Earth’s Magnetic PolesApril 18, 2007
In Star Trek, the USS Enterprise travelled through space independent of any planet. They sustained themselves using advanced technology. One of these technologies was deflector shields, for warding off all the lethal solar radiation (and being a good plot device). On our nice little planet Earth, we also have a shield to protect against solar radiation. The Earth’s magnetic field serves as a shield against high energy particles blasted out from the sun continually. Without it, well we’re not quite sure, but it’s bound to be unpleasant.
The image on the right shows the magnetic field. The direction of the sun can be seen because the field is compressed by solar wind. Also, notice that the Earth’s magnetic field is far larger than the planet. David Coppedge, from the Jet Propulsion Laboratory pointed out “Shuttle and space station astronauts operate within Earth’s protective Van Allen belts and gravitational field. So far, only the Apollo astronauts have ventured outside our safe bubble into the cosmic shooting gallery. The longest mission, Apollo 17, lasted only 12 days. Fortunately, none of the flights occurred during a solar flare. Had the space travelers received such a blast, they would have been dead within minutes.” This is a serious danger for a mission to Mars because of the extended length of the trip.
So now that we know why we care about the Earth’s Magnetic Field, what’s it up to these days? At least for me, I pictured the magnetic field as being as stable as the rock I stand on. (The Earth is a gelatinous glob of molten lava with a thin film across the surface, ponder that). So how do I say this? According to the Canadian Geologic Survey, as of 2001 the magnetic north pole is moving at 40km per year. More over, it’s not really moving in a predictable pattern in the long run. It staggers around Canada and the Arctic, seemingly at random.
Some people have taken all of this recent movement as an indication that we are very close to undergoing a pole shift. Geologic evidence shows that the poles have flipped multiple times throughout history. So the north pole was south and so on. Scientists were originally saying “don’t worry about a pole flip, they take thousands of years and the field just goes down during that time.” Of course, then the implications of that sink in. The Observer has a couple of articles discussing the implications of field collapse using computer simulations. Then I find more scientists with complex computer models showing how the Earth will be saved. Problem is, I’ve found two of them, and they contradict each other. I’m an amateur at a lot of this, but one thing I do know are computer simulations. I’m a computer programmer, in fact I’ll be writing computer simulations this summer. Computer simulations are entirely dependent on the assumptions you encode in them. They’re useful but do not think a computer is any more impartial than a human beings, they’re just fast math calculators.
So where is the real science in all this? It’s hard for people not to assign meaning and emotional value to subjects like this. The most neutral, scientific position is probably also the least helpful “Gee, that’s odd.” The natural tendency is to attract to the most comfortable position, or what benefits us the most. The truth of the matter is that our lives depend on something going on inside of the core of the planet. Something that, when we’re really honest about it, we barely understand.
(More Research on Earth’s Magnetic Field in the next article.)