How to Build a Theory of Quantum Gravity?

We have done a lot of really cool experiments about space. For i are like seeing gravitational waves, incredible. It tells us that space really is sort of fungible and dynamic. And measuring the expansion of the universe, that's also kind of an experiment that tells us what's going on with space. So sometimes experiments can inform us. I think in this case, we really need theory to tell us,. Like how we can do experiments to answer this question. The only experiments i can think of are ones that are at the centre of a black hole or require super colliders the size of a solar system - not things we can get done to morrow.