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New Study Shows Solar System Is Uncommon
Iddo Genuth writes "Research conducted by a team of North American scientists shows our solar system is special, contrary to the accepted theory that it is an average planetary system. Using computer simulations to follow the development of planets, it was shown that very specific conditions are needed for a proto-stellar disk to evolve into a solar system-like planetary system. The simulations show that in most cases either no planets are created, or planets are formed and then migrate towards the disk center and acquire highly elliptical orbits." The research was published in Science magazine; here's the paper on ArXiv (PDF).
Ever since mothers were allowed into academia, all their research has been telling us is that we are SPECIAL.
Cheers!
Atheist: Buddhist in a Prius
If even one thousandth of one percent of stars form solar systems similar to this one, that would still be quite significant.
I have to ask: Under which solar formation model was this conclusion drawn? Because from what I understand, there are a number of competing theories, none of which have come anywhere near being conclusively proven. I actually studied under the creator of one of the models, Andrew Prentice, and was in a position to watch as the predictions of various hypotheses were proven true or false. We've got a long way to go in the field, from what I understand.
I'm entirely missing your point about programming gravity simulations (disclaimer : I have programmed a solar system simulator), and why it should explain the (according to you) rarity of nearly circular orbits. Planetary systems starting off as accretion discs with every original object have a nearly circular orbit, I don't see why planets should keep it, at least for a while.
You just got troll'd!
I dislike pointing this out, but that's an interesting parallel with climate science. I remember hearing recently (on Slashdot?) that climate models primarily base their data on one or two sources that, if altered slightly, would throw the simulations pretty severely, one way *or* the other.
... then what chances do we have of finding a solar system populated entirely by hot large-perky-breasted nymphomaniac supermodels that love nerds?
-- Sex is the antonym of pringles. Once you pop it's time to stop.
Just what are the odds that every alien encounter will be with bipeds that have vocal communication!
Solar Systems Like Ours Are Likely To Be Rare
KentuckyFC writes
"Astronomers have discovered some 250 planetary systems beyond our own, many of them with curious properties. In particular, our theories of planet formation are challenged by 'hot Jupiters,' gas giants that orbit close to their parent stars. Current thinking is that gas giants can only form far away from stars because gas and dust simply gets blown away from the inner regions. Now astronomers have used computer simulations of the way planetary systems form to understand what is going on (abstract). It looks as if gas giants often form a long way from stars and then migrate inwards. That has implications for us: a migrating gas giant sweeps away all in its path, including rocky planets in the habitable zone. And that means that solar systems like ours are likely to be rare."
Better known as 318230.
Research conducted by a team of North American scientist shows our solar system is special
... therefore, God created this solar system specially for man, which is the center of the Universe.
I love this based-on-new-studies "science".
Just because we can't see (yet) any other kinds of solar systems, doesn't necessarily mean ours is "special" !
From what I've read here: http://exoplanets.org/aasjune07s/pr_280507.htm there have been some 236 exoplanets detected to date. I believe that they have the ability to see if these exoplanets are in highly eliptical orbits or not - so how does this simulation tie with the observed reality?
The description of Gliese 436 for example seems to also be an exception to this simulation model - so if out of 236 finds we are already finding systems similar to sol - then this simulation model must be at fault or?
Did you now that the Earth does in fact have an elliptical orbit, and that in January it is actually three million miles closer than it is in July?
Did you also know that the primary reason there is solid carbon dioxide on Mars is the density of the atmosphere, and not the distance to the sun?
Did you also know that if your mommy was any uglier, or your daddy wasn't drunk, you wouldn't exist? It's true! The existence of life is contingent on many factors.
And besides, Charley's in the trees, man, he's in the freakin' trees!
The article says that for a wide range of parameters protoplanetar disks produce a solar system-like outcome relatively rarely.
The research says nothing about the distribution of parameters in real situations, i.e. is the range of considered parameters realistic?
This is nice research but only preliminary.
contrary to the accepted theory that it is an average planetary system.
IIRC, ours is considered typical only because no data existed to show it wasn't. That doesn't make the idea into a 'theory'. Discoveries of extrasolar planets and improved models on more powerful supercomputers are bound to evolve this "Unintelligently Defined Theory" into a better creation story.
;)
Pavlov wouldn't be so famous if he'd used a can opener instead of a bell.
...but slashdot articles about it aren't.
our solar system isn't special, it's orbitally challenged.
Do not trust this signature.
Try modelling tidal effects in your simulation. These tend to drive orbits towards the circular over time.
Real Daleks don't climb stairs - they level the building.
The summary != TFA. Surprise!
"Due to the complexity of the developing system, which includes the disk-planet and planet-planet interactions described, the simulations resulted in random systems. Nevertheless, two dominant cases were detected.
In a disk with low mass and high viscosity, the gas in the disk is removed before a planet can form, resulting in a system that has only rocky, icy bodies. At the other end, in a disk with high mass and low viscosity, planets are formed but are pulled towards the center of the system and acquire highly elliptical orbits around the star.
In the intermediate case, planets form but undergo only modest migration towards the star and their orbits don't become as elliptical. This seems to be the case of the solar system. The simulation showed that this case is realized in a small number of systems, meaning the solar system does not resemble most planetary systems. "
The report is saying that along a spectrum of possibilities, there are a number which produce results different than our system.
1) It says nothing about the real life DISTRIBUTION of these alternatives. If only a narrow band of X values produce the results you want, this isn't necessarily a problem if you're in the high point of a steep bell curve. Look at a H-R diagram - there are clearly 'sweet spots' in stellar development across the range of possibilities. Nothing says planetary development is any different.
2) This of course means little. There is no evidence either way to suggest that life (which is the point of looking for solar systems - I don't think we just have some weird fetish for similar solar systems) can or can't develop on those alternate results. Hell, we may find that solar systems with nearly circular orbits are rare but that's good because they produce the Galaxy's retarded civilizations, and everyone ELSE out there is laughing/pitying us.
FWIW run your own particle/gravity simulation, and find the same results yourself: http://www.spore.com/comm/prototypes. It's awesome, and finally a use for that uber-mega-cpu you just bought.
-Styopa