The present study describes the metric expansion of space based on a novel understanding of gravity and its electromagnetic processes. A singularity in the universe emits electromagnetic energy, which is absorbed by atoms and re-emitted to other atoms. This results in mutual force of attraction, i.e. gravity. We assume that the distance R towards the singularity is constant and r is the distance between two bodies. Then the gravitational force decreases with the decrease of the re-emitted energy, i.e. as 1/r 2 , and in line with Newtonian gravity and General Relativity. However, the universe orbits the singularity and hence R varies. R increases when a certain part of space travels from the singularity, and whereby the energy re-emitted by atoms decreases as 1/r 2 R 2. Consequently, the gravitational force between bodies decreases as 1/r 2 R 2 , resulting in increasing distance between bodies, i.e. metric expansion of space. A theoretical model is presented. The theoretical model describes the mechanisms which results in gravity and expanding space. The study also displays how the electromagnetic characteristics of the singularity and gravity waves and the mechanism creating gravity are measured.