First of all, The Big Bang Theory should be called The Big Bang Model. Just like the Theory of Evolution should be called Evolution. The Big Bang is the cosmic event that started the entire universe. So what exactly happened? Well, it took scientists years to find out what exactly happened, but we finally have a somewhat complete idea of what happened.
This whole thing started with a singularity. The singularity is our whole universe, compressed into something smaller than a grain of sand. It’s even smaller than an atom. So for whatever reason, it implodes. Like, it goes KABOOM. All the information of the universe balloons out at blinding speed. This is where things start to get kooky.
There are 4 fundamental forces in physics: Electromagnetism, Gravity, the Strong, and the Weak force. At the beginning of the universe, all these 4 forces were united. As time passed on, (by time I mean a few milliseconds), these forces split off from one another. Gravity was the first to jump ship. Strong leaves next, leaving the “Electroweak” force left. Then those two split. A main goal of physics in the 21st century is to mathematically prove that all four forces can exist in the quantum model. The EM, strong, and weak force all fit into the quantum model because they all have force carrying particles. But gravity does not. What’s a force carrying particle? Check this page out.
So now we have 4 distinct forces. But we don’t have protons and neutrons yet. That’s because they are made of quarks, a fundamental particle. It was too hot for the quarks to come together. Now, with the temperature cooled slightly, the quarks could come together. But nothing would happen for another 400 thousand years. It was too hot for atoms to form. Then elements formed, then stars, then heavy elements, then planets, then earth, then life, and you know the rest.
I hope you enjoyed this article!
(It was also Einstein’s birthday on the day of writing.)
Note from the author: This article was written in 2021 on my old blog on medium. I am reposting it here for archival purposes. This article has been modified to fit the new blog.