If a GUT is proven, and the four forces are unified, it will still be correct to say that the orbit of the moon is determined by the gravitational force. Explain why.

A Grand Unified Theory is a particle physics model in which, at high energies, the electromagnetic, weak, and strong forces of the Standard Model are merged into a single force.

The confirmation of GUT implies that at sufficiently high energies, the four forces - strong, weak, electromagnetic, and gravitational - are unified. The forces would still be clearly distinct at lower energies, which are the relevant energy levels when determining the orbit of the moon in our standard space. However, at high energies, this new theoretical framework would imply new particles and provide a fresh look at the standard model.

GUT is an abbreviation for "Grand Unified Theory," which is a theory in which three forces, electromagnetic, weak, and strong, are unified at sufficiently high energies. The "Theory of Everything," or TEO for short, is a theory in which gravity is also unified. The question refers to GUT confirmation, but it talks about the unification of four forces, which contradicts the definition of GUT and falls more into the TEO realm.

If the question were GUT consistent, that is, if it only referred to unifying three forces (excluding gravity), the answer would be much simpler because gravity would not be subjected to the unification, allowing us to use the term "gravitational force" without hesitation.