Much like white light, spacetime is also composed of a certain rainbow

When white light is passed through a prism, the rainbow on the other side reveals a rich palette of colors. Theorists from the Faculty of Physics, University of Warsaw have shown that in models of the Universe using any of the quantum theories of gravity there must also be a ‘rainbow’ of sorts, composed of different versions of spacetime. The mechanism predicts that instead of a single, common spacetime, particles of different energies essentially sense slightly modified versions thereof.

We have probably all seen the experiment: when white light passes through a prism it splits to form a rainbow. This is because white light is in fact a mixture of photons of different energies, and the greater the energy of the photon, the more it is deflected by the prism. Thus, we might say that the rainbow arises because photons of different energies sense the same prism as having slightly different properties. For years now it has been suspected that particles of different energies in quantum universe models essentially sense spacetimes with slightly different structures.

Arxiv – Rainbow metric from quantum gravity