In this paper, it is proposed that the size of the classical
electron, which is a stable elemental particle with the smallest concentration
of matter in Nature, can be used to
explain the very big size of the Universe.
In order to reach that objective, the apparent size of heavenly bodies as
seemed each other at very big distances in space, is used as a fundamental concept. Also, it is proved that the size, shape, mass, and
future of the Universe are ruled by
the speed of light, and the range of gravitational interactions.