Where Are All the Extraterrestrials?
Ever since I was a child, I presumed the universe would be teeming with alien life. Star Wars and Star Trek reinforced this belief, and I yearned for the day when we would meet and communicate with other intelligent beings.
But as every potential alien discovery turned out to be natural, and our initial assumptions about the chance that life can naturally emerge from non-living materials turned out to be wildly optimistic, perhaps it is time to honestly reappraise the likelihood of us ever detecting, let alone communicating with other technologically intelligent extraterrestrial species.
In this vast universe, there appear to be around one septillion stars (one trillion trillion stars [1 × 1024]) spread out across trillions of galaxies, vastly more numerous than all the grains of sand on all the world’s beaches. If there is only one planet for every ten stars, then there are 100 billion trillion planets in the visible universe.
Given how enormous the universe is and how many planets exist, where is everybody? Even if we assume only one planet in a thousand is Earth-like; and only one in a thousand of those developed life, and only one in a thousand of those developed intelligence; and only one in a thousand intelligent species developed space travel and exploited their stellar neighborhoods by creating megastructures; there should be at least a hundred billion intelligent species who’ve developed megastructures that are visible across the universe.
And yet, we find nothing, no matter how hard we look. Every possible discovery of aliens has been proven to be either natural or man-made. There are no Kardashev Type III civilizations. There are no detectable Type II civilizations. At the very least, we should’ve observed or encountered one instance of non-biological extraterrestrial intelligence, like a sentient robotic probe, since the bar for their creation and spread throughout the cosmos is vastly lower than the development of megastructures.
The existence of extremophiles shows life can exist in environments that are fatal to most life. This means a world does not need to be within the “Goldilocks Zone” (the distance from a star where water is in liquid form on a body’s surface) as a condition for life to exist, which gives more possible places for life to exist.
If the non-living/living-cell barrier can naturally be traversed given the right conditions, then, statistically speaking, life, especially the single-celled kind, should be everywhere in the universe because life self-perpetuates, spreads, and adapts to different environments.
Even if a condition for life is the presence of liquid water, its existence beneath the surface of planets and satellites due to tidal forces and internal planetary heating means the likelihood of finding extraterrestrial life in our own solar system (say, beneath Mars, Enceladus, Europa, and Ganymede) is not zero. And since the barrier between single-celled and multicellular life has been breached many times, the likelihood of extraterrestrial multicellular life, even in just our solar system, shouldn’t be zero either.
Requirements for Detectable Extraterrestrial Intelligence
Intelligent extraterrestrial life, the type we can potentially communicate with or whose artificial artifacts and presence we can detect, requires certain conditions to exist:
- They originated out of living things (and are still biological or are now post-biological)
- They must possess intelligence (specifically, technological intelligence either presently, or at some point in the past) to expand out of their planet and create detectable artificial artifacts, or, to produce effects that can be detected and identified to be artificial instead of natural.
This article examines each of these conditions to determine the likelihood of detectable extraterrestrial intelligence.
What is the Likelihood Life Can Arise From Non-Life?
In an earlier article, I point out the assumption that life can naturally evolve on a prebiotic earth (abiogenesis) is not just unsupportable by the evidence; the described process of building complex molecules from simpler ones actually contradicts the practices of synthetic chemists – who are the actual experts on the transition of simple to complex molecules (not biologists, geneticists, or physicists).
Virtually everything we initially assumed about the inevitability of creating a living cell from nonliving materials has floundered when we’ve actually tried building a synthetic cell. Craig Venter’s team spent over 15 years and a massive amount of money trying to replicate what nature supposedly did naturally, only to swap the DNA of a living cell with a synthetic one to create a new synthetic biological species (similar to changing the operating system of an already-existing computer).
Don’t get me wrong, Venter’s team did something astonishing, and history will remember his team’s accomplishment as opening the door to utterly improving the human condition. (I, for one, am looking forward to the time when my family will personally benefit from the spin-offs of this invention.) But honesty is required – despite the propaganda by certain parties, they did not create a living cell from nonliving materials and do not know how it can be done. Their process requires already-living cells and will never work without them.
If they couldn’t create life from nonliving materials despite using dozens of the smartest people, supercomputers, and hundreds of millions of dollars over 15 years of effort, no one else can.
In other words, it’s a lot harder to create a living cell from scratch than we assumed. We can’t even retrosynthesize a lipid or nucleotide, much less the simplest living cell.
And since elements and molecules will be the same anywhere in the universe, the same abiogenesis chemistry problems will also exist on other worlds.
When one honestly examines this issue, it becomes clear that the more one knows, the less likely it appears that a living cell can form out of nonliving materials without the involvement of an intelligence. Abiogenesis very well may be true, but until we can actually replicate it using identical prebiotic earth conditions, all the molecular precursors in the world will just remain as “rivets” compared to the complexity of the living cell “airplane.”
And that holds true on this Earth as well as elsewhere in the universe.
What is the Likelihood of Technological Intelligence?
Human beings are unique in many ways among the over ten million living species on earth, and none more so that with our technological intelligence. We are the only species that artificially improves and extends our survival and fertility. We are the only species that teaches general information to others. We amass knowledge and build complex tools and equipment using multiple steps, varied processes, and many different materials. We develop science and math and make sense of our surroundings. And in the near future, we will be the only terrestrial species that will carry other species, in all its myriad forms, into the universe, where the cosmos comes alive with life.
It is easy to believe that barring a species-wide catastrophe, many of us will not be living in sterile space stations in 50 years, but will be living in habitats with complex biospheres. It is likely that in just two-hundred years, we will have tens of thousands of self-sustaining habitats on Near Earth Asteroids (NEA) and in the Asteroid Belt and just a hundred years later, will start migrating into other star systems. Humanity a thousand years from now should occupy a bubble of space at least a hundred light years in diameter and begin constructing Dyson spheres, Ringworlds, Matrioshka brains, Bishop’s rings, and other megastructures that will be detectable across the cosmos. And together with this human expansion will be us bringing along countless other species to populate the universe.
And all of this is thanks to our technological intelligence.
And yet, this ability only emerged in one genus among all the countless forms of life that have existed on earth, and only in the past 50,000 to 300,000 years, despite over 650 million years of animal evolution.
What are the odds that a tiny band of weak hominids emerged in an evolutionary “blink of an eye” as the only technologically intelligent species to dominate and change the world in a manner that has never occurred before?
To put into context how unusual technological intelligence is, here are some numbers:
- Only one species out of over a billion (99 percent are now extinct) developed technological intelligence (just 1 × 10-9 of total species)
- Technological intelligence emerged in just the most recent 50,000 to no more than 300,000 years of life’s 4.3 billion years of existence in this world and over 650 million years of animal life (less than 7 × 10-5 for life and 4.6 × 10-4 for animal life)
One in a billion species is like a half teaspoon of water compared to a full Olympic-sized swimming pool. Technological intelligence on Earth has existed for less than one minute compared to 36 hours for animal life or one minute compared to ten days for life’s existence.
The math doesn’t lie. What these numbers show is the likelihood of technological intelligence on Earth, to say nothing on other worlds, is vanishingly remote. It shouldn’t even exist on this planet. Why then expect it to be common elsewhere?
Redefining the Drake Equation
We now know that there are planets around other stars, and we’ve even identified thousands of exoplanets in our stellar neighborhood. What we haven’t seen is any sign of technological intelligence, and based on how we don’t really know how life can arise from non-life and how unique technologically intelligent humans are despite the existence of a billion of other species in this world’s history, the likelihood of finding (let alone communicating with) technologically intelligent extraterrestrials appears to be vanishingly remote.
What this means is we can put more credible figures in the parameters of the Drake equation while also redefining some of the parameters: [Note: Italics below are modifications for detection, instead of the much harder communication with technologically intelligent aliens.]
N = the number of civilizations in our galaxy where communication detection may be possible
R* = the average rate of star formation in our galaxy
fp = fraction of those stars that have planets and satellites
ne = average number of those planets and satellites that can potentially support life
fl = fraction of those planets and satellites that actually develop life
fi = fraction of those planets and satellites with life that actually develop intelligent life (civilizations)
fc = fraction of civilizations that develop technology that can be detected from outside their star system
L = the length of time the civilizations produce or leave a legacy of detectable evidence of their technological existence that can be detected from outside their star system [redefined, since detection is easier than communication]
R = 7 (around seven stars formed per year in the Milky Way galaxy)
fp = 1 (it now appears likely every star has, at least, one planet orbiting it, factoring natural satellites, free-floating planets, and those orbiting “dead” stars like white dwarfs and neutron stars)
ne = 3 (our solar system has, at least, eight – Earth, Mars, Enceladus, Europa, Ganymede, Titan, Callisto, and Triton)
fl = .5 (although we do not know how it is possible for life to emerge from nonliving materials, to be overly generous, assume half of all potential life-supporting planets and satellites actually develop life given the fine-tuned universe, extremophiles, the presence of liquid water and organic compounds within multiple planetary and satellite bodies, and being open to the possibility that life can be in forms completely foreign to what emerged in our world’s environment [if this estimate is credible, we should find some forms of life in at least three other places within the solar system])
fi = .0000001 to .0000000001. Animal intelligence, even among our fellow Hominidae, cannot compare to human intelligence, and no credible models exist outside “God” or “aliens” that can explain the uniqueness of anatomically modern humans (assume one-in-a-million to one-in-a-billion, but these may still be too high)
fc = .7 (the redefinition allows for the development of radio strong enough to be detected from outside the star system before the development of weapons powerful enough to destroy the civilization, and also allows for technological dead ends)
L = 10 to 1,000,000,000 years (the redefinition allows for a short period of radio transmission before civilizational collapse, all the way to the development of major structures in solar orbit or interstellar space that remain detectable, even a billion years after the civilization’s disappearance)
Thus, the likelihood of the existence of other detectable extraterrestrial intelligences in our galaxy could be anywhere from 7.35-9 (or just 1 in 136 million galaxies the size of the Milky Way) to 735 races, depending on whether the likelihood of technological intelligence is one-in-a-million or one-in-a-billion, and whether the advanced civilization turned inward to virtual reality (VR) or destroyed themselves before creating structures outside their world that could last for a billion years in the vacuum of space.
Either way, the odds of finding technologically intelligent aliens is no better than one for every half a billion stars in our galaxy.
Lastly, while it is tempting to assume all mature, intelligent species would turn inward to VR and avoid creating megastructures to explain the Fermi Paradox, it’s highly unlikely since it is doubtful for all independently evolved intelligent races to share a common psychology satiated by VR. There should be some races, in whole or in part, that would prefer physical existence in this universe and engage in exploration and expansion using von Neumann-type probes traveling at .1C – an ability we will have before the end of the century, and one that will need less than a million years to develop a presence around every star in the galaxy, even without further technological improvement.
In fact, such probes do not need to be a civilizational or national effort. Given the anticipated state of nanotechnology, AI, and system resource exploitation by the end of the 21 st century, it will be possible for just one person to produce the requisite self-replicating master probe to trigger a galaxy-wide presence after just a million years and less than a billion years for entire superclusters.
This makes the overwhelming silence of the universe all the more puzzling. The silence is unthinkable, given what we know and where we can project technology will be in just a few decades.
Note: This article is derived from this author’s upcoming book, Is Jesus “God”?