We are the man, interested to know about the origin of the universe, question our mind ‘from where our universe was created, how and when?” Before discussing it, let us take a short definition of the universe.
The universe is nothing, but is all of space and time and their contents including planets, stars, galaxies and all others forms off mater and energy. Today I am going to discuss about the origin of the universe. So, let’s go and enjoy it...
The origin of universe is origin of everything. There are many theories behind the origin of the universe but the most perfect and acceptable explanation is the big bang theory. According to this theory, at very first-time universe was hot and infinity dense point, only a few millimeters wide similar to a supercharged blackhole. It was near about 13.7 billion years ago this singularity finally exploded.
From that explosion, matter, energy, space and time were created.
But what happened next?
Two major evolution have occurred, for those the universe has got its own shape.
1. Radiation era.
2. Matter era.
First - Radiation era, named for the dominance of radiation, right after the big bang.
There are small stages in this era.
- Planck epoch
- Grand unification epoch
- Inflationary epoch
- Electroweak epoch
- Quark epoch
- Hadron epoch
- Lepton epoch
- Nucleosynthesis epoch
1. Planck epoch:
Time – Immediate after the big bang.
Temperature - 10^40 k
In big bang cosmology, the Planck epoch is the early stage of big bang, before the time passed is equal to the Planck time, tp or 10-43 sec. There is no currently available physical theory to describe such short time and it is assumed that the quantum effect of gravity dominates physical interaction at this time scale.
No matter exists in the universe at this time except energy and four forces of nature – gravity, strong nuclear, weak, electromagnetic. They were belong to a single force category called electromagnetic force. Gravity had separated from this force at the end of the Planck era.
2. The grand unification epoch:
The grand unification epoch was the period in evolution of the early universe just after the plank epoch, starting at about 10^-43 sec after the big bang.
During this period, three or four fundamental interaction—electromagnetism, the strong nuclear, the weak interaction were unified as the electronuclear force. Physical characteristic such as mass, charge, flavour and colour were meaningless during this period.
3. Inflationary epoch:
Temperature : 10^33 k
Time after big bang – 10^-36 sec
At the beginning of this stage universe started to expand rapidly and become very hot. The creation of electrons, quarks and anti quarks has started.
The potential energy of the inflation field had driven the inflation of the universe during this period and as well as the universe had been filled with a dense, hot quark-gluon plasma.
4. Electroweak epoch:
Temperature – 10^20 k
Time after big bang – 10^-32 sec
It was the time when the temperature of the universe had fallen enough that the strong force separated from the electroweak interaction but was high enough for electromagnetic and weak interaction to remain merge into a single electroweak interaction above the critical temperature for electroweak symmetry breaking. Particle interaction at this phase were energetic enough to create large numbers of exotic particle (any kind of nonbaryonic matter), including stable W and Z bosons, Higgs bosons.
5. Quark epoch:
Temperature – 10^16 k
Time after the big bang – 10^-12 sec
The four-fundamental interaction – gravitation, electromagnetic, the strong nuclear and the weak interaction had taken their present forms during this period and the universe was filled with a dense, hot quark-gluon plasma, containing quarks, lepton and their anti-particles. Collision between the particles were too energetic to allow quarks to combine into mesons or baryons. On one word that was the right time for subatomic particle to form.
6. Hadron Epoch:
Temperature – 1010 k
Time after the big bang– 10-6 sec
The universe had cooled down enough for quarks to bring together to form proton and neurons. The average energy of particle interaction had fallen below the binding energy of hadrons.
7. Lepton Epoch:
Temperature – 10^12 k
Time after the big bang – 1 sec
It was the period in the evolution of early universe in which the leptons dominated the mass of the universe. During this phase the temperature was still too high enough to create lepton / anti lepton pairs. So leptons and anti leptons were in thermal equilibrium.
8. Photon Epoch:
It was the time period when photons dominated the energy of the universe. It was about 10 sec after the big bang, when subatomic particles collide with its anti particles to produce photons.
9. Big bang nucleosynthesis:
Temperature – 109 k
Time after the big bang– 100 sec- 20 min
This refers to the production of nuclei. The nuclei of lightest hydrogen 1H1. It is calculated to be responsible for the formation of most nuclei of the universe like He4, along with small amount of H2, D, He3 and a very small amount of Li7.
Second- Mater era:
Now the universe has the enough ability to form elements, the building blocks of matter key with the matter era.
It contains some stages: --
1. Matter domination
2. First molecule
3. Recombination
4. Dark ager
5. Galactic epoch
6. Stellar epoch
1. Matter domination:
Time: 47000 years
As the universe cooled enough the universe large scale behavior become dominated by matter instead. This occurred because the energy density of matter began to exceed both the energy density of radiation and the vacuum energy density. The density of non relativistic radiation (photons) become equal, which determines the smallest structure that can form due to the competition between gravitational traction and pressure effects.
2. First molecule:
At around 100000 years after the big bang the universe has cooled enough for helium hydride, the first molecule to form.
3.Recombination:
Time: 370000 years
The universe has cooled to a point where free electrons can combine with the hydrogen and helium nuclei to form neutral atoms. The electrons and the atomic nuclei were combining for the first time.
The universe was foggy at that time. At though there was a light but it was not possible to see.
4. Dark ages:
Time: few years later from 370000 years after big bang.
At this phase the universe was transparent and had cooled enough to allow light to travel long distance, but there were no light. Producing structures such as stars, galaxies etc. during this time only this ager the temperature fall down from 4000 k to 60 k.
During this time only two courses of photons existed: the photon released during recombination (as neural hydrogen atom formed) which we can still detect today as micro background and photons occasionally released by neutral hydrogen atom.
5. Galactic epoch:
Time after big bang: 200 million years
Ordinary matter: 15.5%
Dark matter: 84.5%
Under the effects of gradually been gathering. As well as ordinary matter had gathered where dark matter was denser and in those places it collapsed into clouds of mainly hydrogen gas. The cluster of atoms and the selling of Galaxies were formed.
6. Stellar Epoch:
Time after big bang: 3 billion years
Current stage of the universe has developed. Formation of stars have took place as hydrogen and helium are the building blocks of everything, planet, man, life and so on.
This ecosystem of the universe is only possible due to development of many stage in the path of formation universe.
Thank you….