Is there a pattern to how our solar system is laid out? You have Mercury, Venus, Earth and Mars closest to the sun, all rocky planets and then you have Jupiter, Saturn and Uranus, Neptune. Does this have something to do with Bodes' Law? Why aren't the rocky planets mixed in with the gas giants?

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The world breaks everyone and afterward many are strong in the broken places. ~ Ernest Hemingway ...

to add....from what we've seen of extra solar systems this is not typical

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The world breaks everyone and afterward many are strong in the broken places. ~ Ernest Hemingway ...

Bode's "law" was once thought to be an actual law, until we saw that plenty of other distribution patterns exist. We can't say for sure, but present knowledge suggests that the early phases of Solar formation, with a strong flow of matter from the Sun, may have blown large amounts of gasses off the inner planets.
What we're seeing now is somewhat limited by our own detection methods, which are skewed towards large, close planets. Not enough data yet to tell if that's typical, only that it's more easily detectable from interstellar distances.

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"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
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Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
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"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

Until we can fully catalog the entire layouts of enough OTHER solar systems, you cannot judge anything by the layout of OUR solar system.

We've only detected a few hundred Jupiter-sized worlds outside our own system, so we don't even have the vaguest knowledge yet as to was is 'typical'....

The rocky planets vs. gas giants situation is due to differing distances from the Sun and the resultant temperature differences. At cooler temperatures gasses have lower kinetic energy and are less likely to escape a planet's gravitational field. Also, at greater distances from the Sun gasses are less likely to be blown away by the solar wind.

Bode’s Law was flawed right at its basis. It proposed that the set (0, 3, 6, 12, 24, 48, 96) is part of a doubling sequence. It is not. The initial value would have to be 1.5 to create a proper doubling sequence. The initial zero used to include Mercury in the “law” was a fudge factor that is frequently overlooked. Later, Neptune proved to deviate from the so-called law.

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Curt Renz - "Centaur"
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In science, a "law" is any mere statistical relation--it doesn't have to be a "rule" that things "must" follow. So, even if Bode's law does not apply to every solar system out there, it would still apply here.

However, I think there is something to Bode's law other than mere coincidence, but its more like a law of "biology", than a law of physics. Protoplanets "compete" for mass. As larger and larger protoplanets "grow" by "ingesting" matter out of the primordial disk, there is a limit to the "search space" they can cover governed by the average orbital eccentricity. In other words, Bode's Law is the result of "niche partitioning" among the major planets.

Mercury's a little off because it's so close to the Sun that atmospheric drag from the Sun itself may have had an effect, plus there are also general relativity effects that aren't predictable using ordinary Newtonian orbital mechanics.

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"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin

And what's more, our sample is highly biased to massive closely-orbiting planets. We could already discover true extrasolar Jupiter analogs (and we probably have), but discovering one requires data points along the complete orbit, that is over 10 years. An extrasolar Saturn analog would be much harder to find, and other planets would be currently impossible to detect.

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Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
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Why would you need data points along the complete orbit? For example, 2M1207b (the first extrasolar planet directly imaged by a telescope) is roughly Jupiter massed, and separated by 46 AU from 2M1207 giving it an oribital period of ~2,400 years. Obviously we haven't watched it that long.

Plenty of Neptune-sized planets have been found, and here's one that's only 5 Earth masses.

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"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin

And therefore we have no idea of its orbit. In fact, we don't even know its current distance from its parent star. The distance you give is the current separation projected on to the plane of the sky, and the period is a guess made by adopting that distance as the semimajor axis of the orbit.

But I agree that in general we don't need to watch an entire orbit to compute its characteristics: just a long enough segment to allow the rest to be calculated with useful confidence. However, I think Kullat Nunu is suggesting that to be sure the observed pattern in the data is an orbit, we probably need to observe at least one cycle.

Grant Hutchison

Well, they say Pluto has an orbital period of 248 years, but it was only discovered 1930. Do we really have to sit around for 248 years "to be sure" that Pluto's observed pattern really is an orbit?

Granted, the 2400 year period for 2M1207b was picked out of a hat--there's no telling at this point how eccentric its orbit is. But 2M1207b and 2M1207 were recently both shown to be a "common proper motion pair". If they're not in orbit around each other, what else would they be doing hanging around together?

But my main point is just that we are getting useful data about planets that are not ultra-close to their parent star.

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"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin

You're mixing data sources, here. You can't compare the direct observation of a body in our own back yard with a velocity signal picked out of the background noise from a distant star. The latter has multiple potential causes, which need to be untangled by observation.

But not data that allow us to say anything much about how the outer regions of a typical planetary system are "laid out". Which I believe is Kullat Nunu's point, and which is certainly my point.

Grant Hutchison

Even when it's a "mere" statistical relation, a scientific law must be followed. Anything else would be kind of unlawful, don't you think?

Now, in pop-postmodernism, of course, all bets are off -- the "law" can be as lax as you will it.

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I'm no expert, but that's what the exoplanet hunters have told. Considering how much distant orbits change when new data points are acquired, a very incomplete orbit probably gives highly unrealistic values. Take for example 55 Cnc d, the outermost planet in the system. It was originally believed to be in a highly eccentric orbit. Now its eccentricity seems to be mere 0.025. Similarly, some of the distant planets have wildly varying values (compare the values of HD 154345 at the Extrasolar Planets Encyclopaedia and the Catalog of Extrasolar Planets. The former suggests a more distant and much more eccentric orbit (9.21 AU, 0.474) compared to the latter more up-to-date values (4.17 AU, 0.050; a very Jupiter-like planet).

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Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

Well, that's good! It shows that the early estimates are rapidly converging on lower eccentricity orbits, so we may not have to wait more than another few years to maybe see other solar systems with Bode-like arrangements.

If it's a statistical law, there are always going to be the exceptions that prove the rule--that's what makes it statistical.

But I take back what I said about Bode's Law being a statistical law. I didn't mean that our solar system is somehow the average of all solar systems.

Instead, I'll stick with the physical (or rather quasi-biological) basis I proposed to explain the striking, obviously nonrandom pattern we observe here. The initial conditions required to produce that pattern may be rare (single, bright star and well-organized disk), but given those initial conditions, one should expect a Bode's-like (logarithmic) spacing of planets.

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"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin

Exceptions do not prove rules, they disprove them, even in statistics. If the law is statistical, then "exceptions" will turn up with a low frequency, which can quantified and checked against observation. If the observed proportion is inconsistent with the theoretical predictions, then something is wrong.

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"All your bias are belong to us." Ara Pacis
"A witty saying proves nothing." Voltaire

I think this is exactly Warren Platt's meaning. In the phrase "the exception that proves the rule", the verb "to prove" is used in the same way as it is used in the phrase "proving ground" -- meaning "to test".
The exceptions test the statistical rule: if they turn up in the wrong proportions, then the rule fails the test; if they turn up in the expected proportions, the rule passes the test.

Grant Hutchison

And also the fact that an outlier just is so rare and odd carries with it the implication that the normal state of affairs is normal.

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"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin

We don't know that it's rare. Only that it's more difficult to detect using current methods.

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort