When was the Big Bang?

The origins of the universe have long been a hot topic of conversation among our greatest minds, and the big bang is a firm favorite for reconstructing our planet’s timeline.

Still, surprisingly few of us understand what the big bang was and, more importantly, when cosmologists think it happened.


Understanding the big bang

Before you can delve into the timeline of the big bang theory, it’s vital you understand what it is.

According to big bang theorizing, the universe began life in a bubble that was smaller than a pinhead and hotter than we could imagine. That sounds somewhat different from what we know now, doesn’t it? Which leaves us wondering; how could a scorching hot pinprick in space turn into the astounding universe we exist in today?

The title suggests a big bang might have played a part, but that isn’t exactly true. More, the big bang began was a sudden expansion that allowed that tiny atom to expand to be more substantial than a galaxy in a fraction of a second.

As the universe expanded and cooled, the energy within began to transform into both matter and antimatter. While antimatter destroyed much of that matter, some survived to become the protons and neutrons. All while our universe was but a second old!

That’s a lot of action in a single second, and the big bang doesn’t stop there. While our universe was boiling in its pre-bang form, this rapid expansion caused it to cool drastically, allowing those protons and neutrons to come together and form both hydrogen and helium nuclei. As many as 9.1 billion years later, this led to our universe as we know it.

To summarize:

  • The universe began life as a tiny, incredibly hot bubble
  • Rapid expansion occurred
  • Within this rapid expansion, the universe cooled drastically
  • This cooling allowed for the forming of protons and neutrons
  • This led to hydrogen and helium nuclei


What evidence is there?

Of course, scientific minds don’t merely pluck theories like these out of thin air. They look for evidence first, and you should too. Luckily, there is some pretty strong evidence in defense of the big bang idea. For those looking to either prove or disprove that the big bang happened, it’s worth considering key factors such as –

  • The universe is still expanding today
  • Microwaves (otherwise known as the afterglow from the big bang) can still be seen
  • Recent discoveries of ancient gas clouds suggesting big bang have been found in space

No one can confirm whether the big bang happened because life, and even space, didn’t exist. Still, there are many telltale signs of universal expansion, even today. Space especially offers strong evidence thanks to the ability it provides to view things that happened billions of light-years ago.

It’s certainly impossible to argue that the big bang theory provides more fact-based evidence than any other origin story. That’s why the big bang theory is the most widely respected and taught of our time.


Where did it all start?

While the big bang theory has stood the test of time, few of us realize where it all began. Or, in other words, who exactly discovered the argument. In reality, the history of the big bang theory involves input from a variety of great minds. Albert Einstein’s theory of relativity certainly played a part, and Alexander Friedmann first discovered the universe was expanding.

Still, its thanks to Belgium astronomer and priest, Georges Lemaître, that the big bang theory began to take place in 1927, though he referred to it as the ‘primeval atom.’ Edward Hubble went on to develop this concept in 1929 when he further explored Firedmann’s original ideas surrounding universal expansion using the world’s largest telescope.

From these building blocks, the big bang emerged as a popular concept among various astrologers. The theory took on new heights when Arno Penzias and Robert Wilson found evidence of cosmic radiation that seemed to prove expansion. And the rest, as they say, is history.


The timeline

Now that you know the big bang basics, it’s time to answer the most pressing question of all – when was the big bang? Or, at least, when do our astrologers think it happened?

We can say with some certainty that the big bang happened around 13.8 billion years ago. It’s thanks to this knowledge that experts have been able to provide an astoundingly accurate big bang timeline. In fact, some scientists have dedicated themselves to mapping the universe from the date of the big bang to the modern-day!

That’s impressive stuff, and we’re going to take a brief look at the timeline they’ve developed.

Within the 1st second of the big bang

  • The Planck era – the closest we get to the beginning to time
  • Grand Unification Era – when super forces begin to break into constituent forces we see today
  • Inflationary Epoch when the expansion of up 90xs occurred
  • Hadron era when electrons and neutrons annihilated each other

One second after the big bang

Universe cools enough for nuclear fusion that facilitates the formation of hydrogen nuclei.

Three seconds after the big bang

The universe becomes too cold for further nuclear reactions. At this stage, the universe consists of around 80% hydrogen, 20% helium, as well as trace amounts of deuterium and lithium.

Three hundred thousand years after the Big Bang

Recombination Era – The universe has cooled enough to form the first stable atoms. By the end of this era, it will be 75% hydrogen and 25% helium and finally transparent to light.

9.1bn years after the big bang

Gas and dust start to collapse and collide to form the Earth, moon, and planets.


A final word

The big bang theory remains the most viable idea of how our universe began. Even today, new revelations are coming to light in support of this idea. That’s why it’s so vital that we understand both when the big bang happened, and the events that our greatest minds suspect happened afterward.

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