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New Study Shows Solar System Is Uncommon
Posted by
kdawson
on Tue Sep 02, 2008 04:13 AM
from the isn't-that-special dept.
from the isn't-that-special dept.
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).
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Great! (Score:5, Funny)
Ever since mothers were allowed into academia, all their research has been telling us is that we are SPECIAL.
Cheers!
Re:Great! (Score:5, Insightful)
I wouldn't read it like that
Space is still the big unknown. If this "shows' anything, it seems more probable that this 'shows' that the simulations aren't complete enough yet.
If they would deduce this from actual statistical data, it would show something, but deducing this from simulation seems a a bit to trustful to the current state of science if you ask me
Parent
Re:Great! (Score:5, Insightful)
I agree. Basing conclusions off simulation models is risky, mainly considered how in the domain of planetary simulations, well established models get entirely questioned every once in a while.
And at this point even actual statistical data is hard to use to conclude anything about our solar system, because of our limited observation capabilities, what we know has a heavy statistical bias.
Parent
Climate Science (Score:5, Insightful)
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Re:Climate Science (Score:5, Informative)
It's an interesting parallel with anything where you base a conclusion off a simulation. But with climate science there are very significant differences.
With our own planet we have reasonable records of how conditions changed in the past and the results of that. We've got extremely detailed recording of the current situation and the recent past. We've got firmly established science showing why those changes would cause those results. The world's climate is a little chaotic and the simulations match that state of affairs.
When modelling planetary discs, we're nowhere near as sure of the physics. We can only get decent observations of our own solar system, and there isn't a disc of dust to observe. Even the best telescopes can barely see the discs of dust around stars. We could barely detect our own solar system around another star, let alone watch it form.
Parent
Re: (Score:3, Interesting)
Actually no we don't have a lot of reasonable data. We have a few hundred point sources from before 1920, and it slowly goes up from there. indeed according to climatologists this past summer should have been warmer than average, yet instead it was cooler. climatologists will need to be right more than 50% of the time if they want me to believe them. Heck just this past weekend the only thing they predicted correctly was the daily highs and lows. They were so far off the mark with wind, clouds and rain
Re:Climate Science (Score:5, Insightful)
And you'll need to stop confusing climatologists with meteorologists.
Parent
Re:Climate Science (Score:5, Funny)
climatologists will need to be right more than 50% of the time if they want me to believe them. Heck just this past weekend the only thing they predicted correctly was the daily highs and lows.
And you'll need to stop confusing climatologists with meteorologists.
What does a meteor have to do with this weekends weather?
Leave science to the scientologists I say..
(They're the authentically named 'ologists for the job).
Parent
Re:Climate Science (Score:5, Informative)
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Re:Climate Science (Score:5, Informative)
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Re: (Score:3, Interesting)
Growth rate of coral. Wow, talk about drinking the kool-aid. How does anyone know what else might have affected the growth rate of coral at the time? And "sediments"? I know this is difficult for people who want/need to believe in the latest fad, but you can't tell someone what the temperatures were without a measurement of said temperatures with an accurate temperature measurement device installed and calibrated to our modern specifications being used by people of whatever time period you are wondering
Re:Climate Science (Score:5, Informative)
Growth rate of coral is one data point. You can also look at ice cores, tree rings, stalactites, isotope analysis of rocks. And sediments can refer to all kinds of interesting information, both organic and inorganic in nature.
You might be able to cast doubt on coral growth rings, but when everything is pointing in the same direction, you've got to pay attention to the most obvious reason for that.
Parent
Re: (Score:3, Insightful)
Which will not give you anything resembling exact temperatures. Which you would actually need to plot "data" points.
Re:Climate Science (Score:5, Informative)
How does anyone know what else might have affected the growth rate of coral at the time?
For one, they look at corals of the same species from around the world which grow in regions of different temperature, salinity, etc., and see how those factors are affect the coral's growth.
The other poster has a more complete answer to the broader question.
but you can't tell someone what the temperatures were without a measurement of said temperatures with an accurate temperature measurement device
That's manifestly false. Oxygen isotope proxies in ice cores are one of the prime examples of good paleothermometers, when they can be used; they depend on the rate at which heavier isotopes are transported in warmer or colder air, which is just physics. You don't need to worry about biological fractionation and such. Other proxies do good or fair jobs, depending on the type and the circumstances. Ocean proxies often do better than land proxies, since conditions are more stable. Almost all proxies are better at measuring temperature changes than absolute temperatures, though.
We have no reasonably accurate measurement of temperature before the existence of reasonably accurate measurement devices.
I'm sure you came to that conclusion from a thorough reading and analysis of the paleoproxy climate literature.
Parent
Mod parent up, not a troll (Score:3, Informative)
And that comment is a troll because you don't agree with it?
Re:Climate Science (Score:5, Interesting)
That sort of situation is commonly called "the butterfly effect". As the saying goes, a butterfly flapping its wings over a highway in australia could be the deciding factor as to the path of a hurricane in the gulf three weeks from now.
While that's a little extreme, it's meant to illustrate the point of highly interactive systems that are "extremely sensitive to initial conditions". For example, a single microbe that hitchhiked on Spirit or Opportunity could lead to the terraforming of mars a millennia later.
Weather has always been considered highly sensitive to initial conditions, meaning very subtle differences in the weather conditions today can have a profound effect on the weather a week later. The interesting thing about weather is that it doesn't take a millennia to change things miles away, it can do it in a couple hours.
Parent
Re: (Score:3, Informative)
I disagree. Simulation is a good method to check your basics and verify patterns. Like all things, it's a tool that you need to know how to use and what to use it for. Only in very well understood fields do simulations give you good numbers to work with. But even in poorly understood fields, then are a way to check your theories, by letting them "run" and see if the results coincide with the expectations and/or actual observations.
So if, for example, you have a theory about how planets are formed, and put i
Re:Great! (Score:4, Interesting)
Number of Planetary systems we have completely explored - None! - We found a new (dwarf) planet Eris 2,500 kilometres in diameter and 27% more massive than Pluto in 2003
All the other planetary systems we have found have massive sampling bias (we can only detect large planets, and easily detect close orbiting large planets)
All of the systems like ours are undetectable or nearly undetectable at present
It's a black swan problem - Until the 17th century a black swan was a metaphor for something that did not exist ... then Australia was discovered along with Cygnus atratus
Parent
Re: (Score:3, Insightful)
Add to that a lot of speculation about planetary formation and who can have any degree of certainty about where our solar system sits in the scheme of things.
We need to observe many more planetary systems before we have a clue.
Re: (Score:3, Funny)
If this "shows' anything, it seems more probable that this 'shows' that the simulations aren't complete enough yet.
Of course. They did not even mention Great A'Tuin, so how could their model be complete?
What is rare? (Score:5, Insightful)
If even one thousandth of one percent of stars form solar systems similar to this one, that would still be quite significant.
Re: (Score:3, Funny)
Re: (Score:3, Insightful)
1/1000th of 0.01%
I think that statistic is a bit hopeful. My current understanding of how the "earth" came to be a hospitable place, is due to a cosmic collision on such a scale that it changed the entire ecosystem of earth. The impact was so massive that it made the event that caused the dino's to be wiped out to look like a pin prick.
I'm sure cosmic collisions of that size occur all the time (speaking astronomically), but what are the chances that "large objects" (earth sized), at the right distance from
Re:What is rare? (Score:4, Funny)
This is assuming the "E.T." is made of meat, like us, which I feel is a common mistake we make when thinking of what could exist elsewhere.
I blame Star Trek.
Parent
Under which model? (Score:5, Insightful)
Re:Under which model? (Score:5, Funny)
Parent
if our solar system is uncommon... (Score:5, Funny)
Re:if our solar system is uncommon... (Score:5, Funny)
Lets say... zero.
If you cam't find a girl on Earth, what are your chances against alien supermen? particularly someone who is built like Gort?
In a bar fight, you can only win at ASDF keyboard battles.
Parent
If you think thats rare.. (Score:5, Funny)
Just what are the odds that every alien encounter will be with bipeds that have vocal communication!
Re:If you think thats rare.. (Score:5, Funny)
Parent
Dupe from 3 weeks ago (Score:5, Informative)
Solar Systems Like Ours Are Likely To Be Rare [slashdot.org]
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 [arxiv.org]). 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 [arxivblog.com]."
Let's define "common" (Score:3, Funny)
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.
Special one (Score:5, Insightful)
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" !
Re: (Score:3, Informative)
Re: (Score:3, Insightful)
Actually, because of current findings, our solar system is quite special.
When we find other similar solar/planetary systems, ours will lose the special status.
Sort of like if you have a "special" child in a classroom. Once this child is removed from regular school and placed into a "special" school where all kids are "special", he is no longer "special".
P.S. What a way to get mod points
Re: (Score:3, Insightful)
Another scientific fact: Absence of evidence is not equal to evidence of absence. Especially when we haven't even been looking for evidence yet.
Re: (Score:3, Insightful)
Yes, but they share the common ground in that neither is a sound foundation for a positive assertion.
"Unique" is a bad word for many people in reference to Earth and its system, but its currently just as likely we are unique as we aren't. We keep hearing about how common Sol-like systems "must" be because of the sheer number of stars in the Universe, but we have yet to find even one. So, that assertion is far from obvious.
The
How does study compare with observed results (Score:5, Interesting)
From what I've read here: http://exoplanets.org/aasjune07s/pr_280507.htm [exoplanets.org] 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?
Is it just me, or does this change every 2 months, (Score:3, Insightful)
... currently?
It's just "educated guessing", nothing more.
Incomplete conclusion (Score:5, Interesting)
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.
"accepted theory" (Score:5, Interesting)
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.
;)
They may be uncommon... (Score:4, Funny)
Given the limits of our technology... (Score:3, Insightful)
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.
political correctness, please! (Score:5, Funny)
Very poor summarization and implied conclusions (Score:5, Insightful)
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 [spore.com]. It's awesome, and finally a use for that uber-mega-cpu you just bought.
Converted (Score:3, Interesting)
Re:Have you every programmed a gravity sim? (Score:5, Informative)
Parent
Re:Have you every programmed a gravity sim? (Score:5, Funny)
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!
Parent
Re:Have you every programmed a gravity sim? (Score:5, Insightful)
Try modelling tidal effects in your simulation. These tend to drive orbits towards the circular over time.
Parent
Re: (Score:3)
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