How our Universe came into existence?

Almost all of us think about who we are, or where we and other things in this world came from, at least a few times in our life. The planets, our sun, moon, Earth itself, all organisms came into existence somehow. It almost feels like magic.

But before anything else, it was the Universe that came into existence. No matter how advanced our science and technology is right now, we are still trying to answer this very basic question – a question that has been puzzling humankind since ages.

In this article, we will try to have a look at the various theories that have been put forward by the brightest minds on the earth regarding the inception of the universe. We will also ponder over some frequently asked questions regarding the vastness of universe.

Table of Contents

Theories of the Origins of the Universe
What was before our Universe?

Theories of the Origins of the Universe

Let’s have a look at the various theories that have been put forward regarding the origins of the universe.

Big Bang Theory

This theory was propounded by Georges Lemaître (a Belgian priest) in the 1920s.

It is the most famous and the most acceptable theory regarding the origins of the universe. It is so because:

It is backed by some experimental proofs and our observations of the universe.
It explains some of the phenomena in the universe pretty well.

But let’s not put the cart before the horse. We should first of all understand what Big Bang Theory is after all.

As per Big Bang theory, our universe originated from nothing, or in scientific terms it originated from a singularity. Singularity is a point of infinite density and very hot.

So, initially our whole universe was confined at a single point of singularity. And then around 13.77 billion years ago, suddenly it started expanding at a very fast rate. This is what we call the “Big Bang”. It gave birth to all the matter, energy, space and time that we see today. That expansion is still going on, our universe is still expanding.

Note

The word “Big Bang” is a misnomer. Neither was this initial explosion big, nor was there any bang. Because for there to be any bang (i.e. any type of sound) there needs to be some medium (like air) present. In reality, even if Big Bang really occurred, it must have been small and silent. But it became big very quickly soon after.

After the big bang there were two stages of the expanding universe:

Radiation era – just after the big bang there was only radiation, i.e. a soup of extremely hot elementary particles. It lasted for tens of thousands of years. This era has been divided into many stages (called Epochs) – Plank, Grand Unified, Inflationary, Electroweak, Quark, Hadron, Lepton, Nuclear.
Matter era – After the early universe cooled down a bit, matter came into existence. This era has been divided into three Epochs – Atomic, Galactic, Stellar. This era has lasted billions of years and is still ongoing.

Big Crunch

Some scientists have suggested that the expansion of universe will stop one day (billions of years from now), and the universe will start contracting then. Just as the universe started with a Big Bang, it will end with a Big Crunch.

Observations in support of Big Bang Theory

There are a few observations and experiments that support this theory to a certain degree.

Cosmic background radiation of the universe

If you were born in the last century, then you might have seen the TVs with vacuum tube. Those TVs used to display a static screen in absence of any signal from the TV station. That static was due to the cosmic background radiation that pervades our universe.

It’s like a smoking gun – the remanent of the big bang, that we still hear and observe all around us. It’s everywhere.

It was discovered accidentally by a couple of scientists, Arno Penzias and Robert Wilson, working in Bell Telephone lab (in 1965). They initially thought that this static is due to some technical fault in their instruments or maybe due to bird droppings on the antenna. But what they had discovered was the “cosmic background radiation of the universe”.

This observation supported the Big Bang theory, and dealt a death blow to the competitive Static universe theory.

Big Bang Theory Vs. Static Universe Theory

For many decades in the early 20th century, there was a fierce battle between two theories regarding the origin of the universe - Big Bang Theory and Static Universe Theory. One of the brightest minds of the 20th century, Albert Einstein supported the Static Universe Theory.

While as per Big Bang theory, the universe started from a infinitesimal point and is expanding ever since.

On the other hand, as per Static Universe theory, the universe is static, i.e. it always was the way it is. It is neither expanding, nor contracting – it’s static. According to it, the universe is both spatially and temporally infinite.

But many observations later on supported the Big Bang theory, and so Static universe theory was rejected.

Doppler’s Effect

Have you ever been to a railway station?

When a train blows its siren while coming towards you, it sounds high pitched. That’s because while it’s coming towards us, the frequency of the sound waves increases. However, when the same train crosses us, and moves away from us, then it sounds low pitched. That’s because when it moves away, the frequency of the sound waves decreases. This is called Doppler’s effect.

The same effect can be seen in case of light waves. If a body emitting light comes towards us, then the frequency of the visible light increases, i.e. the incoming light moves more towards the blue side in the spectrum (called blue shift). On the other hand, when it moves away, then the frequency of the visible light decreases, i.e. the incoming light moves more towards the red side in the spectrum (called red shift).

Edwin Hubble observed that most of the galaxies are red-shifted, i.e. they are moving away from us. Moreover, the rate at which they are moving away is increasing. It proved the fact that not only are we living in an expanding universe, but in a universe that is witnessing an accelerated expansion.

This has further been supported by recent observations by much stronger telescopes, such as the Hubble telescope.

So, if our universe is expanding now, then at some time in the past it must have been smaller than now. At the beginning it probably would have been at one point.

This observation supported the Big Bang theory, and disproved the Static Universe Theory for certain.

What was before our Universe?

Though we do not know for certain how our universe came into existence. But it’s for certain that it must have had some beginning. So, what was there before the existence of our universe?

Well, in short no one knows. All we have are speculations.

Big bang theory cannot explain it because it says that universe started out from singularity. And the concept of singularity is undefined. No one knows what singularity is. It’s like writing that something is infinite, which is a concept that no one can define.

Even our observations using the strongest and latest telescopes can only see a few moments after the big bang. The event of big bang and a few moments after it are covered by a thick cloud of super-dense plasma. Obviously, we have not been able to see what was before big bang either.

But some scientists have given some alternative theories to the “singularity” point of origin. Some of them have been listed below:

As per some scientists, there’s a white hole on the opposite side of the black holes. The white hole emerges in another universe, and that is what creates a new universe via the process of big bang. So, essentially, we have come into existence from a black hole present in a parallel universe.
As per another scientist, there was a super sparse universe in existence before our current universe. But somehow the particles of that universe came together, got super-heated and then big bang occurred.

Note

We will discuss Big Bang theory in much more detail in a separate article. We will also discuss the various theories that aim to describe the nature of our universe separately, e.g. String theory, M-Theory, Standard Model (based on Supersymmetry) etc.

These are the leading theories that can one day become “Theory of Everything” – a theory that explains everything in the universe (by explaining all the 4 fundamental forces of nature – gravity, electro-magnetism, weak nuclear force and strong nuclear force).

One interesting point to note about String theory is that it is based on vibrations (of infinitely long strings). Indian Vedic view of universe (proposed by monks thousands of years ago) is also based on vibrations. This is called Vedic Rashmi theory : the Vedic “Theory of Everything”, which has been written in around 2800 pages.

In fact, the hymns and matras like ‘om’ are supposed to mimic certain frequencies of the universal vibrations. As per Vedic view of the origin of the universe, there were no vibrations in the space before the birth of the universe. Our universe came into existence when vibrations started.

It’s an interesting area of study, if someone’s interested; someone with an open and research-oriented mind.

Winding Up

As some of you may have noticed, we don’t know anything for certain regarding the origins of our universe, or what was there before it. All we have are various theories, more in the nature of hypothesises. Some are completely theoretical, while others have some experimental proofs. But none of them can be taken as the final explanation for certain – they are still theories.

However, if we see how much we have learned about our universe in the last 400 years, especially in the last 150 years, we can be hopeful to find some answer to it soon enough.

Keep your fingers crossed. We are living in exciting times!

Interesting Facts related to Universe

How old is our Universe?

Our universe is estimated to be 13.7 billion years old, as per scientists. Interestingly, the age of the universe as calculated by sages of ancient India was very close to this number. Interesting, isn’t it?

How vast is our Universe?

Our universe is of the shape of a sphere, with a diameter of around 28.5 gigaparsecs (93 billion light-years). 1 light year is the distance that light travels in 1 year.

So, our universe is very big. It’s estimated that there are around 125 billion galaxies in the observable universe, some even bigger than our Milky way galaxy.

And the number of stars in our galaxy are around 100-400 billion (i.e. ten thousand crore to fourth thousand crore). So, the number of stars in the whole universe must be mindboggling.

What is outside our Universe?

No one knows what lies outside our universe. We can only speculate. Some scientists think there may be nothing outside the universe, while some scientists think that there may be other universes beyond the boundaries of our own universe. Some think that “dark matter” is an evidence of the gravitational effects of other universes on our universe.