在学习的过程中,我遇到了这些词:暴涨,核合成,中微子退耦,复合,光子退耦,再电离…
但是我不知道它们先后发生的顺序,所以花了一些时间整理了下表。由于包含很多尚未确定的物理,所以时间、温度和红移是大概或主流的。
chronology of the universe
Age | Epoch | Temperature | Redshift | Comment | ||
0s | ||||||
Planck epoch | ||||||
1E-43s | 1E32K | |||||
Grand unification epoch | Gravity separates. | |||||
1E-36s | 1E28K | |||||
Electroweak epoch | Strong nuclear force becomes distinct from electroweak forces. | |||||
1E-33s | 1E27K | |||||
Inflation | ||||||
1E-32s | 1E22K | Primordial density fluctuations arise. | ||||
Reheating | Reheat to 1E27K. | Quark-gluon plasma | ||||
Unknown Physics | ||||||
1E-12s | 1E15K | |||||
Quark epoch | Weak nuclear force separates. | |||||
Baryon to antibaryon constituencies are established. | ||||||
1E-6s | 1E12K | |||||
Hadron epoch | Quarks combine to form hadrons. | |||||
Possible formation of primordial black holes. | ||||||
Neutrinos decouple with electrons and positrons @~0.4s (1MeV). | ||||||
1s | 1E10K | 4E9 | Hadrons and anti-hadrons annihilate each other. | |||
Lepton epoch | The neutron to proton ratio freezes out. | |||||
Protons and neutrons stop converting @0.84MeV. | ||||||
10s | 3E9K | 1E9 | ||||
Photon epoch | Leptons are no longer produced by collisions of photons. | |||||
200s | 1E9K | 3E8 | ||||
Big Bang Nucleosynthesis | There are nucleosynthesis of light elements: ^{4}He, D, ^{3}He, Li. | |||||
1200s | 1E7K | |||||
The universe consists of a plasma of nuclei, electrons, and photons. | ||||||
Matter-radiation equality @z~3220 | ||||||
Helium recombination @z~2000 | ||||||
2E5yr | 4000K | 1500 | ||||
Recombination | Nuclei (protons) combine with electrons to create neutral (hydrogen) atoms. | |||||
3.8E5yr | Photon decoupling | 3000K | 1100 | Cosmic microwave background is formed. | ||
Dark ages | Baryons exist mainly in the form of hydrogen and helium atomic gases. | |||||
The baryons and the radiation are completely decoupled@z~200 | ||||||
1E8yr | 30K | 30 | ||||
Structure formation | Cosmic dawn | Earliest stars emerge. | ||||
Reionization | 10 | Neutral hydrogen atoms split back into a plasma of free electrons and protons. | ||||
1E9yr | 19K | 7 | ||||
Modern galaxies is formed. | ||||||
star-formation peak@z~1.9 | ||||||
Matter-Dark energy equality@z~0.3 | ||||||
1.38E10yr | Present time | 2.7K | 0 |
Smilie Vote is loading.
there are two universal phase transitions of the baryonic gas: Recombination and Reionization