Forks in the road, on the way to quantum gravity

  title={Forks in the road, on the way to quantum gravity},
  author={Rafael D. Sorkin},
  journal={International Journal of Theoretical Physics},
  • R. Sorkin
  • Published 1 June 1997
  • Physics
  • International Journal of Theoretical Physics
In seeking to arrive at a theory of “quantum gravity,” one faces several choices among alternative approaches. I list some of these “forks in the road” and offer reasons for taking one alternative over the other. In particular, I advocate the following: the sum-over-histories framework for quantum dynamics over the “observable and state-vector” framework; relative probabilities over absolute ones; spacetime over space as the gravitational “substance” (4 over 3+1); a Lorentzian metric over a… 

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