The light that permeated the universe at this time cools with the universe. Today we call this light the Cosmic Background Radiation. The cosmic background radiation today is 3 Kelvin. The first stars form. Structure forms in the universe.
Supernova occur which create elements heavier than Helium.
4.5 billion years ago The Earth and all the planets form around the Sun as the Sun forms from a collapsing gas cloud. 1 billion years ago The Ozone layer forms a protective barrier against UV light. Life appears on the surface of the Earth. 350 - 300 million years ago PA swamps exist which will become the vast coal deposits we mine today. The age ends abruptly 65 million years ago when an asteroid impacts the Earth causing the extinction of the dinosaurs.