Jul 1, 2021
The Origin Of Everything
~From the Big Bang to AI~
Who are we? Why are we here? What is our purpose? Where do we come from?
These are some questions that most of us at some point of our lives have thought about. No matter how busy we are, how ignorant we are, it is in the nature of human beings to question their origins. Sometimes, we dismiss the questions either by saying ‘we don’t have time’ or sometimes because we don’t have the answers to these seemingly obvious questions. But if we venture deep into it, we come to know these aren’t easy questions nor are their answers. In fact, no one has yet answered them with 100% accuration. To give profound answers to these questions, we have to travel back in time to witness the ‘creation’ of everything. But for the time being, it is not in our hands. So what do we do? We come up with theories.
Human beings are part of the animal kingdom. So what makes us different from other animals? Obviously there are many aspects but the most important is the power to reason. Since the time of the first human, people have questioned the things around them. We have tried to add meaning to our existence by understanding the role we play in this huge cosmic arena. With time, the size of this arena kept growing for us and with each new perspective of the magnitude of our universe, we were instantaneously struck by the question of what is outside this realm? At first, we learned of the magnitude of the earth we live in, then the question came: what is outside our blue planet? Then came the answer- the other seven along with the sun making together the Solar System along with billions of comets and asteroids. Then what is outside the solar system? As we widened our perspectives, we came to know that our Solar System is located on the periphery of the humongous Milky Way galaxy, home to about a 100–400 billion stars with our sun being one of this enormous number. Further we came to know that there are other galaxies in the universe to harbour star life in stellar quantities, some even bigger than our own Milky Way floating around in the Cosmos. Till this date, our realm of the observable universe has been stretched far and wide to a 93 billion light years of area and still more to discover each day.
The discovery of this last realm was made by famous astronomer Edwin Hubble. Hubble saw that the light coming from the other galaxies was red-shifted, which meant that the galaxies were moving away from us. This is explained by the Doppler Effect. Given that we are standing on the midpoint of a track. A car goes by honking down the track. As we will observe, the sound of honking becomes the loudest as it reaches us and as it recedes from us the sound becomes fainter. This applies to light as well. We know that there is a spectrum of light which ranges from infrared to gamma rays. The spectrum that we get to see is called the visible spectrum of light containing the colours VIBGYOR. When an object is moving towards us, its light is blue-shifted, like the light coming from Andromeda Galaxy. But when an object is receding, its light is red-shifted. Objects even farther away emit microwave or infrared radiation. Now let us understand how this mechanism works. Light travels both as a wave and a particle. When the light has traveled a long distance, its wavelength gets stretched and so it gets red-shifted i.e., it gets shifted to the end of the visible spectrum. This explains how galaxies emitting red light are receding away from us. This means that our universe is expanding and it is doing so at an accelerated rate. Now, this explains one way our universe must have come into existence. If the universe is expanding as time goes by, it will be contracting into the past. The contraction will finally give us such a state where all matter known to create the universe was clumped into a tiny space and the moment it exploded would be the ‘Big Bang’.
The Big Bang theory is the most generally accepted theory about the creation of the universe. Even the orthodox church accepts it because it allows a ‘moment of creation’ thus allowing God to exist. In fact, Nobel Laureates Robert Wilson and Arno Penzias discovered a cosmic microwave background radiation which was coming at the same rate from every direction. This probably meant that it was the radiation left after the Big Bang travelling through the universe since the past 14 billion years. So how did we come into being from this clumped up state of hot, dense matter?
The first few minutes after the Big Bang was called the inflationary period when the universe expanded million times every second with the expansion rate accelerating with each second. As the hot dense matter cooled a bit, the first matter particles to form were quarks, further cooling and the quarks clumped to form subatomic particles and slowly, the subatomic particles clumped to form atomic nuclei. But this took a lot of while to happen. The infinitely hot universe had to cool a lot so that particles can attract each other. As new particles of matter kept forming, their antiparticles too formed and they kept annihilating each other. Particles and antiparticles are made up of the same matter but their charge is opposite. For example, an electron has a negative charge and its antiparticle positron (also known as anti-electron) has a positive charge. So maybe in this race of annihilation, matter particles outnumbered antimatter particles. As the temperature dropped subatomic particles clumped together to form atoms. The first atoms were that of hydrogen. One proton and one neutron held together at the centre by the strong nuclear force ( although they have the same charge, the strong force overcomes the force of repulsion between them and keeps them attached) and an electron orbits them and is held towards them because of electromagnetism ( particles with opposite charges attract each other). So for a long time, hydrogen was the only element available in our universe. As the universe expanded, matter too did. In some places, the expansion of matter was uniform and in some places non-uniform. When in some areas, hydrogen particles began to clump together they formed hydrogen clouds. When enough hydrogen was gathered in the cloud, they would collapse under their own gravity to form rapidly moving bodies inside which fusion of hydrogen to helium was taking place because of the weak nuclear force. These objects were the first stars. Over the span of their life, they would fuse hydrogen into helium inside themselves to keep them stable from the force of gravity acting from it outside. Once their hydrogen fuel has been exhausted, helium takes over and fuses into heavier elements like lithium,carbon etc, until the star is left with an iron core. Once there is no more matter left for fusion, the star explodes in a supernova sending matter into the universe for the next generation of stars to form. Lives of stars are spectacular and are a whole new topic of discussion. Anyway, this is how new elements reached out of their abode where they were created. Matter from such a supernova explosion must have clumped together to form our Sun almost 5 billion years ago and also our Solar System.
After the formation of our Sun, remnants of matter formed a huge cloud around it stretching for billions of kilometres. This was the solar nebula. As this cloud of matter spinned around its centre, its non-uniform regions clumped and collapsed under their own gravity to form the- Planets! The outer planets tend to be gaseous and the inner planets are rockier. This must have been because the gas clouds surrounding the terrestrial planets must have been sucked in by the Sun’s gravity given that they are nearer to the Sun than the Jovian planets. The eight bodies recognised as ‘planets’ in our Solar System are namely (in order of their increasing distance from the Sun):
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
Other objects in our solar system include moons of the planets, dwarf planets and their moons, asteroids and comets. The comets and asteroids are wanderers. Maybe at some point they were captured by the Sun’s gravity. They are found in three main regions: the asteroid belt between Mars and Jupiter, the Kuiper belt surrounding the boundary of the Solar System and the Oort Cloud which encompasses the entire Solar System.
Now we have managed to deduce our existence from the Big Bang to the first stars, to the formation of our Solar System and our Earth. Now where did we come from is the remaining question.
The earth came into being almost 4.6 billion years ago. At first it was a rocky planet with fuming temperatures and volcanic eruptions. The early atmosphere was thinner and composed mostly of hydrogen and methane. So how did this early hell-like planet get its uniqueness- life?
It is assumed that there was a period when comets bombarded our planet and since comets contain ice, they must have brought water here, and maybe even the first organism! During this cosmic bombardment, an almost planet sized object crashed into our planet. The remnants of this destructive collision revolved around in earth’s gravity for some time and then clumped together to from- the Moon! Thereafter, our planet began to cool down and the first bacteria began to mutate. As conditions developed we now had oceans full of water where other organisms came into being. The first muti-cellular organisms appeared in water bodies. Over time a variety of exciting things took place. The supercontinent Pangea broke into the known continents today (most probably by a cosmic bombarding). Then came the Cambrian Explosion. The earth was overflowing with a variety of organisms. The mutated organisms entered into land for the first time. The most thrilling and dangerous period must have been the fifth extinction when a huge meteor crashed into Earth. All of life was threatened and the entire species of dinosaurs was wiped out. Over time, the earth recovered. Primates began to take over the land. There were many different species of the primate family. There came a time when one of these primate species descended to the land from trees and began using stone tools, they even discovered a thing called fire. Their intelligence grew with time. They began living in groups ( civilization occurred 10000 years ago), started talking through some signs and words, found metals and developed over time and they are what we call today ‘modern humans’. I am one of them and so are you! And we in a way are now destroying ourselves; destroying the precious species gifted with the ability to reason.
We may have answered questions like who we are and how we came here. But why are we here? What is our purpose? Well, we are not in charge of this planet at least; we are making it worse and given the present scenario, if humans weren’t here, earth would have been much better. We haven’t found our purpose yet and who knows whether we will. But as Professor Hawking has said there should be no boundary to human endeavour. Maybe we will never know what our purpose is and maybe we don’t have any! But the pursuit of knowledge is more beautiful than reaching our destination as said by Einstein. For now, we should try and expand our knowledge by not destroying ourselves and our planet. It is in the best interest of everyone.
Written by:
Puja Krishnatraya
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Feedback is most welcomed!
