For some context, there is a very intriguing formulation of General Relativity in terms of entropy. [1] What this suggests is, that gravity emerges from a under

For some context, there is a very intriguing formulation of General Relativity in terms of entropy. [1] What this suggests is, that gravity emerges from a underlying thermodynamical system. In OP the authors construct explicitly one of these systems. Unfortunately together with the success of perturbative quantum gravity [2], this suggests that quantum gravity is just not experimentally accessible. (That's a thought by Freeman Dyson originally.) The formal argument would be, that a lot of different theories lead to the same thermodynamical limit, so that one can not determine the true underlying theory. Or put it in more hacker news terms, the problem is analogous to trying to learn about TCP/IP by looking at the output of black hole simulations, there is the layer of numerical mathematics in between, which is at least very hard to breach. [1] Older guestpost by Grant Remmen on Carroll's blog: http://www.preposterousuniverse.com/blog/2016/02/08/guest-post-grant-remmen-on-entropic-gravity/ http://www.preposterousuniverse.com/blog/2016/02/08/guest-po... [2] For this discussion, it is basically cheating. You quantize gravitational waves on a classical background geometry. The approach works very well because gravity is weak, it also tells us nothing interesting, because one breaks the relationship between gravity and space time (the central feature of General Relativity) by hand.