[Antennas] RE: Our Magnetic field is fading

[Hsu, Aaron]

Watched a program about the earth's magnetic field a few weeks ago.  I think
it was on Discovery Channel or something similiar.  It described the usual
on how the the field protects earth from solar winds and it also went into a
theory on how Mars may have had an atmosphere and slowly lost it due to
solar wind erosion when it lost it's magnetic field millions of years ago.

A facinating thing they found was that up until 780,000 years ago, the
Earth's mag field "flipped" (aka reversed) polarity regularly every 200,000
years or so.  They discovered this quite accidentally when examining core
samples from lava rock - the minerals in lava assume the magnetic polarity
and strength of the earths' magnetic field when in liquid state (lava) and
the field "locks" into place when cooled.  So by taking lava rock samples,
they were able document data about the earth's magnetic field (direction and
strength) in great detail over the past few million years.  They also did
computer simulations based on the data and found that the earth's mag field
is once again showing early signs of "flipping".  The flips (reversals) take
hundreds to thousands of years to complete, so I know I won't be around to
see it.  =)

If I find the name of the program, I'll post it.

73,

  - Aaron Hsu, NN6O (ex-KD6DAE)
    {nn6o}@arrl.net
    {athsu}@unistudios.com
    No-QRO Int'l #1,000,006
    . -..- - .-. .-   ".... . .- ...- -.--"
 

-----Original Message-----
From: FireBrick [mailto:w9ol@billnjudy.com]
Sent: Friday, December 12, 2003 10:28 AM
To: antennas@mailman.qth.net
Subject: [Antennas] Our Magnetic field is fading

http://www.cnn.com/2003/TECH/science/12/12/magnetic.poles.ap/index.html

If the article is true, we will have to find a WHOLE new way to aim our
antennas in just another 2000 years.
Maybe we should start planning now? :-)))

-----------------------------------------------------
You need a Lifestyle change if: Your neighbors think you're a detective
because a cop always brings you home.
-----------------------------------------------------

W9OL, Bill H. in Chicagoland



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