Thursday, March 7, 2019

It's Not The Reversal Of The Earth's Magnetic Poles That Ought To Excite Apocalyptic Alarms

Thee seems to be a lot of arrant babble circulating about a reversal of Earth's magnetic field and the cataclysm that it may portend.  In particular,  that we are headed for some kind of major catastrophe,  taking out billions.  Let me assure one and all it won't happen.

First,  some basics on terrestrial physics.  The Earth has a magnetic field as a result of the molten iron core within it and the free electrons in that molten matter being spun around by Earth's rotation.  The effect is basically a reverse dynamo action, e.g.
Related imageImage result for formation of planetary magnetic field
 Here the rotary motion of the molten iron core creates  strong electric currents that in turn generate the planetary magnetic field with north and south magnetic poles.   We call this a dipole field because two poles are generated by the action.

The planet's dipole field is extremely critical in terms of maintaining its residual magnetic field of roughly 3.1 G (gauss) which in turn implies the capacity to provide a magnetosphere (see top graphic) that's capable of intercepting the high energy particles of the solar wind as well as other solar-flare- triggered particles. e.g. high energy protons. The key point to grasp is that the Earth's spinning iron core generates the Earth's magnetic field (N and S poles)  which in turn gives rise to its protective magnetosphere.  Its basic components are the: magnetopause, magnetosheath and magnetotail.

Now, while the news of a "reversal" of the Earth's magnetic field may sound alarming to many, e.g.  an article in Undark Magazine declared, “It’s time to wake up to the dangers and start preparing,” this is mainly the stuff or pseudo-science and hysteria. The latter is based on hyping the peril of  devastating streams of  "malevolent" cosmic radiation that would wreak havoc on lives and power grids.  In fact, there is a real risk, but it is from enormously violent proton flares or associated CMEs,  originating at the solar central meridian,  and only if there is also no field at all.  But  even that probability is very much less than touted by the scare mongers.

My point is that when one dives into the stories under the headlines  things become much less alarming.   Let's clear the air on the meme that scientists were caught "off guard".   Nope. All scientific "eyes" have been where they needed to be in terms of monitoring the planet's magnetic poles. They weren't tweeting all day or watching FOX News like our so-called President.

All of the  responsible institutions and monitors have remained active and even during the recent federal shutdown those facilities  were not shut down.  They were doing their due diligence and monitoring magnetic pole phenomena, as well as magnetospheric events including any substorms.

Further, both  the United States and Britain have collaborated on issuing an updated World Magnetic Model every five years to make sure everyone’s on the same map.  Can't have any Arctic explorers getting lost because their compasses aren't tracking the real N. magnetic pole after all.   And by way of clarification -  and so no one gets needlessly hyper  -   the Earth’s magnetic poles have always been on the move, and have even swapped places several times over the eons.  As noted earlier the reason is that the molten iron deep inside the Earth "sloshes"  around, shifting the magnetic field with it.  (See the diagrams again).   For now, it is situated four degrees south of the geographic North Pole.

Now, how did the current scare-a-thon get started?  The next update for magnetic pole locations had been due in 2020. But early last year geo-scientists found that the north magnetic pole was heading eastward at an unusually rapid rate, about 35 miles a year. They then decided to adopt a new model, which became available soon after Trump's  shutdown ended.

The model’s out now, which is good news for planes flying over the North Pole, and for airports that name runways in relation to the magnetic north. Also for GPS providers and for anyone else in need of precise directions. For most other places there's minimal  need for corrections. South of the northern tip of Scotland, for example,  the correction amounts to only a small fraction of a degree.  Will you notice that on your compass? Not likely!

Never mind, as in the case of the HAARP (High Frequency Active Auroral Research Program) the conspiracy whackos have worked overtime to get their minions into a lather. Thus, the news of the rational updating of the magnetic pole model has not prevented online tabloids  and assorted crazies (likely from the FOX realm) having an apocalyptic field day.

 Recall in the case of HAARP,  the purveyors  of conspiracy ideations (I hate conferring gravitas using the term "theorists")   claimed that it was capable of "modifying weather, disabling satellites and exerting mind control over people.  Some  crackpots even blamed the program for causing earthquakes, droughts, storms and floods, diseases such as Gulf War syndrome and chronic fatigue syndrome

In the case of the unexpectedly faster moving north magnetic pole, the part that feeds the nutjobs' doomsday scenarios is the possibility that the poles are preparing for another polarity reversal, which would cause a compass to point south instead of north. "Omigod! Compasses pointing north! It's the sign of the Antichrist! Aieeeee!" 

But hold strain! The quirk is normal and over the past 20 million years has occurred, on average, every 200,000 to 300,000 years. The last one was about 780,000 years ago, so another may be overdue.  

That could lead to a temporary weakening of the magnetic field that protects Earth from cosmic radiation. And that’s where the doomsday scenarios pile in. a world in which the inhabitants get bombarded mercilessly by intense solar and other cosmic radiation - literally baking us to cinders. But it's basically BS.  A form of mutated garbage roughly along the lines of the HAARP conspiracy bollocks and "The Great Awakening"  insanity - on which I will have more to write in the near future.

The specter of an Earth left without a magnetic shield has come up before, notably during the Mayan "apocalypse"  that predicted the world would end in 2012.   But which turned out to be a big boring dud  that I'd even predicted beforehand, e.g.


Back then, NASA posted a response that explained the science of pole reversals and concluded that “there is nothing in the millions of years of geologic record to suggest that any of the 2012 doomsday scenarios connected to a pole reversal .   Never mind. All the catastrophe obsessives  -  including a number who showed up on the All Experts Astronomy forum, wasting my time  -  wouldn't let it rest. Or accept NASA's rational explanation. Why would they when we know the untutored brain doesn't operate that way.   

In previous posts I have tried to explain the basis for this. For example,  noting that the brain activity of ancient people lacked the sense of metaphor, irony and individual identity that characterizes a more advanced mind. Such mentalities  also lack self-reference and introspection, a facility which enables modern man to not only think but think about his thinking

All of this was pointed out in Julian Jaynes masterpiece:  The Origin of Consciousness in the Breakdown of the Bicameral Mind', 1976 )  But in the modern context, it means that too many brains are still operating at an ancient or primitive level. I mean look at Donald Trump for instance. No self-awareness, no introspection and absolutely no sense of irony or metaphor.  (Aspects of his troglodyte nature any Dem presidential candidate will need to exploit)

Now, let's leave the realm of fantasy horrors and get to the real and imminent threat:  In a manner of technical speaking, we  humans are causing the Earth to "wobble."   But not from anything to do with magnetic poles drifting.  Rather, the geographic North Pole, the focus of the planet’s spin axis, is also shifting east.  This is not as striking as its magnetic counterpart, but for the wrong reasons: rapid global warming in the Arctic.  The North and South Poles always wander a bit  (geodesy deals with this and  computes yearly corrections), but the movements have increased, and  climate scientists theorize that the redistribution of mass on Earth, i.e.  as glaciers and ice sheets melt,  is one of the major reasons.

 Several recently published studies warn that ice at both ends of the Earth is melting far faster, and oceans are warming more rapidly than previously thought.  This suggests that scientific estimates of a warming planet have been too conservative. Those are the headlines that should be causing real concern.  This is what global citizens and especially apocalypse-prone Americans - ought to be worried about.  Just like I used to tell questioners on All Experts, i.e.  to worry more about climate change than an exploding star in another galaxy.  So also I keep pressing current readers of my blog to reckon planetary threats rationally,  and not waste time obsessing over remote or improbable ones.
Addendum- Technical Details on Magnetic Poles:

The magnetic flux density defined for the Earth is given as (Hargreaves, The Solar-Terrestrial Environment, Cambridge University Press, p. 150):

B(r,L) = M/r    [ 1 + 3 sin 2 L]  1/2

where M is the dipole moment (M ~  10  25.9 G cm 3, with G in gauss), r the geocentric radial distance and L the magnetic latitude (e.g. 70 deg).

Generically, the vector magnetic field at vector position x due to a magnetic dipole of vector dipole moment m at the origin, is given by:

B = {3(m*x)x - 2} / ‖ x‖ 3

Meanwhile, the field components in the r and L directions are respectively (Hargreaves, ibid.)

B(r) = - 2M sin(L) / r 3

B(L) = M cos (L) / r 3

The characteristic time for variation of the Earth's magnetic field is given by the differential equation:

dB/dt = B(r, L) /t

Which can be solved using Fourier transforms, at least approximately.

No comments: