The prevailing cosmological model explaining the origin of the universe from an initial state of extremely high density and temperature approximately 13.8 billion years ago. Evidence includes cosmic microwave background radiation, light element abundance, and the observed expansion of the universe.
Electromagnetic radiation left over from the early universe, about 380,000 years after the Big Bang. It is the oldest li...
A hypothetical form of energy that permeates all of space and drives the accelerating expansion of the universe. It cons...
A value describing the rate of the universe's expansion, named after Edwin Hubble. Its precise value remains debated, wi...
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