Slide: Extracts from Alan Guth's The Inflationary Universe: The Quest for a New Theory of Cosmic Origins.
The Cosmological Timeline
One of the basic predictions of that standard model of cosmology is that the universe is expanding permanently after the initial explosion. The primordial universe was much hotter and denser than the universe is today. Due to the high temperature, matter could not clump together to form structures in form of atoms or atomic nuclei.