The interactive reference to the beginning and evolution of the universe, focusing on the earliest epochs from the Big Bang to the formation of the first stars and galaxies.
About three minutes after the Big Bang, the universe cooled to roughly a billion degrees, allowing protons and neutrons to fuse into light nuclei. This process, known as Big Bang nucleosynthesis, fixed the primordial hydrogen-to-helium ratio that still dominates the cosmos today.
Explore the question of whether time began with the Big Bang, and journey through the major cosmic epochs—from the Planck epoch to the formation of stars and galaxies—guided by the standard Lambda-CDM model of cosmology.
From the Planck epoch’s unimaginable heat to the cool darkness of the cosmic microwave background, the early universe underwent a dramatic cooling as it expanded. This guide traces the temperature milestones that shaped matter, light, and structure.
The first galaxies formed a few hundred million years after the Big Bang, ending the cosmic dark ages. Learn about the epochs of the early universe, the role of dark matter, the first stars, and how telescopes like JWST are rewriting our understanding of cosmic dawn.
