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Solar Winds to Protect Earth During Magnetic Pole Reversal
me98411 writes "A study published in April, hinted at possible anamolies/reversal in Earth's magnetic field. This study found that there is an anamoly in a large patch near South Africa where the Earth's magnetic field points in the opposite direction. Now, according to New Scientist, this planet might be safe during reversal of poles due to formation of replacement field created by interaction with solar winds. Phew! I was worried I will not be able to use my compass." Even better than compasses not being obsoleted, we won't be bombarded with dangerous levels of radiation, or so the scientists say.
The solar winds, which are charged particles being moved by solar radiation, will prevent us from being hit with charged particles and solar radiation?
I like to place meaningful quotes in my sig, so people will know that I know what meaningful quotes are.
are from the Aeronautics and Astronautics
group at the University of Washington.
They also have nice slides on airplane/spacecraft design,
also in PDF here
I would have thought that that alone would indicate that field reversals are not exactly "disasterous" for life on Earth. Poor for human health, maybe, but it's not like we're facing mass extinction.
Actually, given that they're apparently able to identify eras of field reversal in the archeological record, I wonder if anyone has tried to correlate it with periods of extinction or rapid evolution? That would be more interesting to me - at least better than all of the speculation that seems to be going around.
"Phew! I was worried I will not be able to use my compass."
Oh yeah! I forgot about my compass not working! Silly me - I was too busy thinking about the possible massive upsurge of CANCER . . .
Bush and the Republicans are to blame for this!
Nice joke, but were you aware of the huge stack of magnets Bush is having set up at the science station on the south pole? He has errected a giant stack of iron-ferrite magnets a mile high with a magnetic field opposite to that of the Earth. Every day it gets higher. Apparently he is trying to speed up the reversal process, because it is rumored that durring a field shift special instruments can be used that make it easier to locate huge oil deposits under the earth, and these instruments are usually rendered useless by the Earth's magnetic field.
Just food for thought.
Not only has the magnetic north pole wandered by 1100 kilometres in the past 200 years, but its strength is dropping at a rate of 5 per cent a century. "This is the fastest decrease since the last reversal 730,000 years ago," Lesch says
I do find it interesting, I wonder if it could happen in the next 300 years or so?
Just because the solar wind will help produce a magnetic field in place of the Earth's natural one doesn't mean it'll point in the right direction. That compass may be just as useless with this field as it would with none at all. How will you feel when your compass informs you that you're traveling straight up?
During the reversal, there will be some magnetic fields left, but will be more random and spiratic than usual. Your compass will still point somewhere... but that won't have any correlation to where north is.
You can deflect something toward you.
See here for a complete definition of "deflection".
Now, one definition of "deflect" is "to turn aside", but that's not the same as "to turn away".
For example, in a CRT, the stream of electrons is deflected in order to write to the phosphor screen.
On some CRTs, this deflection is done by using charged plates.
The result is that the beam is deflected away from one plate, but toward the other.
The second plate deflects the beam as much as the first (actually, more so), and the deflection is toward the plate (i.e., the plate attracts the beam).
So, it is possible for a mass such as the Earth to deflect a stream of particles toward it.
Those who sacrifice security to condemn liberty deserve to repeat history or something. - Benjamin Santayana
The idea that the atmosphere/ionosphere can be used to set up counter-currents to exclude the solar wind from the planet (or at least shield it a lot) isn't really revolutionary. It's possible that the Earth-magnetospheres people aren't talking to the planetary folks enough, but the latter have been thinking about this for years. When you wonder how the solar wind behaves when it encounters, say, Venus, you're in this regime. It's also the basic category that includes those ever-sexy critters, comets.
I don't know that anyone has done a similar calculation for the Earth and if so if this new model is significantly different. But the basic idea has been out there. We covered it in my magnetospheres class 4 years ago and it was in the textbook well before that.
http://www.pbs.org/wgbh/nova/magnetic/
Granted -- the current flock of satellites should be long gone by the time that happens, but this *will* raise the cost of LEO satelites over time.
Sometimes boldness is in fashion. Sometimes only the brave will be bold.
The long trip to Mars will need strong shielding, just like a space station at the Eeath/Moon's L5 would need (not to mention the sheilding needed to get through the Van Allen belts). Of course a long term habitat would be served nicely by the 'free' sheilding.
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The periodic mass extinctions don't usually coincide with magnetic field reversals. Field reversals are much more frequent than mas extinctions. The main body of empirical evidence for the field reversals are the alignment of magnetic domains in the ocean floor. However, the magnetic field described in this article would be weak and transient. It wouldn't have a fixed north and south. It would have multiple norths and souths, which themselves wouldn't be far more variable than the "normal" magnetic field. If you think about it, since it's being generated by the solar wind, which remains roughly fixed in relation to the sun while the earth spins around, the temporary magnetic field that would form during the reversal would probably remain more oriented to the solar wind than to Earth. It wouldn't be strong enough or constant enough to leave its mark on forming rock. The only thing they really have for it is models. It's a phenomenon that, assuming it happens, wouldn't leave a measurable trace. I guess we'll have to wait until it happens and see how things work.