If you create a theoretical closed system consisting of an electron and a positron, I assume that both the particles have mass. If they have mass, then each must have a corresponding gravitational component. If the positron, on the other hand has an “anti-gravity” component, then the net gravity of the system would be zero, because there would be no attraction between the particles. However, if the net gravity of the system is >0 and you induce a low-energy collision of the electron and positron, annihilating the mass of the particles and creating gamma ray photons, what happens to the gravity in the system? If you extrapolate this experiment to use an object the size of Earth and made of matter and an object the size of Earth made of anti-matter and they have no gravitational attraction, then what of the gravitational space-distortion that this “positive Earth” object would normally exhibit in an open system?