A collection of the key observational evidence that supports the Big Bang model of the universe’s origin and evolution.
The cosmic web is the largest known pattern in the universe—a vast network of filaments, sheets, and voids made of dark matter, gas, and galaxies. This article traces its origin from the Big Bang through cosmic inflation, recombination, and structure formation, and explains how missions like Planck and JWST have mapped its evolution.
Cosmic voids are vast, nearly empty regions between galaxy filaments that hold clues to the universe’s structure and evolution. This guide explains how they form, their role in the cosmic web, and how they connect to the major epochs from the Big Bang to the present day.
Big Bang Nucleosynthesis (BBN) is the process that forged the lightest atomic nuclei—deuterium, helium-3, helium-4, and lithium-7—during the first three minutes of cosmic history. This article explains the physics, the timeline, the observational evidence, and why BBN remains a cornerstone of the standard Big Bang model.
The last scattering surface is the sphere of light emitted about 380,000 years after the Big Bang, when the universe cooled enough for electrons and protons to form neutral hydrogen. This cosmic relic, observed as the cosmic microwave background, provides a snapshot of the infant universe and anchors our understanding of cosmic evolution from the Planck epoch to the present day.
Large-scale structure—the cosmic web of galaxies and dark matter—offers one of the most powerful tests of the standard cosmological model. From the imprint of primordial fluctuations to the growth of clusters and voids, its patterns confirm the Lambda-CDM framework and reveal the history of the universe from the Planck epoch to today.
Baryon acoustic oscillations (BAO) are subtle ripples in the distribution of matter across the cosmos, frozen in when the universe was only 380,000 years old. They serve as a standard ruler for measuring cosmic distances and probing the nature of dark energy.
Galaxy redshift is the foundational observation that revealed the universe is expanding. This article traces how stretched light from distant galaxies became the cornerstone of modern cosmology, from Edwin Hubble’s discovery to the detailed cosmic timeline of the Lambda-CDM model.
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.
Cosmological redshift is the stretching of light to longer wavelengths as the universe expands. This phenomenon underpins our understanding of cosmic history, from the Big Bang to the formation of galaxies, and is a cornerstone of modern cosmology.
Big Bang nucleosynthesis (BBN) is the production of light elements during the first minutes of cosmic time. Its evidence comes from the remarkable agreement between predicted and observed primordial abundances, which also constrains the baryon density and supports the standard hot Big Bang model.
