5 Answers to the Fermi Paradox: Why Haven’t We Made Contact Yet?
By: Gaia Staff | Dec. 7th, 2017
The question posed almost 70 years ago by physicist, Enrico Fermi, arguably remains to this day, “Where is everybody?” There exists no widely agreed upon solution to the Fermi Paradox: If there is sufficient probability other life exists in the galaxy, why haven’t we found it? Astrophysicists and theorists have continued to debate this question with new discoveries constantly adding to the conversation. Here are some of their ideas.
Fermi Paradox Solutions
Enrico Fermi was a brilliant physicist, known for achieving the first controlled nuclear reaction. At the time, he was working at the Los Alamos National Laboratory for the Department of Energy, when one day he and several colleagues began discussing recent stories regarding the UFO phenomenon.
The conversation came to an end, with his colleagues assuming they had moved on from the topic, but later at lunch Fermi shouted in exasperation, “Where is everybody?” They found it amusing, but the question persisted, eventually being fleshed out with a formula that calculated the number of stars, solar systems, and planets in the galaxy and the supposed likelihood of life. It became known as the Fermi Paradox.
Since that day, Fermi’s epiphanic moment has given birth to a number of potential solutions based on three premises: Any extraterrestrial life does not exist; extraterrestrial life exists, but has not yet contacted us; or extraterrestrial life is present, but we are unaware.
The Rare Earth Hypothesis
The circumstances that led to our existence here on Earth today are pretty phenomenal, almost too much so. A laundry list of seemingly improbable events and circumstances allowed life to develop on Earth, one of which is our anomalous moon.
Our abnormally large moon is in near perfect orbit. Most planets our size don’t have moons this large and it is thought that without it, life on Earth wouldn’t exist. The tides, caused by the gravitational pull of the moon, play a key role in plate tectonics. Without plate tectonics, it’s theorized the continental crust would have covered the entire surface of Earth, preventing any oceanic crust. Without the moon, there might not be any oceans.
In our solar system, we’re at a perfect distance from the sun, with large gas giants like Jupiter and Saturn acting as “cosmic vacuum cleaners” on the outer rim. These planets capture the larger asteroids that would otherwise devastate the evolution of life as we know it.
Within the galaxy, our location on the outer edge of a spiral arm also prevents large asteroids, orbiting closer to the galactic center, from coming our way. Also, the inner orbits of the galaxy are mostly dead zones, where high levels of cosmic radiation emit from a massive black hole and a number of incredibly dense neutron stars. Is this the Fermi Paradox solution? We were improbably lucky?
The argument against this theory, proposed by Carl Sagan and Frank Drake, is that we’re pretty mediocre. Our rocky planet is pretty common, as is our solar system, while the region of the galaxy we’re in is non-exceptional, and our galaxy is a type that makes up 77 percent of galaxies in the universe. Therefore, there is a high probability of intelligent extraterrestrial life out there. In fact, there are probably about 200 million planets situated like we are.
The Great Filter
From here out, most Fermi Paradox solutions are based on the Kardashev Scale, a theory about how civilizations might develop to colonize beyond ours. The Great Filter is an attempt to imagine whether there is something preventing us from moving on to the next point of the Kardashev Scale, a Type II civilization that can harness all the energy of its sun.
The Great Filter is a concept, proposed by economist Robin Hanson, which attempts to describe an ambiguity that prevents life from developing past a certain point. It basically states there is something that prevents dead matter from developing and giving rise to life, beyond a certain point. Hanson developed a nine-step list, which may or may not be complete, describing the concept of evolution for intelligent life:
- Life starts with the right star system, followed by:
- Reproductive molecules (DNA, RNA)
- Simple single-cell life
- Complex single-cell life
- Sexual reproduction
- Multi-cell life
- Tool-using animals with big brains
- Our civilization as we know it
- Colonization beyond our level
The Great Filter posits at some point along this scale – most likely the next level beyond where we are now – something will kill us off. Basically, it’s improbable we will colonize beyond Earth or our solar system. Therefore, any other intelligent life forms would be subject to the same principle, and we’ll never meet them. Might there be a chance we made it past the filter? Were other civilizations not as lucky?
Deadly Probes Scenario, a.k.a. The Berserker Scenario
Anders Sandberg, Stuart Armstrong, and Milan Ćirković made a few hypotheses based on Fermi’s Paradox. The Deadly Probes Scenario is one of their most dystopian theories.
In this scenario, the three hypothesize an incredibly advanced, extraterrestrial intelligence created probes to monitor the galaxy or universe for other civilizations or signs of evolving life. These probes are self-replicating, also known as Von Neumann probes, so they can reproduce and autonomously patrol space to prevent another civilization from rising up and destroying them. There would be four conditions these probes might have to meet to possibly exist:
- They would have to be the cause of the great silence – the reason we haven’t heard anyone.
- They’d have to be compatible with our existence.
- They would be silent in their activities so as not to be visible.
- They would be impossible to overthrow by a new civilization.
There would also be two levels of stability with these probes. Type I stability would be a dominant species of probe that prevents other species from emerging, or Type II, which a coexistence of two or more probe species equally competed with each other for rule over the galaxy.
The authors of this scenario don’t think this is a plausible Fermi Paradox solution, at least within our galaxy. Because if it were, those berserker probes would be incredibly inefficient in not destroying us yet.
A Benevolent or Super Advanced Extraterrestrial Intelligence
Another belief, which is a bit more utopian, is we are still in the nascent phase of what we have the potential to become; a highly advanced race capable of things we can only dream of in sci-fi movies. This could theoretically mean an advanced extraterrestrial intelligence has reached this phase and observed us, but is waiting to reveal itself.
Why wouldn’t this race make its presence known? Most likely because it does not want to disturb us in our evolutionary process. This has become known as the zoo hypothesis: Compared to their level of intelligence, they view us like we view apes.
This civilization might understand it is necessary to let nature play its course as, if we became aware of their existence, we might screw something up. Chances are, they’re beyond the petty problems we face today including war, resource scarcity, and primitive modes of transportation. If they were to get involved, we might freak out and destroy ourselves.
They also might be slowly feeding us technology and information waiting for the time when we’re ready for them to make their presence known.
The authors of the Deadly Probes theory also proposed the aestivation hypothesis. Maybe these highly advanced civilizations are hibernating. The hypothesis states these types of civilizations may have uploaded their consciousness onto computers — a theory posited by Nick Bostrom — which would potentially allow for life to last long after the physical body deteriorates.
In this case, these conscious computer entities would want to wait for the universe to cool down to maximize energy efficiency. According to this theory the thermodynamics of computation makes the cost of a certain amount of computation proportional to temperature. Therefore, the colder the universe gets, the less it costs them to expend energy.
According to their hypothesis, these civilizations have seen it all in the universe’s current iteration. There’s no new information for them to obtain. Kind of depressing, right? So, they’re powering down into sleep mode and waiting until things cool down and maybe get more interesting.
The Holographic Universe
This theory gained a lot of traction lately, even though it was first widely proposed in the premise of The Matrix — nearly 20 years ago. Since Nick Bostrom, Elon Musk, and a slew of NASA scientists expressed their belief in this theory, it has become more popular. Maybe we haven’t made contact with extraterrestrial intelligence because we’re living in a computer simulation.
In this case, a number of theories have branched off from the broader concept. One idea is that an advanced extraterrestrial intelligence created a computer program to run a hyper-realistic simulation for whatever reason. If we had the computing power to achieve this, we probably would too. In that case, how deep does the rabbit hole go? Are they living in a computer simulation, too?
This theory seems to parallel the idea of a multiverse or the idea of infinite parallel dimensions. The difference is only a matter of semantics. Then again, the difference between us living in a computer simulation created by an advanced extraterrestrial race and us living in a world created by a god, is also a matter of semantics. Mind blown? Ours too.
So, what is the true solution to the Fermi Paradox? Will we ever find out? Only time will tell.