Isaac Asimov's talent as a science communicator shines particularly brightly in this work, in which he not only explains the full range of scientific uncertainties about the Universe in an accessible way, but also reconstructs the long road humanity has traveled to reach them. The various theories about the age of the Earth and the solar system are framed within the broader context of galaxy evolution and ultimately lead to the great, still unresolved dilemma: how did the Universe begin, and will it have an end, or is it, on the contrary, eternal and infinite?