While in Newtonian gravitation the presence of gravitation is measured by the gravitational pull between two lumps of atoms, composing what we call ordinary matter, in Einstein’s General Relativity, the presence of gravitation is associated with the curvature of the space-time, regardless of the nature of the gravitational source. However, the recent observations from infrared and ultraviolet astronomy show that the contribution of ordinary matter to the universe accounts for only a small fraction.