For centuries, human beings have looked to the sky for answers. Where are we? Who are we? How did this all begin? While philosophers will continue to battle the answers for centuries to come, by looking up to the stars as we have always done, we are the closest we have ever been to understanding how the universe was created.
The Big Bang:
About 13.8 billion years ago, the universe as we know it didn’t exist. Instead, it was about the size of just one single atom. In a time period shorter than a fraction of a second, the universe underwent something known as inflation – it expanded in all directions and dispersed all over, faster than the speed of light. Scientists theorize this event happened because of a groundbreaking observation; the galaxies, planets, and stars, are all moving away, and still expanding from the massive force of the Big Bang.
The mysterious force behind the bang:
All of what we know about the universe comes from a detailed analysis of lots of information we pick up from what’s out there. However, although the Big Bang is a theory accepted by most scientists, there is still a lot we don’t know about what happened in this event. For example, it is still unclear where the mysterious force that propelled our universe came from. One fascinating theory might answer this question: the presence of dark energy. The mysterious dark energy is what is thought to have a significant role to play in the expansion of the universe. It exists in the universe even now and is believed to be the reason for the continuing growth.
The formation of atoms:
Atoms are the building blocks of everything we see around us. First came some of the elementary particles you may know – neutrons and protons. The matter from the universe fused together to form each elementary particle. Within a few minutes of the universe’s creation, the particles fused together and the first atoms formed. You may be wondering what happened to the ‘other’ elementary particle, electrons. Well, those were formed after about 300,000 years, when the universe had cooled down enough. This was a monumental climate change; they fused with protons and neutrons to develop the most abundant gas in space; hydrogen.
The first stars light up the universe:
Until the first stars shone about 100 million years after the big bang, the universe was in complete darkness. However, it was far from idle. In the dark, the particles of gases and matter continued to fuse together, being pulled in by a force we know as gravity. These fusions were what created the stars, the first objects to emit light into space. The stars weren’t the only new celestial bodies in town though; slowly galaxies formed, with planets, gravitational pulls, satellites, meteors, and more. Stars like this formed all over the universe, even within our address in the universe, the galaxy known as the Milky Way.
The formation of the solar system and Earth:
Skipping forward to about 9 billion years since the big bang, we come to a particular moment in time for humanity – the creation of the sun. This means our sun is currently 4.5 billion years old. But don’t worry, it’s still quite young, and is expected to shine brightly onto the solar system for billions of years to come. The solar system is theorized to have formed from a spectacular explosion known as a supernova – when a star dies, and its matter explodes outwards into space. This matter then condensed to form the bodies of the solar system, forming the sun, the planets, and our home, Earth.
The birth of life on Earth:
Our journey on Earth hardly ends at its birth – Earth had a rough childhood. The planet was devastated several times by significant collisions; one of which ended up creating its sole satellite, the Moon. The simplest forms of life, formed about a billion years after the Earth, and it took about 2.5 billion more years for multiple-celled organisms to come about. Within 500 million years, the Earth was home to insects, fish, and even early amphibians. Skip forward another 300 million years, and that’s when mammals came about. A disastrous event, a meteor blast that killed the majority of dinosaurs about 65 million years ago, gave small mammals the chance to grow and propagate – which, 200,000 years ago, led to the existence of modern humans.
Are there alternate theories for the creation of the universe?
The Big Bang theory is widely understood and respected in the scientific community. However, some varying views might explain some things the Big Bang leaves murky. The ‘bounce’ theory is interesting. It states that the universe bounced and expanded from another universe that was contracting. This process would theoretically repeat itself and create a succession of universes, contracting and growing into and out of existence.
What does the future of the universe look like?
The universe has had a long, impressive past, filled with excitement, drama, and monumental events that have impacted human life in every single way. The question arises – how is it all supposed to end? Sadly, the universe will not live forever, but theories try to predict how everything will end. For our home, the Milky Way, there is a collision underway with our neighbour, the Andromeda galaxy. Although, there is no reason to worry just yet – this collision is not due for another 4 billion years, and will not be the devastating explosion you might imagine. The empty space in the two galaxies will merge, and create a new galaxy altogether. As for the universe – scientists have studied the way the universe is expanding for many years. Remember the dark energy discussed above? It is still affecting the way the galaxies propel forward. But there is less matter now because it’s all dispersed away. The dark energy, though, hasn’t changed. Meaning the universe is actually expanding faster and faster. Eventually, everything will move so far away; it will no longer exist within the visible universe. Without matter in close proximity, the last stars will die out and the universe will be enveloped in darkness again.
This end of the universe may seem melancholy, but it is not definitive. In the last few decades alone, leaps have been made in our knowledge of space, time, and the universe itself. There may yet be a hidden answer in the creation of our home that helps us understand our future better. That fraction of a second – the big bang – will continue to be a question that gives us insight to our cosmic address for many years to come.
