Big Bang Theory

We are living in present time. How did we born? Simple, Our parents gave birth us. How did our parents born? From our ancestors, right? Then where did they come from? We all were born in earth, but how was the earth created? The earth was created by some cloud dusts and some gases which was named as solar nebulae. Then how did the nebulae formed? From a billion years ago, a big bang happened and all the cosmic things and the whole universe was formed. But, how did the big bang happened? What was there before big bang? This is the most controversial and debating question of all time. because, no one exactly knows the answer.

The Big Bang Theory:

The model of the Big Bang depended on the perception that the separation between worlds is expanding, demonstrating that the universe is in a steady condition of development. Doing the figuring out, it was felt that in the event that it is extending with time, it more likely than not been little at one point in time. As indicated by the big bang theory, the universe was one amazingly hot, consolidated mass. This immediately cooled and extended in a matter of seconds.

This minor mass extended to a great degree quickly. Numerous changing models exist however as per a generally held model, roughly 10−37 seconds into the development, a thermodynamic progress occurred, causing astronomical expansion amid which the universe developed exponentially. After the underlying vicious and huge blast, around 13.75 billion years back, there was a steady extension of this mass into worlds, stars, and planets, including our own nearby planetary group.

But why the physicists strongly believe in the theory of big bang?

There are many points which proves that big bang theory is correct. At the beginning of the universe, the matters existed in the form of highly ionized plasma. This ionized plasma irradiated infrared radiation which is now discoverable. Due to Doppler shift, the wavelength of the light source decreases with the expansion of the universe and the radiation emitted by a light source gets redshifted which has been proved today. The light emitted by the highly ionized plasma has now entered in the microwave region which is called Cosmic Microwave Background Radiation.

Here is the Cosmic Microwave Background Radiation left by the Big bang.

Here, we will talk about both the conditions after and before the big bang.

What did happen after big bang:

At the early stage of the big bang, there was an unimaginable small, hot, dense point which was really a gravitational singularity. That point is also called The seed of a new universe. Astronomers theoretically proved what happened after big bang. After studying the Cosmic Microwave Background Radiation, the astronomers proposed some cases after the big bang.

After one second of the big bang, various particles and antiparticles like electrons, protons, neutrons, anti electrons or positrons, neutrinos were born and they covered the whole universe.

After three minutes of the big bang some light particles were born by a process which is known as Big Bang nucleosynthesis. The universe cooled down to 10⁹ Kelvin from 10³² Kelvin, deuterium formed by collision of some quarks (protons and neutrons).

It took almost 380,000 years to cool down the whole universe so that particles can make to form atoms and molecules. Because, the particles cannot make any atoms in a very high temperature, they need a perfect temperature to form atoms and molecules. According to NASA, this resulted transparent and electrically neutral gas.

After almost 9 billion years of big bang, our solar system born. The universe is still expanding from due to the big bang. But it is still unknown why the universe is speeding up rather than slowing down. According to some physicists a mysterious matter is helping the universe to expand rapidly which they called Dark Matter.

What did happen before big bang:

This is a very controversial question. No one exactly knows what was there before big bang. But the theoretical physicists and other scientists are now trying to explain this question. Physicists have proposed some theories about big bang which have been included here-

1. Big bang was a unique event:

According to this theory, there was nothing before big bang, because big bang was a unique event. Some theoretical physicists including Stephen Hawking have proposed that space and time also did not exist before it, because space and time were also in the grave of the gravitational singularity. After the big bang, all matters including space and time spread up and that was the beginning of the whole universe. According to this theory, the space and time were exist only in the gravitational singularity and there was nothing before the big bang.

2. Black Hole:

According to this theory, the whole universe came from a supermassive black hole. At the early stage, there was a space-time singularity and the matters were so dense that it became a black hole. But due to its high density, it exploded and all matters were thrown to the hyperspace. According to some theoretical physicists, the whole universe is living inside a black hole. If this theory is true, then inside each and every black hole, a universe should exist.

3. Multiverse theory:

According to multiverse theory, big bang was not a unique event. Our big bang was one of the bangs occurred in space. There were multiple numbers of big bangs occurred before us, or may be some big bangs are still occurring somewhere, but we cannot detect or feel that, as we are so far away from them. From our big bang, our universe formed, like that every big bangs gave birth a new universe in space and thus there may be infinite numbers of universes called The Multiverse. This theory states that there are infinite numbers of bubbles floating in hyperspace. In every bubble there is a universe. Sometimes, these bubbles collide each other or divide into smaller bubbles to form a new universe. This causes a powerful explosion which is the beginning of a universe.

4. M-Theory:

There is an another theory of multiverse which is called M-theory or Theory of Everything.  According to this theory, all particles and matters in this universe are made of strings. Modern physics say that the smallest possible things of a matter are the quarks. They cannot be broken again into smallest things. But string theory says that inside quarks, there exists some strings which carries the characteristics of the matter. These strings are one-dimensional and can vibrate in 10th dimension. Like different wavelength of light produce different lights, different frequencies of sound produce different sounds, as it is different vibrations of the strings produce different kind of matters.

So, why are we discussing about string theory? Because, both the theories are almost same. Although, M theory is just update version of string theory, but these two theories are considered as almost same. According to M-theory, the whole universe is made of an invisible membrane (hence the name) of infinite numbers of strings. Such, there are infinite numbers of membranes parallel to each other each consists of one universe and also called Parallel Universe. This concept is almost same as The Multiverse Theory. Thus, there are infinite numbers of parallel universes in space, and the membranes always kept vibrates as the strings vibrates. Thus sometimes, two of the closest membranes collide and knock back each other. This causes an explosion and forms a new membrane (new universe) between the two membranes. Thus, new universe forms.

Did big bang really happen:

Big bang theory proposes about the early stage of the universe. Many physicists agree with this concept but in some cases it does not provide us satisfactory answers. Famous theoretical physicist Michio Kaku said that big bang may not be the ultimate answer of creating the universe as it does not answer what bang or how bang. The big bang theory is not capable of answering the questions like "What was there before big bang or Why did big bang happen?" So, we should not give up and always search for a better answer.

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