How Did The Universe Begin?

VOICE OVER: Ashley Bowman WRITTEN BY: Nathan Sharp
It's the ultimate question, and one that scientists have wondered about for centuries. Why is the universe here? And how did it start? There's still a lot we don't know about the origins of life, the universe and everything... But the experts have uncovered some secrets to our existence, with some theories more convincing than others!

How Did the Universe Begin?

The universe always has been, and maybe always will be, one of life’s most intriguing and terrifying mysteries. Its expanse and scope is simply unfathomable; Its mere existence is almost mind boggling; And the questions surrounding the universe stack up, and up, and up. What is it? Why’s it there? Does it ever end? And how did it begin?
First things first, our universe may not be the only universe in existence. Some scientists believe in the multiverse theory, or the idea that numerous universes exist side-by-side. According to this theory, different areas of spacetime grew at different rates of inflation after the initial creation, essentially forming different universes with their own unique physical makeup. Theoretical physicist Alan Guth even claims that “most models of inflation do lead to a multiverse”, and that the multiverse is an idea that should be taken “seriously”.
Another possibility is that we’re simply experiencing one specific phase of our universe, with some suggesting that it goes through a life cycle, with rhythmic phases of inflation and deflation. So, just as we’re currently seeing inflation as the universe gets bigger, it could one day deflate and start afresh, with a new Big Bang. If that’s true, we humans could be but a tiny fragment living through the thousandth - or even millionth - phase of the universe’s existence. Which feels comforting and terrifying in almost equal measure.
But when did our observable universe actually begin? It all started about 14 billion years ago with the Big Bang - beginning with what scientists call the Planck Epoch. The Planck Epoch was an unimaginably short period of time – so short, in fact, that there is no current theory to describe or articulate how short it actually was. In this inconceivably tiny period, all types of matter and energy, including gravity, were concentrated into an extremely small and dense state. And when we say small, we mean it. According to Stephen Hawking, the universe at its Planck size was about “a billion trillion trillionth of a centimeter”.
But what happened BEFORE even this? Where did the miniscule amount of matter come from? And how did it form into a tremendously tiny compact ball? No one really knows. According to Hawking, even Einstein’s theories cannot account for it, as they predict not how the universe began, but how it evolved thereafter. But, of course, there are some ideas.
One suggestion, like all matters relating to anything unexplained, is that God did it. In recent history, Pope John Paul II was reportedly open to scientists studying the universe, but he disagreed with debate over its origins. According to the religious leader, the singularity, the initial infinitesimal ball of energy and matter, was the work of a great and godly creator - and should remain insurmountable for science.
A more prevailing and scientific theory is that the universe began with a combination of general relativity and quantum theory. Stephen Hawking and James Hartle proposed that the origin of the universe is comparable to a pot of boiling water. At first, many microscopic bubbles (or universes) briefly form, but collapse before reaching the surface. Eventually, a few bubbles grow large enough and expand - or inflate - before bursting. This metaphorical process could match the Big Bang, with the universe beginning as a tiny, tiny bubble in the pot of spacetime before growing large enough to burst. But still, where did these space bubbles come from? One Hawking suggestion is that “the universe would be neither created nor destroyed. It would just be.” Which still sounds like a fancy way of saying, “No idea.”
Yet another theory makes use of the inflation and deflation principles from earlier. According to the Two-Headed Time Theory, there was previously another observable universe wherein time moved backwards for billions of years, and it deflated rather than inflated. This universe eventually shrank to a subatomic size before rebounding in the opposite direction, resulting in the Big Bang and our current and inflating reality. Will we eventually contract back and deflate again? If the ‘phase theory’ is correct, then yes. It’s the ultimate cycle of life.
So what exactly is (or was) the Big Bang? Essentially, it’s when our inconceivably small ball of matter exploded faster than the speed of light, separating the fundamental forces and kickstarting all of creation. Hawking explains that the universe expanded by a factor of a million trillion trillion “in a tiny fraction of a second”. And as it cooled, various subatomic particles started to form - throughout the quark, hadron, and lepton epochs. And all of that, happened over less than ten seconds.
The twenty or so minutes after the Big Bang is known as Big Bang nucleosynthesis - when various atomic nuclei formed through nuclear fusion, and the elements started to emerge. About one quarter of all the protons and neutrons in the universe were converted to helium. The majority of the other three quarters remained as hydrogen nuclei.
However, the first stable hydrogen atoms weren’t created until 377,000 years after the Big Bang - as part of a process called Recombination. This was also the first time that the universe began to take recognisable shape. As neutral atoms are transparent to wavelengths of light, the universe was finally an observable entity. In fact, this first light can still be found today in something called the cosmic microwave background - or CMB. A remnant of the Big Bang and Recombination, the CMB is a form of detectable electromagnetic radiation, and is observable as a faint background noise in the dark spaces between galaxies and stars.
Eventually, there formed concentrations of dark matter, an as-of-yet unseen state that scientists believe makes up around 80% of the total matter in the universe. Clusters of regular matter were drawn by gravity to these pockets of dense, concentrated dark matter and eventually clumped together to form stars and galaxies. That’s the theory, anyway! From there, the universe expanded over billions of years, propelled by dark energy - another unknown and unseen energy form that’s accelerating the inflation of space.
Our little Earth was formed about 4.5 billion years ago, so about nine billion years after the creation of the universe. Homo sapiens didn’t evolve until 315,000 years ago, and modern humans emerged only around 50,000 years ago. The ideas of cosmic expansion and a theoretical Big Bang weren’t even popularised until 1927. So, it’s amazing how small we humans are within the universe as a whole.
The concepts of dark matter and dark energy are still relatively uncharted territory for even our greatest scientific minds. So, while we may have an inkling as to the creation and inner workings of the universe, we are still a long way from true enlightenment. Where the universe came from, what it is, and how it functions are still major questions that have yet to be answered, and in fact may never be answered in our lifetimes. But the universe goes on, with or without us, into an incredible and unforeseeable future.