Where Are All The Aliens?

THE FERMI PARADOX

From sci-fi movies to conspiracy theories Aliens have always played an integral part in the overall scheme of the universe. But when it comes to the real notion of their existence, things seem to be quite paradoxical.

And the FERMI PARADOX seems to have an answer to it.

Given that our solar system is quite young compared to the rest of the universe — roughly 4.5 billion years old, compared to 13.8 billion — and that interstellar travel might be fairly easy to achieve given enough time, Earth should have been visited by aliens already, the idea goes.

The paradox takes its name from Nobel Prize-winning physicist Enrico Fermi, who supposedly made the above points during a casual lunchtime conversation in 1950 wherein he famously asked his colleagues, “Where are they?”

WHAT IS FERMI PARADOX?

The ‘Fermi Paradox’ describes the apparent contradiction between why there’s no evidence of extraterrestrial life, even though logically, it should have been discovered by now.

WHERE ARE ALL THE ALIENS?

Today, there are numerous potential solutions to the Fermi paradox, including explanations like:

• We’re overestimating the prevalence of intelligent life in the Universe
• We’re overestimating the desire of any single life form to willingly transmit information
• The information is there, we’re just not seeing it or understanding it
• The information was there and might be there again, but humans haven’t been listening long enough to detect it
• Humans are the first to arrive at the interstellar stage and we’re too early to detect other civilizations.

THE ZOO HYPOTHESIS:

WE ARE BEING OBSERVED WITHOUT OUR KNOWLEDGE

Space exploration pioneer Konstantin Tsiolkovsky already reflected on the Fermi paradox in his manuscripts decades before Fermi himself. In 1933 he wrote that alien beings, infinitely more advanced than we are, would find the same interest in communicating with us as we would in trying to communicate with wolves, snakes, or gorillas. But this very notion remains quite questionable.

A much calculated and scientific approach to this question is through Drake’s equation.

DRAKE’S EQUATION:

The Drake equation is an argument that generates a probability to estimate and calculate the number of active and communicative extraterrestrial civilizations present in the Milky Way galaxy.

N = R* × fp × ne × fl × fi × fc × L

N, the number of civilizations currently transmitting signals, depends on seven factors:

R* is the yearly formation rate of stars hospitable to planets where life could develop

fp is the fraction of those stars with planets

ne is the number of planets per solar system with conditions suitable for life

fl is the fraction of planets suitable for life on which life actually appears

fi is the fraction of planets with life on which intelligent life emerges

fc is the fraction of planets with intelligent life that develops technologies such as radio transmissions that we could detect

L is the average length of time in years that civilizations produce such signs

But this equation has a flaw.

Take L, the average lifespan of a detectable civilization. If we look at the average length of the past civilizations here on Earth, it wouldn’t be unreasonable to assume a low value. If the Romans, Incas, or Egyptians are anything to go by, it seems hard to make it past a few hundred years. On the flip-side, you could argue that once a civilization becomes technologically advanced enough to achieve interstellar travel, it could conceivably last many billions of years.

This enormous uncertainty leaves the Drake equation ultimately vulnerable to the optimism or pessimism of whoever wields it. And this is reflected in previous scientific papers whose results give values of N ranging anywhere from 10 to many billions.

But why there isn’t any response to our call? To seemingly have acquaintance over this question one has to understand ‘The Great Filter’

THE GREAT FILTER:

The term was coined by economist Robin Hanson, who proposed that there must be something that prevents non-living matter from coming together to form living organisms and reaching a high level of development on the Kardashev Scale.

This possibility, he claimed, does not bode well for humanity. As he summarized his argument:

“Humanity seems to have a bright future, i.e., a non-trivial chance of expanding to fill the universe with lasting life. But the fact that space near us seems dead now tells us that any given piece of dead matter faces an astronomically low chance of begating such a future. There thus exists a great filter between death and expanding lasting life, and humanity faces the ominous question: how far along this filter are we?”

SO ARE WE ALONE IN THIS UNIVERSE?

If the Great Filter is behind us, though, it bodes well for humanity as a species; the universe may be ours for the taking. If, however, the Great Filter still lies ahead, we may be doomed.

On the bright side, some have interpreted our apparent aloneness in the universe as a good sign — a blessing even — as it indicates we’ve safely made it through the bottleneck. Strange as it may seem, we may be the first species to have passed through the Great Filter.

On the other hand, if we were to detect a signal from a super-advanced technological species that makes us look primitive, it might imply that the Great Filter still lies ahead. Humanity could be destined to take a surprise cosmic test, one that we don’t know what to study for.

FINAL INTERPRETATION :

In general, the solutions to Fermi’s paradox come down to either of the two parts, i.e., either life is much more difficult to start and evolve, or advanced civilizations destroy themselves within a short period of time. And hence the question of “Where is everybody?” still remains unanswered.