Particle physics
Matter–Antimatter Asymmetry
The unexplained fact that the Universe is made almost entirely of matter, even though the Big Bang should have produced matter and antimatter in equal amounts, which would have annihilated completely. Why a tiny excess of matter survived — the problem of baryogenesis — is one of the great open questions in physics and cosmology.
Highlights
- ›Why is the Universe made of matter, not antimatter? Open
Related physics & astronomy
Across fundamental physics
Knowledge connections
- Associated withAntimatter
- Associated withAntimatter
- Associated withThe Standard Model (overview)
- Associated withThe Fundamental Forces
Sources
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.