General relativity taught us that space is something dynamic, like the electromagnetic field: an immense, mobile mollusk in which we are immersed, which stretches and bends. Quantum mechanics teaches us that every field of this sort is “made of quanta,” has a fine, granular structure. It follows that physical space, being a field, is “made of quanta” as well. The same granular structure characterizing the other quantum fields also characterizes the quantum gravitational field, and therefore space.
