The only thing I have trouble grasping is why the wobble or why the tilt of the earths original axis and how long until, or if ever, will the world rebalance itself?
The wobble comes about as the earth's rotation slows over time. Like a kid's spinning top slows and starts to wobble as the imperfections (which have zero effect at high rotational speed) start to come into play as the top spin speed slows.
What's been slowing the earth's rotation speed is the interaction between the electrical energy waves from the sun (electromagnetic radiation) and the earth's own electromagnetic lines of force.
Its "back-emf" it can be called. Look that term up. Its a retarding force generated by interaction between 2 moving intersecting magnetic lines of force. Sun and earth or 2 moving magnets.
THAT was why I spoke about bar magnets and magnetic poles.
The earth's continents are islands of rock (cooled molten lava) on the surface of the earth. Floating on the skin is another way to describe it.
This skin (cooler than the underlying molten core) occurs as the heat of the earth escapes off into space. So the surface cools and it forms into thin skin as it does so. Like the skin on a custard.
In geological terms the skin is called plates and the plates develop fractures/cracks as the rotational forces increase as you move further out from the axis of rotation.
Maximum rotational force occurs at the equator as its the furthest from the earth's axis line. The speed of rotation at the equator is the maximum achieved that can be achieved naturally. The earth we're standing on is moving at about 1500 khr or so in an easterly spin at our latitudes).
To fling an object into space (like a rocket), it must achieve "escape velocity" to escape the gravitational pull of the earth.
If velocity of the earth's surface is maximum at the equator, then man would be crazy not to take advantage of it to use the earths rotational velocity to reach "escape velocity" with as little fuel load as possible. Sling the rocket into space from the fastest moving part of the earth's surface. Near the equator.
http://www.qrg.northwestern.edu/project ... uator.html
That's why countries try to get their space launching pads as close to the equator that they can get. Some who can't do that just use bigger rockets with bigger fuel loads. Brute strength like the USA's Saturn rockets and Russia's Soyuz rockets.
But we digress.
The skin is not uniform (nor does it remain that way) because the plates move independently of each other due to cracks in the skin at plate junctions.
These cracks allow underlying magma to seep through and we have volcanos along those crack lines. A line of fire one might say. Like the plate that gives us the pacific ring of fire.
Another famous crack line is in the USA ( California) and is called the San Andreas Fault.
Its a junction between two plates and every now and again the two plates release built-up tension and we have earthquakes.
The ground (and any manmade objects on it) shake like hell until the tension is released. You might liken it to the drag on a fishing reel.
Where two plates collide going in opposite directions, the edges crumple and are pushed up into the air forming mountain ranges. Himalayas or the US Rocky Mountain Range.
These plates are pretty heavy and the surface tension between the underside of the plate and the underlying magma is pretty high, so the plates move very slowly as the "drift" around.
Hence the term "continental drift".
Remember all those super continents like Gondwana which moved around and broke up into the continents as we know them today?
THAT was why Douglas Mawson and Scott wanted to go to the south pole. Scott wanted to reach it first (he was competing with Amunsden who won the race) AND to bring back rock samples.
Scott died on the way back and was later found AS WERE his rock samples. Petrified seeds from those samples were the same as seeds found in Africa so the Antarctic and Africa were joined
together at one stage.
Mawson meanwhile (a true scientist) had found the south magnetic pole and also took nearby rock samples which proved the same thing.
Anyhow, the lesson here is that these big heavy plates move around on the earth's surface slowly and they certainly do affect the balance of the earth as it spins. Like your soccer ball with mud
on one side analogy.
But because the speed of "continental drift" is much much slower, then the balancing/unbalancing effect is over a much longer time frame than even Milankovich's obliquity changes.
Obliquity changes are on a 41,000 year cycle. The effects of continental drift take much much longer (perhaps millions of years). There won't be a cycle because the continents are drifting all
over the place. Like the skin on an orange slipping around on its centre.
Liken that effect to line on a baitcaster not tied to the reel's rotating spindle. The line just keeps slipping and you can't screw drag on.
Unless something big hits the earth (like an asteroid or comet), the earth will eventually cool down enough for the magma to solidify and the surface of the earth with stop slipping around. No
more continental drift. No more cyclic changes. Earth will become a dead planet rotating around the sun like the others.
Now that's a pretty serious change in climate!
And you know what would have caused all this?
Not any massive geological changes, not any interstellar occurrences, not continental drift, not changes in the earth's axis or magnetic poles.
Mankind and his insatiable appetite for CO2. THAT'S something bound to have more impact than geological changes and only mankind can achieve that.
I only hope that it doesn't happen before the start of the next barra season as I'm experimenting with some lures.