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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.
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.
No, the interaction with the solar wind and the atmosphere will prevent us from being hit with charged particles.
Solar electromagnetic radiation comes through no matter what and is not affected by the magnetic field. In fact, that's something of a similar situation: The Ozone layer, as I understand it, is formed by the very radiation it absorbs. That's why a hole in the Ozone layer forms over the pole that gets no sunlight; Ozone breaks down relatively quickly and without the production mechanism, eventually it all breaks down. It reforms again once it is hit by sunlight again. CFCs were theorized to accelerate the destruction rate of the ozone, which caused a net reduction in the amount there was, starting near the poles since they get less sunlight and already had a lower production pace.
In the reverse direction, note that shielding can sometimes cause a net increase in dangerous radiation, as high-energy cosmic rays that would just pass through a person impact the shielding and bombard the shielded thing (like a person) with a series of lower energy radiations, which may total a lower energy overall then the cosmic ray but have a much greater effect on the person.
Second-order effects very often swamp the first-order effects. This is one of those basic facts of mathematical thinking that is vital to understanding any sort of science, and is one of the reasons having politicians, and people who think they understand science but don't understand this kind of mathematical thinking, scare me so much. Statements like "Higher taxes mean more income", "more shielding means less radiation", and "a lower magnetic field means more radiation getting to the surface" may all sound like common sense, but they aren't; the former two are certainly not universally true (only true under certain circumstances, which if you don't understand the limits you will almost certainly be led astray), this article suggests that the same is true of the third.
It's only confusing if you insist on trying to understand everything solely in terms of their first-order effects; the universe is far, far from that simple.
That said, I have no idea if this simulation is correct or not; I merely observe that there's no reason to dismiss it because it contradicts the results of a simplistic analysis based soley on direct effects.
(Minor nit: The solar wind is simply charged particles streaming away from the sun; they are not necessarily being moved by "solar radiation", which is really too generic a term in this context to be useful.)
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.
I don't think they claimed it would solve the compass problem, only the radiation problem.
BTW, how come it does not work on Mars, which has no significant magnatic field of its own?
Table-ized A.I.
Also, according to a paper in materials science research titled, Cosmic-Ray Neutrons on the Ground and in the Atmosphere And a number of other papers by the same author, the measurements show that the cosmic contribution to background dose rate increases as the strength of the magnetic field decreases.
The error in logic with your argument is that the magnetic field deflects particles before they reach the atmosphere and interact. Once they reach the atmosphere, they interact with the atmosphere (not the magnetic field) to generate the "more dangerous radiation." as you call it. That said, I'm not entirely sure that this radiation is any more or less dangerous. While it is true that the quality factor is lower (what you multiply the energy deposion by to get the increased quantity that is proportional to increased probability of cancer), the energy deposition can be higher (this is true for photons, but not electrons, and I just don't know for protons and higher Z charged particles with kinetic energies in the GeV range).
The article didn't, but the Slashdot post did. Anyway, Mars also has no significant atmosphere of its own either. Of course, this raises the question of why it doesn't work on Venus, which has a very substantial atmosphere, but no magnetic field worth mentioning.
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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