After reading Gillian Turner’s North Pole South Pole, I’ve been toying with a theory of my own concerning the Earth…
What if the Earth’s magnetic field was not caused, ultimately, by its internal composition and activities, but by the Sun’s intense radiation? Here’s the angle I’m coming from…
One of the main features of biological systems is the feedback loop. What if something similar could be going on in the solar system– after all, the Solar System is, when viewed a certain way, PART of our biological system– if the Solar System goes wrong, we all go wrong…
Perhaps the Earth’s magnetic field is negative feedback mechanism, arising when the Earth is in danger of receiving too much solar radiation, and lowering when (for reasons I admittedly cannot presently fathom) it needs the shock of a good burst of radiation.
We know that, currently, the Earth’s magnetic field is creating a shield around us, diverting much of the power contained in the Solar Wind and Cosmic Rays constantly bombarding us. Much of this radiation is diverted into the Van Allen Radiation Belts far above the surface.
However, geological evidence leads us to believe that the Earth’s magnetic field periodically shrinks to nothing or close to it– only to rise again in power and maintain itself until the next field-lowering event occurs. The re-starting of the field could be due to the waves of Solar energy washing through the Earth; all this energy could re-ignite the Earth’s inner electrical currents, causing the re-emergence of the magnetic field.
In a life-form (which Gaia theorists say the Earth practically is), we would likely suspect that some form of feedback interplay is at work here. In the case of the Earth, we could conjecture that, periodically, more or less Energy is needed, and the magnetic shield is the mechanism for regulating this.
Interestingly, each time the magnetic shield goes back up, there’s about a fifty-fifty chance that the North and South poles will be REVERSED. Evidence indicates that, for about 51% of the Earth’s measurable history, the North and South Poles have been reversed from what they are today.
My own guess is that the direction of the magnetic field depends upon the direction of the Earth’s axis at the time of re-emergence of the field. In any time picked randomly during the elliptical travel of the Earth’s orbit, there’s an equal chance of finding the axis pointing at any one of its possible directions.
For the sake of providing an example of what I have in mind… let us say that when the Northern hemisphere is pointed away from the Sun (Northern winter), the North will become Magnetic North. But if the if the Earth’s magnetic field is restarted during Northern summer, Magnetic North will be in the far South.
As a tiny piece of supporting evidence to my contention that the ultimate cause of the Earth’s magnetism is the Sun, I will mention that we have long known that the Sun has a strong effect on the Earth’s magnetic field– and that, indeed, the field daily fluctuates depending on the activity of the Sun.
Also, it might be worth mentioning that the most direct evidence we have for inner-Earth circulations (volcanic eruptions and ocean-floor spreading) indicate up-and-down movement, not movement in the direction of the Earth’s spinning. I’m not saying that there is no movement in the direction of the Earth’s rotation– only that, inner-Earth movements may be too convoluted, without the Sun’s energy contribution, to explain all the starting and re-starting of geomagnetism which seems to have occurred in Earth’s history.
It would be interesting, using my theory, to attempt a new explanation of why some planets (and our own moon) do NOT exhibit magnetism. The moon’s lack of magnetism could be due to something as relatively simple as interference from the Earth’s ever-changing magnetism, keeping it from setting-up its own, Sun-driven field. For Venus and Mars, perhaps their axes are not at the correct angles to the Sun to set-up proper dynamos due to the effects of Solar Radiation. Or perhaps, their inner materials do not readily conduct electricity in relatively steady loops. Or maybe, unlike the Earth, their inner-materials are incapable of re-producing a field once it has deteriorated. For all we know, the inside of our own planet could, uniquely and for long periods, obtain practically “superconductor” conditions, in which currents can cycle and cycle with very little deterioration.