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What manner of nonsense is this?

  1. Sep 11, 2003 #1

    Phobos

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    I was listening to a fundamentalist Christian radio station yesterday (don't ask) and Mr. Scienceguy came on to explain about how the latest measurements of the solar system's angular velocity prove Genesis to be literally true. In a nutshell :wink:, he started by describing the mainstream scientific theory of solar system formation (collapse of a cloud of material) and that historically, scientists believed that a large part (50% or more) of the angular momentum of the whole system was associated with the sun rather than the planets. However, he said, new and more accurate measurements show that most of the angular momentum is associated with the planets (like 98%) rather than the sun (2%). Therefore, he concluded, this proves that the planets formed first, just as stated in Genesis.

    Before I go off and check the details of the latest research on the solar system's spin (unless some helpful member can provide that info :smile:) can someone explain to me how he could reach that last conclusion? Why would more angular momentum (rotational + orbital) with the planets mean they formed first? He didn't say.

    Of course, this is still far from showing that the solar system formed in a few literal days, but I'm sure the weight of evidence was sufficient in his mind.
     
  2. jcsd
  3. Sep 11, 2003 #2
    Very tempted...oh well, I'll leave it alone .

    Hmm. I really don't know. Maybe he assumed that they would have more time to pick up momentum, if they had existed longer (rather stupid, I know, but it's possible; very few creationists actually check with the facts or with logic on their apologetic journey ).

    Anyway, as a matter of form, I feel compelled to point out that the creation account doesn't actually require that the planets existed before the sun did. The very first verse of the Bible states that "in the beginning, God created the heavens and the Earth[/i]". The "heavens" encompasses everything that exists outside of Earth. Thus, when God said "let there be light", he may only have been saying "let light become visible on the planet Earth".
     
  4. Sep 11, 2003 #3

    marcus

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    I consulted a standard vintage handbook, 1972 Allen's Astrophysical Quantities
    and it said the angular momentum in the planets is 3.1E50 units and that in the sun is 1.6E48 units

    the units are cgs because it is 1972, but all that matters is the comparison-----two orders of magnitude more spin in the planets

    I should be interested to know if anyone comes up with more recent figures that are different.
     
  5. Sep 11, 2003 #4
    First of all, I am Christian, but far from a fundamentalist.

    They do so much more harm then good trying to prove the accuracy of the Bible stories. In order to truely understand the Bible stories literally, you would have to have intimate knowledge of the times in which they were written, this, in the case of Genesis, is unknown; intimate knowledge of the Author, Understood to be Moses, but not yet authenticated; intimate knowledge of the language in which it was written, which would mean access to an original or authenticated copy of the manuscript; and many other stumbling blocks to the literal meaning.

    The Bible can inspire in many ways. The creation story in Genesis shows that God brought order out of chaos, it was unique in past religions by bringing order, instead of bringing destruction that led to our creation (such as the Persians believing that a great rock crashed through the stone shield of the sky creating the stars and planets).

    Ignore Mr Science. He's an idiot.
     
  6. Sep 11, 2003 #5

    enigma

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    Fundamentalism is a mental disease.

    but then again, you knew that...
     
  7. Sep 11, 2003 #6

    russ_watters

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    Piece of cake. You just havet to see it from their eyes: There are two theories. Both are on equal scientific footing. One small inconsistency is found in one theory. It is therefore completely wrong which means the other theory must be completely right!!

    Aren't you glad the scientific method is so simple?
     
  8. Sep 11, 2003 #7

    LURCH

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    I have never heard of this "Mr. Science", but isn't there some kind of prophecy about a theater being named after him in the year 3000?

    At any rate, I'll take a stab at his reasoning regarding the distribution of angular momentum in the solar system. He may be referring to the fact that standard models of solar system formation predict that the distribution of angular momentum would be almost opposite of what is; 80% in the sun and the remaining 20% shared among the planets and other solar system debris. Since observation does not match prediction, the model is flawed.

    On the other and, in the "spontaneous creation" view, the planets and the sun were formed independently of one another. By this model, the planets would simply be placed in their orbits and given whatever amount of angular momentum is necessary to sustain those orbits and revolve on their axes. If he has any reason at all behind his conclusions, I would imagine this is it.

    I am a Christian myself, and I may even be a fundamentalist (does anyone have a clear definition of exactly what that word means?), but I cannot agree with these conclusions. But then, I can't really say that I agree with the "planetary migration" explanation, either. I have my own theory, but I am at a loss as to how to test it.
     
  9. Sep 11, 2003 #8

    selfAdjoint

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    Most of the angular momentum in the solar system is with the planets. Do it yourself; you only have to do Jupiter and Saturn to get the result; do their angular momenta from their masses, radii, and periods, and then do the sun as a rotating sphere given its (overall) rotation and size.

    This used to be a big problem with collapsing cloud theories back in the days when those consisted of naive variants on Kant's nebular hypothesis. They all predicted the angular momentum would concntrate at the center. Sometime in the 1950s the problem went away, and I am not sure just how it was handles.
     
  10. Sep 11, 2003 #9

    Janus

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    The modern theory has a proto-sun and an accretion disk.

    Magnetic braking caused by the Sun's magnetic field interacting first with the accretion disk, and later with its own solar wind is what has led to the present situation.
     
  11. Sep 11, 2003 #10
    Were you listening to Dr. Hugh Ross with Reasons to Believe perhaps?
    The program is sometimes interesting, but I have to admit sometimes Dr. Hugh Ross makes claims without much support.
     
  12. Sep 12, 2003 #11

    jcsd

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    Hug Ross is actually a professional astrophysicist who has done alot of work with radio telescopes, I seriously doubt it is him as he would be unliekly to make such an amateurish assement showing total ignorance of what angualr momentum is and how it works.
     
  13. Sep 12, 2003 #12
    Correct me if I'm wrong, but isn't a central source of gravitational attraction, such as the Sun (Or a loose central core of mass equal to the sun, but less dense), required to create angular momentum in the planets? without it there would just be momentum and they would shoot off into space or begin to orbit one another, right?
     
  14. Sep 12, 2003 #13

    selfAdjoint

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    A large cloud or nebula would have some net angular momentum. How would it have acquired that A.M.? By gravitational interaction with the rest of the galaxy (which is rotating, you recall).

    Then the initial A. M. would be concentrated according to whatever physics is acting. If they have worked out that magnetic braking can keep the central core low in A.M. then that would give the present day distribution of A.M. within the Solar System.
     
  15. Sep 12, 2003 #14

    marcus

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    I agree, even without assuming that it acquired it (as you suggest) by gravitational interaction with the A.M. of the whole galaxy.

    Turbulence caused by nearby star formation, supernovae, indeed a lot of random happenings not uniformly or symmetrically distributed in space could, I imagine, leave a residual A.M. in the cloud out of which the solar system formed.

    Saying that the S.S. spin came from the over all spin of the galaxy would beg the question of where the galaxy got its spin. Perhaps best to bite the bullet and say random assymetry up front.

    SelfAdjoint, I have not studied up on this but was wondering----the planets have 100 or more times the spin of the sun
    If the S.S. was condensing it seems to me that the sun would not even be stable if it had 100 times as much A.M.! I dont see how it could even have condensed with so much A.M.
    So although magnetic braking may be a key player, as you suggest, even if one "turns off" magnetic braking hypothetically, for argument's sake, I wonder how the system could condense in any other way besides with most of the angular momentum out in the planets.

    Just an intuitive hunch, havent done a backofenvelope calculation about it. Any reaction?
     
  16. Sep 12, 2003 #15

    selfAdjoint

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    Marcus, the models of my youth, non-magnetic spinning fluid models, did condense OK, but I don't know how. Perhaps they put in the radial distribution of angular momentum by hand? I know they weren't taken very seriously. Many astronomers of the time held to the close approach theory in which another star comes by the sun and "strips off" a string of material which then condenses into the planets.

    You have to understand that in these pre-computer days, models couldn't get too detailed. Hand calculation very quickly became swamped.
     
  17. Sep 15, 2003 #16

    Phobos

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    Hi everyone! Just getting back to my own topic here...glad to see you carried on without me. Seems that you all confirmed my thoughts, but I wanted to make sure there wasn't some logical connection that I was missing.

    Mentat, Artman, enigma, russ_watters - - Thanks, that's what I figured. :wink:

    LURCH, selfAdjoint, Janus - - So, the "new info" he referred to is actually a revision of the model from the 1950s?

    O Great One - - Don't know...I missed the intro. I agree that Dr. Ross makes some unfounded leaps. (based only on one interview I've seen of his)
     
  18. Sep 15, 2003 #17

    selfAdjoint

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    Welcome back phobos!

    Yeah, in my guess some creationist came upon some old opinions that the nebular hypothesis or one of its early modern variants couldn't handle the angular momentum distribution and just went with it without checking further. About par for a creationist.
     
  19. Sep 16, 2003 #18

    Phobos

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    Gather any evidence that fits your worldview...ignore the evidence that doesn't. :wink:
     
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