After the Big Bang and the start of the creation of the universe, within the first two mnutes of time (yes, it's THE beginning of time) 4 epochs have passed: the Quantum Gravity epoch, the Grand Unification epoch, the Electroweak epoch and the Lepton epoch.
The first one "lasted" 10E-43 seconds with the second one ending after 10E-34 seonds have passed (yes, that's 0,00..(34 zeros alltogether)...001 seconds...
After 321,502 years Matter-Radiation starts to decouple, first atoms begin forming (helium and hydrogen) and the Universe becomes transparent. It's the end of the fifth, the Photon epoch.
Right now, approx. 15 billion years have passed since the Big Bang.
