Was the Big Bang Actually the Beginning?
Physicists now think inflation happened first
Hiya!
I’d bet that just about every person has looked at the night sky and wondered how it all began. I know I have. What, or who, created the universe and when? These are some serious questions humanity has sought answers to since we developed the ability to do so.
Scientists, too, want answers and have spent hundreds of years searching for them in our skies. For the last few decades, most of us were taught that everything in the known universe exists thanks to the Big Bang. However, there are some things the Big Bang theory can’t explain, and not everything we observe matches it. Now, new evidence shows that the big bang wasn’t the beginning, that inflation came first. And it explains some of the things the big bang doesn’t.
The Big Bang Theory
For almost a hundred years, the Big bang theory has been the leading explanation for how everything in our universe, including the universe itself, came to be 13.8 billion years ago. Belgian cosmologist and Catholic priest Georges Lemaître presented the idea in 1931.
At the time, scientists were still reeling from the discovery that the universe was rapidly expanding, but Lemaître observed the news with curiosity. Lemaître proposed that the entire universe, and everything in it, began with a single particle explosion at a specific point in time — now known as the Big Bang.
He rationalized that if we can look in one direction to see the universe expanding — becoming less dense and cooler in the process — then looking the other direction should show the universe as denser and hotter. Which would theoretically intensify until reaching a point of origin, a singularity.
Lemaître’s train of thought might seem obvious today, but other experts at the time couldn’t conceive his theory. It was just too much to believe during such an orthodox period.
Of course, since then, scientists learned the Big Bang theory explains more than most other explanations. Though there are some inconsistencies. Most notably that our conclusions around the big bang don’t align with what we see in the universe. So either the big bang is wrong, or it’s not the entire explanation.
Most of us today simply accept the Big Bang theory as the Truth because it doesn’t appear anyone has come up with any other, better, theories in the ninety-one years since Lemaître proposed it.
Some scientists stopped trying to disprove the Big Bang and instead started wondering, What came before it? Some physicists already figured it out — they just didn’t realize it. Now, after reviewing past findings experts are pretty sure of the answer, at least closer to it.
Cosmic Inflation Theory
An inflationary universe was confirmed as a possibility back in 1917 by Willem de Sitter. He discovered the key for an empty universe with a cosmological constant — which describes a rapidly expanding universe.
Essentially, the conditions of de Sitter’s universe would stretch the universe flat, giving the same properties — i.e., the same ingredients and temperatures — everywhere, remove all high-energy relics, and cap off the max temperature reached after inflation ends. Though at the time, this idea was nothing more than an interesting mathematical find, not a plausible explanation for our universe.
Then, American physicist Alan Guth built on de Sitter’s constant universe by developing the theory of cosmic inflation back in 1979. Proposing that all energy isn’t within radiation or particles but in the very fabric of space — which would lead to something like de Sitters expanding universe.
In 1997, Guth published a book titled The Inflationary Universe in which he writes:
“the standard Big Bang theory says nothing about what banged, why it banged, or what happened before it banged. The inflationary universe is a theory of the ‘bang’ of the Big Bang.”
In short, Guth’s idea of cosmic inflation is the act of expansion itself. At one point, all matter, including radiation, existed only as potential energy. Then, that potential energy exploded for some reason, resulting in a stretching and expansion of space.
I know, it’s confusing.
Okay, think of it this way. While the Big Bang indicates that all matter exploded into space from a tiny singularity. Inflation is the expansion of space itself. Inflation takes space and stretches it — taking an extremely hot and dense universe and expanding it into a cooler and less dense one by extending space. So, Inflation stretched space, and the big bang filled the space with matter.
Notably, unlike the big bang theory, inflation theory doesn’t lead back to a singularity. It just points back to something scorching hot and dense that explodes and expands once it reaches too much pressure. Inflation is also ridiculously fast. I mean, all of the space within our universe exploded into existence within a trillionth of a trillionth of a second.
The idea of cosmic inflation answers all the questions left by the Big Bang while also accounting for everything the Big Bang does. Unfortunately, I don’t have the time or space to discuss each one, but if you want to explore on your own, you can check out this article by Big Think which I found interesting.
Perspective Shift
Phew. This is a complicated one. It even took me a couple of days to wrap my head around it. Some physicists think a theoretical particle called the infaton particle would presumably be responsible for cosmic inflation. That inflation stretches space via pent-up potential energy made of infaton particles, then when inflation ends, the infaton particles settle and potentially become matter.
See what I mean? With new answers come a flood of further questions. Even with the big bang and now inflation, we still don’t know what started the inflation or when. Maybe a, or many, supreme beings are responsible. Or perhaps inflation was caused by something else. Who knows?
The point is, we should always keep an open mind and be cautious of binary thinking. How, when, or why the universe began won’t change diddly squat in our daily lives and therefore isn’t worth getting defensive over. But, remarkably, you and I were alive when science finally reached beyond the Big Bang. And that, is pretty awesome.
