How do you know if something is real? Do you believe in it because you can see it? Or do you think it is real because you can touch it?
Scientifically, anything real occupies space and moves forward through the arrow of time. All living and non-living things share this common property. But what if there is no more space to occupy? What if there is no time left to spend?
Sounds Impossible, Isn’t it?
That’s what people believed for thousands of years until the beginning of the 20th century. This is when Einstein published his famous theory of relativity that put an end to the idea of absolute time. Our today’s understanding of space and time is based on the foundation he laid more than a century ago.
We’re living on a small rocky planet revolving around an average-sized star in a spiral-shaped galaxy. Our milky way galaxy contains at least 100,000,000,000 (100 billion) stars like our Sun. I know it looks huge, but it isn’t anywhere close to the size of the entire universe.
The observable Universe contains around 2000,000,000,000 (2 trillion) galaxies (each with billions of stars and planets), some of which are far bigger than our milky way galaxy. If I’ll go ahead and add the total number of stars and planets in this observable universe, it will give us a number so huge that’ll literally blow your mind. That’s how big the universe is.
Next time when you feel egoistic or superior, just think about your tipsy tiny existence compared to our massive universe, and that would be the end of your misconception.
Another amazing thing is that the universe is expanding every second, and almost everything in space is moving apart. Not only that, the expansion is accelerating with time. After another billion years or so, all other galaxies will be so far away that it’ll only be a dark night sky with no visible stars. By this observation, we can assume that the universe must have been compact in the past. If we go back further in time, we can say that everything must have been tightly packed together and space was much smaller than it is today.
Around 13.8 billion years ago, the whole universe was nothing more than a tiny dense point occupying an infinitesimally small amount of space and had a huge mass. There was no space and no time existed before this point. Everything we know or experience came right out of this dense point around 13.8 billion years ago when the big bang happened. It was like a massive expansion of a tiny dense point across all the directions.
To understand this in a simpler way, you can take a balloon and draw some random dots on its surface. Now when you blow that balloon, it will inflate and those points will start moving away from each other. The more you’ll blow, the more dots will move farther away. That’s exactly how the universe has been inflating since the big bang. The surface of a balloon is space and the dots on it would be all the celestial bodies like stars, planets and asteroids.
Everything including matter, energy, space and time came into existence right after the big bang. Nobody knows what was there before big bang or if something like “before the big bang” had even existed or not. All our theories and laws break down at this point. So, if you believe in God, this is where he can fit in and take credit for an unexplained miracle. Though, I find it really hard to believe that the higher dimensional being, whosoever made such a complex design, would be anything similar to our current idea of God.
Right after the big bang, the universe was too hot for any kind of matter to exist. It was just a tremendous amount of heat and energy all across the universe. Slowly, it started to cool down as it expanded and small particles like quarks and electrons came into existence. Quarks then combined to form protons and neutrons, which in turn formed an atom with the electrons revolving around its nucleus. The first atoms formed in the universe were Hydrogen and Helium. That’s the reason they are still the most abundant elements in the universe.
Atoms combine to make molecules. Molecules come together to make proteins. Millions of proteins combine further to make a cell, which is the basic unit of Life. Cells make organs and organs combine together to make Us (Humans). A funny thing is that the cell isn’t conscious like we are. It doesn’t have any purpose or will. Yet, a combination of billions of cells (which is you) is not only conscious but also has a purpose and will.
It took millions of random selections and billions of years to reach from that first atom to the first living organism. Since matter can neither be created nor destroyed, it is possible that a few atoms in our body were landed on Earth as a part of an asteroid that washed away the entire species of dinosaurs. In fact, they might possibly be a part of a giant star that turned into a supernova before those atoms could silently sneak in the darkness to be a part of an asteroid. When they say you’re stardust, they might be stating a fact.
The big bang didn’t only create matter, it also created four fundamental forces that guide the universe and everything in it. A force named strong force binds the protons and neutrons in a nucleus of an atom. Another force called electromagnetic force is responsible for the structure of atoms, their interaction and chemical reactions between them. It creates an electromagnetic field which is the heart of all the modern technology we use today. The third force is a weak force that is responsible for the decay of particles and fusion reactions inside stars. All the bright stars are shining and producing heat due to fusion reactions inside them. The final and the weakest force is called gravity, and it happens to be my favorite. It is responsible for the attraction between all the matter in the universe.
Gravity causes tides in the oceans. It keeps the moon in an orbit around Earth. It also holds Earth in an orbit around the Sun, and the Sun in the orbit around the centre of our milky way galaxy. The bigger the objects are, the more powerful will be the gravity between them. Also, as the distance between two objects increases, the gravity between them becomes weaker.
Before the birth of the first star, there were only gas clouds expanding randomly across the universe. They were made up of the lightest atoms, which were hydrogen and a small amount of helium. Due to gravity, nearby atoms started attracting each other and kept growing into a bigger structure that ultimately started fusing the atoms into each other. That’s how the first star was born. The process of fusing atoms is called fusion, and it results in releasing a tremendous amount of heat and light energy. That’s the reason stars shine so brightly.
Hydrogen acts as a fuel that burns a star for billions of years before it finally runs out of hydrogen and starts dying. All important elements including carbon, nitrogen, oxygen, up to iron are made in the stars where excited atoms of lighter elements undergo fusion to make heavier elements.
When a medium-sized star like our Sun dies, it loses most of its outer layers and becomes a white dwarf before silently fading into darkness. However, a star 8 to 10 times bigger than the Sun dies a much more violent death with a powerful and luminous explosion called Supernova. All the rocky planets, moons and carbon-based lifeforms including humans exist because these giant stars blast their guts out.
As a result of the supernova, all the trapped elements in a star dance open in space. Around 4.6 billion years ago, one such explosion gave rise to our solar system. Heavier elements from a burst star formed the planets like Mercury, Venus, Earth and Mars, and they found a newly formed star to revolve around. We’ve named this star: Sun. The outer planets like Jupiter, Saturn, Uranus and Neptune are majorly made up of hydrogen and helium.
Despite being the weakest among all forces, gravity is still the most impactful force when it comes to heavenly objects. It brings everything closer and binds all the celestial bodies in an orbit around a nearby bigger celestial body. Soon after the formation of Earth, a smaller planet floating in space collided with Earth. This collision was so powerful that it created magma oceans that ejected lots of debris into space around Earth’s orbit. Over time, this debris started getting collated into a single body we call the Moon.
Our planet is at a perfect distance from the Sun to keep H2O molecules in a liquid form. Had it been a bit closer, they all would have turned into vapours. A bit farther and they would have been frozen. Due to being at an ideal distance from the Sun, and frequent bombardment with asteroids, Earth was fully covered in oceans after it was formed.
The first single-celled living organism was born around 4 billion years ago in an ocean on Earth. It took them more than 3 billion years to evolve into complex organisms, including fishes. After another few million years, land emerged from oceans due to tectonic activities. This was when the insects evolved as the first living species to crawl on land. Then, came the reptiles followed by mammals.
Dinosaurs ruled Earth for more than 100 million years before they got wiped out by an asteroid or meteor shower. After their extinction, the flowering plants dominated Earth, and the remaining species continued to evolve. Among those remaining species, some mammals evolved into Apes who were common ancestors of chimpanzees and humans.
The first humans evolved around 2 million years ago. Initially, we were not on top of the food chain like we are today. Our ancestors had to rely on local plants and leftovers of carnivorous beasts. Then they discovered fire and started making tools to hunt. This small discovery changed things drastically. They became hunter-gatherers and migrated huge distances in search of food without any fear. They didn’t have much in possession as they didn’t believe in staying at the same place. Any possession whatsoever would have made the travel difficult. For thousands of years, hunter-gatherers travelled in small groups of 100 to 150 members. A group shared the same space and raised children together. They hunted together and protected other group members from outsiders.
Around 50,000 years ago, a cognitive revolution took place. We can consider it a moment of awakening. Hunter-gatherers learned they can interact in a better way and tell stories. They can develop a language to communicate and form bigger alliances. They can make art and craft. This was the biggest breakthrough in human history and it gave us the power to outsmart any other animal ever walked on planet Earth. Humans became social animals.
In bigger groups and with better cooperation, our ancestors travelled the world. Around 10,000 years ago, they discovered that they can grow essential crops at their own will. They started settling around fertile land and planted wheat and rice. That’s how the hunter-gatherers became farmers and started living in the same place throughout their life. Our concept of home started with the agricultural revolution.
Some people grew rice, while others grew wheat or barley. That’s how we started trading things and came up with a barter system to trade daily essentials. Once our ancestors settled, they started keeping useful and harmless animals around them. Sheep, horses, pigs and cows became the foremost choice followed by dogs and cats.
Around 5,000 years ago, humans became so well behaved and cooperative that they started making civilizations where there were cities, workers, complex records for calculating trades and people to represent those trades. This resulted in huge demand for resources. To cope up with those demands and in desire for more power, different civilizations started wars. Many of them collapsed either due to a war or a natural disaster, and the rest of them converted into countries as we know today.
Over time, we kept ruling Earth as an undisputed species and our population grew. Demands for resources increased further and people became more privileged than ever. So, the big industries emerged and smart entrepreneurs introduced the world to a whole new era of modernization, where people can work for a fixed amount of time and get paid weekly or monthly. This was the rise of an industrial revolution that slowly turned a social animal into a corporate slave.
We have discovered electricity, motors and telephones only in the last 300 years. Two of the biggest wars in human history were fought in the last 100 years. The Internet was invented only around 40 years back. And yet we can’t imagine our lives without our smartphones, cars, air conditioners, refrigerators and TV sets that didn’t exist for the most part of humanity.
None of the great inventors in history was as privileged as we are today. And yet, it was their innovative insight into the future that gave us all the technologies and ideas. This is what makes our lives easier and helps us discover the secrets beyond space and time. They’ve led us to the greatness that made us gods among all other species living on planet Earth. We owe them a huge debt of gratitude and we’re capable of paying our debt, with an added interest.
This wonderful journey from being an infinitesimally small particle to being a godlike genius who is capable of perceiving the secrets of the universe is our own journey. We’ve travelled billions of years through space and time to be right here, at this very moment, where we’re conscious of our existence.