Here and there, inflation ends and gives rise to a slower expansion, and perhaps the formation of matter, light, galaxies, stars, and beings like us.

BBC: The observable Universe and beyond

The pattern in this light acts as a kind of proxy for the history of star formation, and therefore a history of structure in the cosmos.

BBC: Science & Environment

The CMB is the light that was finally allowed to spread out across space once the Universe had cooled sufficiently to permit the formation of hydrogen atoms - about 380, 000 years into the life of the cosmos.

BBC: Planck satellite: Maps detail Universe's ancient light