Plate tectonics, mountain building, and the Flood

This planetesimal theory for the origin of Pangaea simply cannot work.That is because a colliding planetesimal would create a giant crater, not a supercontinent.A planetesimal with Pangaea's volume would have a diameter of about 1000 km, and using this crater-size-calculation page, the resulting crater would have a diameter of ~10,000 km.The other inputs were such reasonable ones as asteroid-like impact velocity, both the planetesimal and the Earth's surface being solid rock, and so forth.And a likely aftermath of that planetesimal strike would be massive volcanic eruptions like those that produced the lunar maria and Earth flood basalts.

Also, someone had asked where all the pre-Pangaea supercontinents had gone. Their material is still in existence; those continents had broken up and reassembled more than once, as I had pointed out in my "Continental Bumper Cars" thread.

I stand corrected.But even an inspiraling satellite does not quite fit. As it approaches the Earth, it will reach the Roche Limit and break apart. That limit is 2.45 times the radius of the primary, for primary and satellite having the same density (if not, then scale the primary's size appropriately). Doing that for a rocky object (3 g/cm^3) yields a Roche limit of 3 Earth radii or 19,000 km.So as that former satellite spiraled into the Earth, it broke apart long before it reached the Earth's surface and ground itself into a big ring of dust and small rocks around the Earth.This ring would be close to the Earth's equator's plane, which is where its remains would fall. But there is no known evidence of remains of an Earth ring, especially one as massive as all of the Earth's continental crust.

Look at Saturn's rings. Or the rings of the other big outer planets. It cannot be coincidence that they are all in their primaries' equatorial planes.The reason that these rings are flattened and in their primaries' equatorial planes is because of collisions -- if a ring is inclined, then its primary's equatorial bulge will cause its particles' orbits to precess at different speeds, and the ring will become blurred. And north-going and south-going particles in the ring will collide with each other as they meet near the primary's equator, with the average outcome being less out-of-plane velocity. Resulting in the ring becoming flattened and in its primary's equatorial plane.So the ring theory for the origin of continents simply cannot possibly work.

LRP:
My understanding of the Roche Limit is that it only applies to invading bodies that are held together by their own gravity.
My planetissimal was held together by chemical bonding in much the same way as our Earth is. In this case the invading object can survive inside the Roche Limit. Anyway it actually helps my theory if some disintgration of the planetissimal had taken place-It would simply assist the spreading process that subsequently followed.Except that the Earth's shape is mostly determined by its gravity and rotation. The maximum departures from a gravity/rotation-determined shape are Mt. Everest (~ +9 km) and the Mariana Trench (~ -11 km). And relative to nearby surface, the highest mountain is Mauna Loa in Hawaii, at about 9 km above the nearby ocean floor (Everest is near the Himalayan Plateau, and the Mariana Trench the ocean floor).The Everest-Mariana difference is 0.16% of the Earth's average diameter, and Mauna Loa's ocean-floor height is 0.7% of it.A mountain's height is controlled by the stresses at its base, and its amount of stresss is ~ (density)*(acceleration of gravity)*(height)Thus, the maximum height of a mountain scales a 1/(accel of gravity).A planetesimal/asteroid just above the Earth's surface would have a typical tidal acceleration of gravity of around ~0.1 Earth gravities, and scaling from Everest-Mariana and Mauna Loa yields a maximum size of ~100 km -- too small!

Except that there has been plenty of time for stellar winds and the remnants of exploding stars to mix with the primordial interstellar gas over the lifetime of our Galaxy.It is about 10-12 billion years old, and 1 km/s is 1 parsec/(million years). Meaning that it is easy to mix over interstellar distance scales without having to move very fast.As to element sorting in the Solar System, that is a byproduct of its formation. Different materials condense at different temperatures, and have different chemical affinities. The Sun had kept ice from forming in the inner Solar System, but not in the outer Solar System, which is why the outer Solar System is much more icy than the inner Solar System.

LRP:
I am at a loss to see your point-are you saying that only bodies less than 100kM in diameter will survive in the Roche Limit?Yes. And I think that that is an upper limit -- rock is not known for great tensile strength.

Actually, it's only the r-process and p-process that operate in stellar explosions and the like; the s-process operates in the interiors of red giants, and produces much of the elements heavier than iron.

LRP:
PERCIPIENT favours the theory that over billions of years explosive events in stars would have produced all the material for our Solar System. This theory is without any real evidence since no one has been able to observe debris from an exploding star being absorbed into anything like a Solar NebulaIt would take several million years for that to happen, and we have not been observing interstellar space in detail for that long. This argument is like saying that all the trees you have ever seen must have been created at their full size, since you have not seen one growing from a seed.and exactly what goes on within the depths of a star is also speculative as astrophysicists will themselves admit.However, considerable progress has been made in that field, and there is actual observed evidence of nucleosynthesis, like technetium in certain stars and nickel-56 in supernovae. Both Tc and Ni-56 have half-lives much less than the age of the Universe, so they must have been produced relatively recently.Any particle that has a high enough velocity to escape the gravity of the exploding star will be diffused evenly into the emptiness of space and not accumulate in one location.Except that it would not need to "accumulate in one location". The Solar System's heavy elements are a small fraction of its mass, which is consistent with mixing.The nebula had to have rotation about a high mass pivotal body.Totally unnecessary. It could get all the angular momentum it "needs" from turbulence.It also had to have all the elements sorted out into useful concentrations-not all mixed together.Except that there are various processes that can sort elements.IPETRICH comments that element sorting in the Solar System is a product of its formation!!You can observe element sorting if you overcook food until it chars in a thermal oven (microwave ones don't work well for this). What happens is that most of the hydrogen, nitrogen, and oxygen of the organic-material parts evaporates, leaving behind the carbon.And the same thing had happened to the Solar System as it formed. Why is the inner Solar System rocky and the outer Solar System icy? It can't be a coincidence that ice evaporates at a much lower temperature than rock.He does not say which theory for formation of the Solar System is being referred to here, as there are so many theories.What theories?The collapse of a binary star is not a quiet merger but a stupendously dramatic event which elegantly provides all that is needed to form all the elements. ...Like the interior of a massive star? Actually, the coalescence of two 1/2-solar-mass stars will not produce enough heat and pressure to perform much nucleosynthesis; this can be determined from how much would make the two stars disintegrate.Any astronomer will tell you that there are more binary stars than single stars and binary collapses are areas of research in some universities and observatories.So what? That does not demonstrate the binary-star origin of the Solar System. And inspiraling pairs of neutron stars are suspected to be the source of r-process elements -- which are mostly heavy elements. But we see a lot of hydrogen in the Solar System and not a lot of uranium.We look at the sun-I see in it the remnants of a binary star and sunspot activity tells me that within it are the remains of another star.How are sunspots supposed to be evidence of that?Starspots have been observed on numerous other stars; are they all coalesced binaries?We look at the oceans-I see the origin of water as hydrogen and oxygen produced in a binary star collapse.Except that the hydrogen comes from the Big Bang and that the oxygen comes from the interiors of long-ago massive stars.(other such non sequiturs snipped...)I just happen to prefer a single unifying theory instead of the ten or twelve different theories proposed by scientists throughout the ages to explain the same evidence.Like what ten or twelve different theories? List them for us.Ofcourse the stumbling block to my theory is not lack of evidence but the fact that it has biblical support.WHAT biblical support?Your theory is dead wrong on several counts, and all you can do is whine that your theory is rejected because it is supposedly supported by the Bible?