Have you ever seen movies like ‘Guardians of the Galaxy’ or read ‘The Hitchhiker’s Guide to the Galaxy’? ‘Imagination knows no bounds’ is proven by such creations of mankind. Super-intelligent planet-sized creatures, fancy ammunition and a world full of residents and things we have never witnessed. All this seems so attractive sitting here on earth. But when Enrico Fermi asked the puzzling question, “Where is everybody?”, it left all of us shaken to our cores.
Are we alone in this ever-expanding universe? Are there more habitable planets like our Earth? If aliens exist, where are they and why haven’t they given us any sign of their existence? Are they similar to us or something completely different? A thousand more questions like these can be asked. Hold on tight, this is just an introduction to ‘The Fermi Paradox’.
The apparent contradiction between there being a high probability of intelligent life like us or more advanced than us existing and the lack of evidence for such cases is known as ‘The Fermi Paradox’. There are billions and trillions of stars in our galaxy like the sun. So as there are myriads of stars, the probability of planets being in the Goldilocks zone also increases. The Goldilocks Zone refers to the habitable zone around a star where the temperature is just right – not too hot and not too cold – for liquid water to exist on a planet. Thus, ideally, there should exist many civilizations like us in our galaxy. Now, just the observable universe is 8.8 x 10^26 meters itself, thus we have a LOT of sample space still left to spectate. This pressingly suggests that there should exist what we call ‘Aliens’.
If we consider the timeline, our sun is a newborn baby as compared to most of the stars in our universe. Surely, just after the big-bang, the universe wasn’t a bed of roses for life to blossom in. Everything was extremely hot and haywire. With the passage of years, everything eventually cooled down and life gained momentum to grow. But if we ourselves are new in this universe, what about stars that were born way before the sun? Shouldn’t they have planets like Earth with life and water? But our shouts in the dark received no responses. The question still remains,
“Where is everybody?
To provide a mathematical insight into our approximations, Dr Frank Drake came up with an equation, which is famously known as ‘The Drake Equation’. Given below is the Drake equation:-
N = R* • fp • ne • fl • fi • fc • L
N = The number of civilizations in the Milky way galaxy whose electromagnetic emissions are detectable.
R* = The rate of formation of stars in our galaxy
fp = The fraction of those stars with planetary systems
ne = The number of planets, per solar system, with an environment suitable for life.
fl = The fraction of suitable planets on which life actually appears.
fi = The fraction of life bearing planets on which intelligent life emerges
fc = The fraction of these civilizations that have developed communications
L = The length of time over which such civilizations release detectable signals
This equation tells us about how we can estimate the number of active, communicative extraterrestrial civilizations in the Milky Way. The unknowns in the Drake equation are anyhow calculated on the basis of our own observations and approximations. Thus, this value is again based on factors which are not concrete and therefore is also the most major setback of this equation. But still, the probability, as well as our hope of finding life in this otherwise dead vicinity, stays alive.
So considering all of this to be true, shouldn’t the universe be teeming with spaceships? Why haven’t we received any signs of extra-terrestrial intelligence yet? Any alien civilization, which arose before us, having a decent infrastructure and knowledge of space travel would try to colonize their galaxy and reach beyond their horizons. SETI (Search for Extra Terrestrial Intelligence) is an organization which was established in the 1980s and is working actively since then in search of life outside earth. Even so, no signals or signs of any kind have been received by us which indicate that anyone is trying to communicate with us. We lack any evidence to prove that aliens exist.
Many have tried to provide answers to the Fermi paradox. Some are convincing. Some make us rethink, ‘Do we really know the truth about ourselves before we find the truth about the unknown?’
There may exist many civilizations out there, somewhere in the vast expanse of the universe, but maybe we are just too far. Travelling to Alpha Centauri will itself take 4.6 years if we are able to travel with the speed of light, even if it is comparatively ‘near’. Imagine travelling to something which we can see, like Andromeda galaxy, which is apparently the closest galaxy to earth. It would take us 2 million years to travel, if and only if, we travel with the speed of light! This makes intragalactic and intergalactic travel impossible options without an unimaginable and advanced technology.
2.Life is a simulation.
This theory seems scary but it exists! Maybe our planet, stars, or maybe our entire galaxy is just a simulation and our meet with the aliens is never meant to happen. All of this, which we live and breathe everyday, what if it is just a simulation? Creepy? Very.
3.We aren’t advanced enough
Yes, it is true that we never really have been reciprocated by the aliens, but what if they didn’t receive our messages in the first place? What if their technology is so highly advanced than us that they work with some other highly advanced medium of communication which is unknown to us? What if maybe they are trying to reach us, but we aren’t that developed to catch their signs correctly? A hard hit to our ego, but is possible.
One of the best and most thought-provoking answers to the Fermi paradox is provided by a theory known as the Zoo Hypothesis. The Zoo hypothesis speculates the behavior of aliens if they exist and the reasons (if any) for lack of communication. It further states that any aliens out there are letting us live in our own cosmic zoo, carrying on with our activities, without disturbing us but keeping a constant track on us. There are just a lot of maybes!
In conclusion, we all are sitting here and just predicting what can and cannot happen or what has already happened. Nobody really knows anything for sure. Well sometimes, things are staring right at us, but we are unable to recognize them. Maybe the answer is right in front of us and we are overlooking it. Whatever it is, it is definitely something very interesting waiting to be solved. Happy thinking!