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Does any field, other than gravity, bend space-time?

  1. Jul 25, 2012 #1
    In particle physics, quantum field theories such as the Standard Model describe nature in terms of fields. Each field has a complementary description as the set of particles of a particular type.

    Does any field, other than gravity, bend (or have any noticeable interaction with) space-time?
     
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  3. Jul 25, 2012 #2

    mfb

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    If you want to describe gravity with general relativity, gravity is not a field - it is the structure of spacetime itself. All energy bends spacetime, so all fields can do this.
    If you want to describe gravity with quantum field theory (neglecting the theoretical issues here), it acts like a field, not like bent spacetime.
     
  4. Jul 25, 2012 #3
    good answer and interesting info. thanks mfb
     
  5. Jul 25, 2012 #4
    Anything in the Stress Energy Tensor interacts with spacetime.....including momentum.
    And I presume dark energy since it has a negative pressure and pressure is also a component of the SET.

    Do any of the Higgs fields interact??
     
  6. Jul 25, 2012 #5

    Bill_K

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    Lacking a theory, it is hard to say how strong quantum gravity acts. It may do something much worse to spacetime than just bend it!
     
  7. Jul 25, 2012 #6
    Bill's post brings to mind a fundamental conflict between GR and QM: I believe no one has yet figured out how to resolve that on one hand GR requires a dynamic spacetime while QM relies on a fixed, non dynamic spacetime structure. One simple way to picture this conflict is that, as you know, elements of the stress energy tensor in GR is the source of spacetime curvature; in QM, the fixed geometric spacetime background, as say in string theory, imparts the vibrational characteristics of particles. Change the spacetime background in string theory and you change the vibrational modes and that means particle characteristics change.

    That's a major reason we can't fit GR/gravity into the Standard Model of particle physics.
     
    Last edited: Jul 25, 2012
  8. Jul 25, 2012 #7
    Good posts Bill K and Naty1.

    Interesting......GR Vs QM.....another example of the long standing differing perspectives.......in attempting to describe the same reality

    someday we will be able to clearly see both perspectives and reconcile them like we now do between Classical/Newtonian Physics and GR.

    Is the particle/gravity changing time-space or is space-time changing the particle?
    or are they both changing each other?


    _________________________________________________________________
    QM says to GR --- "listen its just a bend (in space-time), not the end"......:approve:
     
    Last edited: Jul 25, 2012
  9. Jul 25, 2012 #8
    Hmmm, isn't the metric in GR a tensor field? You take derivatives of it to get the connection and curvature tensors. Aren't they tensor fields as well?
     
  10. Jul 25, 2012 #9
    maybe the same, maybe not...I keep an open mind

    I think about it as being analogously related to distance versus close up view:
    At a mile distant, a house looks tiny; up close, not so much.

    Which 'view' is accurate...which is 'reality' ?

    Then add that the distant view is delayed more than the close view due to the finite speed of light...Then add spacetime curvature and that distant view provides only an apparent position [like gravitational lensing]. Then assume a velocity...then an acceleration....everything begins to change even more....as in length contraction,time dilation, and Unruh type temperature and particle differences....
     
  11. Jul 26, 2012 #10
    ya Naty1 or analogously to two observers in separate frames of references with different accelerations/velocities and their view of ordering of events

    however, fortunately, in GR we are able to reconcile (the differences in viewpoints between) these frames of references accurately, and completely, via the logic/calculations

    but we are not able to fully understand/reconcile fields between GR/QM perspectives, yet
     
    Last edited: Jul 26, 2012
  12. Jul 26, 2012 #11

    tom.stoer

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    Yes, it is true that we have no fully developed and established theory of quantum gravity. But I don't agree that there is still a fundamental conflict which we can't resolve. We have a couple of candidate theories which provide strong hints how this "fundamental conflict" can be resolved and that it already has been done - at least partially. QG theories addressing background independence (I am aware of) are loop quantum gravity, asymptotic safety and some formulations of string theory (especially ideas from gauge/gravity duality). I bet there are more ...
     
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