Were there lost Alien Civilizations?
An Introduction to The Great Filter and The Fermi Paradox
There are more than 2 TRILLION galaxies in the observable universe. That’s around 2,000 billion galaxies; 2 followed by 12 zeros. 2,000,000,000,000 galaxies.
To put that into perspective, if we counted each second and gave each second the value of 1 point, then each minute we will have 60 points (every minute has 60 seconds) and by the end of the day you will have 86,400 points. After continuously counting 24x7 each second for 11 days, you will reach a million points. But to reach a billion points— you need to do that for 31 years! What’s even crazier is that to reach 2 trillion points, you need to do that for a whopping 63,419 years! That’s how big the number is.
Now keeping that menacing number in your head, consider this:-
Our own galaxy — The Milky Way, has around a 100 BILLION stars, EACH star potentially harbouring its own star system just like our solar system. Currently, we have identified around 3,916-star systems and the hunt is still on to find more. Each star system has a habitable zone where everything is just right for life to form on a suitable planet. On top of that, the universe is 13.8 billion years old, ample time for any sort of life to emerge.
With so much happening, the universe should be teeming with life… then WHY DON’T WE SEE ANYTHING?
A similar question was asked by Italian-American physicist Enrico Fermi in a conversation with fellow physicists Edward Teller, Herbert York, and Emil Konopinski. They were talking about things such as UFOs, faster-than-light travel and somehow, they stumbled upon this seemingly paradoxical question- ‘Where is everybody?’. This perplexing yet simple question has puzzled even the greatest of the minds and this led to something known as the Fermi Paradox.
What is the The Fermi Paradox?
The Fermi Paradox refers to the apparent contradiction between the high probability of extraterrestrial (alien) civilizations existing in the universe and the lack of evidence or contact with such civilizations. The paradox is named after the physicist Enrico Fermi, who famously asked, “Where is everybody?” during a conversation about the possibility of intelligent extraterrestrial life I mentioned earlier.
There have been a lot of discussions and debates related to this paradox and a few possible scenarios have been posited:-
- Life itself is rare or non-existent (Rare-Earth hypothesis)
- If there is life, intelligence is rare or non-existent.
- If life is intelligent and progresses, that civilization can’t progress after a certain point due to The Great Filter. (more about this later…)
- It’s in the nature of intelligent life to destroy itself and that point is The Great Filter.
- They’re smarter than us- They are so advanced and so intelligent that we are not even considered ‘life’. Basically, we are too stupid to understand them.
There are a lot of other scenarios and you can read those here but by far the most plausible explanation of this paradox is The Great Filter.
What is The Great Filter?
The Great Filter is the idea that in the development of life from the earliest stages of abiogenesis (chemical evolution) to reaching the highest levels of development on the Kardashev scale, there is a barrier to development that makes detectable extraterrestrial life exceedingly rare.
You can read about the Kardashev scale here:-
What the Great Filter really means is that as life evolves, it is encountered by obstacles and if life can overcome those obstacles — it survives and those who can’t, well… they BECOME EXTINCT.
The most disturbing thing about this idea is that we have absolutely no idea where that obstacle is. It’s possible that life on Earth(us) have overcome that extinction-level obstacle or it might be waiting to devour us…
Things like asteroids, war, nukes, climate change are considered obstacles/filters but we will never really know what the obstacle really is because the only life we know is ourselves and we haven’t come so far to know what it actually is.
And just thinking about this keeps me up all night…
Criticisms:-
1.There is little to no evidence supporting the claims made by The Great Filter and The Fermi Paradox. They are still hypothetical just like the Kardashev scale.
2.It is a very ‘human’ way of looking at it. We humans tend to think alien life would want to socialize with us, but there is a huge possibility that they want isolation. Maybe they think others are a threat or maybe our fundamental definition of life is wrong.
The most famous example of ‘non-living life’ is viruses. They are just protein with some genetic material and their only job is to replicate. They don't respire, produce or convert energy like what other life forms do. But are they still ‘life’?
You can read more about the Fermi Paradox here.
But are they really there?
Frankly, we don’t know. We can make assumptions, hypothesize, conjure up conspiracies about some lost alien civilization, but without evidence it’s just a product of our overactive imagination.
SETI (Search for Extraterrestrial Intelligence) is an organization that is actively searching for alien life using the latest technology and radio signals to reach out to aliens, potentially light years away.
What’s the point anyways?
We hope to find aliens someday and even discovering a tiny microbe would be historic. Their discovery can shake the very foundations of Biology itself. It can also solve the greatest mystery in Biology ‘The Origin of Life’.
Say suppose we find Earth-like creatures such as bacteria, viruses on other exoplanets we can conclude that life requires such life forms universally to form at the start.
If we find intelligent creatures similar to us humans, we can conclude that ‘consciousness’ and ‘intelligence’ is a fundamental evolutionary trait in all types of intelligent life forms.
There can be tons of discoveries of which we have no clue about. We might discover the unknown unknown.
Let me know what you think about aliens in the responses section.
See you in the next one.
