Intuition states that the universe should be teeming with alien life, and yet we find no evidence of it.

The Fermi paradox

In 1950, renowned physicist Enrico Fermi famously blurted out to his colleagues “Where is every body?” That question has perplexed scientists for decades and since then come to be known as the Fermi Paradox. It highlights the contradiction between the high probability of the existence of alien life and yet the complete absence of any evidence for it.

The existence of extra-terrestrial life is highly plausible. The known Universe is estimated to contain over 100 billion galaxies, each with billions of stars and even a small fraction of those stars hosting planets capable of supporting life would result in billions of habitable planets.

Furthermore, research has shown that emergence of life is not that rare of an occurrence after all.

Given the sheer scale of possibility, surely the universe and our own galaxy should be teeming with life and possibly intelligent life, The universe is ~14 billion years old. Surely that’s enough time for other alien life forms to have evolved and with our sophisticated technology, we should have seen some signs, even the faintest of signals.

But we haven’t. That’s the paradox.

It’s truly strange and has puzzled physicists and philosophers all across the world.

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Possible resolutions to the Fermi Paradox

Intelligence is indeed rare:

Many researchers, like David Kipping have used rigourous Bayesian analysis to argue that the odds of intelligent life emerging are very low. Even on our own planet, if we re-ran the tape through Earth’s history, intelligence is unlikely to emerge again.

The Great Filter:

This theory suggests that there are barriers and impediments to progress that always prevent from multi-planetary evolution. Catastrophic events always inhibit a planet to become interstellar.

These filters occur at various stages of evolution such as origin of life, evolution of complex organisms or the ability to develop advanced technology without destroying oneself.

Simulation Hypothesis:

This is perhaps the most intriguing of them all. It hypotheses that we are all living a simulated reality and the simulator’s parameters prevent any contact with alien life.

In such a simulation, the Fermi paradox is a feature & not a bug.

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Conclusion

I personally feel that while emergence of life is fairly common and we could expect to find a lot of it, but intelligent life is rare and for the moment, it seems like we are all alone in a vast and empty universe.

It’s surreal, I have often heard scientists say, that earth is but a small speck on the grand cosmic scale, and yet it’s probably the only speck that matters.