The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. [1] Various cosmological models based on the Big Bang concept explain a broad range of phenomena, [2] [3] [4] including the abundance of light elements, the cosmic microwave background (CMB) radiation, and large ...

Jan 29, 2025 · The Big Bang Theory explains how the universe began with an infinitely hot and dense single point that inflated to form the ever-expanding cosmos we see today.

Feb 2, 2022 · The history of the universe and how it evolved is broadly accepted as the Big Bang model, which states that the universe began as an incredibly hot, dense point roughly 13.7 billion years...

Feb 28, 2024 · New ideas and major discoveries made during the 20th century transformed cosmology – the term for the way we conceptualize and study the universe – although much remains unknown. The universe's first stars were 30 to 300 times more massive than our Sun and millions of times brighter.

Mar 6, 2025 · The big bang is how astronomers explain the way the universe began. It is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now—and it is still stretching!

Feb 11, 2025 · Big-bang model, widely held theory of the evolution of the universe. Its essential feature is the emergence of the universe from a state of extremely high temperature and density—the so-called big bang that occurred 13.8 billion years ago.

Mar 15, 2022 · During the first three minutes of the universe, the light elements were born during a process known as Big Bang nucleosynthesis. Temperatures cooled from 100 nonillion (10 32) Kelvin to 1 billion...

About 13.8 billion years ago, the Big Bang gave rise to everything, everywhere, and everywhen—the entire known Universe. What caused the Big Bang? What happened that first moment at the beginning of the Big Bang? When did the first stars form?

Most physicists believe the universe was born in a big bang 13.8 billion years ago. In it, the energy making up everything in the cosmos we see today was squeezed inside an inconceivably small space – far tinier than a grain of sand, or even an atom.

Aug 12, 2014 · If the Big Bang theory is true, how did it lead to all the planets, stars and galaxies we can see today?