Connections between the four known types of interactions are being sought in order to unify them and to describe all the interactions using only a single one of them or using a completely new type of interaction. This paper presents a possible simple solution to the problem for the gravitational force and the electromagnetic force only. A simple interpretation of this solution assumes that our Universe is moving at the speed of light. This requires a model of the entire Universe, which would have to be infinitely large and therefore would have to contain an infinite number of universes like ours. This can also be used to build a new model of two kinds of forces, by combining gravity with motion at the speed of light and transforming it into an electromagnetic force, as if these two kinds of interactions depended only on an observer in a certain reference system. This is the second work of three that belong to my physics trilogy. I assume that the mathematical formulas used here are understandable to most people interested in physics, while the other two works, on new formulas for solar energy production and gravitational force, require a little more knowledge of mathematics and physics.