Matter outlasts antimatter
For every billion annihilating pairs, one particle of matter survives — and everything is built from the remainder.
- When
- Known to
- ± 20 million years
- Era
- Primordial
Matter and antimatter should have been produced in equal amounts and annihilated completely, leaving a universe of radiation and nothing else. Instead a tiny asymmetry — roughly one extra quark per billion quark–antiquark pairs — left a residue behind after the annihilation finished. Every atom in every star and every person is made from that leftover. The mechanism that produced the imbalance remains one of the major unsolved problems in physics.