[–] Cooking_with_Alf 1 points 2 points (+3|-1) ago 

the theory of magnetic pole swaps comes from plate tectonics. There is a massive fault line that divides the Atlantic ocean. If you see satellite scans that magnify the fault lines, you will notice zig zag patterns where the magma has been ejected from the fault and cooled to rock, over and over, for millions of years. This pattern has a north trend, then a south trend, seemingly in the same distance from each other (between zigs and zags). As far as we can tell, that pattern of back and forth plate movement makes geologists think the plates alter their course based on the poles' polarity. Being that we still have a very breathable atmosphere, and it has roughly been the same for millions of years, perhaps predating the time table shown to us by the fault in the Atlantic, I would wager that we will be OK.

[–] The_Cat 0 points 3 points (+3|-0) ago 

That's not how this works at all. When the lava cools, magnetic iron aligns with the external magnetic field, and then gets locked in as the rock solidifies. If you look at the orientation of the inherent magnetic field of the rocks at the mid atlantic ridge you can see a pattern of reversals, as the external magnetic field flips back and forth throughout the ages. The magnetic field does not determine the movement of the plates.

[–] Cooking_with_Alf 0 points 0 points (+0|-0) ago 

unlike you, I didn't look at wikipedia. Still ball park.

[–] runningbear 1 points 0 points (+1|-1) ago 

What about the effects from the sun and other cosmic radiation?

[–] bman0321 1 points 0 points (+1|-1) ago 

Who knew superstitious hut burning would give hu-mankind some archeological empirical data on earth's magnetic field. Way better than tree ring proxies.

[–] What_was_that_2 0 points 0 points (+0|-0) ago  (edited ago)

Those Bantu peoples and their crazy burning ideas, who would of know.