Why two mass attracts each other?

Discussion in 'Physics & Math' started by hansda, Mar 19, 2013.

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  1. Tach Banned Banned

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    I meant exactly what I meant.
     
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  3. hansda Valued Senior Member

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    "So, through Newtonian method also perihelion precession can be calculated. Except planet Mercury, for all other planets his calculations are almost correct."

    You agree with this?
     
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  5. Tach Banned Banned

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    ....but the result comes out incorrect, different from measurement


    Incorrect, all perihelion advances calculated in Newtonian mechanics are incorrect. I understand that you are a staunch relativity denier but you need to learn how to face reality.
     
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  7. hansda Valued Senior Member

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    May be Newtonian calculations are not very correct, because he did not consider the frame-dragging effect.
     
  8. Tach Banned Banned

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    Nothing to do with frame-dragging.
     
  9. hansda Valued Senior Member

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    Frame-dragging is part of GR only.
     
  10. Tach Banned Banned

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    ...but frame dragging has nothing to do with the discrepancy between Newtonian prediction and GR prediction for the advancement of the perihelion.
     
  11. hansda Valued Senior Member

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    Do you mean the Sun does not cause any "frame-dragging" effect?
     
  12. Tach Banned Banned

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    Did you understand the sentence:

    ...but frame dragging has nothing to do with the discrepancy between Newtonian prediction and GR prediction for the advancement of the perihelion?
     
  13. hansda Valued Senior Member

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    So, this discrepancy is due to what?
     
  14. Tach Banned Banned

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    post 766
     
  15. hansda Valued Senior Member

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    Reference?
     
  16. Tach Banned Banned

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    Rindler, pages 242-243. It is time you stopped playing games.
     
  17. hansda Valued Senior Member

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    Can you give a online link for this reference.
     
  18. Tach Banned Banned

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    No, you need to spend the money and buy the book. Or take a class.
     
  19. hansda Valued Senior Member

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    Do you know, why perihelion precession happens? Due to attractive force or repulsive force(consider the Sun at the centre of the orbit)?
     
  20. Tach Banned Banned

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    there is no such thing as repulsive force, you have been told this repeatedly, you need to stop trolling.
     
  21. eram Sciengineer Valued Senior Member

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    He's not trolling, he's just really, really thick.

    Please Register or Log in to view the hidden image!

     
  22. Q-reeus Valued Senior Member

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    Markus - you have been logging in several times each day since my #770 query, so what exactly is the problem in not extending the minimal courtesy of responding? Till now expected better of you than to (non)react with an evident snub. Whatever - have become used to that kind of thing here.

    Continuing in monologue mode, I find it confusing and strange that a schizophrenic response to 'gravity does/doesn't gravitate' abounds amongst GR trained folks near a century after GR was finalized as a theory, and that after a 10-year gestation period. As a Google search reveals. So what is the truth? Best I can tell, the 'pro gravitates' camp simply appeals directly to the non-linearity of the EFE's. Now it's well known that in EM a non-linear medium (say dielectric) will give rise to a bulk charge density whenever a field is imposed - hence a source density arises. But evidently it's more subtle in GR, and this piece seems to convincingly argue 'nay gravitates' is right:
    http://www.physicsforums.com/blog.php?bt=6136
    (note the 'yes' position there is related to speculative quantum gravity corrections approaching Planck energy levels - thus wholly irrelevant to classical GR discussion)

    My own admittedly lay thoughts are that it seems 'gravity does NOT gravitate' was actually built in to GR from the outset via the Ricci flat postulate, as discussed in preamble leading up to equation (1) here:
    http://mathpages.com/rr/s5-08/5-08.htm

    That sure looks to me like about as clear as it gets in saying that a gravitational field is not it's own source in GR - as a foundational principle. Yet amazingly the same author goes on later to declare " it implies gravitational energy gravitates just as does every other form of energy." in referring to the ET (LHS of EFE's). Where 'hand-wavy' enters and leaves in all this is maybe anyone's guess. I realize this can slide into 'pseudo-tensor' territory, but any takers?
     
  23. eram Sciengineer Valued Senior Member

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    Nice hearty chunks of text. Hard to digest though.
     
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