Ever wondered as to why we have not found any aliens up till now? Well, there are many theories as to why we have not found any aliens but at the end of the day they are just theories and they all try to answer the same question that is asked by The Fermi Paradox stated by an Italian-American physicist Enrico Fermi. The Fermi paradox is the striking counterstatement between the unavailability of evidence of extraterrestrial life and various higher estimates of their probability.
Try to guess as to how many stars are present in just our milky way galaxy. According to the NASA scientists, the universe has around 100-400 billion stars in our milky way galaxy.
In the above image, every single dot of light is a star except for the centre, which is a black hole. In 2013, NASA said that there are more than 40 billion stars that have planets in their habitable zone – the zone where water can be found and life can thrive and, approximately 11 billion of those stars are of the size of our sun. After considering the fact that our star is very young on a cosmic scale and life might have much more time to grow around other stars but the question still arises, “Why have we not seen any alien life yet?“. That is the exact question asked by Enrico Fermi in The Fermi Paradox to which there is still no concrete answer till date.
Although, some popular theories try to answer the question asked by The Fermi Paradox which is addressed further in this blog. These theories are accepted by a lot of scientists around the world.
Scenario 1 – The Great Filter
In this scenario, it is theorized that there are many filters which cannot be passed and hence life comes to an end. We have faced such filters, since the first cell came to existence on our planet we have been hit with 2 extinction level of asteroids, out of which the one that killed the dinosaurs is the most famous. The asteroid that came before that was around 450 million years ago. Perhaps, there can be more such filters that had prevented life to advance in the universe. There may even be more filters out there for us such as – a nuclear war or maybe another asteroid. If there is a filter ahead of us then this scenario sounds spine-chilling.
Scenario 2 – Aliens exist but they hide
This scenario accepts the fact that aliens life exist as a type 3 civilization and are hiding themselves as a precaution. Well to those who perhaps don’t know that there are 3 types of civilizations, measured on a Kardashev Scale proposed by a Soviet astronomer Nikolai Kardashev. Type 1 civilization a.k.a. Planetary civilization is the one that can utilize 100% of its planet’s resources. If you are curious to know about us, we come at 0.79 on that scale. Type 2 civilization is called a Stellar civilization which is capable of utilizing 100% energy of its star as well as the surrounding planets. It is possible for us in theory but practically it is unattainable. Type 3 civilization is called as Galactic civilization which is capable of ruling its host galaxy but we have already entered the realm of science fiction with type 2 civilization so I am not going too deep with type 3.
Scenario 3 – We are all alone
Maybe life is rare and precious. Probably the most realistic scenario based upon the facts is that we are all alone in the whole universe and if our planet becomes uninhabitable then all traces of life will vanish from the universe. The thought sure is scary but is entirely possible as well. If we are to accept this scenario then we have all the more reason to protect and preserve life on our planet.
Irrespective of what scenario you chose to believe, one fact remains that we are not capable of interplanetary travel yet and until we are capable of sending mass amounts of people to inhabit different planets, all we have, is our earth and we must plan to save our planet first. At the end, we must not forget that our generation may never witness colonization on different planets so we must save what we have around us. So plant more trees and reduce pollution because if we don’t take precautions now then there might be a filter ahead of us that may get us extinct. Save Earth, Save Life!
If you have any more theories do tell us in the comments below. Give it a like if you liked the blog.
(Featured Image Source: vox.com)