The Fermi Paradox is the contradiction between high probability estimates for the existence of life beyond earth and the total lack of evidence or contact from those lifeforms. Consider the sheer size and shape of the universe, with even conservative estimates for how many star systems could support life, and then consider the fact there’s literally no known evidence for life.
There are no alien signals blaring through space in the same way ours do, no spaceships floating around from civilisations thousands or millions of years our senior, not even relics or graveyards from long dead ones. So as Enrico Fermi said, though this is paraphrased as nobody knows the exact wording, “Where is everybody?”
Enrico Fermi is an Italian-American physicist who you may know from the recent Christopher Nolan movie, Oppenheimer. He’s referenced relatively briefly as one of the key participants in the secret U.S. research product, called the Manhattan Project, that produced the world’s first atomic bombs. However, the question was posed by Fermi, not for the first time ever (Konstantin Tsiolkovsky in 1933), in 1950 during a lunch at Los Alamos National Laboratory.
N = R* • fₚ • nₑ • fₗ • fᵢ • f𝒸 • L
The Drake Equation was formulated by Frank Drake in 1961 with the intent of stimulating scientific dialogue at the first scientific meeting on the search for extraterrestrial intelligence (SETI). Many of the variables are not known with certainty, so this equation has always been used more as a tool rather than a definitive method of calculating the number of civilisations.
When filled with optimistic but plausible values, The Drake Equation often results in a significant number of advanced civilisations in our galaxy alone. However, even when filled with much more conservative numbers, the number of civilisations aside from ourselves in our galaxy is still much more than what we see evidence of - zero.
This theory proposes that at some point in every civilisation’s evolution there comes some sort of impassable wall or filter that makes it impossible or extremely hard for life to continue. For example, perhaps there’s a technology that all civilisations inevitably develop that kills them (nuclear weapons, AI, etc), or maybe viruses always eventually wipe civilisations out.
What this means is that if this is true then we’re either the very first advanced civilisation, or we’re among the very last. One thing to note regarding this theory is that the chance of us being first is ridiculously low, especially considering the age of the universe.
Another is that if civilisations have existed before us then we’d surely see some evidence. I understand that things decay over extremely long periods of time. However, there are things we have created on Earth that will last an extremely long time. The golden records aboard Voyager 1 and Voyager 2, sent into deep space with data on our civilisation, should remain at least partially intact for 5 billion years. Uranium 238, used in nuclear fuel, has a half life over four billion years and thus our nuclear waste will be around for a very long time also.
Perhaps one day our ability to detect these signs will improve and we’ll find the relics we search for. However, at this moment, it seems as if nothing as complex as ourselves has ever lived before us.
This hypothesis quite simply proposes that life like ours on Earth is extremely rare or unique. The conditions necessary for the evolution of intelligent life are so complex and rare that in the entire universe it has only happened once.
Similar to the great filter, civilisations might have limited life spans due to self destruction (war, ecological disasters, or technological catastrophes), meteor impacts, gamma ray bursts or something else that could wipe them out.
The Zoo Hypothesis suggests that Earth and all life on it is purposely isolated, like animals in a zoo, purely to be observed. The extraterrestrial civilisations watching us purposely avoid contact, likely to see how we evolve untainted by their influence.
A lot of people support the theory that we’re in a simulation. The idea is quite simple. Consider the evolution of games. One day they’re physical games with dice, cards, etc, the next it’s two rectangles on a screen hitting a ball, and the next we have Grand Theft Auto and Call of Duty. Eventually perhaps our technology will allow us to simulate the early universe, or early civilisation, consciousness, etc.
It’s a natural development that likely occurs with any advanced civilisation. So the question is, are we the first ever reality and we’ll be the first to create a simulation? Or, the far more likely option, we’re the last in an infinitely long chain of realities that simulate realities that simulate realities?
If we are in a simulation, perhaps our creators have decided not to let us encounter extraterrestrial life. Maybe they just didn’t code the simulation to have more than us?
An eerie theory that suggests all civilisations in the universe are purposely avoiding giving off signals that they exist, like hunters in a “dark forest.” Their reasoning being to protect themselves from being found by a hostile civilisation.
Perhaps the distance between stars is simply too great to overcome, and other advanced civilisations are either not interested or capable in achieving neither travel nor communication beyond their systems.
Similar to the simulation hypothesis, perhaps a lack of life beyond Earth is because we were created by a God, rather than simulated by a more advanced civilisation. Consider the fact that one of the many reasons we often say there’s no God is because we don’t see proof of a God. If we saw proof of a God then we’d undoubtedly believe it.
The universe has laws and rules that govern how it went from being an infinitely small point, to the big bang, to the universe we know today. If the universe suddenly differed from these set laws (the speed of light, gravity, etc) then we’d ask, “Is this an act of God?” But it never happens. However, all our evidence and calculations point towards there being more life than just our one planet, yet we find nothing. Is this the one thing in the universe that truly defies logic? Something devine?
It’s a harrowing and mind-blowing thing to consider – the idea that we’re totally alone. The fact we’re here now proves that life is possible, yet we see nothing beyond. I believe that, as our technology advances, our ability to see beyond our solar system will improve and perhaps we’ll find the answers we’re looking for - evidence of past or current life.
The first step is likely to be non-advanced life, bacteria and what not - I think that will be an unquestionable certainty within my lifetime. Advanced life? Only time will tell.
