BIG BANG THEORY.WHY SHOULD WE BELIEVE IT?

 How the universe was made ? 🤔... By the Big Bang around 13.7 billion years !!! ago 😑. well that's what people told us , right? but how do we know when universe was created ?? because no one live that loooonnggg...😅. but before solving that , I have to give a bit of intro about the BIG BANG THEORY... 

So all of you, get ready to listen some very boring stuff🥱🥱 

The big bang theory says, that around 13.7 billion years ago, everything which exist in this universe was compressed in a single dot of size smaller than an atom.

and because of some mysterious reason, that tiny dot exploded. and everything stared to form, after about one million years the gas started to condense and form Protogalaxies, during the next  bla.. bla... bla.. blaaaaaaaaaaaaa..... ( 2 hours of reading later 😅) today billions of years later the universe as a hole still expanding.

  

 BUT NO ONE EVER TELLS...

HOW DO WE KNOW THAT IT IS EXPANDING?😡

AND WHO MADE HIS THEORY?😡😡

WHY IT IS WIDELY ACCEPTED ALL OVER THE WORLD?😡😡😡

AND HOW DO WE KNOW WHEN BIG BANG OCCUR? 😡😡😡😡

IF YOU WANT TO KNOW ANSWERS FOR All, THESE QUESTIONS THEN STAY TOONED AND READ THIS POST TILL END

(Well if you had read till here without getting your head burst 🤯🤯... ( Then congratulations 🎉🎊 you are a nerd 🤓)... Just a joke don't get offended 😅 ...

  
IMPORTANT NOTE - If you want to use this Content for commercial gain (for e.g. making a video or publishing your own post) you can't just copy and paste the content of this post ... you have to make your own script and have to do more research on your own for commercial use. 

1st we are going to clear the question- "How do we know, that our Universe is expanding"

I am going to take you through a timeline, so that we can understand everything step by step ... 

1927

before the 1920s most of the scientists believed that our universe is Static.But, in 1927 a professor of physics, Georges Lemaitre,found that, 

our nearby galaxies is going far from each other,it means that the contents of the galaxies ( planets and stars ) is also going far from from each other , 

this conclude that everything in this universe is going far from from each other.(Note -  before Lemaitre many other Scientists proposed that, structures of universe is going far from each other)

refresh your mind with this-



Lemaitre explains this by universe expansion, means he said, our nearby galaxies is going far from each other because, " our universe is expanding"

but why  ? what is the connection between these two?... 

for that we have to do an activity 

1.Take a balloon and draw some circles on it 😅.

2. now inflate it .

3. You will observe that the distance between the circles is increasing. 

Now assume the balloon as our universe 😅 and the circles as the structures of the universe ( planets, stars, dust clouds etc...)


means if the contents of the universe is going far from each other, then we can also say, that our universe is expanding.

After more advanced observation in 1929 by Edwin Hubble  from Mount Wilson Observatory, provided the experimental evidence that confirms the universe expansion.

But if everything in this universe is going far from each other , than why we can able to stand on earth ??? and our most nearest galaxy (Andromeda) is coming towards us... 

so that didn't make any sense right?..

answer for this is - Gravity and dark energy 

dark energy is something which causes our universe to expand ( its like filling more air in the balloon) we can’t see or feel it but it exist , we can only see and feel its effect ,

 but there are localized areas where , gravity is powerful than this dark energy, and held objects together .. for e.g. our sun is holding the entire solar system together, 

because of his so damn powerful gravity, and powerful gravitational force is also responsible for attraction of Andromeda galaxy, towards us.

Now lets head to the second question - 

who made big bang theory ?

Now in 1931 Lemaitre proposed another theory called primeval atom. In which he claims that , if our universe is expanding, then 

by reversing the time we can see it getting more and more compressed, and eventually a time will come when we reach to singularity. 

And from here the "origin of everything, THE BIG BANG THEORY ORIGINATED."

Now here comes the last question -

How do we know when big bang occurred ?

well for that scientists look for the oldest thing in our universe ..
and currently the oldest one is a galaxy name - GN-z11 . which is 13.4 billion years old.. 

(some people also say that the oldest thing is GRB 090423, which was a gamma-ray burst, but i found
GN-z11 more promising.)

and if the first star is born around 0.3 OR 0.4 billion years ago then,

we can say our universe is 13.7 or 13.8 billion years ago.

But we still haven't observed our all of the universe, right?... So that means we still can't say the age of our universe 😅😅😅😅😅😅.. 

But, is big bang can be believed widely, only on the basis of universe expansion? no right?, so the second pillar that support the big bang theory is – Cosmic microwave background radiation, CMB.

I had already explained about it, in a very simple language in a different post, to redirect on that, click here.

Well that's it for this post... but there is lot more to understand about the big bang theory, but reading it will be kinda too boring, that's why i am currently working on a Youtube video, where i will explain about this theory in more details with the help of some cool motion graphics..

that video will be out in mid March 2020, on this channel - https://www.youtube.com/channel/UCtN4Ju1OG2qrx5SmQ0LjMmg