Thread: What the heck caused the wobble of the Earth every 20 thousand years ?

I can see your point, nether the sun or moon is on a true 90 degree path from the earth's poles. What I learned of the wobble was that the earth's mass, in it's infancy, was completely evenly distributed. That, at this time, the rotation was the closest to a non-wobble state. Then meteors started to pelt the earth giving us the water that cooled the surface and started the raining process that cleaned the atmosphere. As the world cooled, water started to pool creating the first oceans, lakes ect..

At this time the earth’s mass was still evenly distributed, then some cataclysm caused Pangaea to split and gave us the seasons we all recognize today. As the ice became a stable representation in the north and south of our world, it added mass that was not previously there. The extra mass, as I understand, is trying to adjust to the equator but is counter-balanced by Newton’s first law, the extra mass of the Himalayas and the offset created by the other pole.

When I think of it I think of it like this: There are three main mass disturbances. The Himalayas, created by Pangaea splitting, was the first and is closest to the equator because the disproportion cased the world to shift as such. The second was most likely the South Pole, causing the first to shift north. And as the stable land lock point became available, the northern mass imbalance began to form. It, in my head, is like spinning a ball-baring that has a theoretical perfectly proportioned mass (Like the infant earth did). And while it is spinning you put a drop of quick drying epoxy on the top of it. Since the spin is not on a pivot, the extra mass part moves from the location of where it was dropped and ends up at the equator of the spinning ball-baring.

Originally Posted by grapes

No.

Most of the arctic ice is floating, and is no more involved in an imbalance than ocean water. Einstein didn't really say much about geophysics, although he did give some more or less favorable reviews to some of the work of Velikovsky, I think.

The precession is mostly a result of the interaction of the tidal bulge (20 kilometers at the equator) with the moon and sun. There are other wobbles, of much smaller magnitude, but even then the sea ice doesn't have much effect.

It will be interesting to see what happens when the ice melts and adds mass to the equator while degreasing the mass at the poles.

Originally Posted by Scott Phillips

... The Himalayas, created by Pangaea splitting, was the first and is closest to the equator because the disproportion cased the world to shift as such. ...

This is just wrong. The Himalayas were not formed by the split of Pangaea. The Himalayas are being formed by the collision between the Indian subcontinent--which once was an island--and Southern Asia. I use the present tense because this collision is happening now. The land mass that forms the Himalayas was once a coastal plain. It is now a series of the highest mountain ranges on Earth. These mountains are actually being scrunched even higher by the on-going collision.

BTW, do you know anything at all about plate tectonics?

Originally Posted by MisterMe

This is just wrong. The Himalayas were not formed by the split of Pangaea. The Himalayas are being formed by the collision between the Indian subcontinent--which once was an island--and Southern Asia. I use the present tense because this collision is happening now. The land mass that forms the Himalayas was once a coastal plain. It is now a series of the highest mountain ranges on Earth. These mountains are actually being scrunched even higher by the on-going collision.

BTW, do you know anything at all about plate tectonics?

His tectonics may be off, but the imbalance of mass distribution with in the sphere of the earth may still be a major contributing factor to the gross precision of the poles.

What does BTW stand for?

Originally Posted by Wayne Bruinekool

...

What does BTW stand for?

By The Way.

Originally Posted by Wayne Bruinekool

His tectonics may be off, but the imbalance of mass distribution with in the sphere of the earth may still be a major contributing factor to the gross precision of the poles.

It's not, so far as we know.

The kind of imbalance that he describes results in the Chandler wobble, a much more violent wobble, that tends to shake things into uniformity over just a hundred years or so.

From our point of view the poles wobble in a repeating circle every 20 thousand years. The masses of the earth are in a state of continual change, so the calculation of the wobble should also change. The earth is living system, that one moment will give one result while in the next give another. I am not trying to say that one moment Pangaea existed and the next the Himalayas existed. But the path created by the split results in the push of mass that makes the other. Over time the three mass sources pop up and create a wobble that would repeat over time if they remained constant. With this post, I what I am saying is that in 20 thousand years the earth will not meet with the same orbital conditions but will be in some other unknowable orbital pattern because of all the variables are themselves changing in time.

Like, if we stop global warming caused by humans, the polar caps will start replenish themselves. The continental plate pushing on the Himalayas will melt under the crust and they will fall. The forces causing the ring of fire will balance themselves out and volcanic activity would raise world wide, as a way to alleviate the internal pressures of the planet. And, most notably to our thought of how our planet rotates around the sun, the moon will spiral out of orbit and move into outer space. These are variables that probably do not appear in the calculation of the idea that the earth has a repeatable wobble.

I would say the answer to the original question is this: imbalance. This has caused the wobble as we observe it. From the mass of our planet trying to create a balance, to the orbits of the bodies in the sky. The orbit and rotation will continue to be disturbed until our sun novas.

Originally Posted by grapes

It's not, so far as we know.

The kind of imbalance that he describes results in the Chandler wobble, a much more violent wobble, that tends to shake things into uniformity over just a hundred years or so.

Yep,that's the one. Finally,someone with a clue...

Pretty deep Scott...I like your thinking on this.Ya seem to have a pretty good understanding of the way of things

Originally Posted by Lew South

It's a gravitational effect, mostly "caused by the gravitational forces of the Moon and Sun on Earth's equatorial bulge" (from wikipedia). I'm pretty sure it has nothing to do, at least directly, w/ the Sahara or the Great Lakes.

Axial precession (astronomy) - Wikipedia, the free encyclopedia

Interestingly enough, despite the fact that precession takes 25,700 years to run full cycle, and nutation takes 18.7 years, celestial navigation requires the navigator to look up and incorporate both precession and nutation in the pre-comps.