13.7 billion years ago, After the Big Bang , the universe has passed through different phases.
Most of things happened just a second after the Big Bang.
Six eras passed in 1 second after the Big Bang :-
Plank epoch or plank era
This era ended after approximately 10^-43 second. The temperature was very high and four fundamental forces were one super force. 10^-43 second is also called 1 plank time. At this point the universe spans a regiona of 10^-35m only which is called 1 Plank length.
Grand Unification epoch
This era ended after 10^-36 second and gravity splitted from other fundamental forces.
This era ended after 10^-32 second. The universe underwent rapid exponential expansion. This expansion is known as cosmic inflanation.
From 10^-36 to 10^-12 seconds, strong nuclear force saperated from other two.
Universe cools of to below 10 quadrillion degrees and four fundamental forces were saperated completely. Quarks, electrons and neutrinos form in very large, quarks and anti-quarks annihilate but due to baryogenesis, very few (one in every billion pair) survives and ultimately combines to form matter.
Temperature cool of to a trillion degree and allow quarks to form protons and neutrons.
This much happened within the one second after the big bang.
After the annihilation of hadrons, Leptons and Anti-Leptons dominate the mass of universe The era ends at three seconds.
Temperature of the universe falls to the point where protons and neutrons combine through nuclear fusion to from the nuclei of simple elements. This era ends at 20 minute.
Universe is filled with plasma, after annihilation of leptons and anti-leptons, most of the energy of universe is present in form of photons. Universe will in this state till 240,000 years.
Ionises Hydrogen and helium atoms are capturing electrons and are neutralizing their electric charges. Universe is made up of 75% Hydrogen and 25% Helium and just traces of Lithium.
This is the time after 300,000 years, the universe is totally dark, no stars have been formed yet. It will remain dark till 150 million years.
Stars and galaxy formation
The dense cloud of cosmic gas is collapsing due to its own gravitational pull and is becoming hot enough to start nuclear fusion between Hydrogen atoms.
The first stars have formed,they are short-lived and Supermassive.
Larger stars are burning quickly and exploding in supernova a events and their ashes are going to form subsequent generations of stars.
Galaxies are forming and gravitational force is pulling the galaxies toward each other forming clusters and superclusters.
Solar system formation
8.5 to 8 million years after the big bang our solar system has formed.
Today, the age of universe is 13.7 million years, our universe is expanding and old star suffs are recycling to form new stars….