The Beginning of our Universe: The Big Bang

Have you ever wondered what led to the beginning of our beautiful universe? Well, we cannot say for certain, but with all the scientific evidence we have it is most likely The Big Bang. 

The Big Bang Theory is a physical Theory that suggests how the universe might have been formed. 

The theory suggests that before the universe was formed there was a dense and super hot point. This point which had no atoms and no structure is said to be a singularity. Now this singularity went through extreme hot which resulted in its rapid expansion and subsequent cooling. This expansion continues until today and will most probably continue for a long time. 

This whole event was named The Big Bang. 

The first person to propose that the universe might be expanding was Georges Lemaître in 1927. 

His proposal was confirmed by Edwin Hubble two years later.

We also have evidence to back the Big Bang theory. It is a phenomenon called cosmological Redshift which occurs due to the Doppler effect of light.

When an object moves far from us (I am talking light years), it takes light a lot of time to reach us. Due to this, the wavelength of light stretches and the light reaches the end of the spectrum and appears red.

As I told you before, the universe is continuously expanding, the space between expanding, leading to our galaxies moving away from each other. This leads to cosmological redshift, and Redshift is used to determine the distance between two heavenly bodies.

Some people have suggested some alternatives to thw Big Bang theory. The most popular ones include The Steady State Theory, Eternal Inflation, etc. However, these have been rejected by most cosmologists.

If you have any questions, or if I made any mistakes, or you want to me write about a topic, feel free to comment! 

Astrobiology: The search for life

Astrobiology is a field of space science that focuses on the origin, evolution, and future of life in our universe. It combines principles from astronomy, planetary science, geology, oceanography, etc. 

Astrobiology explores the origin, evolution, distribution, and future of life. 

In simpler terms, astrobiology tries to uncover the following topics:

~The conditions in which life began on earth and how it evolved and adapted according to the climatic changes over the years;

~ Whether life can exist outside the earth, and if so, where does it exist? 

~The future of life on and outside Earth; and

~ The indicators of life, which suggest that life may exist or may have existed at a place. These indicators are called biosinatures.

These are profound questions that have puzzled humanity. The answers to these questions would amend the fate of humanity and lead to new paths of development. And that is why astrobiology plays a significant role in space science.

The Fermi Paradox: But where is everybody?

"But where is everybody?", said the Italian physicist Enrico Fermi in 1950. 

In the statement, he was trying to say that the universe is billions of years old, which is why there are high chances of life, even intelligent life to exist somewhere. However, we merely have any evidence of or had an interaction with a such civilization. 

In simple words, this theory asks, "If they exist, why don't we know about them?"

Just to be clear, the theory doesn't deny the existence of extraterrestrial life in any way, instead, it asks why haven't we met them yet. What is stopping us? 

Whether extraterrestrial life exists or not has been a topic of debate throughout the history of space exploration.

So in this post, I'd be covering the most popular theories as to why we haven't come across any intelligent civilizations outside our earth.

THE GREAT FILTER:- The first theory states that there is an obstacle or a hurdle, an unknown force that prevents civilizations from reaching the point of being interstellar. In simple words, every civilization has to perish before another comes into being. This means that there could have been civilizations here, but before we were formed, or civilizations would exist after we are gone.

DARK FOREST THEORY:- This theory lays down the idea that civilizations exist at the same time as us, but they don't want to be known or want to know about other civilizations, fearing destruction. 

THE ZOO HYPOTHESIS:- This theory says that maybe civilization, exists, they have developed enough to detect us; but they want to interface with our lives, because of ethical reasons. Just like in a zoo, we observe animals but never try to bother them.

THE RARE EARTH THEORY:- This theory suggests that we are alone, just alone. The conditions needed for life to exist are unique to Earth. 

WE CAN'T DETECT THEM:- This means that intelligent life exists, they are interested in exploring life outside the earth. However, we cannot detect them because they are really far from us.