About 13.8 billion years ago the universe was born, with space
and time coming into being in the same instant. By the time the
universe was 1 second old, the four forces in nature had acquired
their present characteristics, elementary particles had obtained
their mass, and particles constituting the nuclei of atoms were
created. The nuclei of light elements, hydrogen and helium, were
formed within the first 10 minutes of the birth of the... more...