Intro to Cosmology

What happened before humanity existed? How did everything around us come about? Will one day our universe end? These are all questions relating to the study of Cosmology. Cosmology is the study of how the universe came about, works, and how it is changing. Cosmology, also known as Big History, basically takes history to a much, much wider scale going all the way back to the Big Bang. We are writing this series of articles based on the Crash Course Playlist Big History. In this article we will be talking specifically about the Big Bang, what happened during the big bang, and cosmic background radiation.


The Big Bang was the beginning of when space and time were created making spacetime 13.8 billion years ago. “Big History” starts at the beginning of everything, because there wasn’t really a then before the Big Bang because there was no space or time. A concept we all struggle to understand. So, don’t feel bad if this isn’t making crystal clear sense, we’re all confused. The story of Big History starts at the Big Bang, but also ends many billions of years from now when the universe dies. Yes, we do believe that the universe will die in around 200 billion years.


The Big Bang was when the universe started expanding from nothing extremely quickly. When the Big Bang happened, it expanded to something a billion times larger than the universe we have today. Then, all matter except one billionth of it was annihilated making the one billionth, all matter that exists. All the stars, planets, galaxies...all of it, only one billionth of what was first created when the Big Bang happened. At first, the only elements were hydrogen and helium. But, then one day they started to combine making pressure and heat forming stars.


Cosmic Background Radiation was the leftover radiation of the Big Bang. And that radiation is used for many electrical devices we have today. Cosmic Background Radiation is also probably the best evidence we have for the Big Bang theory too. We can see what was happening 13.8 billion years ago happen on the stuff 13.8 billion light years away since the light traveling can only go so fast. So we can clearly see that there was nothing happening 13.8 billion years ago when the big bang happened. Not only that but we can also study the series of events in the universe by listening to the Cosmic Background Radiation and studying the disruptions. This can help us discover what happened before humans existed.


In this article we talked about the big bang, what happened during the big bang, and Cosmic Background Radiation. Cosmology is one of the most fascinating subjects because you are able to see how the universe took shape to the world we know today. Because the truth is, humans are only a speck in the universe and have only existed for a minuscule amount of time. There still are many unanswered questions and seemingly impossible theories such as how time did not exist before the big bang.


Sources: https://youtu.be/tq6be-CZJ3w?list=PLYIgTSXNWR9xsG49lJY3ujeW8ROmnZmm4

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