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In my perception of the universe, there's the theater which is the 'spacetime' and the actors meaning the 'particles'. If i got it right, GR claims that the 'actors' effect the 'theatre' by 'bending' it. Also in order to combine GR and QM, some beleive in the existence of the 'graviton'. Does this mean that the 'theater' is no longer needed since gravity is not a property of spacetime anymore? Does the hypothetical existaence of the graviton cancels out the spacetime and it's 'curvature'?

If gravity is 'transfered' trough 'gravitons' and its not a property of spacetime and its curvature, how can we explain its impact to EM transmision ? How does a particle (graviton) can influence the path of motion of another particle (photon) in space?


marked as duplicate by Qmechanic Sep 8 '18 at 17:52

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The theater is still needed in either case simply because we observe and measure the theater. The difference is whether or not the theater is built by the actors.

In GR the theater arises dynamically from the distribution of the actors’ stress energy tensors. In QM the theater is a static background that is added separately.

At this point we don’t have a solid quantum gravity theory, so how that works is still unfinished. Gravitons would naively be starting with a pre-existing theater and then the actors doing a small remodel dynamically.

Of course, this is a fuzzy metaphor and hides a lot of important complications, especially regarding the dynamic nature of the theater in GR.