00003:The Evolution (1)

Space....

When we think about space, the things which strike our mind are Astronomy, stars, darkness...etc. 

So, Astronomy is the study of Universe, but there is an interesting branch of Astronomy, which is Cosmology. 

Cosmology is the study of the beginning and the evolution of the universe. 

 
 

Scientists have been searching for the beginning of everything & how this universe has been created ; Which remains as an unsolved question. 

The main theories that show how universe has been created are: 

1. Big Bang Theory 

2. Pulsating Theory 

3. Steady State Theory  

 
 

Though there are many such theories describing the birth of universe, Big Bang Theory is considered as apt cosmological description of the Universe. 

 

One day, nearly 14 billion years ago, something extraordinary happened. 

                     Our universe was born. 

 

The timeline of the big bang expansion is as follows:

1. Time = 0: Big Bang
2. Planck Era
3. Inflation
4. Quark Era
5. Hadron Era
6. Synthesis of light atomic nuclei
7. Radiation Era
8. Recombination
9. Dark Ages
10. Cosmic Down
11. Structure Formation
12. Birth of the Solar System 
13. Time = 13.8 billion years : PRESENT DAY

Timeline of the Big Bang

As this theory suggests, Universe started from Singularity... 

 
 

Everything around you, what you see, what you feel, your books, the air you breathe and everything around you were born out of a single moment of creation. 

Universe was not formed out of explosion; it was a process of steady expansion. Even now, the universe is expanding and it will be expanding continuously every single moment.  

 
 

What is the size of the universe...? 

We cannot determine the exact size of it, but a bit of what we can see spans some 92 billion light-years. 

A Light-year is distance travelled by light in one year and you know how fast light travels, it travels with a speed of 299,792,458 meters per second, now how big is a billion, it is 1000 million!!  

Imagine, how big is this Universe if just the little observable part is 92 billion light-years long... 

 
 

You cannot even imagine how big the Universe is, it is that huge.

As space expanded and cooled, atoms and molecules of matter condensed together under gravity to form the stars, galaxies and even the planets which make up the majestic night sky today..

" The very first galaxies actually grew from the seeds sown in the heat of the Big Bang "

What we can see of galaxies now is just the tip of the cosmic iceberg. 

There is invisible material about 5 times that of visible material in the Universe , which is correctly called "Dark Matter".

Thank you for reading, more to be continued in the next one!