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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!
The question isn't whether it is special, but HOW special. And TFS failed to even give a fake number to calm us data freaks down.
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!
Have you actually tried running your simulation for (simulated) four billion years? Don't you think that over a long period of time the various objects would act on one another to even their orbits out? That's the way I understood our current setup arose.
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.
Modelling has indicated that the solar-system isn't as common as previously thought. Scientists estimate that only 2^2340987890 similar solar systems exist in the local group.
POKE 36879,8
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!
... currently?
It's just "educated guessing", nothing more.
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.
Given the limits of our technology to detect extrasolar planets, how are "they" able to make this conclusion, especially when it is based on simulation? We are able to detect Jupiter-sized planets right now, yes? How about we wait for some better technology that can detect Earth-sized planets more accurately before we go rushing to the idea that we are "special". While the that idea intrigues me, it would certainly make the galaxy a more boring place.
Bearded Dragon
Citation please? Or explanation? Something other than claim asserted by appeal to your personal beliefs?
How about the fact that a circle is a very special kind of ellipse? For every circle with a specific radius (or orbital speed), there's an infinite number of non-circular ellipses with the same average radius (or orbital speed).
So once you throw randomness into the mix (like gravitational interaction between multiple bodies), you're infinitely more likely to end up with a non-circular orbit than with a circular one.
I'm afraid I have no citations for you, nor am I a mathematician, but with a bit of luck, one will be along shortly to explain this with a lot more accuracy than I can. (Unless I'm totally wrong, in which case I hope he'll explain why.)
They performed 100 simulations and got a result compatible with our solar system. If only 1% of solar systems ended up similar to ours with planets, there would still be tremendous number of similar solar systems out there. I don't think this is anything to be worried about.
our solar system isn't special, it's orbitally challenged.
Do not trust this signature.
OK, I think I see your reasoning, basically increased entropy in accordance with thermodynamics, right? I'm not saying you're wrong, I'm just saying that you might be misapplying the laws in this specific case.
For example, the earth and the moon. The moon at one point had a certain rotational speed (on its own axis) and another speed for its orbit around the earth. The two are now exactly (AFAIK, or very close) the same.
I believe your argument, if applied, would say that the chances of the day-length matching the year-length would be very small, that it was the "special case" and that the longer you leave it, the more likely it would be that the orbits would not be synchronous.
However, due to "tidal locking" (see wikipedia) the moon would indeed eventually tend to have a synchronous orbit.
All I'm saying is, perhaps there is some affect such as this in effect when it comes to near-circular orbits etc.
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
The thing is, despite the simulations, a lot of the observed exoplanets have highly eccentric orbits.
Perhaps that is because the systems not like ours (massive planet with short orbital period, etc) are the ones that are easier to detect. This would skew our observations and make it look like those are more commonplace, when in fact they could be the wierd ones. We will not know until we have instruments that can detect a system like ours at a distance.
Remember, You are unique...just like everyone else.
I was once one of the believers. I was sure that Star Trek like civilizations were out there just waiting to shake my hand one day. Then I heard about the Fermi Paradox and the missing link hit me. All of those people who point at the Drake equation are only seeing half of the story. The Drake equation tells us that because of the incredible size of the galaxy, even if the probability of intelligent life is very small, there would still be millions of smart planets. What it fails to address is that not only is the galaxy very big, it is also very old. Assuming that there are lots of intelligent planets out there, and that given our own technology level we could colonize the entire galaxy in about 50 million years if we put our minds to it, we should have seen evidence of some colonization effort from some other civilization by now. Try reading "Rare Earth" to see the long list of things that had to happen to make intelligent life on Earth possible. The basic premise of that text is that basic life (bacteria etc) is common but complex life (plants and up) is either very rare or we are it. There is no paradox. They are not there. We are special.
And that comment is a troll because you don't agree with it?
The brains of a chicken, coupled with the claws of two eagles, may well hatch the eggs of our destruction.