Earth Zoom To The Milky Way Galaxy.
Timeline: the end of the universe. Early universe: Big Bang to 300 million years • The universe begins with a cataclysm that creates space and time, as well as all the matter and energy it will ever hold. • As the universe expands and cools, it becomes less dense, and the basic forces of nature become distinct: first gravity, then the strong force, which holds the nuclei of atoms together, followed by the weak and electromagnetic forces. • Fundamental particles and energy arise: quarks, electrons, photons, neutrinos and so on.
These smash together to form protons and neutrons. Eventually, neutral atoms are formed as electrons link up with hydrogen and helium nuclei.