Glossary · term

Reionization

Cosmology

Aliases
reionized, reionize
Domain
Cosmology

Definition

The stripping of electrons back off intergalactic hydrogen by the first stars and quasars, between about 150 million and a billion years — the universe's second, and final, phase change.

Open on the Glossary shelf — the interactive card, the filters, and everything alongside it.

From the Glossary database in Notion, last edited 2026-08-17. This page is the row, rendered by the build; nothing on it is written by hand.