Are space, time, and gravity all just illusions?

The Universe, as we know it, has a fundamental flaw staring us right in our faces, letting us know that our knowledge is incomplete. The four fundamental forces are described by two different and mutually incompatible frameworks: General Relativity for gravitation, and Quantum Field Theory for the electromagnetic and nuclear forces. Einstein’s theory on its own is just fine, describing how matter-and-energy relate to the curvature of space-and-time. Quantum field theories on their own are fine as well, describing how particles interact and experience forces. But where gravitational fields are strongest, and on the smallest of scales, we have no way of describing nature. The physics of our greatest theories breaks down.