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Force messenger particles -graviton

  1. Mar 22, 2010 #1
    hi all this is my first post i am not a physicist but i do have a basic understanding, at least more than the average person on the street i guess.
    my main problem is a lack of mathmatical understanding which holds me back but does not stop me enjoying physics.

    i have a question i would like to get some feedback on so here goes

    i recently watched a lecture that stated there are several particles that act like force messenger particles one of which is the graviton

    so if gravitons are moving between the earth and the moon they are in effect saying to each other "be atracted to each other" which has me scratching me head i was under the impression that gravitational atraction was due to the geomitry of curved space time ie the sun warps space time trapping the earth in a gravity well

    so why the need for a graviton ?
  2. jcsd
  3. Mar 22, 2010 #2


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    Welcome to PF!

    Hi rmshepherd ! Welcome to PF! :smile:
    "curved space time" is general relativity.

    "messenger particles" (or mediating bosons) are quantum field theory.

    As you've probably read elsewhere, general relativity and quantum theory are two different mathematical approaches which nobody has yet managed to reconcile with each other (ie, to "unify").

    (usually we say that quantum theory applies for very small distances, and general relativity and the rest of physics applies for larger distances)

    So we don't need gravitons to explain gravity …

    unless we want to unify quantum theory with the rest of physics. :wink:

    (as to whether gravitons actually move between the Earth and the Moon, see https://www.physicsforums.com/showthread.php?t=386721")
    Last edited by a moderator: Apr 24, 2017
  4. Mar 22, 2010 #3
    ok i see so in quantum physics relative effects play no part in the mathmatical model ?

    i have read about the compatibilty problems with quantum physics and gravity as a layman
    it seems to me though that if general relativity is an acurate model this would dismiss the graviton even if the math cannot be reconciled.

    in the quantum model are there any ideas as to the workings of the graviton or any indications that that particle would be important in terms of gravity if it was found to exist (im assuming it hasnt been found yet dangerous i know)

    i dont expect hard answers i just enjoy the debate
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