[austintorn@aol.com]

Many quantum gravity scientists think that space emerges as an approximation of something discrete, the apparently smooth continuum of space being an illusion, like a movie or the smoothness of water, and that causality is fundamental, especially below the level of space’s emergence.

The three keys are emergence of space from the quantum world, and discreteness and fundamental causality within the quantum world.

Sally, maybe we are already in such a Universe, but it's hard to demonstrate it at the moment.