On Wed, 25 Oct 2006 17:46:22 -0500, "Jim Macklin"
wrote:

Or it just does like the AC current in the power grid and
switch to the other side of the power curve. The actual
material doesn't have to move, the energy to flip over
billions of tons of spinning matter isn't there. But as an
A/C generator, it is just a question of electrons.

A while back Scientific American devoted a lot of space to this. There
was also a program on it at least a year ago.

Apparently the core is not a uniform spinning mass. There are
convection currents up and down as well as the circulating currents we
normally think of. Depending on the orientation, the flow across the
top may be N,S, E, W, or some where in between. It appears the
reversals are not a singular event, but may happen in stages and at
different times through out the overall reversal. I don't think they
are even sure of how these events may even interact...if they do.

I've not seen any information on the total time expected for a
complete reversal to happen. Indications (some isolated events that
appear to be reversals) are that we are starting into or could be well
into a change. Does it take 10 years, 100 years, or a 1000 years once
its started? I don't think any one knows enough to even make a guess
except for those based on core samples which are again going to be
local. OTOH I believe they are pretty well documented along the mid
Atlantic ridge which is probably the best accessible global record
that spans many millions of years. There they have done surveys using
magnetometers to get some pretty detailed maps along with a number of
core samples. http://www.geomag.bgs.ac.uk/reversals.html

A comparable surface feature is the mid African rift valley where the
rift and active volcanoes can be seen. That is one wide valley, but
the eastern walls are virtually straight up. I've never seen the
western side..

Now stop and think... The New Madrid fault lies atop a "failed rift"
http://earthquake.usgs.gov/regional/...php#february_7
between St Louis and Memphis. What if it decided to start opening
again? Even a major quake along that fault would be something to
behold. They figure if it lets go like it did back in 1812 there
would be substantial damage clear up into lower Michigan and it'd
shake the skyscrapers in NY and NJ. These have not been single events
but a series of large events over several months.






"Ross Richardson" wrote in message
...
| Jim Macklin wrote:
| The Earth is rotating and orbiting within a strong
magnetic
| field of the Sun, [not to mention the whole Universe].
|
| The magnetic pole is not located on the axis and as a
result
| the variation wanders. It appears that the Earth's
magnetic
| field is electromagnetic and AC.
|
| The Earth doesn't physically flip over, the phase angle
| flips.
|
|
|
| "Ross Richardson" wrote in message
| ...
| | Larry Dighera wrote:
| | On Wed, 25 Oct 2006 06:17:38 -0500, "Jim Macklin"
| | wrote in
| | :
| |
| |
| | BFD, All those radios are called Aids to navigation
for
| a
| | reason, they are conveniences.
| |
| |
| | Were you aware of the design flaw in GPS as
implemented?
| I just
| | thought it might be a good idea to provide the
| information to those
| | weren't.
| |
| | Of course, this issue makes no mention of solar mass
| ejections, that
| | can potentially knock out any satellite.
| |
| | It appears that we are (finally?) seeing some
| technological innovation
| | tickling down to the GA fleet, but I'm becoming
uneasy
| with the
| | apparent lack of robustness engineered in these
early
| systems.
| |
| |
| | CAL found Paris with just a compass and a chart.
| |
| | Yes. It was an Earth Inductor Compass*. I've never
| seen one of those
| | in any aircraft in which I've flown, let alone
piloted.
| |
| |
| | *
http://oldbeacon.com/beacon/earth_inductor_compass.htm
| |
| |
| | Did anybody see NOVA on PBS last night. The earth is
| overdue for a pole
| | reversal. According to the program, we are already
seeing
| issues towards
| | that. Interesting program.
| |
| | --
| |
| | Regards, Ross
| | C-172F 180HP
| | KSWI
|
|
| What this program stated and I had read it elsewhere, is
the magnetic
| core within the earth had flipped every 200K to 700K
years. Geologist
| know how to figure this out from core samples. They said
the last one
| was over 700K years ago. The north magnetic pole (as we
know it) flips
| to the south pole.
|
| --
|
| Regards, Ross
| C-172F 180HP
| KSWI

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com