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Einstein and the graviton

  1. Apr 18, 2014 #1
    We know that there are force carrying particles for the strong and weak nuclear force, and the electromagnetism force. But in Einsteins theory of relativity, he states that gravity is the bending of space time, not a force. So if there is no force, why do we say there must be a graviton?
    Ps I'm just an undergrad student that has a interest in particle physics. I just don't understand most of it!!
  2. jcsd
  3. Apr 18, 2014 #2
    This is an open question in physics that many people are working on. The "classical" or general relativistic theory of gravity and the way we look at things from a quantum perspective (like in particle physics) do not mesh as they are now.
  4. Apr 18, 2014 #3


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    There doesn't have to be a graviton. It's just that current quantum theories use the concept of "force mediators" in the form of bosons to explain how different particles interact with each other. However, General Relativity is not a quantum theory. We have yet to develop a quantum theory of gravity nor have we observed gravitons, so we cannot claim that gravitons exist.
  5. Apr 18, 2014 #4


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  6. Apr 19, 2014 #5
    Even though gravity isn't a real force, GR predicts the existence of gravitational waves and according to QM all waves without exception must be quantized hence the need for the graviton. While the above argument isn't really a "proof", it is definitely a strong argument making the existence of gravitons highly likely.
  7. Jan 26, 2015 #6
    This is the first EVER answer to this question, in over a decade of asking and searching, that I can accept as actually addressing the issue. Brilliant. Lots of like!!

    So is this why quantum physicists postulate a heavy particle rather than an essentially weightless one, as the infinitely long range of gravity would seem to require?
  8. Jan 26, 2015 #7

    Vanadium 50

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