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.
Recombination marks the moment about 378,000 years after the Big Bang when free electrons and protons combined to form neutral hydrogen, allowing photons to travel freely and making the universe transparent. This epoch gave birth to the cosmic microwave background and set the stage for the formation of stars and galaxies.
A comprehensive guide to the cosmic dark ages, the period when the universe was shrouded in neutral hydrogen, and how the first stars and galaxies emerged to end the darkness. This article covers the full cosmic timeline, key missions, and the evidence that shapes our understanding of this pivotal era.
Population III stars are the hypothetical first generation of stars, formed from primordial hydrogen and helium. They were likely massive, hot, and short-lived, and their radiation reionized the early universe. This article explores their formation, properties, and cosmic significance.
The photon epoch was a period in the early universe, from about 10 seconds to 380,000 years after the Big Bang, when photons dominated the energy density. During this time, atomic nuclei formed via nucleosynthesis, and the universe remained a hot, dense plasma until recombination produced the cosmic microwave background.
The Grand Unification Epoch was a fleeting period in the early universe, from about 10⁻⁴³ to 10⁻³⁵ seconds after the Big Bang, when three of the four fundamental forces were unified. This article explores that epoch, its place in cosmic history, and the full timeline from Planck time to the present day.
Before recombination, the universe was an opaque plasma of free electrons and photons. When electrons and protons combined to form neutral hydrogen, light finally decoupled, creating the cosmic microwave background. This article explains the physics behind this cosmic milestone and why no telescope can see earlier with light.
Explore the Big Bang model, from the Planck epoch to the formation of stars and galaxies. Learn about cosmic inflation, the cosmic microwave background, and the evidence supporting our modern understanding of the universe’s origin.
The hadron epoch was a critical phase in the early universe when quarks first bound into protons and neutrons. This article explains its place in cosmic history, its key processes, and why it matters for understanding the matter we see today.
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.
