Hot Big Bang and the cosmic microwave background
Expansion and relic radiation support an earlier hot, dense Universe.
Key knowledge
The hot Big Bang model describes the observable Universe evolving from an earlier hot, dense state as space expands and cools. The cosmic microwave background is relic radiation released when matter became sufficiently neutral for light to travel freely; its spectrum and small variations constrain cosmological models.
Conditions and scope
- The large-scale model assumes approximate homogeneity and isotropy; it does not describe every local structure as expanding.
- This record does not establish a physical singularity, a cause of the Universe or the microscopic nature of dark matter and dark energy.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
ESA's account of CMB observations, expansion and large-scale model assumptions; no CMB map or parameter estimate was newly analysed.
2026-10-10 · English hot-state/expansion and relic-radiation scope checked against ESA's Planck page; precise cosmological ages and densities are excluded.
Foundational review
2026-10-10 · Fresh primary-source inspection of the complete compact record, including every statement, equation, quantity and material condition, followed by independent AI editorial review. This check does not certify all linked lessons or every passage of every cited publication.
Sources from other places
Agreement within this scope
Expanding hot early Universe, relic CMB and cosmological constraints.
Model constraints do not settle every question about the earliest state.
European Space Agency
- Planck and the cosmic microwave background International (European collaboration)English
What is the cosmic microwave background?; How many space missions?; What is the standard model of cosmology?
- Planck and the cosmic microwave background
Entry details
Permanent link to this entry ↗- Record identity
- cosmos-hot-big-bang
- Revision
- core.1
- Structured reference record
- Essential core · first collection