The last decade in theoretical physics has simply settled this question – whether someone likes it or not – and the answer is “No”. The spacetime geometry cannot be fundamental at the Planck scale. It is subject to transitions, dualities, and holography, among other phenomena that prove that it must be flexible and it cannot arise from a graph because a graph is too local. In neither of the existing descriptions we can find a discrete spacetime and it seems rather unlikely that there exists a description where it is discrete.

— Quantum Graphity

— Lubos Motl

2012.02.01 Wednesday ACHK