General relativityist propagandists, also called gravityists and Einsteinists, like to say that IG is pseudo sceintific nonsense inspired by religious scripture and has no scientific basis. This is unfortunate but not surprising since any old fool can understand how spacetime is treated as a 4-dimensional Lorentzian manifold which is curved by the presence of mass, energy and momentum (or stress-energy) within it; it takes a real genius to understand what is written in the Gospel of the Flying Spaghetti Monster.