Isaac Asimov’s facility as a scientific communicator is manifest in this work, in which he not only easily expresses scientific certainties about the Universe, but also reconstructs the long road that human beings have traveled to achieve them. The various theories about the age of the Earth and the Solar System are referenced in the more general framework of galactic evolution and then – finally – the great dilemma not yet resolved: How did the Universe begin? Will it end or is it eternal and infinite? With black and white photographs.