For as long as humans have been able to think deeply enough to contemplate our own existence, we have wondered about the beginning of time and where we, and everything else in the cosmos, came from. There have surely been as many thoughts and ideas on this topic as there are people to imagine them. Many of the early theories are still around today in the form of religion. Other theories developed over the centuries have involved evolution, alien visits and perhaps, no beginning at all.
To understand where we came from, we must first understand how the universe came to be. In the past century the scientific community has arrived at a theory that today, has become widely accepted as fact by that community. The Big Bang has become almost unanimously accepted by scientists worldwide as the event that started everything. Everything that exists in the cosmos was launched by the Big Bang. Every quark, every atom, every molecule, every moment, every day, every thought, every beam of light, every sound, every breath of life, all directly descend from the Big Bang.
What was this spectacular event, how did it happen, when did it happen, and how do we know it happened?
Or, did it happen?
The theory follows the logic that in the beginning of time – or at least as far back as we have evidence for – all matter in the universe was compressed into one point, smaller than the head of a pin, known as a singularity. All of the billions of galaxies, filled with billions of stars, billions of planets, moons, comets, asteroids, black holes, dark matter and anything else, compressed into one massively dense point in space – less than the size of a pin head.
Then, at one moment in time, about 14.5 billion years ago, for an unknown reason, this point of matter exploded in a fury of heat and gases and began violently expanding outward at an enormously rapid speed, at an unimaginable temperature. As it all expanded, this material, in the form of hydrogen atoms, flew outward through space, the atoms attracting each other through the force of gravity. Over millions of years they gathered in clouds, then millions more years on top of that, so large and so heavy that they could generate their own energy through fusion – they became stars.
As these stars attracted more and more matter, they became so big and heavy, occasionally they would explode in a Super Nova, creating new atoms, new molecules and new elements. Over time these elements gathered together and became meteoroids. These meteoroids also attracted more and more matter and developed powerful gravitational fields of their own, until they became large enough to be considered asteroids and then planets. This was the birth of a solar system, which then attracted other solar systems, other stars and, eventually, galaxies formed – billions of them.
That is the essence of The Big Bang Theory. But, how do we know this all happened? Where is the evidence?
The Big Bang was first theorized decades ago when it was observed that almost all galaxies in space are retreating from our point of view. They are travelling away from us no matter which direction we look in the sky. There is no direction we can look where the galaxies are heading toward us. *
Imagine standing in a large, grassy, field and looking around yourself and seeing millions of butterflies, all flying away from you. Everywhere you look, butterflies flying away, but they aren’t all flying in the same direction; some are flying north, some south, some west, some east and some in all directions in between. The only thing they have in common is that they are all flying away. None are flying toward you, none are flying perpendicular to you, all are leaving from your point in the field.
From this observation, what could you conclude about the past location of these beautiful butterflies? You could conclude that they all began their journey in the location you are standing now. Couldn’t you?
Keep in mind, butterflies can do something galaxies can’t do; they can flutter, and they can change direction. Galaxies, on the other hand, travel in straight lines, so, since all galaxies are travelling away from us in all directions, we can conclude they were once in the same location, or at least, the same vicinity.
Imagine the massive quantity of matter in the universe. Just the planet Earth on its own is hard to grasp, but with the help of maps and globes we are able to do it. Now consider the difference in size between the Earth and the Sun. If the Sun were the size of a beach ball, the Earth would be the size of a marble. Now imagine trillions of stars, many the size of the sun, many larger. The singularity, the object in space prior to the Big Bang, contains all of this compressed into a point the size of a pin head. The concept seems unbelievable, doesn’t it? How could so much matter be compressed into such a tiny space?
If you have difficulty believing this theory, you are not alone. As I have read about it in books over the years, I have found it difficult to accept. I couldn’t get my head around it. However, I reluctantly believed it. Why? I believed it because it was fully calculated, analyzed, scrutinized, debated, evaluated, and even observed by the greater scientific community.
As years went by, I began to hypothesize for myself; not in the sense of coming up with a new theory; I hypothesized it in this way: over the centuries there have been many scientific theories that have been widely accepted by the scientific community for a significant length of time, only to be proven wrong when some new evidence comes to light. This happens often, and to be fair to scientists, they assume this disclaimer in their theories.
So, I hypothesized that the big bang theory would eventually suffer the same fate. Something else would be discovered that would replace it.
Then it happened. One day I picked up Katie Mack’s book: The End of Everything.
Katie Mack is currently sitting in the Steven Hawking chair of the Perimeter Institute in Waterloo, Ontario. I’m giving Katie all of the credit here, but there may well be other books that cover the same information.
There is now a revised big bang theory (it still has the same name) which allows for a much larger point than that of the head of a pin (the singularity). The theory now allows for all of the matter of the cosmos to be in a compressed form everywhere or anywhere in space. Space itself is believed to have been much smaller in size 14.5 billion years ago, because it has been expanding ever since. It is the fabric of space itself that is expanding along with the matter and that is the cause of the observable retreat of all galaxies from one another.
Beyond the initial singularity, the Big Bang Theory has not changed. Everything else still stands. It remains, and probably will always remain as the widely accepted (by the scientific community) theory of the beginning of the universe.
BT
*The exception is our closest galactic neighbour, Andromeda, which is on a collision course with our galaxy, The Milky Way. The two galaxies will converge millions of years in the future and become one galaxy. We know if a galaxy is approaching us or retreating from us by the way it is colour shifted when viewed through scientific telescopes
