What could be the worst-case scenario upon announcing the discovery of extraterrestrial technological intelligence? This list is not inclusive.
Scenarios after Human-ETI Contact. This list is not inclusive of all possibilities.
Potential Consequences:
1. Mass Panic:
The crisis of order. Exploitation could surge, with doomsday cults gaining followers and charlatans claiming to be “ambassadors” for the aliens, preying on the fearful.
Economic collapse might occur, as markets could crash due to radical uncertainty following an extraterrestrial discovery. Misinformation would fill the information vacuum, leading to conspiracy theories and fear-mongering, potentially inciting violence and civil unrest.
However, studies of disasters (including the COVID-19 pandemic) suggest that true, sustained mass panic is less common than often assumed.
2. A Retraction: The Crisis of Credibility
What if subsequent investigations prove the discovery to be false, requiring a retraction? This could discredit the entire SETI field.
Such a scenario would be a catastrophic embarrassment. The field already struggles with what some call the “giggle factor,” and being discredited for a generation could severely damage public trust in scientists and science as a whole. Securing funding for future searches might become nearly impossible after a failed extraterrestrial discovery.
3. Humanity Dethroned: The Crisis of Meaning
What if the extraterrestrial discovery implies that humankind no longer occupies the pinnacle of evolution in the cosmos?
Religions centered on human exceptionalism could face a fundamental crisis. However, studies on this subject have shown that the impact may be negligible.
Will Discovering Extraterrestrial Life Challenge Religion?
Examining the reaction of religion to the existence of extra-terrestrial intelligence. Will beliefs be challenged or transformed? Discover more.
Read More
contactproject.org
Our entire worldview, which places humanity at the center of meaning, could be invalidated. This could lead to profound, species-wide depression, a loss of purpose, and what philosophers term “cosmic despair.” Why strive, create, or even continue if we are but ants on an unremarkable anthill?
(I disagree.)
4. The Optimistic View (The Cosmic Perspective):
Would this discovery temper humankind’s worst instincts, such as warfare, and diminish the power of despotic rulers?
Carl Sagan and others have hoped that knowing we are not alone would foster a “cosmic perspective.” Realizing we are all citizens of a fragile, shared planet in a vast cosmos could make nationalism, racism, and warfare seem petty and childish. Such an extraterrestrial discovery could unite humanity and pose a threat to despotic rulers whose power relies on manufacturing “us vs. them” conflicts.
(I agree.)
5. The Pessimistic View:
A despotic ruler thrives on controlling information and manipulating fear. An alien intelligence could become the ultimate propaganda tool.
A dictator might claim that the aliens pose a demonic threat, justifying crackdowns and military expansion to “protect” the populace.
They could also claim that the aliens have endorsed their rule, creating a new “divine right” to govern after such an extraterrestrial discovery.
The discovery could trigger an unimaginably high-stakes Cold War, where nations fight not for territory or resources but for control of communication channels and any technological secrets the aliens might reveal.
(Well, that’s why we have HAM radio operators and satellite dishes.)
In 1985 I was living in Galway, on the west coast of Ireland. I regularly raided the local library in Augustine Street for reading material. It no longer looks like this, but I remember walking up the stairs on the left:
Old Galway Central Library, Augustine Street, from memory
The Mysteries of Pulsars Capture My Imagination
There, I discovered a book about pulsars. As I read, I was struck by the remarkable characteristics of these cosmic phenomena—they emitted incredibly regular radio pulses, seemingly ticking like celestial clocks. Something about their precise periodicity raised a suspicion in my mind: Could these signals be of artificial origin? The idea gnawed at me. It seemed almost too perfect, too synchronized, to be purely natural.
Antony Hewish in front of 4.5-acre array, image by Cavendish Laboratory, University of Cambridge.
Delays and Doubts: The Scientific Community’s Caution
What puzzled me even more was the fact that the researchers who first detected pulsars waited nearly two years before publishing their findings. When they finally did, they explained the regular radio transmissions as the result of some natural astrophysical process—perhaps rapidly spinning neutron stars or some other exotic object. But I couldn’t shake the feeling that something was being hidden, or at least not fully explored. Why delay the publication? Why rush to explain away the strange signals with a natural cause, when they could just as easily be a message—or evidence—of intelligent life?
First Observation Of Pulsar, image by Cavendish Laboratory, University of Cambridge.
A Personal Mission: Reaching Out to a Nobel Laureate
I found myself unable to let go of the thought. I decided I had to try and get some answers directly from someone who knew the science firsthand—Professor Antony Hewish himself, the Nobel laureate who played a key role in the discovery of pulsars.
The walk to the phone booth on Eyre Square was not long—just a few minutes—but to me, it felt like a journey into the unknown. I passed by the familiar sights: the cobblestone streets, the bustling cafés, and the distant clang of the clock tower. The square was busy with people, their conversations and footsteps creating a constant hum. I could feel the cool breeze on my face, carrying the faint smell of brewing coffee from nearby cafés, mingling with the crisp air of a typical Irish day.
Pádraic Ó’ Conaire statue on Eyre Square, Galway
Making the Call: Asking the Expert About Artificial Origins
As I approached the square, I paused briefly to steady my breathing. I reached into my pocket, clutching the handful of Irish pound coins I had carefully gathered for this purpose. I looked at the phone booth—a small, glass-panelled box standing at the corner of the square, slightly worn but functional. Its faded paint and the faint smell of old metal reminded me of countless moments of waiting and hope.
I stepped inside, feeling the cool metal of the door handle against my hand. The interior was dimly lit, with the faint glow of the coin slot and dialing pad. I took a moment to collect myself. The hum of the city outside seemed to fade into the background as I lifted the receiver and inserted the coins one by one into the slot, hearing the satisfying clink as they dropped into place.
The phone was a rotary-style model, but it worked—reliable and straightforward. I stared at the dial pad, my fingers trembling slightly as I entered the number for the Cavendish Laboratory in Cambridge. The line was long-distance, and I had only a limited amount of coins. I whispered a quiet prayer that the call would go through.
The Interview
Finally, I heard the connection click. A calm, measured voice answered.
Antony Hewish on the phone (AI generated)
“Hello?”
“Professor Hewish?” I asked, trying to keep my voice steady.
“Yes, speaking,” came the reply.
I hesitated for a moment, my mind racing with questions. Then I blurted out, “I’m calling to congratulate you on the discovery of pulsars.”
There was a brief pause, and I could almost hear him smiling on the other end of the line.
He thanked me politely, then I took a deep breath and asked, “I find the subject absolutely fascinating, and I was wondering—are you absolutely certain that pulsars are not of artificial origin?”
He responded with quiet confidence, “Yes, I am certain.”
And then he proceeded to explain, his voice steady and reassuring:
“Pulsars are fascinating objects. They are highly magnetized, rapidly spinning neutron stars—remnants of massive stars that have gone supernova. As they rotate, their intense magnetic fields funnel particles toward their magnetic poles, which act like cosmic lighthouse beams. When these beams sweep past Earth, we detect them as highly regular radio pulses.”
Reflections Under the Galway Sky
I listened intently, my mind swirling with his explanations—ones I’d heard before, yet they only deepened my curiosity. I asked again, perhaps more insistently:
“And you are 100% sure that pulsars are not of artificial origin?”
Hewish chuckled softly on the line, “Yes, absolutely certain.”
I thanked him for his time, and before used up all my coins, I ended the call. Stepping back onto the street, I looked up at the grey, cloudy sky, pondering the vastness of space and the mysteries it still held. The conversation left me with a lingering question: could we someday truly find signs of intelligent life out there?
One Second of Error in 30 Million Years
The universe’s most precise timekeepers—the most stable pulsars—are so remarkably accurate that they would drift by only a single second over tens of millions of years. Their stability rivals—and in some respects even surpasses—that of our most advanced atomic clocks.
The most stable known millisecond pulsar, designated PSR J1713+0747, exemplifies this extraordinary precision. Its rotational period is so consistent that it would accumulate an error of just one second after approximately 30 million years.
When we talk about the superiority of pulsars as cosmic clocks, we’re referring to their ability to keep perfect time over millennia—far beyond the reach of any human-made clock. Engineers can build clocks that lose only one second in 300 billion years, but such devices are fragile, often breaking down within a few decades. Pulsars, on the other hand, can continue their steady ticking for billions of years, offering an unmatched cosmic standard of time.
In the context of the Extraterrestrial Intelligence Search, in 1980 the mathematical physicist and cosmologist Frank J. Tipler published a paper, “Extraterrestrial intelligent beings do not exist.”
Reference: Extraterrestrial intelligent beings do not exist, Tipler, F. J.
Tipler sought a universal principle to explain the Fermi Paradox: the apparent absence of extraterrestrial beings on Earth. He contended that if extraterrestrial intelligent beings existed, then their manifestations would be obvious. Conversely, since there is no evidence of their presence, they do not exist.
Von Neumann Probes
Frank Tipler argued that if any extraterrestrial civilization ever built self-replicating von Neumann starprobes, those probes would grow exponentially. They would fill the galaxy in a few million years. Since we don’t see them here, Tipler concluded there are no other intelligent civilizations.
• Tipler assumed each probe would land on a new world and make just one or a few copies before moving on. However, he had no reason to limit its reproduction so drastically.
• Even if each probe were only 10 grams and doubled once per decade, in about 150 generations we’d have the mass of an entire galaxy. This conversion to machines would be on the order of 1 followed by 54 zeros grams (1 quindecillion tons). Moreover, this transformation would occur in less than 15 million years.
• Because we see no evidence of such galaxy-eating machines anywhere, Tipler said no one else ever invented them. Therefore, no one else is out there.
SAGAN’S RESPONSE
Carl Sagan pondered the arithmetic of Tipler’s solipsist argument. His response is a classic in the realm of science and philosophy. He draws attention to the limitations of our current knowledge and the vastness of the universe. By stating, “Absence of evidence is not evidence of absence,” Sagan cautioned against jumping to conclusions based on what we don’t know.
Sagan and William I. Newman challenged Tipler’s assumptions and conclusions, proposing a more realistic colonization model based on population growth and organization. This alternative model estimates a galaxy-crossing time of approximately one billion years, significantly longer than Tipler’s few million years.
Sagan further suggests that self-replicating probes are subject to evolutionary divergence, imposing unacceptable risks to altruistic extraterrestrial intelligent life (ETI). The ETI only communicate with other ETI through signals. This argument assumes that self-replicating machines are essentially uncontrollable because they must evolve.
Sagan and Newman also propose that the emergence of powerful weapons of mass destruction may impose a universal brake on unchecked expansion. This could potentially limit the spread of advanced civilizations. Ultimately, they emphasize the importance of experimentation in resolving the Fermi Paradox. Systematic searches using radio telescopes and other tools are necessary to settle the question of whether we are alone in the universe.
Reference: The Solipsist Approach to Extraterrestrial Intelligence, by Sagan / Newman 1983QJRAS..24..113S Page 113
Terrestrial Shortsightedness
Imagine New York in 1894, its streets choked with the clatter of hooves. Its futurists were drowned in calculations of manure. They predicted that by 1944 New York would drown in horse manure.
The futurists only saw linearity: more carriages, more waste, an apocalypse of filth. However, they could not fathom the silent revolution already stirring—the internal combustion engine, the horseless carriage—a paradigm shift that would render their equations relics.
So too might we falter when envisioning the starfarers of tomorrow. To assume interstellar travel or contact must devour suns is to chain possibility to the physics of this moment. What of the technologies unimagined? The spacetime shortcuts, the dark energy harnessed, the self-replicating probes born of nanoengineering? The cosmos whispers of mysteries we have yet to decode.
Carl Sagan may have cautioned Tipler that his reasoning could mirror that of the horse-cart prophets. One may fail to see beyond the boundaries of the known. The universe is not merely a puzzle to solve with present tools. It is also a frontier that reshapes the solver. As we once tamed fire and split the atom, so too might we one day dance with the fabric of spacetime itself. The answer to the Fermi paradox may not lie in the scarcity of civilizations. It may lie in the humility of our assumptions.
After all, the stars are not merely endpoints. They are teachers. Their greatest lesson might be this: To traverse the light-years, we must first learn to think in ways as boundless as the dark between galaxies.
Reference: The Great Horse Manure Crisis of 1894
By the late 1800s, large cities all around the world were drowning in horse manure. The London Times predicted in 1894 that in 50 years’ time, every street in London would be buried under nine feet of manure.
Why has nobody built rotating spacecraft to simulate gravity?
Pictured: a fairground ride from the 1950’s, I call it a GRAVITY DRUM.
A whole spacecraft is expensive to rotate, but small spaces on space stations or ships could easily be rotated.
Can those small spaces be big enough to provide meaningful and healthy artificial gravity?
From my physics knowledge I recall that gravity and acceleration are the same.
If I remember correctly, 1 g is equal to an acceleration of 9.81m/sec per second. In other words, a wheel with a circumference of 10 meters would have to be spun about once per second to simulate 1 g in Zero gravity? Not quite.
Alas, it’s a bit more complicated than that, and thankfully we don’t have to spin the wheel quite so fast. That’s a bonus!
Here are a few handy calculators to work out wheel sizes and rotation rates to simulate Earth gravity:
SpinCalc, solves for gravity, radius and rotation rate,
A wheel with a circumference of 10 meters would have a diameter of 3.18 meters. This would be a handy size for artificial gravity experiments, even on Earth.
Would it be comfortable to spend any time in this? The wheel should rotate at about 24 RPM to simulate 1 g. It could be compartmentalized in to 1 x 2 meter beds, holding ten crew.
So at least during their rest period spacefarers would have the benefit of normal gravity. The astronauts are lying on the inside of the wheel, a bit like in the fairground ride illustration but with more privacy.
We know that the negative effects of zero gravity are really serious and numerous. Even 2.5 hours of daily treadmill exercise are insufficient to prevent these effects:
fluid redistribution: Bodily fluids shift from the lower extremities toward the head. This precipitates many of the problems described below .
fluid loss: The brain interprets the increase of fluid in the cephalic area as an increase in total fluid volume. In response, it activates excretory mechanisms.
electrolyte imbalances: Changes in fluid distribution lead to imbalances in potassium and sodium and disturb the autonomic regulatory system .
cardiovascular changes: An increase of fluid in the thoracic area leads initially to increases in left ventricular volume and cardiac output. As the body seeks a new equilibrium, fluid is excreted, the left ventricle shrinks and cardiac output decreases.
red blood cell loss: Blood samples taken before and after American and Soviet flights have indicated a loss of as much as 0.5 liters of red blood cells.
muscle damage: Muscles atrophy from lack of use. Contractile proteins are lost and tissue shrinks. Muscle loss may be accompanied by a change in muscle type.
bone damage: Because the mechanical demands on bones are greatly reduced in micro gravity, bones essentially dissolve.
hypercalcemia: Fluid loss and bone demineralization conspire to increase the concentration of calcium in the blood.
immune system changes: Loss of T-cell function may hamper the body’s resistance to cancer — a danger exacerbated by the high-radiation environment of space .
interference with medical procedures: Bacterial cell membranes become thicker and less permeable, reducing the effectiveness of antibiotics.
vertigo and spatial disorientation: Without a stable gravitational reference, crew members experience arbitrary and unexpected changes in their sense of verticality.
space adaptation syndrome: About half of all astronauts and cosmonauts are afflicted. Symptoms include nausea, vomiting, anorexia, headache, malaise, drowsiness, lethargy, pallor and sweating.
loss of exercise capacity: This may be due to decreased motivation as well as physiological changes.
degraded sense of smell and taste: The increase of fluids in the head causes stuffiness similar to a head cold.
weight loss: Fluid loss, lack of exercise and diminished appetite result in weight loss. Space travelers tend not to eat enough.
flatulence: Digestive gas cannot “rise” toward the mouth and is more likely to pass through the other end of the digestive tract “very effectively with great volume and frequency” .
facial distortion: The face becomes puffy and expressions become difficult to read, especially when viewed sideways or upside down.
changes in posture and stature: The neutral body posture approaches the fetal position. The spine tends to lengthen.
changes in coordination: Earth-normal coordination unconsciously compensates for self-weight. In weightlessness there is a tendency to reach too “high” .
Compared to these adverse effects of zero gravity, here are some studies by a psychologist named Graybiel from 1977 on the effects of rotating a human on his own axis here on Earth, like on a spit (from https://psycnet.apa.org/record/1980-22567-001).
GRAYBIEL ROTATION COMFORT ZONES
Graybiel concluded that 1.0 RPM: even highly susceptible subjects were symptom-free, or nearly so 3.0 RPM: subjects experienced symptoms 5.4 RPM, only subjects with low susceptibility performed well 10 RPM, adaptation presented a challenging but interesting problem. Even pilots without a history of air sickness did not fully adapt in a period of twelve days.
The “adaption” that Graybiel is talking about is the getting used to the absence of the rotation, after the body had been spun.
What that feels like we all remember from childhood.:
Pirouette
I must say that spit rotating a human on his own axis in the horizontal under the influence of Earth gravity is most likely to be very far removed from what a human may experience in an artificial gravity drum in weightless space.
I’d go as far as to say that Graybiel’s rotation comfort zones have absolutely nothing to do whatsoever with artificial gravity by centripetal force. All he proved in his paper “Somatosensory motion after-effect following earth-horizontal rotation about the Z-axis” is that the after effect of spinning someone rapidly is disorientation of the vestibular system of the ear, leading to dizziness, aka vertigo.
But let’s see if these Graybiel’s comfort zone figures can be applied. The SpaceX Mars rocket is going to have a diameter of 9 meters. Would it be possible to create a comfortable habitat for sleeping or resting spacefarers within the confines of this rocket?
A 9 meter drum would need to rotate at 14 RPM to simulate 1 g, or at 8 RPM to achieve 1/3 of Earth gravity. Graybiel’s findings would indicate that the space available on the SpaceX Mars rocket would be too small.
However, I believe that the gravity (centripetal force) acting on the body as it lies down, not spinning about itself and on one level , will be more comfortable than twirling rapidly around one’s own axis.
In Drum Gravity Bed Units there would be no head-to-foot acceleration gradient.
DRUM GRAVITY BED UNITS The drum gravity bed units are conceived of as an add-on module to a spacecraft or space station, be it in transit, orbit or on the Moon, Mars or asteroids to provide more natural gravity.
Have prototypes of this concept been built?
In a certain way: Yes! The first picture in this post is a fairground attraction from the 1950’s.
Did humanity really forget from the ’50s how easy and fun it is to enjoy artificial gravity? Apparently the fairground visitors subjected themselves to the experience voluntarily and enjoyed it.
“Rotor Ride”
Simple gravity devices like this could help spacefarers to maintain their health, after the device is tweaked.
Here are the calculations on the von Braun wheel from 1952 used in the movie 2001: A Space Odyssey:
They envisioned a rotating wheel with a diameter of 76 meters (250 feet). The 3-deck wheel would revolve at 3 RPM to provide artificial one-third gravity. It was envisaged as having a crew of 80.
Fast forward 70 years (not much has happened since the 1950’s):
SAHC HUMAN CENTRIFUGE The SAHC human centrifuge began testing and operations in about 2020. It’s to investigate the tolerability and use of artificial gravity on astronauts and their health, to counter the effects of weightlessness. What’s taken so long?
The machine measures 5.6 meters in diameter. It would be small enough to put in the SpaceX Mars rocket. But it needs a few more seats.
With the Short-Arm Human Centrifuge (SAHC) in Cologne — provided by the ESA — artificial gravity will be created to afford fundamental research in medicine and human physiology. The main focus is on the possibility to extend e.g. bed-rest studies to test methods of artificial gravity based counter-measures for medical risks due to weightlessness.
Technical data:
Max. radius at outer perimeter: 2,8 m Max. overall payload: 550 kg
Max. centrifugal acceleration (foot level, test subject height 185 cm): 4.5 g Max. revolution of centrifuge rotor (software limit): 39 rpm
Scientific applications
Development of effective countermeasures for neuromuscular and skeletal degeneration of astronauts using Artificial Gravity, etc…
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