On The Net
The Great Filter
by James Patrick Kelly
questions
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I sometimes get asked questions about being a writer by people who have just a passing knowledge of science fiction. “Where do you get your ideas?” is probably the most common. Answer: Actually, ideas get me. Or, “Are you some kind of scientist?” Answer: Nope, English major. Or, “So you write about the future?” Answer: I write about possibilities, most of which never happen. I always answer honestly, but try not to say too much, since I’m very aware that in polite conversation my enthusiasm for our genre can lead me to wander deep into TooMuchInformationLand. This has happened more than once in response to the question: “Do you believe in UFOs?” Answer: Arrgh!
The idea of extraterrestrial creatures visiting Earth in spaceships was first proposed by H.G. Wells http://hgwellssociety.com in 1898’s The War of the Worlds https://gutenberg.org/ebooks/36. Alas, the surprise attack of his mysterious and malign Martians has infected the human imagination from that day to this. Perhaps our distrust and/or fear of intelligent others from advanced civilizations arise from what some allege was homo sapiens’s original sin. Although there is Neanderthal https://www.nhm.ac.uk/discover/who-were-the-neanderthals.html and Denisovan https://www.nytimes.com/2024/03/02/science/denisovan-neanderthal-dna.html DNA mixed into our gene pool, we no longer share this planet with our cousin hominids. Whose fault is that? The answer is shrouded in prehistory, although recorded history is replete with examples of exploitation and domination within our own species. As Stephen Hawking pointed out https://www.cnet.com/science/stephen-hawking-wants-to-find-aliens-before-they-find-us/, “Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn’t turn out so well.”
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limits
So I get that we might be spooked about aliens aboard UFOs secretly checking us out, not only because they might covet our resources and real estate, but also because they might well debunk our core notions of ourselves and the Universe. This is why there is a long history of first contact fiction in this magazine. But they’re stories. I don’t for a moment believe that agents of some galactic civilization are lurking around the Solar System, much less teasing us with glimpses of their flying saucers. Yes, we have made progress filling in some of the blanks in the famous Drake Equation https://www.youtube.com/watch?v=6AnLznzIjSE, which gives us a speculative framework for estimating how many advanced civilizations there might be. For example, we now believe that almost every star has at least one planet, so there are trillions of worlds out there. But they are all really, really far away. Maybe Captain Kirk can warp around the Universe without suffering the effects of time dilation due to relativity, but in the Universe where the rest of us live, nothing can exceed the speed of light in a vacuum. And even attempting to accelerate a spaceship to a significant fraction of 186,000 miles (300,000 kilometers) per second would require a mind-boggling amount of energy. That’s because Special Relativity https://www.sciencealert.com/special-relativity tells us that when you accelerate the mass of your spaceship, your velocity increases, and when your velocity increases, the mass you are accelerating increases. The nearer you get to the speed of light, the energy required to accelerate rises exponentially to infinity. And our UFOers would require an equal amount of energy to decelerate before they can pull up Earthside.
If you have some math chops, click over to UFOs: how to calculate the odds that an alien spaceship has been spotted https://theconversation.com/ufos-how-to-calculate-the-odds-that-an-alien-spaceship-has-been-spotted-162269. The site offers a Bayesian analysis https://en.wikipedia.org/wiki/Bayesian_inference of the probability that we’ve been visited by aliens, using such evidence as there is (not much) against the probability that intelligent aliens exist at all by way of the Drake equation. The author’s conclusion: “I end up giving a one in 500 million chance to UFOs being aliens after looking at the footage.”
Sounds about right to me.
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factors
In 1950 the Nobel Prize-winning physicist Enrico Fermi https://www.nobelprize.org/prizes/physics/1938/fermi/biographical and some friends sat down to lunch at the Los Alamos National Laboratory in New Mexico after a busy morning of atomic bomb making. The subject of extraterrestrials came up, and in the ensuing discussion Fermi famously asked, “Where is everybody?” That is, if there really were aliens, why haven’t they visited already? He never published on the subject, but his question has become known as the Fermi Paradox https://www.space.com/25325-fermi-paradox.html. Although radio astronomer Frank Drake https://www.nhm.ac.uk/discover/who-were-the-neanderthals.html did not answer Fermi’s question in 1961, his equation suggested a line of inquiry.
Drake argued that N, the number of advanced civilizations whose electromagnetic emissions might be detectable, can be estimated by assigning a value to an assortment of factors. Multiply R* or the number of stars suitable for life, fp or the number of planets orbiting those stars, ne or the number of those planets which can sustain life, fl or the fraction of those planets where life actually arises, fi or the fraction of those planets where intelligent life emerges, fc the fraction of civilizations that develop technology that can be detected, and L the length of time such civilizations might flourish. Of course, the “equation” can’t be solved, since the values of many of the factors are highly speculative, especially the last two, fc and L, which contemplate both the rise of intelligence and technological civilization.
In 1964 Soviet astrophysicist Nikolai Kardashev https://en.wikipedia.org/wiki/Nikolai_Kardashev proposed his hypothetical Kardashev Scale https://www.space.com/kardashev-scale as a framework for thinking about what might characterize an advanced civilization that humans might be able to detect. His idea was to look at how much energy the hypothetical aliens might consume, arguing that the higher their energy use, the more detectable their technology would be. His scale has been subsequently much modified with parameters other than energy consumption, but is here simplified into four types of civilizations. A Type 0 civilization extracts energy from organic or non-renewable sources, like burning wood, coal, and oil. If you imagine a hundred campfires burning in a scatter of neolithic villages, that might be a megawatt or 106 watts. A Type I civilization has a complete mastery of all energy sources on its home planet, including energy that reaches it from its local star, estimated at around 1017 watts. By these definitions, humankind is not yet a Type I civilization, but is perhaps three-quarters of the way to achieving that level. A Type II civilization could capture all the energy from a star, possibly by building a Dyson Sphere https://earthsky.org/space/what-is-a-dyson-sphere around it, estimated at 4×1026 watts, while a Type III civilization would definitely be interstellar, since it would have the ability to harness the energy output of all of the stars in its galaxy, estimated at 4×1037 watts. What is interesting here for the UFO apologist is that aliens producing high energy technologies that we might be able to detect might also have the answer to the enormous energy needs of sub-lightspeed travel between stars.
Might. But still no answer for Fermi’s question.
In 1998 economist Robin Hanson http://robinhanson.com/home.html published an essay entitled The Great Filter—Are We Almost Past It? https://mason.gmu.edu/~rhanson/greatfilter.html, which examines potential barriers to the rise of life, intelligence, and civilization. Since we only have ourselves as a model, there might be unknown factors that would short circuit continued evolutionary development along the lines outlined by the Drake equation’s possibilities. But what are its probabilities? We do know that humanity has passed certain steps—we are alive and intelligent—but there is no guarantee that life will arise on any of the trillions of suitable planets in our galaxy, or that our civilization will continue to progress toward a Type I civilization and beyond. Since we don’t have credible evidence of other civilizations, what might have prevented their development—and what might yet disrupt ours?
Alas, the grim news of the world does nothing to allay the suspicion that there might be some great filter in our future. In a 2022 paper, Avoiding the “Great Filter”: Extraterrestrial Life and Humanity’s Future in the Universe https://arxiv.org/ftp/arxiv/papers/2210/2210.10582.pdf, JPL Senior Research Scientist Jonathan H. Jiang https://science.jpl.nasa.gov/people/jjiang and others address those fears with examples ripped from today’s headlines. The authors “. . . postulate that an existential disaster may lie in wait as our society advances exponentially toward space exploration, acting as the Great Filter: a phenomenon that wipes out civilizations before they can encounter each other.” They propose “several possible scenarios, including anthropogenic and natural hazards, both of which can be prevented with reforms in individual, institutional, and intrinsic behaviors. We also take into account multiple calamity candidates: nuclear warfare, pathogens and pandemics, artificial intelligence, meteorite impacts, and climate change.” And they urge “a necessary period of introspection, followed by appropriate refinements to properly approach our predicament, and addressing the challenges and methods in which we may be able to mitigate risk to mankind and the nearly nine million other species on Earth.”
So think about it, will you please?
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exit
Meanwhile, as I am writing this, the Pentagon’s recently created All-Domain Anomaly Resolution Office https://www.aaro.mil has released a report https://media.defense.gov/2024/Mar/08/2003409233/-1/-1/0/DOPSR-CLEARED-508-COMPLIANT-HRRV1-08-MAR-2024-FINAL.PDF reviewing all the government investigations into UFOs—excuse me, our government insists we call them unidentified anomalous phenomena (UAP)—since 1945. UFOologists will recall that there have been many, among them 1960’s Brookings Report https://en.wikipedia.org/wiki/Brookings_Report, 1968’s Condon Report en.wikipedia.org/wiki/Condon_Committee, and Project Blue Book https://en.wikipedia.org/wiki/Project_Blue_Book, which was terminated in 1969.
Takeaway of the latest report? “AARO found no evidence that any USG investigation, academic-sponsored research, or official review panel has confirmed that any sighting of a UAP represented extraterrestrial technology. All investigative efforts, at all levels of classification, concluded that most sightings were ordinary objects and phenomena and the result of misidentification. Although not the focus of this report, it is worthwhile to note that all official foreign UAP investigatory efforts to date have reached the same general conclusions as USG investigations.” Nothing to see, move along.
Redundantly, the report goes on. Not only have there been no sightings but “AARO found no empirical evidence for claims that the USG and private companies have been reverse-engineering extraterrestrial technology. AARO determined, based on all information provided to date, that claims involving specific people, known locations, technological tests, and documents allegedly involved in or related to the reverse-engineering of extraterrestrial technology, are inaccurate.” Take that, Roswell faithful!
But going forward, do feel free to stop by their spiffy new website to report any UAPs you happen to witness.
Copyright © 2024 James Patrick Kelly