CMB polarization, first detected in 2002, offers a unique window into the earliest moments of the universe. By analyzing the patterns of polarized light from the cosmic microwave background, cosmologists can test theories of inflation, probe the physics of the primordial plasma, and trace the evolution of cosmic structure.
Explore the evolution of the universe from the Planck epoch to the present day. This guide covers cosmic inflation, the cosmic microwave background, the first atoms, the dark ages, reionization, and the formation of stars and galaxies within the standard Lambda-CDM model.
Recombination is the epoch when the universe cooled enough for electrons and protons to form neutral hydrogen, releasing the cosmic microwave background. This article explores the timeline of the cosmos from the Planck epoch to structure formation, the role of recombination, and the evidence from missions like COBE, WMAP, and Planck.
The Copernican principle states that Earth is not a privileged observer, while the cosmological principle extends this to say the universe is homogeneous and isotropic on large scales. Together they underpin modern cosmology, from the Big Bang to the cosmic microwave background.
The horizon problem asks why distant regions of the universe have nearly identical temperatures despite never being in causal contact. Cosmic inflation solves it by stretching a tiny, causally connected patch to cosmic scales, explaining the uniformity of the cosmic microwave background and the origin of structure.
The Hubble constant (H₀) quantifies the expansion rate of the universe. Astronomers measure it using two independent approaches: the local distance ladder (Cepheid variables and Type Ia supernovae) and early-universe probes (cosmic microwave background and baryon acoustic oscillations). The discrepancy between these values, known as the Hubble tension, is one of the most pressing problems in modern cosmology.
The damping tail is the high-multipole region of the cosmic microwave background power spectrum where temperature fluctuations are exponentially suppressed by photon diffusion and Silk damping. It provides a precise probe of the baryon density, the epoch of recombination, and the physics of the early universe, and has been measured by COBE, WMAP, and Planck.
The cosmic microwave background (CMB) is the oldest light in the universe, a relic of the Big Bang. Its near-perfect blackbody spectrum and tiny temperature fluctuations provide powerful evidence for cosmic inflation, the theory that the universe expanded exponentially in the first fraction of a second. This article explains how CMB observations confirm inflation and traces the cosmic epochs from the Planck era to structure formation.
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.
Baryogenesis is the hypothesized process that created the observed imbalance between matter and antimatter in the early universe. This article explains the cosmic timeline, the Sakharov conditions, and how this asymmetry led to the universe we see today.
