant stock, you can
buy deep mine shafts. No magnetic
field for any length of time would mean some serious problems for life as we
know it."
It's not quite that bad. Most of the radiation shielding comes from the
atmosphere. When you fly in a plane at 35,000 feet (as I'll be doing tomorrow
morning), you're exposed to radiation levels that are dozens of times higher than
at sea level. Yet airline flight crews who spend long periods of time at these
altitudes show no (or ambiguous) evidence of health effects.
That said, sure, if the field strength drops for a few thousand years, cancer
rates would probably increase measurably. Are we doomed? Well, there have
been dozens of polarity reversals in the past fifty million years, and no major
extinction events. So no. Probably not doomed. Sicker? Yes.
And added:
"No one really wants to spend the money on the basic science needed to look
into this in real detail, it just isn't sexy enough, or urgent-seeming enough"
Well, we do spend a lot of money on cancer treatment. Since that's the
primary health effect, it probably makes sense at a public policy level to work on
all forms of cancer instead of those specifically related to increased cosmic
ray levels.
And there's another problem besides lack of urgency. No one really has any
great ideas on what to do! After centuries of study, we still only have computer
simulations that *may* mimic features of the dynamics of the Earth's core
(and they do show random fluctuations and polarity reversals, so they *seem*
relevant at least). But we really don't know what's going on 4000 miles beneath
our feet, and there doesn't seem to be any way to get around that basic
ignorance.
Frank R
[ ] Mystic, Connecticut
[X] Chicago, Illinois
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