Wolfram speculated on this idea: if spacetime is a graph, it may approximate the 3+1 topology on average, but in some places two distant nodes can be connected

Wolfram speculated on this idea: if spacetime is a graph, it may approximate the 3+1 topology on average, but in some places two distant nodes can be connected by a direct link. I'd speculate further that such isolated links may be enough to entangle low-level quantum properties of two particles, but not enough to be a tunnel even for a single photon.