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Mars, Mercury May Have Formed From Earth and Venus
goran72 sends along a report on a radical new theory of planet formation that suggests that Mars and Mercury were formed from the scraps of Earth and Venus. The theory has testable predictions — for example that the compositions of the rocky inner planets should be more similar than the current theory of planet formation would have them.
Also, I wonder how they get the protoplanetary disk to break up into bands. Saturn's rings aren't really banded as much as you might think. The degree to which they are is largely due to moons (or their on-going generation). Left to themselves, the rings should spread and homogenize.
Very true but the 4 inner planets have almost circular orbits.
Any planet that get flung around will have a very eliptical orbit.
Orbits get circularized by a number of effects over time, both orbital and viscoelastic coupling. Hot-Jupiter orbits somehow get circularized, after all, and they're much harder to circularize than smaller planet orbits.
The Hot Jupiters are a different thing. They are caused by the system having enough material to cause drag and slow them down enough to collapse the orbit.
Any process that can move Jupiter and super-Jupiter size planets will easily reposition smaller planets.
http://www.geoffreylandis.com
The Structure of Scientific Revolutions, Thomas Kuhn's magnum opus, should be required reading before engaging in a debate on science. There's an aphorism that goes "all theories are wrong, but some are useful." We can and do use theories we know have flaws because in the vast majority of cases, they predict and explain what happens in nature. When a better theory comes along to explain the observations, we begin to use that one instead.
It's absolutely useless to say "this theory is wrong!" as long as the theory, however flawed in some cases, works well in the general case. What do you propose to replace it? Does your replacement make specific, verifiable assertions about nature that are more correct or accurate than those of the prevailing theory? I thought not.
(On the off chance that it does, and you can provide evidence, please, submit an article to Science or Nature; you'll be famous for generations.)
Your comment on frozen lines in plasma not withstanding. Its an approximation, that works well for a lot of cases. And anyone in the field will tell you that. Newer models allow this to be relaxed more and more. But really it doesn't change things that much with typical astronomical plasmas.
And the different redshift thing? Could you be more specific? There are really no theories that predict the comsmic microwave background and isotope ratios other than the big bang. Which also leads to the standard red shift interpretation. There really nothing else we have come up with that works. We have just have so much red shift data now. There really are no alternative that explain this without some serious arm waving.
and are humble enough to admit that maybe you don't know
I'm sure you are humble enough for both of us.
The Grey Goo disaster happened 3 billion years ago. This rock is covered in self replicating machines!
Eccentric orbit's are destabalized during the process of circularization which then either ejects them OR crashes the orbit. But it is also true the eccentric orbits tend to be a bit more stable than true circular ones...but only a little.
I never said the sol system had a hot jupiter. But it had been cited in the grandparent therefore I was adressing the issue. Hot Jupiters happen in specific conditions where the gas that formed the original system was thick enough to not get blown away quickly. Therefore the jupiter sized planet, with it greater porportional size and gravitational field effect due to lower density, are disporportinaly slowed through friction. As they slow they eat or eject all inner planets until they get close enough so that the solar wind HAS cleared everything out.
The sol system did not have these conditions therefore no hot Jupiter.
With the higher density but smaller size of rocky planets they are not as likley to experience the slowing effect before they clear the neighboring space therefore any moving will probably be due to colision or near collision with other large bodies and will be entierly random.
The reason Venus, Earth and Mars probably haven't moved is because the planets chemistries match theory fairly closely. Planetary genesis theories suggest that there will be subtly chemical differences at varius altitudes from the star. Mercury has unexpected chemistry which could come from collision (there is evidence for such an event) or being moved
Jupiter sized planets can only form out past the "Snow line" where water can form ice. Otherwise you get terrestrial planets that max out a few times bigger than earth.
When a jupiter sized planet moves into a terrestrial orbit it EATS the planet already there.
Since the earth is still here, no hot jupiter ever existed in sol system.
When astronomy has a crisis in the next 5-10 years or so, perhaps most of you will be surprised. For a good starting point to see what I am talking about, do some research on black holes and what Schwartzchild really said vs. what is commonly attributed to him in colleges and textbooks everywhere (ask yourself if the most amateur of journalists would report so inaccurately). Or research Edwin Hubble and the fact that there are two equally valid interpretations of the redshift equation and we have settled the question of which to use by making an assumption. Or explain to me how a star that is powered by an internal thermonuclear reaction could have an atmosphere that is many times hotter than its surface (if you think that's a simple matter, you do not appreciate the question). Or why it is that a steady, flowing stream of charged particles is called an electric current everywhere it is found, unless those charged particles come from the sun and compose what is called the solar wind? Or why Hannes Alfven, the originator of what is now called magnetohydrodynamics, has thoroughly discredited his own theory, including during his Nobel Prize speech (especially the part about magnetic field lines being "frozen" in plasma), yet scientists continue to use this discredited theory to come up with fanciful ideas like "magnetic reconnection"? It's time to come up with new ideas instead of unscientifically shoring up old, failed ones in the name of preserving your funding.
The first two statements are insinuations and don't actually say anything (I'm not going to spend many hours reading Schwartzchild, Hubble, etc based on a vague insinuation). As for the high energy of the Sun's corona, the entire Sun is a rotating ball of plasma with strong magnetic fields and a power source in the center. That makes numerous opportunities to create highly energetic particles and throw them out. A steady flowing stream of charged particles is not an electric current because we haven't assertained the most important characterist of a current, namely that there is a net flow of charge. For example, water is a flowing stream of charged particles. However, the charges are tightly bound to each other so there's no EM effect until you almost touch the water. The Solar Wind contains a lot of charged particles, but it is electrically neutral, there is no net flow of charge. It is a plasma without an electric current.
Hannes Alfven hasn't "thoroughly discredited" magnetohydrodynamics. And "appreciating" a question like "How did the universe get here?" doesn't mean the question is well-defined. It implies that there's some process that makes universes. There may well be no such thing.
Having said that, you have mentioned a large variety of subjects: the Sun and its plasma environment, black holes, origin and current dynamics of the universe, and plasma dynamics. A lot of that we really don't have a good grasp on and it is likely that we'll see serious challenges to our understanding of these phenomena.
Mars is from Earth, Mercury is from Venus.
...and methane is from Uranus.
Sorry..
You just got troll'd!