Pole Reversals

Back by popular demand- my creation science series. Just kidding, this is for you Geno, if you’re out there:).

Disclaimer: This is not an academic research paper. This is my personal blog in which I record my miscellaneous musings, thus the name of the blog. Having said that, I do read and few of my ideas originate with me. My main sources for learning about the magnetic field of the earth and pole reversals have been John Morris in his 3rd edition of The Young Earth, Charles Hapgood’s Path of the Pole (though I really love his Maps of the Ancient Sea Kings), and of course various articles and web pages on the internet.

In my last post on evidences for a young earth I mentioned the decreasing magnetic field of the earth. Since 1835 measurements of the magnetic field have been decreasing. The reason this is a strong argument for a young earth is because if we extrapolate backwards, we find that the magnetic field of the earth would have been too strong to sustain life even 20,000 years ago.

What I didn’t address at that time, but will now, is pole reversals and how they affect YEC (young earth creationism). In other words, does evidence of reversals of the earth’s polarity disprove or cause a problem for YEC? The answer is it depends on the nature of these pole reversals and there is mounting evidence that these pole reversals actually lend support to the young earth theory, rather than take away from it. The main issue, as I see it, is one of time. But before getting into pole reversals and their implications, let me attempt to explain the main theories about the earth’s magnetic field.

Traditionally, evolutionists have held to the dynamo theory of the earth’s magnetic field which proposes a self-exciting movement in the core of the earth of molten iron and nickel, which in turn generates electric currents. Reversals, according to this theory, would occur when the fluid motions cause the electrical currents to slowly decay all the way down to zero and then build up again in the opposite orientation. This theory has the advantage of being able to postulate how the earth’s magnetic field could sustain itself over billions of years.

Creationists have traditionally held to the freely decaying electric current theory which proposes the earth’s magnetic field is generated by circulating electric currents in a rather stationary core fluid, decaying in intensity over time. This theory has the advantage of making sense with the measured decay of the earth’s magnetic field over the last 170 or so years. In other words, the decay we would expect due to electrical resistance according to the free decay theory, is in fact what we observe over the time of human history that the earth’s magnetic field has been measured.

Both theories also have drawbacks to them. The slow reversal rate (millions of years) proposed by the dynamo theory would have deadly effects on life for long periods of time (as the field approaches zero and then slowly moves away from zero in the opposite orientation). We know from “absolute” dating techniques that there is evidence of life dating back millions of years in the fossil record (of course YECs contest this “absolute” dating). In other words, the dynamo theory is not consistent with the geological record which shows life dating back beyond 700,000 years ago (when the most recent pole reversal is thought to have occurred). (Actually, some have proposed pole reversals as recently as 20,000 years ago which would present even more of a problem.) Another recent challenge for the dynamo theory has to do with the pole reversals of the sun. It was previously believed that the sun’s magnetic field was also a dynamo, but we now know the sun reverses its polarity every 11 years coinciding with its sunspot cycle. Field reversals of this extreme frequency and rapidity present a problem for the dynamo theory. There have also been recent reports of very rapid reversal events on earth that occurred during the time lava cooled (as little as 15 days).

The freely decaying field theory also has drawbacks. For one thing, archeological measurements show that the earth’s magnetic field was about 40% greater in 1000 AD compared to now. This is a bigger difference than can be accounted for by decay by electrical resistance alone, although in recent history (as long as the earth’s magnetic field has been measured) it does appear that decay follows simple electrical resistance. And of course if we propose a linear decay rate for the earth’s magnetic field then there is no room for polar reversals.

The revised decay theory, or dynamic decay theory, of the earth’s magnetic field takes cataclysmic events into consideration (such as the Biblical flood). It postulates that the flood provided the force to “break up the fountains of the deep” (Gen 7:11) which initiated fluid convection in the outer core. This strong magnetic flux would cause the entire earth’s magnetic field to reverse. “Continuing movement would cause continual rapid field reversals, which would be recorded in rocks being deposited on the earth’s surface.” (John Morris in The Young Earth 3rd edition p. 86) Morris goes on to explain that these rapid reversals within a decaying field use up its energy even more rapidly, contributing to and hastening the overall decay of the field. (Relate this back to the debate over the problem of excess free energy release during accelerated decay.)

So, the dynamic decay theory is consistent with recent historical observations of field decay, but also allows for multiple rapid reversals in polarity in the past due to some cataclysmic force in the past, like the Biblical flood, which caused shifting of continents and all sorts of other geological upheaval, as well.

Some of the problems of the dynamo theory have also been addressed by McFarlane’s alternative magnetic field theory based on electrodynamics. “He proposes a system of electronic cells in a crystalline metal core with hot spots of heavy metals releasing alpha and beta particles. Due to the high heat the alpha particles are unable to combine with the free electrons. ‘Consequently an electron current flow is produced and conditions are set up for the generation of current loops throughout the inner and outer core. ... magnetic fields are produced as a consequence, in accordance with the right hand rule of electromagnetic theory.’” (http://www.arizonaenergy.org/EarthEnergy/earth_magnetic_field_reversal.htm quoting from McFarlane’s article which I did not have access to, "Origin of the earth’s magnetic field" by Ernest McFarlane). An alternative pole reversal theory has also come out of this called the disorderly-flip theory. Rather than decline all the way to zero gauss, the disorderly flip theory proposes that the magnetic field would decline in a more disorderly way perhaps decreasing to 20% or so of the original field strength and then increasing in the opposite orientation. This would solve the problem of the evidence of life surviving pole reversals of the past. This also makes it a more optimistic view of pole reversals, since many believe we’re overdue for one.

It’s interesting to me that Hapgood’s classic work on polar shift and pole reversals was written to address major problems with evolutionary theory, especially natural selection. He believed his more cataclysmic view of pole reversals and subsequent climate and continental change could help to accelerate the time table of events needed to take place for natural selection to be a plausible theory.

While I am no expert in this field, it has been my observation that the young earth and old earth scientists have actually moved closer to one another on their theories of the earth’s magnetic field and of pole reversals. They still disagree to the dating/timing of everything, but their theories more closely resemble one another now than previously. The YECs believing the Biblical flood is the primary cataclysmic event in the past that set a series of pole reversals into effect. Evolutionists believing it was another unknown set of cataclysmic events.

It’s hard for me to imagine a series of catastrophes as great as the description of the flood of the Bible. The flood was not merely a big rain, but “the fountains of the great deep were broken up, and the windows of heaven were opened.” (Genesis 7:11) God declared ahead of time His intention to “destroy from the face of the earth all living things that I have made.” (Genesis 7:4) Does this leave us with a few questions? Yes. The main one being how did Noah and the others on the ark survive? Was it a pole reversal that didn’t go all the way to zero so that survival was possible? Did God supernaturally shield the passengers of the ark? I have no idea. It does seem to make sense though that we’ve seen a decline in large mammals coinciding with the decrease in the earth’s magnetic field that YECs would peg to the period after the flood. In other words, it helps explain why the dinosaurs became extinct.

We all have bias and preconceived notions. I have been honest with you from the beginning that my bias is I believe the Bible to be the very Word of God, not simply the recordings of mere man. If it comes down to it, I will believe the Bible over science, but I don’t believe it has come down to that. Scientific theories are just that, until proven otherwise. Once disproved, scientific theories are discarded, as the freely decaying electric current theory has been discarded by YECs in favor of the dynamic decay theory. Since none of us has actually journeyed to the center of the earth, and since none of us was alive 5,000 years ago (or 700,000 years ago for those who prefer that time scale), much of what we theorize about the earth’s origins and workings will remain just that, theory. But I love the words of Psalm 100, especially the last verse. “For the Lord is good; His mercy is everlasting, and His truth endures to all generations.”