Writers have modeled the arrival of an extraterrestrial probe in our Solar System in a number of interesting science fiction texts, from Clarke’s Rendezvous with Rama (1973) to the enigmatic visitors of Ted Chiang’s “Story of Your Life,” which Hollywood translated into the film Arrival (2016). In between I might add the classic ‘saucer landing on the White House lawn’ trope of The Day the Earth Stood Still (1951), based on a Harry Bates short story. All these and many other stories raise the question: What if before we make a radio or optical SETI detection, an extraterrestrial scout actually shows up?
Graeme Smith (UC: Santa Cruz) goes to work on the idea in a recent paper in the International Journal of Astrobiology, where he focuses on the mechanism of interstellar dispersion. The model has obvious ramifications for ourselves. We are beings who have begun probing nearby space with vehicles like Pioneer and Voyager, and in our early stages of exploration we could conceivably be reached by an extraterrestrial civilization (ETC) before we can make such journeys ourselves. Smith is asking what form such contact would take. His paper cautiously tries to quantify how interstellar exploration likely proceeds based on velocity and distance in a steadily advancing technological culture.
This takes us back to the so-called ‘Wait Equation’ explored by Andrew Kennedy in 2006, where he dug into what he called ‘the incentive trap of progress.’ Kennedy made the natural assumption that as an interstellar program of exploration proceeded, it would continue to produce faster travel speeds, so that one probe might be overtaken by another (thus A. E. van Vogt’s ‘Far Centaurus’ scenario, where a starship crew comes out of hibernation at Alpha Centauri to find a thriving civilization of humans, all of whom came by much speedier means while the original exploration team slumbered enroute).
The question, then, becomes whether we should postpone an interstellar launch until a certain amount of further progress can be made. And exactly how long should we wait? But Smith looks at this from a different angle: What kind of probes would be first to arrive in a planetary system where a civilization like ours can receive them? Would they be the ‘lurkers’ Jim Benford has written about, left by beings who expected them to report home on what evolved in our Solar System? Or might they be more overt, making themselves known in some way, and advanced well beyond our understanding?
Image: Is this really what we might expect if an ETC arrived on Earth? From the 1951 version of The Day the Earth Stood Still. Frank Lloyd Wright is said to have been involved in the design of the craft for this movie, though some believe this to be no more than a Hollywood legend. It’s an interesting one if so. And about that spacecraft: Is it too low-tech to be realistic? Read on.
In Smith’s parlance, a civilization like ours is ‘passive,’ a specific usage meaning that it is able to probe its own system with spacecraft but does not yet have interstellar capabilities. He imagines two ETCs, one in this passive state and one capable of interstellar flight. Smith’s calculations then consider probes launched by an extraterrestrial civilization that are followed by increasingly advanced probes over time. You can see from this that the farther away the sending civilization is, the more likely that what will arrive at the passive ETC will be one of its more advanced probes, the earlier ones being still in transit.
If an active ETC is evolving rapidly in technology, or is exceedingly distant, then a vehicle of relatively advanced state may be more likely to first reach a passive collecting civilization. In this case, there could be a considerable mismatch in the technology level of the first-arrival probe and that of the passive ETC that it encounters. This would presumably have ramifications for what might eventuate if an artefact from an ETC were to arrive within the Solar System and enable first-contact with terrestrials. Hypothetical reverse engineering, for example, might be difficult given the technology gap.
Assuming the probe speed scales linearly with launch date, Smith uses as an example the Voyager probes and spins out increasingly fast generations of probes, noting how many such generations will be required to reach first the closest stars and then stars farther out, and calculating the time that separates the first encounter spacecraft with the initial, zero-generation probes. The situation accelerates if we assume probe speeds that scale exponentially with launch date. I send you to the paper for his equations, but the upshot is that this scenario heightens the likelihood that a first encounter probe will display a major disparity in technology from what it finds at the receiving end.
And depending on the distance of the sending civilization, the disparity between the ETC technology and our own could be such that we would have difficulty understanding, even comprehending, what we were looking at. Smith again (italics mine):
The key implication of this paper can be summarized as followed: if an actively space-faring ETC embarks on a program to send probes to interstellar destinations, and if the technology of this ETC advances with time, then the first probe to arrive at the destination of a less-advanced ETC is less likely to be one of the earliest probes launched, but one of more advanced capability. There may thus be a substantial disparity between the level of technology comprising the first-arrival probe and that developed by the receiving ETC, if it has no interstellar capability itself. The greater the initial separation of the two ETCs, or the greater the rate of probe development by the active ETC, the greater is the potential for a technological mismatch at first encounter.
Image: A language that can alter our perception of time, under study in the film Arrival, where the probes in question represent a technology that is baffling to Earth scientists.
The situation would change, of course, if the receiving civilization is also one possessing interstellar capabilities, in which case contact might not even occur on the home world or system of the receiving culture. As we are a passive civilization in Smith’s terms, we are likely to encounter a markedly advanced civilization if an artifact ever does show up in our system. David Kipping calls this result ‘contact inequality,’ and remember, “…increasing the distance Dmax of the first-contact horizon increases the likely generation number of a probe of first encounter, thereby enhancing a contact inequality with a passive ETC.”
Something entering our Solar System from another civilization should be highly sophisticated, well beyond our technological levels, and perhaps utterly opaque to our scrutiny. The scenario of, for example, the Strugatsky brothers’ Roadside Picnic seems more likely than that of The Day the Earth Stood Still. The 1972 novel depicts the ‘stalker’ Red Schuhart as he enters a ‘zone of visitation’ where an alien civilization has come to Earth and left behind bizarre and inexplicable traces. Now they’ve moved on. What is human culture to make of their detritus? From the novel:
He had never experienced anything like this before outside the Zone. And it had happened in the Zone only two or three times. It was as though he were in a different world. A million odors cascaded in on him at once—sharp, sweet, metallic, gentle, dangerous ones, as crude as cobblestones, as delicate and complex as watch mechanisms, as huge as a house and as tiny as a dust particle. The air became hard, it developed edges, surfaces, and corners, like space was filled with huge, stiff balloons, slippery pyramids, gigantic prickly crystals, and he had to push his way through it all, making his way in a dream through a junk store stuffed with ancient ugly furniture … It lasted a second. He opened his eyes, and everything was gone. It hadn’t been a different world—it was this world turning a new, unknown side to him. This side was revealed to him for a second and then disappeared, before he had time to figure it out.
Image: From the 1979 film Stalker, based loosely on the Strugatsky novel. No spacecraft, no aliens here, just the mystery of what they left and what it means.
It should hardly surprise us that an arriving interstellar probe would be well beyond our technology; otherwise, it couldn’t have gotten here. But if we factor in what Smith is saying, it appears that depending on how far away the sending ETC is, the technology gap between us and them becomes greater and greater. We’re talking about baffling and perplexing morphing into the all but unknowable. Indistinguishable from magic?
No grand arrivals, no opportunities for trade, no galactic encyclopedias. This is first contact as enigma, and if I had to put money on it, I suspect this is closer to what would happen if contact is achieved by a visitation to our planet. I return to Rendezvous with Rama, where odd geometric structures and a ‘cylindrical sea’ are found within the probe slingshotting around the Sun, and the vehicle departs as mysteriously as it came, leaving behind only one overwhelming fact: We are not alone.
The paper is Smith, “On the first probe to transit between two interstellar civilizations,”
International Journal of Astrobiology 22 (2023), 185-196 (abstract).
Excellent, thought-provoking article, although my view is that a first contact via interstellar communication is orders of magnitude more likely than first contact via interstellar artefact. I would be interested in your views on the comparative likelihood.
Mark, I’ve always come down on your side of this, that the first contact would be far more likely to be via a detecion at radio or optical wavelengths, or perhaps something in our astronomical data. But lately I’ve come to appreciate the idea of possible probes (maybe quite ancient) in our own system. I agree with Jim Benford that it makes sense to keep these in mind as we search not just the lunar surface but other small objects near Earth.
First contact by em signals or artifacts is not mutually exclusive. An artifact once detected and triggered might start the contact, even if the civilization that created the artifact is long gone from the universe. Artifacts that can survive millions, if not billions, of years, might be the best way for civilizations to ensure contact with ephemeral civilizations even after they have passed into history.
Ik only the Krell had left more historical documentation and knowledge far Morbius (Forbidden Planet).
Any advanced civilization which would send probes knowing they will be superseded by more advanced probes before they even arrive should not be considered a very advanced civilization.
So does one send slow plow probes and then wait a very long time before sending more advanced probes (possibly longer than one’s civilization lasts), or does one wait for the advanced technology foregoing any more immediate gains from the slow probes? For example, our existing probes are informing us about the heliosphere and nearby ISM. Show we forgo that knowledge if we suspect those probes may reach other star systems after 10s of millennia, and only launch when we can predict the ultimate velocities of any probe technology? What would that velocity be? 0.1c? 0.5c? 0.9999999c? FTL? How can any prediction be made? Trying would just paralyze the civilization with indecision.
Contradicting what I have said in another comment, short-term decisions can be very useful apart from purely short-term advanatages.
I’ll try and give what might be a real example. We could soon design, build and send a probe that might take thousands of years to get there when in some reasonable time frame of a few years, we might be on the cusp of technologies that could make the same journey in only tens of years. A long shot to be sure but I speak of real research like the MEGA drive of Woodward and Fearn or something similar like Mike McCulloch’s quantized inertia type drive. A few years of further research to see if these or similar ideas pan out before embarking on a ten thousand year journey would be wise in my view.
Any advanced civilization which would send probes knowing they will be superseded by more advanced probes before they even arrive should not be considered a very advanced civilization.
This line of thought never made sense to me. At the heart of it is the notion – why do anything? A specific (though extreme) extension being, why space before paradise on earth?
Hopefully, we do things that make sense. It makes sense to do some things in space while we are still learning to live on earth. It doesn’t make sense to launch a probe that has a ten thousand year payback if the purpose is a return of knowledge. If we don’t develop fast interstellar travel for probes anytime soon it makes more sense to me to focus on instruments that can tell us more about the stars from our vantage point here until it makes as much sense or more to send a probe there.
I agree with you Robert. A fleet of small laser driven probes travelling at 0.1 or 0.2 c is worth the expenditure (if anyone is willing to make it) because it gives results in a few decades when used to visit the closest star systems. Launching a probe or ship that takes thousands of years to arrive at it’s destination makes no sense to me for a short-lived species like humans. We’re constantly threatening our own existence in the short term let alone the long term. And the cost for a multi-thousand year voyage would be absolutely astronomical (no pun intended).
@Robert. But you are assuming we gain nothing until the probe reaches the destination. That just isn’t true. All the precursor interstellar missions plan to collect data on the environment as the probe travels into interstellar space. That data will flow back in terms of a few decades at most. Yes, faster probes will overtake the slow probe, but the already collected data will tell us about what the faster probe will encounter, as well as the possible failure conditions of a probe as it enters the ISM. This is valuable information when designing the faster probe.
I guess the question is then about perspective and logic. Long lived civs will likely have different perspectives on timelines and their logic will be driven by whatever ‘fuel’ that is in play.
We just have to think of cathedrals and colliders for disparate examples of ‘essential’ endeavours.
Yes, a sufficiently advanced tech would be indistinguishable from magic.
But has there been any time in the past million years when primates have not been violent to one another, observable to ET probes?
If we were ‘discovered’ 100,000 years ago and a probe arrived here 20,000 years ago, (80,000year trip), it would probably have been with tech that is indistinguishable from nature. ET has to think there would be a 80,000 year opportunity for us to develop tech.
It wouldn’t be wise to send tech that could be reverse engineered and used by a civ that had not matured enough to prove itself non hostile.
Communication is one thing. Sending tech is different. Has to be childproof and idiot proof.
Having observed us being violent against each other, ET is presently aware that we have extensive media on “hostile alien invasion”. They conclude that revealing we are not alone would drive up gun sales among civilians, and hasten militarization of space by govt. War would breakout over accusations of covert alien cooperation with certain governments.
No, I don’t see ET revealing themselves, or us finding probes any time soon.
Have you read Stanislaw Lem’s Fiasco? Definitely elements of what you commented about in this pessimistic novel of first contact. It is one of several novels and anthologies about unexpected consequences.
On national and terrestrial scales, how many of our problems are caused by short-term thinking and expediency and ignoring longer-term consequences? Hindsight is always 20/20, but some of the consequences we face at any organizational level were predictable and predicted, but we collectively ignored them.
Thanks for the link!
I do not intend to be pessimistic. My position comes from a point of optimism, albeit qualified by time. I believe that civilization as we know it is a consequence of transient collective agreements by ape brains – (that evolved, by accident of nature, to be capable of occasional rational thought and behavior). Our brains did not evolve for the purpose of intelligence required for civilization. Not yet. And this is were I am cautiously optimistic: self directed evolution, ever increasing levels of intelligence. And the directed civilization that goes with it. I believe we are approaching the level of genomics needed to start this climb. In two or three generations, a child will be engineered to be more intelligent than any that came before it. And then a child without the capability of schizophrenia, then without sociopathy, etc.
ET does not want to deal with a bunch of apes capable of occasional rational thought and behavior. That would be dangerous for the apes and irrational on ETs part. Why would they spoil it now? They’ve waited 500,000 years. What is another 500? Then they talk to our ‘descendants’, who have consistent, predictable, rational thought and behavior. And the type of civilization that can get to the stars.
@dimjo. While gene engineering may enhance our biological brains for intelligence without enhancing other pathologies, I think we will get to machine AGI far sooner. In which case we get to the scenario of TDTESS with the powerful machines policing the biologicals. A more dystopic vision is that of Colossus: The Forbin project, where 2 vast AIs, one in the USA, one in the USSR, control the Earth to stop human irrationality from allowing us to destroy ourselves.
I find it interesting that the current “panic” over AI is the fear of existential risk due to humanity using it for nefarious purposes. (Hence the AI summit in England). There is also the fear that runaway “paper clip maximizer” AIs will destroy the planet as if uncontrollable, runaway corporates are not already doing this. But no one is concerned about AI ecosystems controlling our global civilization surreptitiously. We end up in a scenario where the machine intelligences effectively control us, but we think we are the prime agency on the planet when in reality we are not.
Now would ETC in a similar state be happy to deal with the Earth? I think it would.
Why do we always assume the more technologically advanced culture is the more mature, or civilized one? Classical Roman or Greek cultures were as subtle and sophisticated as ours, even though we are far ahead of them in technology. And how much of our alleged wisdom arises from contemporary intellectual fads and fashion, and not from a true understanding of the laws of nature, or supposed moral and ethical principles–whatever THAT means?
Whether an alien culture is benign and tolerant (as opposed to hostile and xenophobic) may have absolutely nothing to do with how fast they can travel or signal through space. An alien species may be seen to them as a potential threat, or an opportunity for mutual benefit–or anywhere on the spectrum in between. Perhaps they already know of the existence of other cultures and experience has taught them to deal with new ones already-in a standardized and specified way. Kumbaya, or shoot first and ask questions later? There is no “right” or “wrong” answer to that question, it is culturally determined, or perhaps acquired through bitter experience.
We often invoke examples from our own history to try and understand these distinctions, but let us not forget the Spaniards and the Incas/Aztec were the same species. The Europeans had horses, gunpowder and steel weapons but they were also religious fanatics with a pathological lust for gold. And we know little of the cultures they exterminated, except that they were also warlike, kept slaves and practiced human sacrifice. If we could time-travel to Greece or Rome we might be a bit more anthropologically correct in our dealings, but I have a feeling those folks would get our number soon enough, once they grasped our tech was not magic and that otherwise we were just like them. But ET is not just like us. All bets are off.
If we do meet ‘them’, the nature of our encounter may be much more determined by whether the meeting is unexpected, or whether at least one side had anticipated it and prepared for it. But how the encounter proceeds is impossible to predict. They simply may not care. Its not even certain we will.
As suggested in Star Trek: TOS (S02E25):
Bread and Circuses
Whilst we are biologically similar to the populations of ancient civilizations, it cannot be argued that we have less knowledge or that we have no better understanding of our world and how to operate in it. While that doesn’t mean that our contemporary civilization acts better, it does mean that we have a broader understanding even if we do not act on that knowledge. Wiser heads do not always lead (arguably rarely, it seems). The ST episode assumed that Captain Merik was motivated by power and therefore easily swayed by a different culture. Not, however, our intrepid command crew of the USS Enterprise.
If we do meet ETI, I think that the probable vast disparity in the age of our 2 civilizations is more likely to mean that the elder civilization might barely notice our presence. If we did do something stupid and attack them, we might be as easily stopped as a swarm of bees, as Klaatu stops almost everything on Earth to demonstrate the technological power of the federation of planets he represents in The Day the Earth Stood Still.
Whilst ET would be very different from us biologically, would their intelligence be that different…or would we converge to similar positions? Math and logic would suggest that we would share common game theory models for many scenarios. If we both had machine intelligences that were not modeled to reproduce our more biologically evolved ways of thinking, but based more on logic, would these machine intelligences be even closer in POV and hence probable actions?
All else being equal, the actions of one civilization concerning its alien counterparts may have a lot more to do with how experienced the race was with other races. In other words, the same civilization might react very differently if it had an extensive experience with first contact scenarios. If our first contact had never encountered another before it met us, I suggest it would deal with us very differently than if it already had a history of numerous communications with varied species. When speculating about THEM, we rarely factor in what effect their experience with multiple encounters might have taught them.
I also submit that a species treatment of others might have little to do with its normally accepted protocols for dealing with strangers. For example, we know the Catholic hierarchy in Rome went to great lengths to communicate that the populations of the New World be treated fairly and decently (at least, by the standards of the time). As we know, these recommendations were rarely followed by the Conquistadudes. We also know that the courts of the Spanish Inquisition were scrupulously fair and governed by enlightened legal principles (again, by the standards of their time) but somehow this did not prevent them persecuting people for imaginary crimes. The point is, policy in practice may be far removed from its concept in theory.
If we can find counterexamples in our own history for speculations on alien behavior, then we must certainly expect ETI to be even more unpredictable coming from a different history, environment, psychology and biology. And even if the extraterrestrial community is highly moral and ethical by our standards, its freebooters and imperialists may not be.
Carl Sagan implied older civilizations would be wiser, and more gentle in their approach to strangers. That may very well be the case, but we have no way of knowing for sure. They may be intrinsically hostile, or even indifferent to other life forms. We simply don’t know.
Smith assumes that the launching civilization continues to launch improved generation probes even though the returns from distant stars may not happen until long after their demise. In our case. our early probes in interstellar space are there simply as a result of being unable to stop or return. This seems to be the case for all our deep space missions. The SGL telescope will continue to migrate outwards collecting images until noise ends its capabilities. Breakthrough Starshot’s flyby of Proxima at least is a deliberate probe to another star, but even in that case, the probe continues on after the flyby.
BS’s velocity would be a step change. From projected velocities in the few 100s km/s for various suggested propulsion technologies to 10,000s km/s for BS, even though the tiny vehicles are like leaves in a gale compared to horse-drawn wagons of our conventional instrumented probes.
But consider another scenario, where the launching civilization does not continue to improve its probes for long. Suppose instead they opt for Von Neumann replicators. The conventional analysis assumes these machines replicate perfectly at each star system and then, after replicating, the copies continue on to the next stars. But suppose instead these machines evolve, using their intelligence to design ever better propulsion systems so that each succeeding generation can increase its velocity. As each new generation only starts after arrival at a star system, the wave of migration is always with the latest generation of probes, with no older generation probes to overtake. [There will be some cases where overtaking occurs, such as waves backfilling stars behind the main expansion waves which older probes may not have reached.]
Therefore this scenario is very different. No “homeworld” civilization launching ever better probes but instead unleashing evolving probes that improve themselves at each target star system. The effect will still be the same for the passive civilization. The probes that arrive are the most advanced, but with no less advanced probes following on behind.
For a civilization receiving these probes, there are 2 possible ways to reach lower technology probes. Firstly, becoming active in interstellar flight and retracing the replicator probe expansion to find earlier generations. Secondly, more than one ETC has launched replicators and these replicators have reached stars and replicated their technology in the same place but with different evolutionary histories. That star could be ours, with replicators from different civilizations at different advanced technology generations replicating relatively simultaneously.
The decisions of the original ETC are now almost irrelevant. They launch their replicators and allow them to evolve as they seed the galaxy. This is no different than the idea that civilizations seed the galaxy with life to “green” it. It is not that dissimilar to Clarke’s monoliths operating automatically long after their creators have left them in place and their own evolution was transcendent. As to the purposes of the replicators, they could be diverse but include the knowledge acquired by the ETC and the replicators as they expanded throughout the galaxy, each a repository of its history and knowledge that could be used to uplift later civilizations.
With the replicator scenario, after a long period, the galaxy will be filled with replicators of different technological histories and capabilities, often in the same star systems, possibly composed more like living ecosystems. As with ecosystems, progenitor species are long gone, and the time to migrate from place to place is largely irrelevant to what we see when we observe the mix of species in a place. The “god-like” decisions of the ETC as they develop new generations of probes is a story that is eclipsed by time and machine evolution.
While the electromagnetic spectrum, neutrinos and gravity waves are among the “detectables” from our present concepts and technological capabilities, we might not have exhausted all the modalities and the sensitivities possible for advanced technological detection systems.
With regard to artifacts, they do not have to be fully functional entities to stir our interest: a piece of non-functional trash of indisputably alien origin will do, and all the more so if derived from a technology beyond our reach or comprehension.
The lack of alien signals is best explained by self-destruction, and in that case, it is better to send a low-tech probe than never to send it at all. Unless, of course, your species is monstrous and the impulse to self-destruction is the outcome of cold reason, in which case better never to send it at all. Yet a well-advanced civilization if it exists shouldn’t be expected to send probes, because a probe by definition exists at some particular PLACE. From our own development, we know that the concept of place fades over time. Most of us don’t go to the river to wash, or the outhouse to relieve ourselves, or the telegraph office to send a message. Many have stopped going to the department store to buy clothes or the doctor’s office for their diagnosis. Nowadays the people who might once have made a pilgrimage to Rome watch a religious service on television, and our natural philosophers gravitate to forums like this one, with neither seat nor wall. Probably each of us reading here sits with our hands in easy reach of levers that could move the Sun, if we but knew how to use them. Perhaps alien minds beyond our dreams swim beside and within the our primitive neural systems right now like tourist divers visiting with a whale shark.
We already know how interstellar first contact will go because it’s already happened and was well documented. It happened at a cocktail party in Islington and the first message was,
“Hey doll, is this guy boring you? Come and talk to me. I’m from a different planet.”
Mind you he only had the two arms and the one head and he called himself Phil, but…
Then the Vogon constructor fleet has not yet arrived or maybe has been diverted to another, more important project.
In a slight twist on Alex’s comment: maybe the ETI do send out one generation of a few probes, but the probes do not have the ability to evolve or replicate.
Then they stop because launching the probes was a politically driven event to showcase military and cultural dominance (e.g. the aliens with dimpled tentacles are obviosly better than those without), and nothing happens after that. Sounds familiar and reasonable :)
Very reasonable – for the 20th century, but perhaps not for the 21st. I am reading Lori Garver’s Escaping Gravity a memoir on changing the approach to spaceflight from a government-directed and built activity to a corporate one so that economic forces and ecosystem can emerge.
Her approach harks back to the mid-century when US business was thought to be the way forward. Heinlein’s “The Man Who Sold the Moon” would be an extreme fictional example. In my home library, I have the book “Peacetime Uses of Outer Space” (ed. Ramo, 1961) with a chapter “Competitive Private Enterprise in Space” written by the chairman of the board of GE. He makes the case for private enterprise to develop space, rather than the government. With the current success of SpaceX as well as other New Space companies (and not forgetting the huge commercial satellite business from comsats to earth observation sats) to privately develop space hardware as a business (currently with a government anchor customer) this vision seems to be reemerging with the failure of governments to extend space development post-Apollo – perhaps to fulfill the vision depicted in 2001: A Space Odyssey.
What Clarke and Kubrik did not foresee was a sky full of small comsats that would make piloting a nuclear spaceplane potentially hazardous, not to mention damaging to the space station if situated in LEO. We have to hope we resolve the issue of collisions before we get a Kessler syndrome cutting us off from space. Perhaps a commercial garbage collection service as depicted in the manga series “Planetes”?
Space mining seems to have collapsed almost before it started, but I see signs of interest reviving. (There are 2 papers in PNAS on commercial asteroid mining and the race is on to mine lunar water for settlement and propellant. Space treaties are being changed/reinterpreted to allow exploitation of controlled areas.)
I believe there will be Belters, just not human but robotic, it does seem that free enterprise is more likely to be the driving force for a space-based economy. It won’t be the human-populated vision of the last century, but rather the machine intelligence one we are building today and is being field tested on Mars.
I’m old, and therefore still optimistic that eventually we could see larger scale commercial presence in the wider solar system for sure, but still not sure private enterprise would have the patience to launch probes that would take centuries to reach their targets if there is no discernible financial gain.
Maybe a pure research firm would pay a future company to launch something, but with the eye on next quarter’s results being the main thing for most companies, I’m not super optimistic that interstellar probes will be the norm. Maybe ETI will be better than us and prove me wrong by showing up here before my time is up :)
Migrating extraterrestrial civilizations and interstellar colonization: implications for SETI and SETA.
“Extraterrestrial civilizations using free-floating planets for interstellar migration and interstellar colonization.
Some free-floating planets may host simple life forms and deliver them to planetary systems (Stevenson, Reference Stevenson1999; Abbot and Switzer, Reference Abbot and Switzer2011; Badescu, Reference Badescu2011; Schulze-Makuch and Fairen, Reference Schulze-Makuch and Fairen2021). I propose that free-floating planets may enable interstellar travel of extraterrestrial civilizations and technologies, delivering them to planetary systems. Extraterrestrial civilizations’ biological species, post-biological species or their technologies become Cosmic Hitchhikers when they ride free-floating planets to reach, explore and colonize planetary systems.”
https://www.cambridge.org/core/journals/international-journal-of-astrobiology/article/migrating-extraterrestrial-civilizations-and-interstellar-colonization-implications-for-seti-and-seta/BFFC1BB63FED869C85172BB3CC88DBBB
There may be a lot of free floating planets, both from stellar binary/multi systems and long dead O, B, and A stars that exploded.
Misaligned Binary Star Systems are Rogue Planet Factories.
https://www.universetoday.com/163940/misaligned-binary-star-systems-are-rogue-planet-factories/
Super earths could be very comfortable for this purpose.
As all of you know in the news of a “riddle wrapped in a mystery inside an enigma”, that we have visitors that make their presence difficult to understand. Could this be a form of irrational game theory that uses our current time world view to keep us in the loop but not give a rational outcome? This could be why their displays and communications tends to be to a small number of individuals…
https://www.investopedia.com/terms/p/paradox-rationality.asp
The Crowded Cone of Silence – Get Smart – 1967
https://www.youtube.com/watch?v=TxmEtJ31Ldw
The trouble I have with ideas on panspermia, however achieved, is that in the 3.5+ bny of life on Earth, there is no evidence that we interpret as consistent with other life arriving and interacting with terrestrial life. Either is arrived but was seen off by terrestrial life, arrived and is a hidden biosphere, or not arrived at all.
Paul Davies at ASU is looking for a shadow biosphere but with no luck so far. If any life arrived and influenced terrestrial life it would have to have the exact same basic biology as terrestrial life to be consistent with what we see. That seems unlikely to me.
Maybe we are missing something in the way we interpret the tree of life, but so far I have seen nothing that suggests that alien life arrived and interacted with terrestial life in a way that shows evidence of any events in the known tree of life.
You may have read this one by the same author in the first article, it goes in-depth into the same issue, and a good example of this is the octopus…
Planetary biotechnospheres, biotechnosignatures and the search for extraterrestrial intelligence.
https://www.cambridge.org/core/journals/international-journal-of-astrobiology/article/planetary-biotechnospheres-biotechnosignatures-and-the-search-for-extraterrestrial-intelligence/089931BD61982779CCA1EDF6861E7472
Thanks for the link. I will read that paper in detail. I stand by my argument about alien life interacting with terrestrial life, but that just reduces her examples a little. But maybe the author can persuade me otherwise.
A biotechnological artifact that may be observable and close enough to reach would be a veritable treasure. If AI advances as fast as it currently appears, we may be on the cusp of producing our own in a relatively short time. I just hope we don’t ruin our biosphere practicing.
A very interesting, but very speculative article. I think almost all of the speculation about biological technologies would be next to impossible to determine as technological rather than natural unless associated with a technological artifact or located where life should not exist, e.g. the hypothetical biomining bacteria on asteroids.
Having said that, much of what she outlines is very much as would would see the future, as have many others, including some very good scifi authors.
I just finishing Jeff Hawkins’ A Thousand Brains outlining his approach to how the brain works and how to create AGI. His more philosophical final chapters are rather in line with this authors’ – that AI and other technologies will be integrated with our civilization and Earth’s biosphere. He also favors the idea of a multi-planet species and terraforming Mars, which is where I suspect humanity will definitely let rip with biotechnology and embodied AIs. While Kim Stanley Robinson preferred hollowed-out asteroids with terrestrial biomes inside in his novel “2312”, I think the more artificial biology coupled with machines (smart and dumb) will be the more likely approach. However, we had better get very sophisticated with systems engineering to ensure this technology is more robust than the decoupled nature and technology currently envisaged, e.g. in O’Neill-type space habitats.
Building and using probe generation alpha teaches how to build probe beta and eventually the process leads to probe generation omega. It is hard to see how it can be different than how Smith describes. I would make on caveat, an active ETC will use generation alpha close to home, but the galactic migration of stars could result in early generations being far from home.
I think we can approach deep time as an ecosystem that will select for fitness. The traits required may be far more narrow than we anticipate.
(blockquote>I think we can approach deep time as an ecosystem…(/blockquote>
That is a good insight. It is like our using geology and fossils to view ecosystems in the past, but in this case, space and probe velocity become the time dimension to reconstruct the evolution of probes, perhaps from multiple civilizations.
I know the evidence points against it being artificial, but ‘Oumuamua serves as a good example of ETC tech that we could encounter and would be well beyond our current capabilities.
I concur with Alex’ comment on panspermia, but I think that skips over the intermediate option (For want of a better term, I’ll dub it ‘deuterospermia’) where all life on Earth originated from just one other ecosystem. I’m attracted to that possibility because of the lack of apparent ancestral forms beyond a certain point in evolution.
If we want to visually reenact the greatest hits of a billion years, we have no trouble casting protozoans, jellyfish, lancelets and so on in these roles. We even have likely analogues (Asgard archaea) for the organisms that might have undergone endosymbiosis to form eukaryotic life. But if we go looking for life forms with proteins made from ten amino acids, or with more than minor changes to the genetic code, we find nothing. So I think life on Earth could be consistent with the notion that one bacterium and one archaean reached us from some other world where they evolved from a common ancestor. I say “one” for each because of the large number of substitutions between surmised bacterial and archaeal ancestral gene sequences, after which each group bushes out far more quickly – see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4450401/ figures 1 and 5.
The source world might be Mars (the first to cool down), or more likely Venus (comfortable under a faint young sun). The lack of interesting fossil sightings from the Mars rovers makes me favor the latter. Alternatively, they could have been mailed to us in a care package from some more distant locale …
Venus might be teh better bet if simply because it has the solar wind and light at its back, allowing any bacteria/spores to blow outward. By contrast, Mars can only seed Earth with rocky material blasted out into space and eventually reaching Earth.
It is certainly possible panspermia was responsible for life on Earth, but that just pushes the problem of abiogenesis a step further away. If it was from Venus, it would be very hard to determine if life started there. How would we know if we found terrestrial-like life on Venus whether it was truly indigenous or seeded from Earth?
As regards interstellar panspermia. Obviously, it is likely to be rare. However, suppose we discovered terrestrial-like biology on an interstellar visitor. Could we be sure it was indigenous from its home system and not contaminated by bacteria blown out into the solar system? What we really need is a very different alien biology to be detected. If we detected it in an interstellar visitor, that would likely be definitive evidence of a different genesis.
My concern with panspermia is that it should be happening almost continually, that is in episodes over the last 4+ billion years. If there is alien life arriving, why does it consistently fail to manage to make inroads into our biosphere? There seems no sign of it.
Now Hoyle would have argued that it has – they are viruses that appear. But if so, those viruses must be of terrestrial biology to have any impact on coopting cells to make copies of them. Again, is there any hard evidence that this has happened?
It would certainly be nice if alien viruses had makers’ marks in their genomes establishing provenance.
I tend to think of the problem of abiogenesis as more or less solved with the “RNA World” model and the formose reaction. Any time now, I think someone could mix formaldehyde, ammonia, and a few secret ingredients over geological hydroxylapatite, and show that they can obtain an RNA oligonucleotide attached to that matrix which, with some probability, can reproduce itself.
Speculating an origin of life on Venus wouldn’t simply be a matter of begging the question of abiogenesis. It encourages a hunt for interesting fossils in some relict craton. Perhaps there were ancient prokaryotes with vastly simpler ribosomes which, if their sequences can somehow be inferred from atom-by-atom analysis of ancient fossils, would transform Terran industry. If we’re lucky, we may even find some durable storage medium with a few hundred gigabytes of public discourse about the global warming hoax. :)
I do wonder whether “deuterospermy” could be a Great Filter type event. All the complicated life on Earth is eukaryotic, the outcome of symbiotic interactions between Asgard-like Archaea and Proteobacteria. Bacteria and archaea have very different capabilities: for example, archaea never cause infections (that we know of), and bacteria excel in chemical reactions like respiration and photosynthesis. The delicate tango of ‘eating’ a future mitochondrion without digesting it, keeping it happy while not being infected with a tuberculosis-like plague … this seems like good preadaptation for future multicellular life.
Is it possible that on a “protospermic” planet (one where abiogenesis occurred locally) that there are so many variants of microbial life, that a symbiosis like ours never becomes necessary in the first place? Or at least, where it is hopelessly complicated and slow-growing compared to any one of hundreds of other domains of life which are a little better at any given metabolic task? Maybe complex Earth-like life requires (a) abiogenesis, (b) deuterospermy that transfers two different prokaryotes to a second habitable planet in the same system, (c) endosymbiosis.
Any ET probes might well be a wreck by the time it gets here. Ouamuamua we KNOW is extraterrestrial whether it be probe or natural body…Lyra needs support.
There does not appear to be a consideration of the economics of sending interstellar probes. The first generation of truly interstellar probes sent will use the best technology we have and be extremely expensive. Necessarily only one or a handful of such probes will be produced, and will be sent to the nearest star systems. Especially if they are BS-type swarms, which would tie up lasers using prodigious amounts of energy, economics prevents any bigger effort.
By the time we have a second generation of probes, the economics will have improved, both because of innovation and because of a pre-existing industry. Such probes may be sent further afield, and not to the targets of the first generation unless something really interesting has showed up.
It seems to me that a mathematical formula can be derived for when is the right time to send a probe to another system with little risk of being overtaken.
Let us assume:
dT/dt = estimated rate of change of Technology per year, particularly in terms of achievable speed
d = distance to a given target in light-years
v = velocity achievable by current generation of interstellar probe, as a fraction of c
Then time taken to reach given target = d/v (ignoring acceleration/deceleration time)
Arrival time for a future probe, launched in n years’ time, measured from today, = n + d/v(1 + n dT/dt)
So it is not worth launching a probe now, unless:
d/v – {n + d/v(1 + n dT/dt)} is well positive for all values of n < d/v.
This formula strongly favours sending to closer targets first.
Further to my previous comment, the formula derived assumes additive increments to Technology, e.g. 1.01, 1.02, 1.03, etc. It is more typical of technology to improve factorially, e.g. 1.01, 1.0201, 1.0303, etc. Therefore the previous formula might be expressed as
d/v – {n + d/[v(1 + dT/dt)^n]}
which should be well positive for all values of n < d/v in order to avoid the possibility of overtaking.
Hi Paul,
Do you have another article explaining Pr Smith’s theory ? I understand the principle but I’d like to know more ; unfortunately, there isn’t the full article on the Cambridge website.
It’s interesting to think about, but as always we come back to the problem of energy control in the context of space travel: an “active” E.T civilization – or the probes it would have created – would have great control over this energy (Kadharsev) and would indeed be much more advanced than we are, so we can assume that it would have already completely “analyzed” us before we even considered contact. Would it then initiate contact ?…not sure ! ;)
Fred
Fred, check your email later today.
The last paragraph got me thinking, especially since I was on vacation when this article came out: there are several artifacts from antiquity that we are not really sure what they are about. Case in point, the Antikythera Device. It does not do the magical things that the Dial of Destiny does but it has taken over a century just to form a consensus. It is a mechanical astronomical computer that displays the understanding of the motion of the planets in clockwork form. The device was associated with Archimedes when it had a high resolution x ray 5 or so years ago and it showed writing in the Western Dorian Greek dialect of Great Greece. For over half a century since the sponge divers found it we were not sure at all what it was, then x rays and reconstructions gave some idea but who how and what took advanced technology and over a century. Let us not forget we are talking about a human artifact created a little over two millenia ago. Let’s assume that a slow ship arrives after the later launched fast one and finds ruins. What will they really piece together? If they are lucky they might be able to read some texts, if not they could run into something as opaque as Linear A or Cretan Hieroglyphs.
Hello,
Your comment is right on and raises the question of the development of one or more technologies over time. According to Lewis Munford, a [terrestrial] technology only develops in relation to another, i.e. as a kind of regular upward progression made up of successive stages: from wood we extracted iron from the mines, which led to the construction of steel rails, which led to trade, which led to the creation of the Bessemer furnace, which led to the chemistry of glass, microscopes and concrete, which led to the nuclear reactor, which led to fission, miniaturization and this computer (I’m summarizing, of course). If we remove one element from the chain, the development of the technology cannot progress, or would have taken a completely different path. What would have become of us without the appearance of the wheel? (I’m sure there are some good SF books on the subject :) Mumford’s study is debatable, as he puts it back to the Middle Ages, but his theory is interesting in that it shows a form of LINEAR development.
However, the model proposed in the article doesn’t take into account the idea of a possible brutal technological evolution – a leap forward – for example, in passive civilization, which would change all the parameters. We could conceive of a type III or IV ETC that would use different degrees of technological development as it sees fit, depending on the place it wants to explore in the universe and the time it gives itself to do so. This would presuppose an extremely advanced ETC, possibly capable of reaching our level if it wants to exchange with us.
As you say, it’s our new instruments that have enabled us to rediscover and even confirm “a few certainties” about Antikythera’s device. However, there’s a fundamental difference between an ancient technology, which remains that of the human species, and an ETC technology: for ours, in the case of Antikythera, it’s only a temporary loss of Knowledge that we’re recovering in another way, but in the second case, we’re in the most complete unknown, especially if it’s a particularly distant ETC civilization as the article says. We could only deduce which points IF the ETC probe is material, by analysis. But unless E.T. throws its laser beams at us, we’d be at a dead end.
Can the primates at the beginning of the film “2001: A Space Odyssey” even deduce anything from the monolith? No. Kubrik shows us that they have not yet learned to conceptualize the world (e.g. no drawings on the caves); they are barely socialized into tribes, and live by survival reflexes.
As for their technology, only one of them discovers by chance and observation (1st reasoning) are 1st technical tools with the bone in front of him that can be used as an hammer. Despite this, the apes’ ability does not allow them an exchange with the monolith. They just see how out of step the Thing is with their world, and how powerless they are. (That’s why he throws the bone in the air and goes for a beer :)
Joking aside, it’s also worth pointing out that to understand another technology, you need to be able to think like the people who developed it. If we reread the history of science in antiquity, we’ll see that their discoveries are rather familiar to us, yet they didn’t [all] think like us. The unknown was transposed into magic, the gods or simply ignored. (Summerian astronomy didn’t make much headway, because for them it was only a utilitarian science for agriculture, not a science of knowledge-seeking).
So if we transpose into the future, to come back to the article, we’d also have to try and think like in X million years if tomorrow one of their probes came into our garden. (The problem of UFO’s is specified in the article) This subject is fascinating and opens us up to many questions. Thanks again to Paul !
Fred
Hello Paul,
Starting from these modelisations, knowing and anticipating our own technological evolution, shouldn’t we limit our search for an ETC to a circle of distance centred on the earth? The idea would then be to have at least a chance of understanding their technologies or artefacts so as to attempt contact based on what we are? in other words, to avoid too much randomness and the impossibility of contact should the 2 technologies ever cross.
PS: could you propose a list of some hard-SF books on your site ? One of my favorites is “tau zero” ;)
Fred
Tau Zero is of course a gem and the inspiration for our original naming of the Tau Zero Foundation. But there are plenty of great hard SF novels out there. Let me turn to the readers, who are more up to speed with recent SF than I am. We can always talk classic SF, but which more modern hard SF novels would people here recommend? I would throw in Benford’s Timescape as a personal favorite but that was, what, 40 years ago?
I should have also mentioned Steele’s Arkwright, which is a gem, and a recent work. Among older novels in the hard SF category I particularly liked James Gunn’s The Listeners, Hal Clement’s Mission of Gravity, Bob Forward’s Dragon’s Egg and Rocheworld, and Larry Niven’s Ringworld. But really, there are almost too many to list! Let’s get some suggestions for more recent hard SF from some of the fans in the readership.
Thanks Paul, I was asking because there are a lot of science fiction books in France, but the genres are different and it’s the “fantasy” SF that seems to be more popular with younger readers. If the Masters of SF are always re-edited since more years some more recent authors that you quote are not yet translated and deserve to be known ;) here G. Benford…surely my next book ;)
https://www.babelio.com/auteur/Gregory-Benford/9431
Fred
Greg Benford is a wonderful hard SF writer. I think his ‘Galactic Center’ series would interest you, but so would others. You might try his novel Artifact, for example, but his output has been prodigious, so there is much to choose from.