Updated: Jan 27, 2022
By Anisha Kumari,
Everything has its beginning, even silence and darkness. The beginning of the universe is the beginning of everything. There are many theories on the origin of the universe, from Time’s arrow to The Big Bang theory. About 13.8 billion years ago, the universe is believed to have formed from an infinitely tiny, condensed head mass called singularity which exploded to form matter. This is called the Big Bang theory. It was then space and time began. However, it is impossible to figure out what happened before the big bang. The theory was initially put forward by the founder which included the young PhD scholar Stephen Hawkings.
What happens after that? Before that question, the stumbling question is ‘why it happened? This question can’t be answered, because we don’t know what would happen if it would not be in the movie. And since our physics prohibits us to look before the big bang, it is sincerely hard for us to determine the causality and the reason behind the big bang. Coming to the question 'what happened after?'
Our physics is reasonable to calculate the after-big bang universe. Since a singularity has a negligible classical area, it can be questioned that after the explosion how much area it could create. The answer was given by Andrie Linde and Alan Guth, independently. It is called ‘eternal inflation’. Inflation here indicates that our universe in the initial time was inflating like a balloon, and the energy which is inflating is called dark energy. If we look at the physics of inflation, then it is remarkable to see that inflation occurred just in a matter of milliseconds. Our observable size universe could have been created in a tiny milli-second in that inflation. Universal expansion followed inflation and our universe still expands. After inflation cooled, our universe had four forces in nature namely, Gravitation force, Electromagnetic force, Weak force and Strong force.
The inflationary stage wasn’t like the current universe. At that time, there were no stable particles and evidently no matter. A particle is the creating block of the universe, as well as the operating block. A particle doesn't need to be fundamental. We study particles under the physics of the standard model. In a standard model that is captured in the fig;
Photo credit: Wiki commons
The standard model describes the particle under two categories; 1) Fermions and 2) Bosons. Fermions are matter blocks and Bosons are force carriers. Fermions include electrons, muon, all quarks etc, and they are the most fundamental particle. The quarks; up, down, top, bottom, charm and strange forms different baryons and mesons. Protons (that are made of two up and one down) and neutrons (made of one up and two down) are baryons, and they largely comprise the area of the atom. So without quarks matter is impossible. Bosons are force carriers, for instance, photons that carry electromagnetic force.
Besides these achievements, our standard model doesn’t define everything. For instance, it doesn’t define dark matter, though it should be there to balance the universe. It can’t tell us why there are just particles rather than anti-particles. The whole physics should be defined using one formalism, physicists call it ‘Theory of Everything’. It hasn't been found yet. If it gets in our lap, we would almost define the universe under just one tree, and it would be the most important achievement of humankind.
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 Institute for Advanced Study. Inflation Theory.
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