Big Bang Theory: Radiation Era

Planck Epoch

• No matter existed in the universe at this time.

• Only energy existed in this epoch together with the four fundamental forces of nature called Supergravity or Superforce (Gravity, Strong Nuclear Force, Weak Nuclear Force, and Electromagnetic force).

• The temperature at this epoch is 10^40 Kelvin.

• At the end of this epoch, gravity will disappear.

Grand Unification Epoch

• It happens at 10^-43 seconds.

• The temperature at this epoch is at 10 to 36th Kelvin.

• At the end of this epoch, Strong Nuclear Force will disappear.

Inflationary Epoch

• It happens at 10^-36 seconds.

• The temperature at this epoch is at 10^ 33rd Kelvin.

• The universe expanded rapidly from the size of a primeval atom to that of a grapefruit.

• Many particles were formed namely leptons, quarks, and other particles.

Electroweak Epoch

• It happens at 10^-32 seconds.

• The temperature at this epoch is at 10^ 20th Kelvin.

• The last two forces of nature namely the Electromagnetic and Weak Nuclear Force disappear.

Quark Epoch

• It happens at 10^-12 seconds.

• The temperature at this epoch is 10^16th Kelvin.

• Many particles formed in the Inflationary Epoch namely leptons, quarks, and other particles have not yet formed into subatomic particles because it is still too hot.

Hadron Epoch

• It happens at 10^-6 seconds.

• The universe cooled down very fast thus forming protons and neutrons.

• The temperature is at 10^-6 Kelvin.

Lepton and Nuclear Epoch

• It happens in about 1 second.

• The temperature at this epoch is 10^9th Kelvin.

• Ends when the universe is about 100 seconds old.

• The leptons (electrons, neutrinos, and other light particles) are still produced in pairs, because they are light.

• Ends when temperature drops below 1 billion K.