Where the facts come from
Sources
We checked the wording of each claim against a cached copy of these pages on 14 November 2026. Links go to the live pages, which can change; if a date or a figure has moved on, the fact-check log will need a fresh pass.
NASA Science, Webb Telescope & The Big Bang, a short Q&A with Nobel laureate Dr John Mather (checked 14 November 2026)
https://science.nasa.gov/mission/webb/big-bang-q-and-a/
Checked 14 November 2026. Short label on the site: NASA.
NASA Science, Hubble Big Bang (checked 14 November 2026)
https://science.nasa.gov/mission/hubble/science/science-behind-the-discoveries/hubble-big-bang/
Checked 14 November 2026. Short label on the site: NASA.
NASA Science, WMAP Overview (checked 14 November 2026)
https://science.nasa.gov/mission/wmap/wmap-overview/
Checked 14 November 2026. Short label on the site: NASA.
NASA Science, Big Bang and the Evolution of the Universe, Physics of the Cosmos (checked 14 November 2026)
Checked 14 November 2026. Short label on the site: NASA.
NASA Science, The Big Bang (checked 14 November 2026)
https://science.nasa.gov/universe/the-big-bang/
Checked 14 November 2026. Short label on the site: NASA.
Encyclopaedia Britannica, big-bang model, by the Editors of Encyclopaedia Britannica (checked 14 November 2026)
https://kids.britannica.com/scholars/article/big-bang-model/79147
Checked 14 November 2026. Short label on the site: Britannica.
Encyclopaedia Britannica, expanding universe, by the Editors of Encyclopaedia Britannica (checked 14 November 2026)
https://kids.britannica.com/scholars/article/expanding-universe/33443
Checked 14 November 2026. Short label on the site: Britannica.
Encyclopaedia Britannica, cosmic microwave background, by Frank H. Shu and the Editors of Encyclopaedia Britannica (checked 14 November 2026)
https://kids.britannica.com/scholars/article/cosmic-microwave-background/471314
Checked 14 November 2026. Short label on the site: Britannica.
NASA pages were checked at their published science.nasa.gov addresses. Britannica articles were checked in the Scholars edition at the URLs above; we quote the article body only, not “Ask Anything” or Top Questions blurbs.
This site is independent. It is not an official publication of NASA or of Encyclopaedia Britannica.