New Model Predicts That We’re Probably the Only Advanced Civilization in the Observable Universe | Universe Today

New Model Predicts That We’re Probably the Only Advanced Civilization in the Observable Universe

The Fermi Paradox remains a stumbling block when it comes to the search for extra-terrestrial intelligence (SETI). Named in honor of the famed physicist Enrico Fermi who first proposed it, this paradox addresses the apparent disparity between the expected probability that intelligent life is plentiful in the Universe, and the apparent lack of evidence of extra-terrestrial intelligence (ETI).

In the decades since Enrico Fermi first posed the question that encapsulates this paradox (“Where is everybody?”), scientists have attempted to explain this disparity one way or another. But in a new study conducted by three famed scholars from the Future of Humanity Institute (FHI) at Oxford University, the paradox is reevaluated in such a way that it makes it seem likely that humanity is alone in the observable Universe.

The study, titled “Dissolving the Fermi Paradox“, recently appeared online. The study was jointly-conducted by Anders Sandberg, a Research Fellow at the Future of Humanity Institute and a Martin Senior Fellow at Oxford University; Eric Drexler, the famed engineer who popularized the concept of nanotechnology; and Tod Ord, the famous Australian moral philosopher at Oxford University.

The Drake Equation, a mathematical formula for the probability of finding life or advanced civilizations in the universe. Credit: University of Rochester

For the sake of their study, the team took a fresh look at the Drake Equation, the famous equation proposed by astronomer Dr. Frank Drake in the 1960s. Based on hypothetical values for a number of factors, this equation has traditionally been used to demonstrate that – even if the amount of life developing at any given site is small – the sheer multitude of possible sites should yield a large number of potentially observable civilizations.

This equation states that the number of civilizations (N) in our galaxy that we might able to communicate can be determined by multiplying the average rate of star formation in our galaxy (R*), the fraction of those stars which have planets (fp), the number of planets that can actually support life (ne), the number of planets that will develop life (fl), the number of planets that will develop intelligent life (fi),  the number civilizations that would develop transmission technologies (fc), and the length of time that these civilizations would have to transmit their signals into space (L). Mathematically, this is expressed as:

N = R* x fp x ne x fl x fi x fc x L

Dr. Sandberg is no stranger to the Fermi Paradox, nor is he shy about attempting to resolve it. In a previous study, titled “That is not dead which can eternal lie: the aestivation hypothesis for resolving Fermi’s paradox“, Sandberg and his associates proposed that the Fermi Paradox arises from the fact that ETIs are not dead, but currently in a state of hibernation – what they called “aestivation” – and awaiting better conditions in the Universe.

In a study conducted back in 2013, Sandberg and Stuart Armstrong (also a research associate with the FHI and one of the co-authors on this study) extended the Fermi Paradox to look beyond our own galaxy, addressing how more advanced civilizations would feasibly be able to launch colonization projects with relative ease (and even travel between galaxies without difficulty).

As Dr. Sandberg told Universe Today via email:

“One can answer [the Fermi Paradox] by saying intelligence is very rare, but then it needs to be tremendously rare. Another possibility is that intelligence doesn’t last very long, but it is enough that one civilization survives for it to become visible. Attempts at explaining it by having all intelligences acting in the same way (staying quiet, avoiding contact with us, transcending) fail since they require every individual belonging to every society in every civilization to behave in the same way, the strongest sociological claim ever. Claiming long-range settlement or communication are impossible requires assuming a surprisingly low technology ceiling. Whatever the answer is, it more or less has to be strange.”

In this latest study, Sandberg, Drexler and Ord reconsider the parameters of the Drake Equation by incorporating models of chemical and genetic transitions on paths to the origin of life. From this, they show that there is a considerable amount of scientific uncertainties that span multiple orders of magnitude. Or as Dr. Sandberg explained it:

“Many parameters are very uncertain given current knowledge. While we have learned a lot more about the astrophysical ones since Drake and Sagan in the 1960s, we are still very uncertain about the probability of life and intelligence. When people discuss the equation it is not uncommon to hear them say something like: “this parameter is uncertain, but let’s make a guess and remember that it is a guess”, finally reaching a result that they admit is based on guesses. But this result will be stated as single number, and that anchors us to an *apparently* exact estimate – when it should have a proper uncertainty range.  This often leads to overconfidence, and worse, the Drake equation is very sensitive to bias: if you are hopeful a small nudge upwards in several uncertain estimates will give a hopeful result, and if you are a pessimist you can easily get a low result.”

Frank Drake writing his famous equation on a white board. Credit:

As such, Sandberg, Drexler and Ord looked at the equation’s parameters as uncertainty ranges. Instead of focusing on what value they might have, they looked at what the largest and smallest values they could have based on current knowledge. Whereas some values have become well constrained – such as the number of planets in our galaxy based on exoplanet studies and the number that exist within a star’s habitable zone – others remain far more uncertain.

When they combined these uncertainties, rather than the guesswork that often go into the Fermi Paradox, the team got a distribution as a result. Naturally, this resulted in a broad spread due to the number of uncertainties involved. But as Dr. Sandberg explained, it did provide them with an estimate of the likelihood that humanity (given what we know) is alone in the galaxy:

“We found that even using the guesstimates in the literature (we took them and randomly combined the parameter estimates) one can have a situation where the mean number of civilizations in the galaxy might be fairly high – say a hundred – and yet the probability that we are alone in the galaxy is 30%! The reason is that there is a very skew distribution of likelihood.

“If we instead try to review the scientific knowledge, things get even more extreme. This is because the probability of getting life and intelligence on a planet has an *extreme* uncertainty given what we know – we cannot rule out that it happens nearly everywhere there is the right conditions, but we cannot rule out that it is astronomically rare. This leads to an even stronger uncertainty about the number of civilizations, drawing us to conclude that there is a fairly high likelihood that we are alone. However, we *also* conclude that we shouldn’t be too surprised if we find intelligence!”

Is anybody out there? Anybody at all? Credit: UCLA SETI Group/Yuri Beletsky, Carnegie Las Campanas Observatory

In the end, the team’s conclusions do not mean that humanity is alone in the Universe, or that the odds of finding evidence of extra-terrestrial civilizations (both past and present) is unlikely. Instead, it simply means that we can say with greater confidence – based on what we know – that humanity is most likely the only intelligent species in the Milky Way Galaxy at present.

And of course, this all comes down to the uncertainties we currently have to contend with when it comes to SETI and the Drake Equation. In that respect, the study conducted by Sandberg, Drexler and Ord is an indication that much more needs to be learned before we can attempt to determine just how likely ETI is out there.

“What we are not showing is that SETI is pointless – quite the opposite!” said Dr. Sandberg. “There is a tremendous level of uncertainty to reduce. The paper shows that astrobiology and SETI can play a big role in reducing the uncertainty about some of the parameters. Even terrestrial biology may give us important information about the probability of life emerging and the conditions leading to intelligence. Finally, one important conclusion we find is that lack of observed intelligence does not strongly make us conclude that intelligence doesn’t last long: the stars are not foretelling our doom!”

So take heart, SETI enthusiasts! While the Drake Equation may not be something we can produce accurate values for anytime soon, the more we learn, the more refined the values will be. And remember, we only need to find intelligent life once in order for the Fermi Paradox to be resolved!

Further Reading: arXiv

Matt Williams @

Matt Williams is the Curator of Universe Today's Guide to Space. He is also a freelance writer, a science fiction author and a Taekwon-Do instructor. He lives with his family on Vancouver Island in beautiful British Columbia.

View Comments

  • How can we understand the universe when we can't even understand ourselves, like why do we even exist, or the nature of consciousness..

  • They are right!! We are the ONLY advanced civilization in the universe. all other SUPER advanced civilizations that stay HIDDEN from mediocre civilizations like our own.

  • If an intelligent alien race capable of intergalactic travel decided to seed the universe then it might well choose a sort of plant pot program. Plant the seed of life somewhere suitable in a galaxy, not too near the edge, not too near the centre, maybe another one on the other side of the SMBH in the centre so they can't interact until they reach a certain maturity. Just like gardeners.
    All that said someone has to be the first!

  • I believe there is far simpler explanation why we perceive universe as "dead".
    We are just at the beginning of understanding quantum technology.
    Once we understand entangled spins, radio communication as is will become obsolete. No more useless transmission will go out to space.
    The communication will become instant over any distance, secret and reliable. And, more or less undetectable from outside world (at least using our current understanding of physics).
    And, as the radio waves detection part of the paradox will essentially become 0, the whole equation will resolve to the same zero.
    We would have to be extremely lucky to just perceive a radio transmission within the extremely short time frame (from universe perspective) when the civilizations use something as primitive as radio.

  • Could it be that civilization/species come and go like brief flashes of light in the sky?

    To make contact our tiny time-frame must overlap with that of another peer civilization somewhere in the universe before we (or they) go extinct. We're not only separated by distance but also by time - lifespan of a species. This should alter any formula for probability of finding intelligent life. But where is this accounted for?

  • Declaring the Fermi Paradox solved by the most trivial -and absurd- way is simply shameful.

  • This is a narrow minded, superficial and badly informed treatise on a question that has been dealt with many times before in a more qualified fashion. There is no mention of 'Rare Earth', the important book by the astronomer Donald Brownlee and the geologist Peter Ward who gathered together for the first time all those arguments that spoke against the existence of extraterrestrial life (2001). Also Simon Conway Morris' groundbreaking 'Life's Solution. Inevitable Humans in a Lonely Universe' (2003) about the 'mathematical hyperspace of proteins' and evolutionary convergence is unknown to the authors. And what about 'Evolution through the Stochastic Dyadic Cantor Set: The Uniqueness of Mankind in the Universe' (2015) by Diego Sebastian L. Mahecha Rodriguez, a truly mathematical approach to the question that makes the pompous 'Drake equation' look like what it is, a childishly cluttered row of pretty arbitrary parameters/factors? Nope. Maybe Eric Smith's ingenious 'The Origin and Nature of Life on Earth: The Emergence of the Fourth Geosphere' where he explains that life is not a purposeful deployment of organisms, but rather the result of an energetic imbalance between the reactive-friendly atoms carbon and oxygen (and their molecular compounds) and their environments, an 'evasion', a solution to a chemically stressful situation, an 'explosion' that needs an incredible amount of concurring conditions to happen - which makes it so highly improbable? Njet.

    It may be forgiven that the authors don't know my own treatise 'The Uniqueness Hypothesis - Why There is Only One Place in the Universe With Biological Life' from 2009 as it was initially only published in German. But now it is available in English on

    By the way, even if the great Ethan Siegel believes it (his brillant article in Forbes, the Drake equation cannot be fixed for a very simple reason: it has no numerical solution for the most probable scenario, and the only one we can ascertain by today's scientific standards, which is what I call the Uniqueness Hypothesis: Life has only emerged once in the history of the universe, there is and there will be no second source.

    • The Rare Earth hypothesis is largely outdated, based on false premises (such as the wrong occurrence rates of solar type stars and terrestrial planets in the HZ, the need for a moon, a Jupiter, etc.), it is as such very deterministic and smells like creationism. And indeed, a creationist was hired as a prime consultant.

      Your own Uniqueness Hypothesis also sucks: I read it and it is full of bias and circularity. Modern neo-religiousness and self-declared determinism.

      Simple truth is, we don't know yet how (un)common life is and intelligence.
      But what is telling is that it all consists of the same matter and follows natural rules and processes.
      And those are all universal.
      Once we thought we were unique in every possible way, one Earthlike planet.
      Now we know that solar type stars and (terrestrial) planets are a dime a dozen, water is ubiquitous.

      The more we discover, the more common we are.
      Maybe it is exactly that, what some people find so hard to accept. Hence, all the fake spirituality.

  • So, basically you can fill in this equation with whatever you want, to come up with whatever result you think is fun. Reading about the Drake equation makes you dumber.

  • If an advance civilization is far enough away we might now know about it for billions of years. The farthest observable star is currently 55 million light years away. They could have mastered intergalactic travel 54 million years ago and we still wouldn't know about it for a million years.

  • I just turned 60 and maybe I've watched too many Alien moves over my life, but what if we find intelligence that is not friendly or indifferent to other intelligent life? Until very recently, we've managed to wipe out other intelligent life on this planet - like the whales and gorillas. What if these other Alien intelligence decides to put Galactic Hyperspace Bypass through our Solar System? Our star and the orbiting planets could be bulldozed out of existence by this Alien intelligence in order to provide a passageway through space. There are worse things like becoming food for Aliens. We harvest cows, pigs, sheep and other herbivores for food, don't we?

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