|  Cosmological History | 
Important Changes and Events > s.a. history of cosmological models; observational cosmology.
| Time | Size | Redshift | Temperature | Density | Comments | 
| −1.37 × 1010 yr | 0 | ∞ | ∞ | ∞ | Big Bang | 
| + tP | Quantum-gravity effects | ||||
| +1 sec | 1010 K | 5 × 105 g/cm3 | |||
| +4 sec | 5 × 109 K | 3 × 104 g/cm3 | |||
| +3 min | 109 K | Nucleosynthesis starts | |||
| 1016 GeV | Grand Unification? | ||||
| 1100 | Decoupling, transition radiation → matter domination | ||||
| +380,000 yr | 1000 | 3000 K | Recombination, last scattering surface | ||
| +400 × 106 yr | 10 | Reionization – first stars | |||
| −1.0 × 1010 yr | 1/6 | Galaxy formation | |||
| −4.6 × 109 yr | Formation of Solar System and Earth | ||||
| 0 | 1 | 0 | 3 K | Present | 
References > s.a. cosmology;
  early-universe cosmology.
  @ General: Pilipenko a1303 [printable cosmological calculator].
  @ Special epochs: Loeb IJAB(14)-a1312
      [the habitable epoch 100 < (1+z) < 110, with cmb temperature in the 273-300 K range];
    Avelino & Kirshner ApJ(16)-a1607
      [the dimensionless age of the universe is close to 1].
  > Online resources:
    see NED Cosmology Calculators page.
 main page
  – abbreviations
  – journals – comments
  – other sites – acknowledgements
  send feedback and suggestions to bombelli at olemiss.edu – modified 11 mar 2018