Please turn on javascript in your browser to play chess.
Science Forum

Science Forum

  1. 08 Jul '08 05:24
    What exactly is it about this theory that purports to explain the development of the planets of our solar system? The claim I heard is that "computer models" show the theory to be correct, "except for Uranus and Neptune, which refuse to follow the program". Does this sound fishy to anyone else? I mean, I think I could write a program that would show a bunch of rocks hittin' each other, and call a press conference to say "Here's the Accretion Theory Proof!" But I doubt I'd get any believers. So what's the deal with computer models "proving" anything?
  2. 08 Jul '08 07:44
    Originally posted by PinkFloyd
    What exactly is it about this theory that purports to explain the development of the planets of our solar system? The claim I heard is that "computer models" show the theory to be correct, "except for Uranus and Neptune, which refuse to follow the program". Does this sound fishy to anyone else? I mean, I think I could write a program that would show a b ...[text shortened]... I'd get any believers. So what's the deal with computer models "proving" anything?
    I think we all believe in Accretion Theory on essence, but some pecularities cannot be solved with this theory alone. We have to take some catastrophic events into concideration also, like collisions.

    When we've refiende our observations of other planetary systems in various degree of age, then we can tell more.

    But in essence it is correct.
  3. 08 Jul '08 07:59 / 1 edit
    Originally posted by PinkFloyd
    What exactly is it about this theory that purports to explain the development of the planets of our solar system? The claim I heard is that "computer models" show the theory to be correct, "except for Uranus and Neptune, which refuse to follow the program". Does this sound fishy to anyone else? I mean, I think I could write a program that would show a b I'd get any believers. So what's the deal with computer models "proving" anything?
    …I mean, I think I could write a program that would show a bunch of rocks hitting each other…

    Yes, that is correct. Any idiot that has learned, say, java, can write a program that would show a bunch of rocks hitting each other. But can you do it by making the computer simulation be solely controlled by a single mathematical formula that represents the physical behaviour of mater? -that’s the tuff part!

    …So what's the deal with computer models "proving" anything?…

    I have noticed that is a common misconception that computer simulations can “prove" things in the sense that they can “prove” that something did occur or will occur or can occur in physical reality. Strictly speaking, they don’t, although they can add considerable weight to a theory. Strictly speaking, a computer simulation can only “prove" that a theory “makes sense” if what the computer simulation says closely fits with the known evidence.

    Sadly, I have often read in various science journals of many scientists claiming that their computer simulation “proves their theory correct” and I think that is a mistake -they should be very careful of exactly what they claim they can “prove“. They should carefully say their computer simulation “proves their theory makes sense because it fits well with the known physical evidence” instead.
  4. 08 Jul '08 12:52
    Originally posted by PinkFloyd
    So what's the deal with computer models "proving" anything?
    I agree with Andrew Hamilton. Generally a computer simulation as with many experiments regarding past events mostly serves to show whether or not a proposed sequence of events is possible. It does not necessarily prove that the sequence of events actually took place as simulated.
    It may also serve to show whether or not a particular outcome is likely.
  5. 08 Jul '08 14:58
    Originally posted by Andrew Hamilton
    Sadly, I have often read in various science journals of many scientists claiming that their computer simulation “proves their theory correct” and I think that is a mistake ...
    I think this part may be part cause of the editors and journalists that interview for the respective newspaper rather say that than using the rigor a professional scientist would use. Maybe some do but in my experience scientists are hesitant to say something is proven.

    I agree that you can't really prove stuff with computer analysis.
  6. 08 Jul '08 20:02
    Originally posted by Andrew Hamilton
    [b]…I mean, I think I could write a program that would show a bunch of rocks hitting each other…

    Yes, that is correct. Any idiot that has learned, say, java, can write a program that would show a bunch of rocks hitting each other. But can you do it by making the computer simulation be solely controlled by a single mathematical formula that rep ...[text shortened]... es their theory makes sense because it fits well with the known physical evidence” instead.[/b]
    That was very clear and informative. Thanks AH.
  7. 08 Jul '08 20:34
    Originally posted by Tera
    I think this part may be part cause of the editors and journalists that interview for the respective newspaper rather say that than using the rigor a professional scientist would use. Maybe some do but in my experience scientists are hesitant to say something is proven.

    I agree that you can't really prove stuff with computer analysis.
    Come to think of it, I think you are almost certainly right about that. Editors and journalists may often be temped to sensationalise what the scientist says and, at other times, they may, through no fault of their own, subtly misunderstand what the scientist says because they don’t quite fully understand the true nature of science and scientific method. Either way, this can result in them to either misquote or misrepresent what the scientist says or claims to have discovered.
  8. Standard member sonhouse
    Fast and Curious
    09 Jul '08 05:24
    Originally posted by PinkFloyd
    What exactly is it about this theory that purports to explain the development of the planets of our solar system? The claim I heard is that "computer models" show the theory to be correct, "except for Uranus and Neptune, which refuse to follow the program". Does this sound fishy to anyone else? I mean, I think I could write a program that would show a b ...[text shortened]... I'd get any believers. So what's the deal with computer models "proving" anything?
    I don't have a link, but there was a recent scientific american article about this subject. The gist is dust in a giant spinning cloud around a newly formed star will have areas of greater density just from the normal mixing that would occur with ultra-large volumes of such material, as it condensed from an even larger cloud and formed the star in the first place. So gravity basically takes over and the larger natrually occurring pieces win the gravity race and attract more dust than smaller pieces of stuff, so the slightly larger ones will preferentially attract more dust and become even larger, after it becomes about 1 km in diameter things start getting interesting, now they will start colliding with each other and becoming larger but losing some mass due to the collision but still be more massive after collisions than before, so the left over material will be attracted back to the collider and become larger still. This self limits eventually, especially at the 'ice line', the place in the new system where it is far enough from the main star for ice to form and therefore ice comets to become larger. inside the ice line several effects happen, the leading edge of a condensing cloud will be drawn towards the sun more than the trailing edge and so the proto planet will be drawn ever closer to the new sun. So it is very chaotic, not neat and orchestrated like a dance. But the computer sims have produced systems like what we are seeing in our newly developed technology to figure out what the orbits of planets are around relatively nearby stars.
  9. 11 Jul '08 16:33
    Originally posted by sonhouse
    I don't have a link, but there was a recent scientific american article about this subject. The gist is dust in a giant spinning cloud around a newly formed star will have areas of greater density just from the normal mixing that would occur with ultra-large volumes of such material, as it condensed from an even larger cloud and formed the star in the first ...[text shortened]... loped technology to figure out what the orbits of planets are around relatively nearby stars.
    zz