The Big Bang: The Cosmological Event
13.82 Billion years ago · Prehistoric
Approximately 13.8 billion years ago, the observable universe began expanding from an extremely hot, dense state in what cosmologists term the Big Bang. Evidence supporting this model includes the observed expansion of galaxies documented by Edwin Hubble in 1929, the cosmic microwave background radiation detected by Penzias and Wilson in 1965, and the measured abundance of light elements matching nucleosynthesis predictions. NASA's WMAP and ESA's Planck satellites refined the universe's age estimate. The event marks the origin of space, time, matter, and energy as currently understood.
Key Figures
Alexander FriedmannEdwin HubbleGeorges Lemaître
Locations
Universe
Topics
cosmologysciencespace
Connected Events — 4 Connections
The Big Bang produced the primordial hydrogen gas that gravitationally collapsed to form the first stars hundreds of millions of years later First Star formed
The Big Bang initiated the rapid expansion described by cosmic inflation within the first fraction of a second Cosmic Inflation
The Big Bang produced the conditions for nucleosynthesis of hydrogen, helium, and lithium in the first minutes Big Bang Nucleosynthesis
The habitable temperature window occurred 10 million years after the Big Bang, a direct consequence of the universe's ongoing adiabatic expansion and cooling Cosmic Background Temperature Enters the Liquid Water Range
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