Approximately 380,000 years after the Big Bang, the universe cooled enough for electrons and protons to combine into neutral hydrogen, releasing the cosmic microwave background. This pivotal moment, called recombination, marked the universe’s transition from an opaque plasma to a transparent state, setting the stage for the first stars and galaxies.
The Lambda-Cold Dark Matter (ΛCDM) model is the standard model of Big Bang cosmology, describing the universe’s origin, evolution, and composition. This guide explains its key components, the cosmic epochs from the Planck epoch to structure formation, and the evidence supporting it.
Explore the compelling evidence for the Big Bang theory, from the expanding universe and cosmic microwave background to the formation of the first elements. Learn how astronomers have pieced together the story of our cosmos.
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.
Redshift is the stretching of light from distant galaxies, revealing the expansion of the universe and the history of cosmic evolution from the Big Bang to the present day. This interactive guide explores the epochs, evidence, and missions that define our understanding of the cosmos.
The Planck space telescope mapped the cosmic microwave background with unprecedented precision, revealing the universe’s age, composition, and evolution. Its observations refined the standard cosmological model, measured key parameters like the Hubble constant, and provided a detailed picture of the early universe from the Planck epoch to the present day.
The Big Bang timeline traces the universe from the Planck epoch through inflation, the first atoms, the cosmic microwave background, the dark ages, reionization, and the formation of galaxies. This guide explains the key epochs, the evidence from missions like COBE, WMAP, Planck, and JWST, and how the Lambda-CDM model ties the story together.
The cosmic microwave background is uniform to one part in 100,000, a puzzle solved by cosmic inflation. This article explains the CMB’s origin, the epochs of the early universe, and how missions like COBE, WMAP, and Planck have measured it.
SPHEREx is a NASA near-infrared space observatory that will map the entire sky in 102 colors, gathering spectra of over 450 million galaxies to probe cosmic inflation, the history of galaxy formation, and the abundance of water and organic ices in planet-forming regions.
The cosmological principle is the foundational assumption that the universe is homogeneous and isotropic on large scales, meaning it looks the same from every location and in every direction. This principle underpins the standard Big Bang model and allows us to study the entire cosmos from a single vantage point.
