In this equation, H is the Hubble parameter (expansion rate), ρ is the average density of matter and energy in the Universe, S is the scale factor, and k is a number that describes the overall curvatu...In this equation, H is the Hubble parameter (expansion rate), ρ is the average density of matter and energy in the Universe, S is the scale factor, and k is a number that describes the overall curvature of the Universe. The age of the Universe will be the amount of time that passes between the beginning of the Universe and the point at which the scale factor again becomes zero (blue line intersects the x-axis).
