Sunday, July 1, 2012

Explorer I, Einstein and the Theory of Crustal Displacement

   There is  fringe theory in earth science by Charles Hapgood, called the "Crustal Displacement Theory."  His idea, put forward in the 1950s, was that the earth's crust might get extra heavy near the poles due to the buildup of ice caps, and that this might cause the earth's axis to shift or rotate, kind of like an orange peel could slide around the inside of the orange.  This is postulated to be the event that ended the Ice Ages around 10,000 BC or so. 

   Support for this occurs because some ancient maps show a land mass corresponding to Antarctica, with rivers that supposedly could not exist if it were glaciated.  Also it helps to explain flood myths in the Bibile and elsewhere. 

   This idea may sound pretty crazy, and perhaps at the end of the day it is.  But Albert Einstein wrote the introduction to Hapgood's book.  So if it is crazy, at least Hapgood is in some rather good company.  For that reason, several fringe archeologists have been interested in Hapgood's theory,  and wondered if it is possible that Antarctica might have been the source of the Atlantis myths.  If so, it would have been  free of ice in the ancient time, until put into a deep freeze with some polar shift.  Popular author Graham Hancock has discussed this theory in some of his writings (and in fact, if any of my readers know Graham, I hope you'll attract his attention to this blog.  

      The Crustal Displacement theory begs the question of why Antarctica can be covered in ice that is million of years old if it only froze over 11,500 years ago, and I guess that is as good a reason as any to not believe it. 

    More than that however, for some time I've been aware that the math controlling Crustal Displacement idea bears a lot of similarity to the real problem of spin stabilization, which was worked out for satellites in the late 1950's.  Oddly, the math for this was well known by the 19th century if not earlier, but our best and brightest in the space program didn't understand it when they designed the Explorer I satellite shown below.

    Briefly, they wanted the satellite to be cigar shaped to fit on the rocket, but in earth orbit they wanted to stabilize it by letting it rotate like a spinning top.  But once they launched the satellite, it didn't rotate like they wanted it to, and within hours it was in a flat spin. 


    Why didn't Explorer I stabilize properly?  Well the mathematicians went back and reviewed what they were doing.  It's sort of like the kid's trick, of spinning an egg like a top.  If you have a hard boiled egg, it behaves like a rigid body, and you can stabilize it by spinning it on the pointy end.  But an uncooked egg cannot be spun this way, not at all.  It winds up lying on its "side" which is the most stable configuration  (i.e., it can not fall over once it is lying on its side.  The mathematicians had treated Explorer I as if it were a perfectly rigid body, suitable to be stabilized around its "minor axis" or the centerline as it sat on the launch pad

  Every real object has an axis that it "likes" the most, including both Explorer I and the Earth.  The salient point is that it wasn't a passing asteroid or some other event  that caused Explorer I to change its orientation.  It just did it by itself.  

   Similarly, you could imagine situations in which the earth might get "top heavy,"  such that it is no longer the most stable axis of rotation (mathematically, the earth earth would be rotating around a minor axis of rotation rather than the major axis).  In such a case, the earth's axis would continue to be inclined at 23.4 degrees.  But the north pole would be whatever point results in the most stable rotation.  No external force needs to be applied to the earth to get it to rotate in this way.  By the same token the fact that the earth's oceans bulge at the equator does not have anything to do with the stability of the earth's poles.   What matters is the stability of the solid portion only (in other words, if you could magically remove the oceans, the stable axis is the one that stabilizes the solid crust.  The liquid ocean, molten magma  and the molten outer core of the earth  do NOT determine the most stable axis of the earth's rotation.

     Hapgood imagined that this might happen if the ice cap got very thick.  But, jeepers Hapgood, the earth is 12,756 km, and the ice cap is only a few kilomaters at most.  
    What matters most is the configuration of the solid portion of the rotating body, not the liquid portion.  So perhaps if the boundary between the earth's crust and liquid interior were to change, the earth might realign itself, as shown below.

Figure 1.  The earth is sometimes descriged as a "bumpy sphere," with most of the land masses in the northern hemisphere, although the north pole is underwater.  

 

Figure 2.  Conceivably, the earth's rotation could become unstable if the solid crust and mantle region become thicker at the poles and/or thinner near the equator.  In this case the solid portion of the earth would simply reorient itself by shifting by up to 90 degrees.  The earth's axis would continue to be inclined at 23.4 degrees.  Note the position of the pyramid shown as a reference.  


This is referred to as the "polhode" (pole wander) process, and as mentioned above, the math for this was accomplished in the 19th century.  People didn't really understand it very well until the 20th century when Explorer I was used as an object lesson. So here are the salient points as the apply to "crustal displacement."


1.  Yes it is possible for the earth to become "top heavy."  However, this is not likely to happen due to ice cap formation unless the ice caps were to become many, many miles thick.  A much more likely scenario would be for changes in the boundary between the solid crust and the liquid interior to be the precipitating event.  


2  Hapgood's idea was that some cataclysmic event would caused Antarctica to move from some temperature location to the south pole.  However, Antarctica is not Atlantis.  It could not have shifted in a major way because we know darn well by now that the ice has been there for millions of years.  


3.  Although there are a few maps that show rivers in Antarctica, this is not proof of anything other than, at best, ice melts in the summertime. If Antarctica were truly located at a temperature location in the recent past, this should be evidenced in the physical ice record.  I'd be much more impressed if there was a ye olde map with a different north and south pole.  But even then we have to trust the physical record first and foremost.  


4.  Records such as this do exist, but they are millions of years old, not thousands of years old. 


5.  The stable principal axis of rotation depends upon the moment of inertia of the solid crust  only.  The shape of the ocean, and in particular the bulge at the equator doesn't matter for this problem, as it is just following the tendency of gravity, modified by centrifugal force from the earth's rotation.    
 
6.   The earth's axis of rotation would not change if the earth reoriented itself as I have described, and would continue at 23.4 degrees.  But there would be a new north and south pole.  


So while Hapgood's interpretation is way off on how this might occur, the fact of the matter is that is possibe for the earth to reorient itself, possibly due to a change in the interfacial boundary between the solid crust and the liquidlike interior.  We can be pretty sure that that did not happen recently because of the historic stability of Antarctia ice.  We can be sure that it was not not not temperate anytime recently.  


In the distant past, however, it may make sense to see if the earth might have shifted to relocate the poles, and possibly  resultied in huge climate changes.  If this happened however, there would be major changes in the geologic ice record and other physical records.    

I don't know enough about contemporary earth science to know if anyone has articulated this type of model formally in a peer reviewed publication. If they have, and I haven't properly credited it, I apologize. But it might be that this idea is original with me.   So if someone out there thinks that this should be developed in a more formal article, I would be happy to contribute to that.   




4 comments:

  1. Elliot -- great article, I enjoyed it.

    Regarding flood myths; the idea I've heard advanced is that flood myths were the ancient's way to explain out of place fossils. Great floods were the most logical explanation for the appearance of seashells and fish fossils in mountain strata.

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  2. Yes, I could see that if you were some ancient philosopher, finding a fossilized fish on the top of a mountain might make you think that the Gods had gotten pretty upset about something.

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  3. Elliot, Very interesting article. It might explain a lot...

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