Everyone loves them some aliens. But …if the encounter is to work out to the satisfaction of all concerned, it is best if the aliens not be too advanced (because they could brush us aside like ants) or too primitive (we might brush them aside like ants). No, there’s a Goldilocks zone for aliens, in which they are close to the same tech level as humans … and can interact peaceably with us.
Which leads me to wonder: just how likely is it that two unconnected civilizations could reach the same technological level (roughly) at the same time?
Time for some large, round numbers.
The universe is about 13.8 billion years old. The boundaries of the era in which rocky planets could form are a bit fuzzy, but Kepler-444 seems to point to them. Say the boundaries are 11 billion years old, plus or minus a billion years. OK, the era of rocky worlds starts about ten billion years ago. Humans are perhaps 300,000 years old as a species. Most of our advanced technology is less than a century old. To put that in cosmic terms, humans are about 3/100,000 times as old as rocky planets, while our whiz-bang tech is 1/100,000,000th as old as rocky planets.
To put it another way: if we imagine that ten billion years as one day, humans have been around for a bit over 2 1/2 seconds. High tech has been around for about a thousandth of a second.
For a second species from an unrelated world to have evolved into intelligence and invented tech—specifically tech that hit human levels at just that thousandth of a second…it’s extremely unlikely. Even the possibility that we’d show up in someone’s sky while they were still playing with stone axes seems unlikely1 .
But alien races are fun! So how can authors deal with the grim numbers? The usual way: denial, anger, bargaining, depression, and acceptance.
Denial
The easiest way is to ignore the implausibility. It helps not to be aware of it, so for all the authors choosing this path, sorry about everything above between “The universe…” and “unlikely.” And also footnote 1. Try not to think about it. No, I’m not going to give examples of authors in denial.
Anger
Don’t deal with the issue within your story but do shout angrily at people who point out the problem. The extreme example of this tactic is what I once called the SFnal Lysenkoist Tendency: when actual, tested science contradicts some detail in an SF story, attack the science. Again, no examples will be pointed out.
Bargaining
Offer the reader a semi-plausible explanation—in exchange for which, it is hoped that everyone will pretend it all makes sense.
Semi-plausible explanation 1: Assume that every tool-using species save for humans is a knucklehead. The poor aliens have been slowly puttering along at their own, very slow pace, and suddenly humans pop up among them, so young that their first vacuum tube radios are in museums and not ancient fossil beds. The classic example is Arthur C. Clarke’s Rescue Party but there are others. So many others.
Semi-plausible explanation 2: Postulate a cap on technological advancement. Perhaps there is hard limit to progress, one we will encounter in the near future. If we’re lucky, the cap is that the law of diminishing returns limits the effectiveness of science at a point not too much more advanced than the one we’ve reached. R&D looks easy to humans because we’re still collecting low-hanging fruit. Shane Dix and Sean Williams’ Evergence books are one example of this ploy.
It’s also possible that high tech species will develop tech up to the point where they can destroy themselves (as we can), at which point they destroy themselves (as we might.) Envision On the Beach, repeated across time and space until habitable planets cease to exist.
Semi-plausible explanation 3: Perhaps there’s a causal link between the various civilizations. The humans in Brian Stableford’s Optiman suspect that the reason they and their bitter enemies appeared on the galactic stage at the same time is that they are pieces in a game played by superior beings. Similarly, the various species in the Lensman Saga have been subject to Arisian tinkering since time immemorial.
The worlds of Ursula K. Le Guin’s Ekumen all have humanoid species operating at roughly the same tech level (somewhere between stone axes and starships) because they were seeded on their respective worlds by the Hain in ages past. Time, natural selection, and some genetic engineering did the rest. It’s not clear if the Shing (who show up in City of Illusions) are Hainish in origin, but the non-technological aliens in “Vaster Than Empires, And More Slow” suggest that the Shing may be Hainish foundlings, because the true aliens are very alien indeed.
If not descended from the same ancestors, perhaps alien species can be descended from animals shaped by humans. Neal Barrett, Jr.’s Aldair series is set on an Earth populated by genetically engineered animals that were carefully redesigned to look humanoid. Why long-absent humans would have done this is unclear to the series’ porcine protagonist. Answering this question could fill a series—in fact, it did.
On a similar note, Lawrence M. Schoen’s Barsk books are set in a distant future populated by intelligent animals created by humans. The various species come in a variety of shapes, but they share tech that they inherited from humans.
Perhaps it’s humanity that has been alienified. John Varley’s Eight Worlds and Charles Sheffield’s Proteus books provide examples, as do Tanith Lee’s unfortunately incomplete Four-BEE series. When one can edit genes, adding and subtracting, the results can be wonderfully diverse.
Another method that works is to postulate a synchronizing event. In Niven’s Known Space setting, for example, a galaxy-wide war killed off everything with a brain a billion or two years ago. There still seem to be a lot of high tech species showing up in the same part of the Milky Way in a very short period, but the event at least reduces the scale of the problem, particularly given the presence of the tech-spreading Outsiders.
Depression
This is not recommended because too much time spent on the implausible aspects of one’s setting may preclude writing any further books in it. While the issue wasn’t quite the one I am discussing here, Charles Stross’s Eschaton series fell prey to its own author’s successful “disbelieve” roll.
Acceptance
Accept that either we’re the top dogs in the observable universe because everyone else is still working on multicellularity, or that we’re not and we’re sharing the universe with beings more powerful and more insightful than we are: Gods, if you’re an optimist like James Alan Garner (as seen in his League of Peoples novels), or demons, if you’re a paranoid xenophobe from Providence.
1: In fact, Earth has had complex life only for about one twentieth of the time rocky worlds have been around; even finding life on the order of salamanders or fish might be long odds.
In the words of Wikipedia editor TexasAndroid, prolific book reviewer and perennial Darwin Award nomineeJames Davis Nicoll is of “questionable notability.” His work has appeared in Publishers Weekly and Romantic Times as well as on his own websites, James Nicoll Reviews and Young People Read Old SFF (where he is assisted by editor Karen Lofstrom and web person Adrienne L. Travis). He is surprisingly flammable.
[1]In fact, Earth has had complex life only for about one twentieth of the time rocky worlds have been around; even finding life on the order of salamanders or fish might be long odds.
There’s also the point that technological progress goes ‘boink’ isn’t monotonic. We can see this if we look around at our everyday existence. Clothing technology, for example; clothes fifty years old may look unfashionable, but they aren’t technologically obsolete. We’re still wearing woven cotton, knitted wool and so on. Compare that to computer technology.
Or think about it in historical terms; if a 1918 infantry division went into battle against its 2018 counterpart, the result would be a catastrophe. If a 100 AD Roman legion went into battle against a 200 AD one, no one would notice much difference. It may be that if you don’t crack a few important discoveries – like maybe “the scientific method” – then you don’t get much in the way of steady technological progress.
So it might not be too implausible simply to postulate that these aliens got as far as, say, black powder and steam engines, and then just… stopped.
One problem with this kind of calculation is that it always assumes every planet will only develop a technological civilization once. That doesn’t make sense. A single species could go through multiple cycles of technological rise and fall — or a planet could produce multiple successive technological species. When a new evolutionary trait emerges on a planet, it’s usually because the necessary foundations for that trait have been laid, so it’s likely to emerge more than once. Here on Earth, we’ve become increasingly aware that it’s arrogant to assume we’re the only intelligence on the planet; other great apes, elephants, cetaceans, cephalopods, and certain birds all show signs of sophisticated intelligence and in some cases nascent tool use. If we, say, migrated to space and left the Earth free of our depredations, any of them might evolve into another technological civilization within a few millions or tens of millions of years. Indeed, it seems likely to me that the rate at which a planet produced new sapient species would probably increase over time, as the foundations for it spread to more and more taxonomic branches.
So if you throw in the cyclical emergence of multiple successive civilizations on a single world, that tends to reset the clock and increase the probability of finding civilizations relatively close to our level.
@1/ajay: You’re quite right. The tendency these days is to assume that the current, Industrial-Age level of swift technological progress is a universal constant, but if you study world history, it’s actually the exception to the rule. Technological progress, like biological evolution, follows a pattern of punctuated equilibrium. Things remain in a steady state with limited change for most of the time; it’s only when conditions change enough that old solutions no longer work that you get a period of rapid adaptation and innovation, and that only lasts until things reach a new state of equilibrium where things are well-adapted to the status quo and further change would do more harm than good.
There’s also no set schedule on how long or short a time it might take for a civilization to advance, because it is dependent on the need for change. Human agriculture and civilization emerged when climate change made hunting and gathering no longer sufficient for survival, compelling the development of new subsistence methods. If that climate change had happened 10,000 years later, we’d still be hunter-gatherers today. If it had happened 10,000 years earlier, we might be a galactic civilization today. That’s another thing that adds flexibility to the question. Yes, it’s probable that any civilization we meet might be tens of millennia older or younger than us, but it might have developed to our level of civilization tens of millennia slower or faster than we did.
Personally I have no problem with denial. Science fantasy is fine by me.
@2: “A single species could go through multiple cycles of technological rise and fall.”
Of course, as it has done on earth :-) [Well, we all believe the stories of Atlantis, right?]
But more seriously, we show every sign of being able to send ourselves back to the Stone Age, or at least the Dark Ages. The trick is just to not completely destroy the planet on any one collapse of civilization.
“Indeed, it seems likely to me that the rate at which a planet produced new sapient species would probably increase over time, as the foundations for it spread to more and more taxonomic branches.”
That doesn’t seem likely to me. Creatures evolve to fill a niche. If we left the planet, I’m certain another species would fill our niche, but it’s pretty much occupied at the moment. You might have a sapient, technological, species on land, another in the water, and possibly one in the air, but I’d be surprised if there were more.
@james: It’s probably a Very Good Thing that you won’t cite references of authors in the denial stage, because I suspect almost every SF author who’s had alien races in their stories has been there!
@4/auspex: I’m not saying there’d be multiple civilizations at the same time. I’d saying that the number of species intelligent enough to have a chance of producing a technological civilization would increase over time, and thus the rate at which successive technological civilizations would emerge on a given planet would probably increase over time. The larger the number of intelligent animals there are sharing the planet when the current civilization destroys itself or migrates the space, the shorter the time you might have to wait before one of them starts building tools of its own. The more chances something has to happen, the more likely it becomes.
I would actually love to see the OP cite examples of denial and anger :D
@2: In addition to the way technological aptitude advances in fits and starts, there’s also many fields of knowledge where once you figure out the science involved and apply it, you’re basically done, there’s no further technological progress to be made. Say we discover FTL and go out there and meet other FTL capable species. All of whom will be using the exact same FTL tech because there’s only one loophole in the speed limit imposed by relativity, so everyone will be on a level playing field. There are hard limits to how good you can make a rocket engine. We have pretty much reached the end of the road in terms of making our computer circuits more compact. And so on.
ChristopherLBennett @@@@@ 2:
So if you throw in the cyclical emergence of multiple successive civilizations on a single world, that tends to reset the clock and increase the probability of finding civilizations relatively close to our level.
The problem is that not all planets are even remotely equal in age. The Sun is about 4.6 billion years old, in a galaxy that has stars that are older than 12 billion years. Even if you select for stars similar to the Sun within our own neighborhood, you get ages ranging from 1 to 10.6 billion years (e.g., this list of “solar analog” stars).
And even in the “what if corvids evolve advanced intelligence after we perish or move elsewhere” scenario, you’re looking at, as you suggest, millions or tens of millions of years between successive civilizations. Which still makes encountering another civilization that has technological level within a few thousand years of your own extremely unlikely.
@8/Peter Erwin: Of course, but what I’m saying is that if intelligence and civilization emerge over and over again cyclically on a single planet, then it doesn’t matter how old the planet is in the absolute, as long as it’s old enough for intelligence to have arisen at least once. If you and another species are relatively close to the same point in the cycle, it doesn’t matter if it’s the other planet’s first or thirtieth iteration of the cycle.
“Which still makes encountering another civilization that has technological level within a few thousand years of your own extremely unlikely.”
Yes, of course, but substantially less unlikely than if every planet only developed civilization once in its entire history. Instead of, say, one chance in 100 million that it would happen, maybe it’s more like one chance in a thousand. Which is good enough if your goal is to tell a work of fiction that your readers don’t find prohibitively improbable.
Why would moving into space mean abandoning the Earth? When my father’s family moved from Scotland to Hawaii, it just meant there were Nicolls in Scotland _and_ Hawaii. Have humans ever abandoned regions larger than an island? Even the British Isles, where humans and their close relatives have been completely expunged on a number of occasions due to the unsuitability of that region for long term occupation, people keep moving back once it returns to a state of moderate (temporary) habitability.
I think
Might be an example of a tech limitation in the first case (see, for example, Campbell’s … Twilight? I think> where a race of aliens kept nuking itself back into a million years of stone over and over) and the second an example of a causal connection.
Come to think of it, the long term trend on Earth is for the average encephalization quotient to rise over time, which could have an amusing consequence. It seems reasonable that the more kinds of bright tool users a world has, the more rolls of the dice they have for one of them to develop starships. So it might be reasonable to have settings where the detail that marks humans out as unusual (aside from the monumental buttock to brain mass ratio humans have, which I believe is the largest in the animal kingdom) is that we’re the only ones who didn’t invent the slide rule in the context of other, just as smart, tool-using species.
Or, given the recent discovery of Denisovan-Neanderthal girl, and the presence of Denisovan and Neanderthan genes in humans, maybe our hat i we’ll form pair bonds under a very wide variety of partners; anytime that’s between mutually fertile individuals, the two species combine. Humanity’s theme song might be Bow Chika Wow Wow.
ChristopherLBennett @@@@@ 2:
Technological progress, like biological evolution, follows a pattern of punctuated equilibrium. Things remain in a steady state with limited change for most of the time; it’s only when conditions change enough that old solutions no longer work that you get a period of rapid adaptation and innovation, and that only lasts until things reach a new state of equilibrium where things are well-adapted to the status quo and further change would do more harm than good.
I suspect that’s not really an accurate description. Technological evolution is uneven, sure, but the rate has been gradually increasing for a long time: the evolution between, say, 1000 and 1500 AD was more rapid than that 500 and 1000 AD, which in turn was more rapid than that between, say, 1500 and 1000 BC. And I think it would be hard to argue for a consistent pattern of “long periods of steady state punctuated by short periods of rapid innovation” on a civilizational, let along global, scale.
(I’ll leave aside the question of how often biological evolution really follows a “punctuated equilibrium” pattern.)
I freely admit humans are insanely good at entrainment. Humans in general, I mean. Not me specifically.
The problem is that our sample size for intelligent life is just too low to draw any conclusions.
One thing these essays always assume is that every species is developing and evolving independently. I reject that theory.
There will be a time when we colonize other planets and run into other species. we could have a grand republic or grand empire that spanned hundreds of stars and then collapsed into a proverbial interstellar dark ages for a time. 20,000 years later we reinvent the ability to travel interstellar distances and then we are surprised that we encounter people that look more or less like us along the way. I think civilizations will rise and fall and homogenize all over the galaxy. Even if we only had the ability to travel via solar sail at 1/10th light speed, we could cross the galaxy in a million years which would allow for the rise and fall of 10,000 societies.
@10/James David Nicoll: “Why would moving into space mean abandoning the Earth?”
Possibly, if a civilization recognized the potential of other species on its planet to develop sapience and civilization of their own, it might eventually (say, over the course of thousands or millions of years of civilization) choose to leave the planet so that those other species would have the same chance to evolve civilization that they had. (I’ve always wanted to write a story along those lines, and it does come up to an extent in something I’m currently marketing.)
Alternatively, an advanced civilization might evolve into some form that doesn’t need the Earth anymore, say, by becoming posthuman AIs or undergoing a Greg Egan-style Introdus into cyberspace. Or it might follow a route like Iain M. Banks’s Culture and decide that living in artificial megastructures is superior to living on planets.
@11/Peter Erwin: China had laid the foundations for an industrial revolution 700 years before Europe did. But it didn’t industrialize, because it didn’t need to. It was already the most prosperous society on Earth. It had everything it needed at home, and everyone who wanted to trade came to China, so China had no incentive to develop advances in transportation. So its technology remained at a stable level (one that Western-biased historians have long condescendingly mischaracterized as “stagnant”) rather than undergoing a burst of innovation. Europe 700 years later, by contrast, was hungry for new resources and trade opportunities, driving innovation in faster transportation, and eager to compete with Asian porcelain, silk, and other goods, driving innovation in factory methods. It had not only the potential for an industrial revolution, but the need for one, as well as a social order that promoted innovation and trade and added further to the mix. It was only when all the right ingredients aligned at the same time that it happened, even though some of the ingredients had been in place in other cultures much earlier. (Carl Sagan argued in Cosmos that even the Ancient Greeks could’ve industrialized 2000 years ago, but their slave-based culture saw science as an abstract intellectual pursuit and disdained physical labor as the work of inferiors, so that prevented scientists from getting together with engineers and investors and developing applied science and industry.)
Besides, we’re not just talking on a scale of a millennium or two here. That’s a blink of an eye. If we’re talking about the evolutionary history of planets, we need to look on scale of hundreds or thousands of millennia. How many thousands of years were human beings just as intelligent as they are now, yet satisfied to live at a steady level of technology? Human history is over 30,000 years of enduring stability and 8-12,000 years of fitfully accelerating advancement. My whole point is that it’s short-sighted to assume that the more recent state of affairs is guaranteed to be the norm for all time to come. We can’t assume that, not when it’s such a small percentage of the whole. It might just be an aberration that hasn’t settled down yet. We don’t have a long enough perspective to know for sure.
Niven/Pournelle and James Hogan had “precursor” species predating an intelligent species that humans encountered. Niven/Pournelle also had cyclic civilizations, human and other.
@15
In David Bryn’s Uplift series, the intelligent species of the galaxy deliberately abandon planets and leave them fallow for huge spans of time deliberately to allow for the emergence of new sapient and presapient species.
There’s also the question of cultural (or even biological) bias; that some species won’t develop in certain ways because they simply don’t need to (like an otherwise-advanced insect-derived species never developing advanced robotics or AI because they have enough specialized subspecies and a high enough reproductive rate that they’ve just never needed to automate anything).
“Humans don’t develop starships because that requires a temporal horizon on the scale of millennia and the poor wee bastards only last a century, tops. And you can’t freeze them for later, either. Also, wow, ever park one of those guys on an unshielded reactor?”
Humans, cosmic orchids!
David Lake’s Breakout series
1 Walkers on the Sky (1976) [also as by David Lake]
2 The Right Hand of Dextra (1977)
3 The Wildings of Westron (1977)
4 The Gods of Xuma or Barsoom Revisited (1978)
5 Warlords of Xuma (1983) [only as by David Lake]
6 The Fourth Hemisphere
was set in a universe where humans had the great fortune not to encounter the truly advanced (but not especially nice) civilizations because those guys saw our neighbourhood as boring and rarely venture out to it. Species more or less like humans generally were too short lived to bother with star flight, which meant most either find some way to live on the resources of a single world, or destroy themselves.
Humans decided to wreck Earth and then colonize other worlds. The first was easy, the second not so much.
@19/James: ““Humans don’t develop starships because that requires a temporal horizon on the scale of millennia and the poor wee bastards only last a century, tops.””
That argument doesn’t hold up, because it used to be commonplace for humans to devote their lives to efforts that they knew would not be completed in their lifetimes, such as the building of the great cathedrals of Europe. Even within the past century, the Hoover Dam was built to last for 2000 years.
https://www.centauri-dreams.org/2013/11/01/les-johnson-big-projects-and-deep-time/
In England, there have been groves of oak trees that were planted with the intention of being used to build Royal Navy ships centuries later when the trees had grown large enough — and actually were used centuries later, exactly as planned.
https://www.centauri-dreams.org/2010/04/01/apocryphal-tales-and-long-term-results/
And of course there are all the people over the millennia who have colonized new lands and faced hardships and dangers because they believed it would benefit their descendants in centuries to come. Humans have always been capable of planning far past our own lifetimes, because we’re wired to care about our descendants. (Although of course there are examples of supreme shortsightedness as well, as with climate change denialism, say.)
ChristopherLBennett @@@@@ 15:
Yes, that’s a common picture of recent Chinese history. The problem is that if you look at Chinese history more closely, the idea of stable, basically unchanging technology from ca. 1000 AD onward doesn’t really hold.
Let’s take a look at the “stable” technology of China post-1000 or 1100 AD:
1. There were major advances in shipbuilding early in the period, with progressively larger and more capable ocean-going ships, culminating in the giant ships of the Qeng Ho “treasure fleets” of the early/mid 1400s. (In fact, the initial consolidation of the Ming dynasty required the construction of over 2100 ocean-going ships in the early 1400s, to carry grain from southern China to the new Ming capital of Beijing, at least until repairs and expansions to the Grand Canal were complete.)
2. There was also an increasingly expansive and printing industry, with movable metal type introduced in 1490 (following earlier experiments with movable type made from other materials, like ceramics), and multiple-color printing from 1580 onward. The transformation was perhaps not as rapid as the spread of printing in late 15th Century Europe, but by the end of the Ming dynasty, printed books were the norm, and were ever more affordable.
To give a limited sense of how much this expanded the availability of books in China: Near the end of the Song dynasty (late 1100s), the imperial library held about 45,000 juan (chapters, more or less). By the end of the 1500s, individual collectors in multiple cities could boast of personal libraries with sizes of 50,000-100,000 juan. (And a relatively poor scholar could complain of owning too many books to ever read…)
(Continued from previous comment):
3. Gunpowder weapons were of course invented in China earlier, but again there was significant improvement throughout this period. The late 1200s saw the first bronze “guns” (initially firing spears or arrows). These were subsequently developed by Europeans into proper cannons in the early 1300s, which were in turn adopted by the Chinese; the first cast-iron cannons were in fact made in China in the 1350s, and were used by rebels against the Mongol Yuan dynasty. By the 1590s, the Chinese army which fought the Japanese invasion of Korea had arquebuses and both siege and field artillery. A comment on this AskHistorans page notes that “In the battle of Jaomodo in 1696, Emperor Kangxi mobilized 80,000 soldiers with 300 cannons. This soldier:cannon ratio was unseen in Europe at the time.” (It’s a ratio of 270 soldiers/cannon, similar to that seen in some European armies during the Napoleonic Wars.)
4. Several scholars have argued for an “agricultural revolution” in 17th and early 18th C China, driven by the use of oilcake fertilizer (the waste left from squeezing oil out of soy, cottonseed, and rapeseed), increased use of oxen, double-cropping of fields (e.g., alternating wheat and rice in the same year), as well as the introduction of New World crops like sweet potatoes and maize.
And so on. It’s not really a process of “punctuated equilibrium”, with basically “stable” technology from 1100 on.
@22/Peter Erwin: Of course I’m not saying technology didn’t change at all; I wouldn’t know any of the things I’m saying about Chinese technological history if I didn’t know that as well, because it’s all part of the same subject. I’m saying that progress was incremental and steady rather than rapid and accelerating, even though the potential for an industrial revolution existed for centuries. I’m saying that the overall historical norm is for progress to happen, yes, but to happen at a gradual pace, rather than the ever-accelerating asymptotic curve that many people short-sightedly assume must be the universal and eternal norm just because it happens to be the case during the tiny sliver of history in which they happen to exist.
@11 Peter Erwin
I’ll leave aside the question of how often biological evolution really follows a “punctuated equilibrium” pattern.
Probably wise. Evolutionary biologists are still arguing about this. The evidence for hominins is equivocal – if we look at cranial capacity in Homo erectus/ergaster, there’s evidence of anagenetic change over a million years (given that the fossil record for hominins is lousy, as it is for a lot of organisms). On the other hand, for H. erectus/ergaster, we have little or no evidence concerning evolutionary rates from the neck down – they may have exhibited stasis in the structure of the postcranial body. Certainly the limb and torso proportions of H. erectus/ergaster appeared without much evidence of slow transition from the morphology characteristic of the australopithecines. In other words, a group of organisms may display one evolutionary mode for one feature, and another for another feature.
OK, I’ll get off my hobbyhorse now.
@24/Raskos: The thing is, equilibrium does not have to equal stasis. It just means a steady, sustained state, and that can mean a steady rate of gradual, moderate change as opposed to a sudden burst of rapid or accelerating change. In evolution, the idea of punctuated equilibrium was introduced as an alternative to the assumption that the rate of evolutionary change was constant over time. Saying that it instead tends to be characterized by bursts of rapid change with long periods of relative stability between them does not mean that there’s zero change in those stable periods, just that it’s much more gradual compared to the rapid bursts. And that’s the point I’m trying to make about technological progress — that it doesn’t maintain a constant rate for all time, but has historically (and prehistorically) been characterized by bursts of rapid advancement with long periods of slower, more subtle progress between them. And, more to the point, that we happen to be in one of those bursts of atypically rapid progress, so we shouldn’t assume that the rate of change we’re used to is the permanent default setting for all time.
When sex robots become sufficiently advanced technology, what remains to be discovered? Let’s hope we survive that, and smartphones.
Then again, presuming humans can be made in factories when we realise the old fashioned processes has all the disadvantages mentioned in Aldous Huxley’s “Brave New World”, let’s consider Spirit and Opportunity. Spirit is represented by the JohnCampbell mode where Earth-men are just better than aliens, which you mentioned; what I have in mind for Opportunity is the time-honoured method of capturing a flying saucer that crashes, and immediately assimilating its technology. Or maybe not immediately… our technology will have to advance to understand theirs. And what if there is a sex robot factory on board the saucer… Still, it’s been pulled off. Perry Rhodan did it, after all.
But it’s equally likely that the flying saucer will crash amongst a flange of screaming monkeys like in “2001”. It took a long time to get beyond that little mistake. :-)
We could either be alone, and intelligent species exceedingly rare. Or perhaps we are the first kids on the block.
Or the aliens are stuck in a kind of interstellar cul de sac like in The Mote in God’s Eye.
Although it is more fun to consider than it is plausible, I always liked Vernor Vinge’s Zones of Thought, where the closer you are to galactic center, the harder it is to do cool things like build supercomputers, create artificial intelligence, and travel at speeds exceeding the speed of light. And Earth is stuck in the Slow Zone.
ChristopherLBennett @@@@@ 23 & 25:
I think the technological history of the human race can probably be described as “incremental but accelerating”, since the technological changes between, say, 0 and 1000 AD were greater than the technological changes between, say 10,000 and 9000 BC, which in turn were probably somewhat greater than the changes between 100,000 and 99,000 BC.
that’s the point I’m trying to make about technological progress — that it doesn’t maintain a constant rate for all time, but has historically (and prehistorically) been characterized by bursts of rapid advancement with long periods of slower, more subtle progress between them.
Can you give me what you think are some examples of this from before, say, 1000 AD? That is, examples of a “burst of rapid advancement” followed by “a long period of slower, more subtle progress”?
@28: You don’t think the invention of agriculture was a burst of advancement? Then there’s the burst of scientific innovation in Ancient Greece — atomic theory, heliocentric astronomy, etc. — followed by a period of slowdown and religious dogma thereafter, with a lot of that knowledge being deliberately destroyed and needing thousands more years to become widely known again.
Anyway, my whole point is that we have to keep the long term in mind. If we’re talking about species evolution and the history of the universe, that means the really long term, where even 10,000 years is a temporary blip. Even if the rate of progress has tended to accelerate, more or less, over recorded history, that doesn’t necessarily mean it always will, even millions of years from now. There may be some plateau we can’t easily surpass. Heck, some would argue that we’re already at a point where progress has gotten so fast that it’s doing more harm to the planet and society than good, so that maybe we need to dial back if we want civilization to be sustainable. We can’t know. We can’t assume that the patterns of the past must inevitably continue into the future, because we only have one example of a civilization’s progress and that example is unfinished.
@29, as I have said before the Middle ages were in fact a period of relatively rapid technological development especially in agriculture and the applications of wind and water power.
Heliocentrism lost out to Ptolemy’s complicated earth centered system which was far from lost. In fact an awful lot of totally wrong Greek ‘science’ survived and impeded further development by their authority.
@30/roxana: Of course the knowledge survived; that’s not the question. We’re talking about the speed of progress, not about knowledge being lost.
@25
Actually the evolutionary model of punctuated equilibria does require stasis, more or less, between speciation events. This may involve variation over time around a mean, but it’s essentially a Monte Carlo process – no net directionality. Eldredge and Gould were trying to explain the apparent lack of morphological change over time in invertebrate fossil lineages, and also noting that the sorts of microevolutionary processes hypothesized to produce new species from old would happen in a geological eyeblink.
That’s what evolutionary biologists tend to say. You may be right for civilizations – we’ll never be able to view them and biological evolution at the same level of resolution.
@28, @29,
Greek mathematics can also be thought of an an example of this, with Thales and the Pythagoreans being the innovators and Euclid, Apollonius, and Archimedes being consolidators.
In this case further progress was not halted so much by religious dogma as by attachment to a mathematical worldview that had come to seem relatively complete and aesthetically satisfying.
Indeed the Arabs who came along later made only commentaries upon Greek geometry; their invention of Algebra was “something else”. And when some philosophers in the 12/13th century began to think for themselves about the nature of infinity, they were initially responding to Aristotle, not Archimedes. (Aristotle being rather easier to improve upon.)
I recognize the picture at the top of the page as representing the Kepler-42 system. I’ve asked NASA but have not been able to learn the name of the artist. This star is 126 light years from here, having a mass 0.13 times that of our Sun and a luminosity 0.0024 times the Sun’s.
Some while back, tired of “the search for Earthlike planets,” I went hunting for Sarr, the home planet of the sulfur-breathing protagonist in Hal Clement’s novel Iceworld. (Have Powerpoint, will travel.)
In the picture above, the planet closest to the star is Kepler-42c, the nearest match for Sarr in the data available at the time I was looking. Sarr’s radius is 0.77 that of Earth; 42c’s radius is 0.73 Earth radii. 42c’s orbit has a a semimajor axis of 0.006 astronomical units, snuggled up less than a million kilometers from its small, dim parent star. Its “estimated equivalent temperature” is 720 Kelvin, give or take 73 K. Sarr’s temperature must be around 770 K or more, given its sulfurous atmosphere, but there is plenty of room for 42c’s actual temperature to be that high.
Hal Clement gives the length of Sarr’s day, 13 hours, but not its year; Kepler gives 42c’s year, 11 hours, but not its day. If 42c is tide-locked, as seems likely, then its day would also be 11 hours, pretty close to Sarr’s.
Sarr is said to be 670 light years from Earth, so it is considerably further away than Kepler 42, but otherwise Kepler 42c is a decent match for the homeworld of Clement’s hero, Salman Ken.
There are a lot more worlds to be found in exoplanet databases than the Earthlike (whatever that means) ones. Maybe your own favorite planet from SF is in there somewhere. Take a look.
@33/Keleborn: In my mention of religious dogma, I was thinking specifically of the murder of Hypatia and the destruction of the Serapeum and its surviving scrolls from the Library of Alexandria, with Greek science being suppressed and destroyed in the name of Christian dogma, although of course much of the knowledge was preserved despite the efforts of the fundamentalists.
But you do get my point — that a period of invention of new ideas was followed a period of stability in which those ideas were deemed complete and sufficient, until the next time there was impetus for a burst of innovation.
One possibility is that FTL travel is like digging the Chunnel – you have start at both ends and meet in the middle. So we can never travel to any planet that hasn’t already developed FTL travel, and more advanced aliens couldn’t travel to Earth before we invented it ourselves.
@26,
Wasn’t that Poul Anderson’s The High Crusades?
Supposing that FTL is possible, I wonder: what kind of person would be most likely to discover it? And will they be looking for it when they find it?
@38: They might be looking for it, but they won’t confirm that something is truly FTL until they literally don’t see it coming before it arrives!
@39/Ian,
Somehow I think I should have seen that one coming. Or maybe not … :)
The superadvanced civilizations find us too immature and dull to be worth bothering with (and too much a reminder of their own embarrassing pasts), so they prefer to keep out of the way while we’re playing and squabbling with the other children.
Of course, if we really want to be rational about this then we’re up against the Fermi Paradox, which makes it all too likely that either there are very few other folk out there or that interstellar travel is just too darn hard. In the face of that I choose denial every time.
@29: Then there’s the burst of scientific innovation in Ancient Greece — atomic theory, heliocentric astronomy, etc. — followed by a period of slowdown and religious dogma thereafter
I could point out that what you’re referring to is an awfully long period for a “burst”: basically, from the 6th C BC (Thales, Anaximander) to the 2nd C AD (Ptolemy, Galen), which is about 800 years.
But the real problem is that none of that is technology. (And we’re talking about technology, not philosophy and science.)
@29: You don’t think the invention of agriculture was a burst of advancement?
The “punctuated equilibrium” model means that the normal “equilibrium” state is a low, more-or-less constant rate of technological innovation. And then there are occasional, short “bursts”, where the rate of innovation shoots up to something considerably (several times? ten times?) higher, after which things fall back to the background rate for a long time.
So, given that’s your model: roughly when do you think the agricultural “burst” started, and when did it end?
Look, okay, I was only using “punctuated equilibrium” as a rough analogy, okay? It’s a metaphor. I didn’t expect it to be taken so damn literally.
@41/OneRatNoWall: “Of course, if we really want to be rational about this then we’re up against the Fermi Paradox, which makes it all too likely that either there are very few other folk out there or that interstellar travel is just too darn hard. In the face of that I choose denial every time.”
That’s ignoring the more likely answer to the Fermi Paradox, which is simply that we don’t yet have the means to detect alien life and have been going about it the wrong way. Past SETI methods have mostly been based on a very arbitrary set of assumptions — that aliens would be actively trying to contact us or that their signals would be broadcast rather than tight-beamed, and that they’d communicate on the particular wave band that we chose to search in mainly because it was easy to search in. There could be plenty of civilizations out there communicating by tight-beam laser — which is far more likely because it’s got a higher data rate and less signal loss than the hydrogen-band radio signals we’ve mostly been searching for — and we’d never know it because Earth didn’t pass through any of the beams.
It’s really quite arrogant how quick many people are to assume that our inability to detect anything “proves” there’s nothing out there, rather than proving that we’re still at too primitive a stage of SETI efforts to be able to spot what’s out there. We’ve only been at it for a few decades, so it’s way too early to give up the search.
Of course, the more valid formulation of the Fermi Paradox is not about why we can’t detect alien signals, but about why they didn’t already colonize Earth millions of years ago, given the comparatively short time it would take to colonize the whole galaxy in proportion to the age of the galaxy. That’s a trickier question to answer. Although it could be another case where we’re narrow-mindedly assuming that the mindset of our own recent history is a universal default. Just because our own planet’s recent past is characterized by aggressive colonialism, that doesn’t mean that aliens would be just as expansionistic, or that such expansionism would inevitably go on forever until it encompassed the whole galaxy.
In short, there are too many things we just don’t know, so to rush to the conclusion that aliens must not exist at all strikes me as just evading the question.
There must be a bottleneck somewhere.
If we are lucky, it is behind us – e.g. the transition from single cell to multi-cell organisms.
If we are not lucky, it is ahead if us – e.g. the turning of humanity into a space-based civilization. See for example Aurora, by Kim Stanley Robinson.
These two examples are by no means the only ones, and some bottlenecks can be in either category, e.g. the nuclear world war.
Personally, I subscribe to the idea (without any proof whatsoever) that the Universe is full with bacteria and moss, but the highly organized and intelligent life is extremely rare. For now we fundamentally don’t understand too many things e.g. dark matter (if there is any) to figure what is going on.
PS On a sad sideline: Jacqueline Pearce a.k.a. Servalan from the Blake’s 7 just passed away. :(
Almost all of the invasion stories I’ve encountered also ignore the question of “why.”
There is literally nothing on Earth that couldn’t be acquired elsewhere, far more easily if one has access to FTL (indeed, getting physical resources off Earth would be the hardest part in most cases, which is why we ourselves are looking at asteroid mining). The only unique things about Earth are its biosphere and the presence of sapient life –two things that might well be common anyway, and would probably only be of interest to scientists (as opposed to conquerors, traders, miners, or anyone not engaged in pure research).
One of Brian Stableford’s series posited that the one resource that will always be in short supply even in post-scarcity economies is other people to push around.
Come to think of it, there’s an old time short story where aliens show up and graciously hand us all sorts of advanced technology. The twist is, this is because they’re planning on crushing humanity but they prefer fair fights.
@48/James David Nicoll: One thing to keep in mind is that long-distance international trade throughout history was heavily driven, not by basic necessities of survival, but by luxury items like silk, porcelain, rare spices, and the like. Rich people’s craving for new, rare, exotic items that they could show off, and the prestige they could gain by boasting about how much money and trouble it took to acquire them, drove an enormous amount of global commerce and politics. It wasn’t that they couldn’t get equivalents at home — it was that the value of the trade items was specifically in how exotic their origins were.
So interstellar trade might well be driven by the same dynamic. Sure, you can get all the water or precious metals or carbon compounds you need by mining your own star system’s asteroids and comets — but you can’t get luxury items like the unique plants and animals of an alien world, or the textiles and artifacts and art and music created by an alien culture. Sure, you could just ask the aliens to beam you the molecular patterns by laser transmission and 3D-print copies out of indigenous materials, but it wouldn’t have the prestige of genuine, imported originals.
@38,39,40 You guys made me laugh out loud! ;-)
@47 I liked the way the aliens in the ‘V’ TV show came to steal our water, driving past moons, comets, asteroids and rings made of ice to get here. Not to mention that Earth’s water is at the bottom of a fairly steep gravitational well, making it harder to retrieve.
This seems like an appropriate time to link to this venerable Ares essay.
49/ChristopherLBennett
H Beam Piper has luxury goods being the only reliable interstellar trade items.
And yet Piper’s ships are huuuuge.
And the larger ones are up to and perhaps beyond three thousand feet. In fact, one 1500 footer has about one fifth the cargo capacity as the US’s current rail capacity. That’s a lot of bottles of high end brandy and sunstones.
@49: It wasn’t that they couldn’t get equivalents at home — it was that the value of the trade items was specifically in how exotic their origins were.
I think that’s overemphasizing the “it’s valuable because it’s everyone knows it’s from somewhere else far away” angle, which I suspect is much more of a modern development. (Though I’d agree that fetishes for the exotic and the “authentic” are potential drivers of trade in advanced societies.)
People in ancient and medieval Europe didn’t value pepper from the Indies because, unlike their local pepper, it was from far away, they valued it because they didn’t have anything equivalent — and it was useful for improving the taste of food.
People in ancient Egypt didn’t value lapis lazuli because it was from Afghanistan (which they had no idea about), they valued it because it was beautiful (and rare). Similarly, people have long imported gold (if they didn’t have it locally, which not everyone did) not so they could boast about where the gold came from, but because it was, well, gold.
53,
Well, that’s why going Space Viking tends to destroy the local economies of the Sword Worlds. All sorts of stuff that normally wouldn’t be shipped just gets stuffed in there.
@50/Alan: I always chose to assume that the Visitors’ need for our water (which I think they requested openly) was a cover for their real intention of harvesting us for food. The problem remains, though, that Earth’s scientists should’ve seen through that cover story immediately for the reasons you mention.
@54/Peter: I never mentioned gold, so I don’t understand why you brought it up. I was explicitly discussing luxury items as a driver of trade. That obviously does not mean that there was no trade in essentials, just that not all trade was about essentials.
“People in ancient Egypt didn’t value lapis lazuli because it was from Afghanistan (which they had no idea about), they valued it because it was beautiful (and rare).”
Exactly. They found it beautiful because it wasn’t something they saw in their everyday lives, because it was a novelty. They had plenty of their own rocks, but they’d spend a lot of money for this particular type of rocks because they couldn’t get it domestically. It was the difference from the norm that made it valuable to them, rather than an intrinsic material benefit.
So you’re not actually contradicting my point here, you’re supporting it. Aliens coming to Earth to take our water or our oxygen is silly, because those can be found anywhere. But aliens coming to Earth to obtain our spices or our textiles or our jazz recordings or our movies (sorry, “historial documents”) or our tasty human flesh is another matter, because those are things they’d value for their uniqueness.
Going by The Beak of the Finch, evolution can actually be quite rapid when needed. The status quo would be a rapid jittering around an average point that’s relatively stable in the environment. If there’s a big outside change, the species will change rapidly, then jitter around the new stable point. Though of course shifting existing alleles is easier than creating new organs from scratch.
People may have planned for Hoover Dam to last a long time, but they expected to get benefit in short order. Likewise colonists expect to help themselves and their children; benefit to distant descendants is nice but not the motivation. People bring up cathedrals, but while those could take centuries before being deemed done, AIUI they provided usable space (and prestige) much quicker. Planting replacement trees is the only really long-term payoff example… and it’s also pretty cheap to do.
If FTL took 1000 years of sustained effort before generating any payoff, I’d say there is no example of humans doing something like that.
“aggressive colonization” is what life in general does. Life next to empty living space expands into that living space. Demographic-transition humans are the exception. And it’s not like there’s a huge moral element to turning dead asteroids into space habitats or sapient robots.
Trade has always had a mix of useful and luxury goods; ocean trade is cheaper than land trade and so can be biased toward bulky useful goods. Europeans looking at the silk route would have a skewed view of Asian trade, compared to shipping riding the monsoon winds in the Indian Ocean, from Africa to SE Asia or China.
@57/drs: It seems to me that developing the technology for interstellar flight would create many more immediate benefits, in much the same way that the original Space Race produced a lot of valuable spinoff technologies like Kevlar, memory foam, etc. I mean, in order to build starships, you’d first need to build a prosperous and productive interplanetary infrastructure in order to obtain the resources and facilities to build the starships. You’d need to develop highly efficient power systems, drive systems, life support systems, etc. All those things could immensely improve people’s lives in the short term.
@35, Okay about that: Hypatia died because she was on he wrong side of a political dispute between the Bishop of Alexandria and the civil authorities. The Library of Alexandria’s famous collection had been destroyed and dispersed several times since the burning by Caesar but not this time. Hypatia’s students included high ranking chuchmen who were shocked by her death. Far from destroying Greek ‘science’ the church worked to preserve it and to hunt out surviving documents. In short Carl Sagan was full of baloney.
@59,
That’s interesting. I wasn’t so sure I bought his argument about Greek Science dying out because people had devoted their interests to creating gimmicks and toys either. After all, didn’t programming get started with the player Piano?
As a friend of mine says the Middle Ages must have stole Sagan’s girl and killed his dog. His picture of a Dark Age was totally ahistorical. Granted the centuries just after the collapse of the Western Empire were a low point but Europe had recovered for the most part by the Carolingian Renaissance and after that there was fairly steady improvement in technology and standards of living.
“in much the same way that the original Space Race produced a lot of valuable spinoff technologies like Kevlar, memory foam”
Most such spinoffs are urban myths, promulgated by space fanatics; NASA even has had its own webpage debunking many of them. Kevlar was developed by DuPont to create better tires. Memory foam was developed under NASA contract… to improve the safety of aircraft cushions. (People forget what the first A stands for.) And in fact “mess around with space for the spinoffs” has not appealed to any of the 200 countries on Earth today.
“Fanatics?” That’s needlessly insulting.
@45: Which is why I also mentioned the “travel too hard” option, and talked about physical visits rather than just messages.
Arrogance: no. Undue pessimism: hopefully. (I prefer to be happily surprised than disappointed.) It could very well be that we’re just early to the party.
@64: My whole point is that we’ve been searching for extraterrestrial intelligence for about two minutes, proportionately, and have probably been looking for the wrong things most of that time anyway, so it’s staggeringly shortsighted and hubristic to assume that just because our brief, fumbling efforts haven’t found anything, it means there’s nothing in the entire universe to find. We’ve barely even started looking yet, but there are people making up countless theories to “explain” why we’re alone, and that’s just stupid. At the very least, we should wait a few more centuries until we’ve developed the means to do an exhaustive search. The eagerness of so many people to jump to the conclusion that we’re the only life in the universe is inexplicable to me. Unless it’s the same overweening arrogance that led humans to assume that we were created in God’s image or that the entire universe literally revolved around us. I guess some people just don’t want there to be any competition. But that’s not science.
@10: I don’t remember the Campbell offhand, but my immediate response to your explanation #2 (essentially what the first several commenters hopped on) is Brown’s “Letter to a Phoenix”, which argued that Atlantis was just the latest of the 6 ~30Kyr cycles the immortal narrator had seen (with IIRC no certainty that there were no cycles before his birth). Complete rubbish for Earth even with the lesser archaeo/paleonto/paleoanthropological knowledge of ~60 years ago (although perhaps not quite as counterfactual as Niven’s <i>Protector</i>) but an easy handwaving for other solar systems. And wrt Niven’s contribution to SE #3, did you know that he once proposed (allegedly nudged by Spinrad) to tear it all down, making the billion-year history a forgery/conspiracy?
@27: 2001 brings up a variation of SE #3: bored aliens uplift everywhere within reach. On a local scale, Parke Godwin did this in Waiting for the Galactic Bus, even though the savants of that civilization had math proving it was impossible.
@34: if a planet is tide-locked to its primary, would it not have a day (or night) of infinite length, as once believed for Mercury?
@36: why wouldn’t someone with more ambition than Earth in Barnes’s Thousand Cultures tetralogy send slowships to planets that merely look interesting (rather than being known to have relatives on them) to create the other ends of FTL links?
@60: didn’t programming get started with the player Piano? According to Wikipedia, the player piano dates from late 19th to early 20th century. The Jacquard loom was invented in 1804, and Ada Lovelace was theorizing about how to use Babbage’s engine (if he ever finished it) by (crudely) the mid-19th. (One can argue that her work was lost, and not rediscovered until it had been reinvented — but in that case the player piano, which has no options, would be preceded by the almost-as-unbranching tabulation of the 1890(IIRC) US census.) There may be examples of toys leading to tech, but I don’t think that fits.
@66 Yes, depending on how hard it is to build slowships. Barnes himself has his slower-than-light ships only developed centuries from now, with incredibly advanced technology. The Thousand Cultures backstory also has aliens broadcasting the FTL transport blueprints by radio, which is a logical alternative to just waiting around for someone else to invent it. Same for Sagan’s Contact.
If our understanding of physics is basically correct, we’re not going to learn about life outside our galaxy. Or have I missed something?
@37: one of several settings where alien technology falls out of the sky and is either understood, or not but used anyway. I’ve got a technically earlier one, from 40,000 years ago, not a Jules Verne character but same cool (so far inaccurate) title –
https://en.wikipedia.org/wiki/Master_of_the_World_(comics)
Another case is an alien planet that has a spaceship crash on it, but it’s a cheat, a fake that is designed to be copied by the planet’s population to suit someone else’s purpose.
If aliens attack and we shoot some down, that works too.
@68/NancyLebovitz: “If our understanding of physics is basically correct, we’re not going to learn about life outside our galaxy. Or have I missed something?”
It was announced earlier this year that there may have been a detection of exoplanets in the Andromeda Galaxy. It’s hard to do, but all exoplanet detection is about teasing out tiny variations in the light we detect from space. Hypothetical methods for detecting biosignatures on exoplanets are along similar lines — e.g. getting spectroscopic data of their atmospheric composition or detecting reflection signatures characteristic of chlorophyll or the equivalent. It’s just a matter of getting enough magnification/sensitivity, and as the linked article shows, there are some circumstances where gravity lensing can give us enough magnification to detect planets in another galaxy. So it might be possible to eventually detect life extragalactically as well, although of course it would be life as it was hundreds of thousands or millions of years ago.
ChristopherLBennett @@@@@ 70:
That study wasn’t about the Andromeda Galaxy (2 million light years away); it was about a galaxy at a redshift of 0.295 (3.9 billion light years away), which was acting as the gravitational lens for a background quasar much further away.
Also, the “detection” that’s reported is a purely statistical one: to explain tiny variations in the lensed X-ray light from the background quasar, they infer a population of gravitational “microlenses” in the lens galaxy. The estimated density of stars in the lens galaxy isn’t high enough, according to their models, so they argue for effects from free-floating planets as well (planets orbiting stars would have only tiny effects in addition to their host stars, and so were not considered in the models). It’s kind of a cool paper, but it’s a *very* indirect result. No individual planets were detected in any way, shape, or form, nor would you be able to learn anything about them. (And, again, these are a postulated population of free-floating planets, too cold to support any plausible life.)
Could we learn something about planets orbiting stars in the Andromeda Galaxy? If we generously assume that we might be able to learn something about the atmospheres of planets within 20 light years of Earth using next-generation telescopes (e.g., the European Extremely Large Telescope, with its 39-meter mirror), then you would need a telescope with a light-gathering power 100,000 times that of the E-ELT, which means a diameter at least 300 times larger (so: more than 10 km in diameter) to learn equivalent things for planets in the Andromeda Galaxy.
[Edited to add: if you want to read the original article, there’s a preprint version here.]
“Another case is an alien planet that has a spaceship crash on it, but it’s a cheat, a fake that is designed to be copied by the planet’s population to suit someone else’s purpose.”
That would be the planet Krikkit, I assume.
Krikkit. That’s the planet with the folk singers, isn’t it?
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Maybe time is vast, and species are only technological for a short time. But the UNIVERSE is also vast; there are a huge number of stars, with a huge number of possible planets. Any GIVEN planet is unlikely to overlap with us in time, but somewhere in the universe, LOTS of planets should, because there are just THAT MANY stars.
Two problems with the analysis:
1. There are a huge amount of stars (and presumably planets) out there. Even a 1 in 100 million chance becomes likely when you are talking about billions or trillions of potential sites.
2. We have no idea if how human life has evolved/advanced is a norm. We might be an outlier – either fast or slow. It’s rather arrogant to assume we are the only intelligent life in a massive universe. But we simply don’t know. We simply have no data, and we won’t have any data until we start reaching other star systems.
@76/allock: But we’re not talking about billions or trillions of potential sites here — we’re talking about one site, Earth, and the likelihood that the nearest alien civilizations to ours, the ones we have a chance of detecting or contacting, would be at close to our technological level rather than millions of years ahead or behind. Yes, you’re right that, statistically speaking, it’s inevitable that some pair of near-adjacent star systems somewhere in the universe would arrive at the same technological level around the same time — but it’s highly unlikely that Earth specifically would be part of that pair. That would be like winning the lottery, or getting struck by lightning. There’s a big difference between the odds of something happening to anyone and the odds of it happening to you.
There are examples here on Earth of cultures that advanced to a specific stage of technology then did a pretty hard stop, and some that got further then slid back.
Before Europeans visited the western hemisphere to stay, people in what would become the USA and Canada were stuck at the level of basic agriculture at best, with some still operating as hunter/gatherers. What metalworking they had was with rare bits of found metals.
Down in what would become Mexico they worked gold and copper, they had much more advanced agriculture, stone and wood working and other neat things.
Further south, the peoples had begun backsliding from their peak by the time of Columbus, Cortez, Vespuchi etc. They *had* cultivated vast swaths of ancient grassland, fertilizing with charcoal. By the time the Euros arrived they’d abandoned much of the fields to jungle and some of their cities like Machu Pichu were ghost towns. In the northern continent some cities in the southwest had been abandoned, having reached a technology peak a bit higher. There’s evidence the Incas, Mayas, and Aztecs weren’t the first peoples here to reach similar achievements.
Nobody over here invented the keystone arch. Doorways and other opening in stone walls were limited in span to the longest single stone they could cut and lay horizontal without it breaking. Yet some of them had the knowledge and ability to fit stone so closely we still don’t know how it was done – because the governments of countries where such artifacts are won;t allow anyone to pick up just one stone from one of those walls to have a look.
Some people here invented wheels, but as yet the only evidence of use is on children’s pull toys. Why were there no wagons and carts or chariots?
No concrete on this side of Earth, when Romans had it almost 300 years BCE.
They hunted the horselike animals to extinction, long enough before permanent European contact that they’d forgotten such animals existed.
There’s a start for a time travel / alternate history story. Go back to the western hemisphere and introduce the keystone arch, ride the animals, don’t eat them, wheels, they make life so much easier – and when combined with horses and archery they can help vanquish your enemies. Tilling charcoal into the land is a good start, but you need to rotate different crops. Why mess around with stone when you can take this process and cast your own stone in any shape you like? May as well show them how to make plywood too. Come back a few years later to show them iron smelting.
A problem with detecting alien transmissions, or aliens detecting ours is time. We’ve only had radio transmissions distinguishable from nose for about 100 years. Amplitude Modulation radio with voice is barely that old.
But even those transmissions are useless for detection by aliens. We’ve had radio capable of punching through the ionosphere for only 60~70 years.
That puts the furthest away an alien civilization could hear us at less than 70 light years away – and only if they were specifically listening for signals from this direction.
Now nearly all of our signals going out are digital, and encrypted. We’ve gone back to transmissions indistinguishable from noise – without the hardware and software to decode the signals.
An alien civilization 50 light years away, aiming big antennas right at us all this time, would have picked up first weak analog voice transmissions, steadily getting stronger.
Suddenly, stronger analog transmissions in a different format (Frequency Modulation) would appear. Their scientists would scramble to figure out the new system. Perhaps they’d be puzzled why the earlier system continued in use instead of rapidly being supplanted by the new.
A few years later something new is added. Their scientists figure out it’s video, but why at least three slightly different formats? A few years after that there’s another change, they figure out its color information. For the first time they can see what the people of this other world truly look like!
They watch our news of space exploration, the launching of many kinds of satellites. They exhibit their version of humor at our silly stories of contact with many sorts of aliens.
Then things begin to change. Some of the signals are altered to where they’re impossible for the equipment they’ve built to receive and display. They quickly adapt and can see our transmissions again. (The aliens cracked Videocypher!) But in a short while the transmissions are mostly scrambled again. Working diligently, they crack Videocypher 2.
But worse comes soon. The signals don’t change but their content does. It’s the same frequencies but the content is nothing but apparent noise. They tease out that it’s now digital and construct receivers to decode it – but their success is short lived as practically overnight almost all of it goes to undecipherable snow due to very strong encryption.
Earth has gone dark to the aliens. They can’t even pick up the few purely analog broadcasts left because they’ve abandoned and scrapped their old receiving equipment and nobody wants to fund rebuilding it new, just to see if there’s anything left to hear.
They never bothered aiming a deliberate communication signal our way because they know it’d take 50 years to get here, and from our signals they know we wouldn’t be listening for it anyway, and we’ve sent out nothing acknowledging that we’ve detected any of their radio ‘leakage’.
Gregg Eshelman @78:
... people in what would become the USA and Canada were stuck at the level of basic agriculture at best
No, they were in the process of gradually improving their agriculture, by adapting southern crops like maize to local growing conditions and combining it with local domesticates. Maize cultivation only reached New England about a thousand years ago; it was still a (relatively) new technology when the first English settlers arrived.
Further south, the peoples had begun backsliding from their peak … and some of their cities like Machu Pichu were ghost towns …
Um, no. The Inca Empire — probably the largest empire ever created in the pre-Columbian Americas — reached its largest extent under Huayana Capac, who began his rule in 1493 (yes, that’s the year after Columbus’s first voyage). Could it have gone on to become even bigger? We’ll never know, because it was during his reign that European diseases began devastating the empire, followed by a civil war among his sons, and then the arrival of Pizarro.
And Machu Picchu was a royal estate, with a population of about 500-750, established around 1450 for the royal family’s personal use. All the available evidence suggests it was still in use when the Spanish invaded, and was only abandoned afterwards. (If the royal family goes away, there’s no use sticking around in an estate no one is going to use, and there’s no one to replace the staff that leaves or dies.)
No concrete on this side of Earth, when Romans had it almost 300 years BCE.
And then concrete usage basically disappeared after about 500 AD, not returning until the 14th C. (Those lazy, backsliding Euros!)
Gregg Eshelman @79:
Actually, the strongest radio signals coming from Earth are from military radars, particularly the ICBM detection systems. These are still operational.
They never bothered aiming a deliberate communication signal our way because they know it’d take 50 years to get here, and from our signals they know we wouldn’t be listening for it anyway…
Except that we are, in very limited ways, “listening for it”, so they’d be wrong. (Or they wouldn’t make that mistake.) Really, if they have been monitoring us that intensely, the shift to digitized and encrypted communications would be a sign that we’re still advancing technologically, so if anything we’d be more capable of detecting and deciphering their transmissions. (“Hey, looks like they’ve got computers now!”)
@78-80, Lack of heavy draft animals limited New World civilizations, sooner or later their agricultural base would fail because they were unable to take the next step up from hand farming. Nor is it surprising that wheeled vehicles never took hold with nothing to pull them. The pre-Columbian history of the Americas is a record of empires rising then failing as they prove unable to sustain themselves agriculturally.
@78/Gregg Eshelman: “Before Europeans visited the western hemisphere to stay, people in what would become the USA and Canada were stuck at the level of basic agriculture at best, with some still operating as hunter/gatherers. What metalworking they had was with rare bits of found metals.”
That’s a profoundly ethnocentric and biased mischaracterization. Native American civilization wasn’t “stuck” at a level inferior to European civilization; it simply specialized in different things, advanced in different areas. Europeans were better at metalworking, but Americans were far better at agriculture and building with organic materials. North American longbows at the time of first contact had better range and accuracy than European firearms of the day. And Native American agriculture was second to none. Over 60% of the food crops we eat today worldwide were domesticated or bred into existence by Native Americans.
ChristopherLBennett @83:
I agree with you that Gregg’s comment was overly ethnocentric and biased, but I think you’re in danger of trying to push things too far the other way. E.g.,
Americans were far better at agriculture and building with organic materials.
I think that’s an exaggeration, at least. There were quite a few significant crops domesticated in the Americas, yes, but there seem to have been far fewer domesticated trees (for fruit, nuts, or oil), for example. (There’s some evidence for “incipient domestication” in the Amazon rainforest, but nothing like the full domestication and widespread planting of things like olive, citrus, or apple trees.) Almost all tree-based fruits and nuts eaten in the modern world are either Old World (Eurasia+Africa) domesticates, or were domesticated in the last few hundred years. And it’s well-known that they had fewer domesticated animals.
I doubt you could argue that Mesoamerican irrigation techniques were actually more sophisticated or superior to the most advanced techniques in contemporary Eurasia or Africa.
And what’s the argument for “far better at building with organic materials”? Nobody knew how to use wood in Eurasia? Eurasian ships and navigation methods were certainly more sophisticated than anything in use in the Americas.
North American longbows at the time of first contact had better range and accuracy than European firearms of the day.
And in comparison to European longbows or crossbows? Or to Eurasian composite bows? (And of course Europeans also had cannons, which were arguably more effective weapons in the early 1500s.)
Over 60% of the food crops we eat today worldwide were domesticated or bred into existence by Native Americans.
Though Gregg is correct in suggesting that “what would become the USA and Canada” did not originate those crops.
@84/Peter: The point is, it’s ethnocentric and simplistic to try to rank different cultures on some hierarchy of who’s “better.” That’s not how it works. Different is just different, not superior or inferior. Every culture is better at some things and worse at others, or they find different but equally effective ways of doing the same thing. History and anthropology are not a game show. There’s no sense trying to pick a winner.
As has been mentioned, evaluating the Fermi Paradox on the basis of what we’ve observed doesn’t say much other than no civilization in range seems to have hung out any big “Hello, Galaxy!” signs. I take more from lack of nearby signs of colonization or exploration. An inquisitive, or acquisitive, civilization with sub-light space travel could fill the galaxy in a few million years.
For me, it’s less “where are they” and more “why haven’t they visited us?” Which, of course, is still, at best, only mildly suggestive.
I take more from my sense of the Drake Equation, that certain of the factors are extraordinary tiny. I have yet to hear a convincing explanation of how chemistry evolved to RNA. And the jump to multi-cellular life is another amazing, even fantastic, event.
I’m struck by how few of the star systems we’ve seen look anything like ours. The sample is biased by how we manage to even see these systems, but still, just how rare is the solar system? Big gas giants in the outer system protecting the inner system from bombardment.
The Moon, because of tidal pools, is thought by some to be crucial to our evolution from the sea. The Moon’s creation may have added iron to the Earth’s crust that also is significant in the habitability of the Earth. How rare is a habitable zone planet with such a Moon?
And, at a mere 13.8 billion years, we’re early, early in even the near-term life of the universe. If one trillion years is a 24-hour day, we’ve shown up at around 19 minutes after midnight. There’s a long day yet to go.
A final thought: Once intelligent life does reach space-faring technology, how long does that civilization last? (Hello, Foundation.) Our Earth models indicate they tend to fall. How does that effect Drake and Fermi?)
What’s going on with the editor here? It seems like it lets you enter a longer comment than it will post. I’ve been getting my tail chopped off!
Solar tides are about 1/3rd the Moon’s. If stronger tides are required, look to dimmer stars.
@86, It is beginning to look like Earth and its solar system isn’t ‘mediocre’ at all but possibly uniquely fortunate.
@89: Our sample size is far too small for any confidence, but I’m beginning to suspect that may be so. I have a growing opinion that a correct evaluation of Drake’s Equation may have the probability of intelligent life so low as to insure we’re alone in the galaxy, maybe even the cluster. We may be quite unique, indeed.
Or maybe we just showed up to the party really early. We’re to, millennia hence, be known as the mysterious Ancestors.
(A burning question I have: how unique are gas giants with spectacular ring systems? And it’s not like Saturn’s rings will last forever… they’re here for us to enjoy now as get ready to leap off this planet.)
What that what? Comments I enter are getting tail-chopped. Trying to edit the one above, it says I have 0/13000 characters… in that short comment.
(Edit: Hmmm. Works goodly on the PC. Apparently a problem with the iPad or that new Bluetooth keyboard I bought for it.)
I still say it’s both premature and incredibly arrogant to assume that our inability to find alien life after a paltry few decades of looking with crude, inadequate methods means there’s nothing there to find. Let’s at least have the patience to look for a few more centuries before we start jumping to the conclusion that we’re alone.
Moral attitudes do not equate to evidence. EVIDENCE shows Earth is not mediocre and that life bearing planets may not be a dime a dozen. It isn’t arrogant to concede those facts.
@93 Incomplete evidence.
@94, admittedly. Further evidence may emerge but at the moment we have strong indications that our planet and our system are not ‘mediocre’.
@93/roxana: The one has nothing to do with the other. Yes, the Solar System is not typical. But no, it is not reasonable to jump from that to the assumption that life is rare in the universe, because we don’t know remotely enough yet about what kinds of planets or star systems can support life.
Personally I would LOVE to find a planet of Horta like living rocks. Would’t you?
@97: That’s a non sequitur. I’m saying that the evidence is strong that even star systems very different from ours are likely to host Earth-sized planets with liquid-water temperatures on their surfaces. Contrary to the beliefs of the “Rare Earth” theorists back in the ’90s, current evidence and theory suggest that the likelihood of a given star system having at least one potentially habitable planet is in fact extremely high, maybe 50% or more. So the idea that Earth is some unique oasis in a barren universe is outmoded. Life-bearing conditions are probably quite common, though there are still all sorts of unanswered questions about the probability of life actually emerging or evolving beyond microbes or achieving intelligence.
@97/Roxana: Oh yes! But without telepathic Vulcans, it would be hard to establish communication.
If they aren’t intelligent, we could get pet rocks.
@98, I love non sequiturs but in fact I was responding to your suggestion that ET life need not resemble ours. Only rereading I don’t think that’s what you were saying at all. Sorry.
@100/roxana: That was not what I was saying, no. I was saying it’s impetuous and arrogant to jump to the conclusion that we’re the only life in the universe just because our paltry few decades of looking haven’t yet turned up results. It’s absurd to give up so easily. “Did you ever find your keys?” “No, they weren’t in the first two places I looked, so I concluded they never existed at all.”
@101 And we were looking for keys that looked like a Victorian cellblock lock, when what we should have been looking for was the fob for our car too. We’re looking in too few places, for probably the wrong things.
Of course we’ll probably never know for sure, given the distances involved, until we get live on-site observation and confirmation. We’re gonna have to go, to know.
@102/random22: Exactly. We’ve only just begun coming up with new, more credible ways of searching. We’re still at the beginning of the search, not the end. The only reason to jump to the conclusion that we’re alone in the universe is the same kind of arrogant egocentrism, the need for humans to be special, that led us to assume we were at the center of the universe and created in God’s image. Every time we’ve thought we were uniquely privileged in the universe, science has deflated our hubris. There’s no reason this should be any different.
Ever since I first started hearing about the “Rare Earth” theorists around the turn of the century, I’ve felt that they were trying to twist the evidence to fit a desired conclusion. Like the “Galactic Habitable Zone” idea. They made some valid arguments for why habitable planets might be less common closer to the center of the galaxy (due to higher radiation/supernova levels) or farther out toward the edge (due to fewer heavy metals for planet-forming), but there was an unsupported logic jump from “less common” to “completely absent.” I always felt it made more sense to call it a Galactic Temperate Zone rather than a Habitable Zone. (And both arguments have since been debunked. We now know that low metallicity only reduces the likelihood of a star forming Jovian planets, not terrestrial planets, and that even if the percentage of habitable star systems in the inner disk is lower, the sheer number of star systems there is sufficiently higher to more than cancel that out.) Also, the Rare Earthers ignored the fact that stars that formed in one region of the galaxy could be perturbed inward or outward to other regions. It always seemed to me that they wanted to force the conclusion that Earthlike planets were rare, and thus they overstated their conclusions and ignored some pretty obvious counterarguments. It was taken seriously for a while, but it always seemed like junk science to me. And most of it has been shot down by subsequent exoplanet discoveries.
@103: “The only reason to jump to the conclusion that we’re alone in the universe is the same kind of arrogant egocentrism, the need for humans to be special, that led us to assume we were at the center of the universe and created in God’s image.”
That seems, at least in my case, an unfair (and kind of insulting) assessment of the opposing position.
I’m not jumping to any conclusion, my logic is certainly not based egocentrism, arrogant or otherwise, and my analysis has nothing to do with religion.
As I said initially, I don’t place much weight on SETI-type results. We absolutely agree they mean almost nothing. Nor do I place much weight on lack of contact from them.
So it’s not the Fermi Paradox that drives my thinking, but my consideration of the Drake Equation.
Firstly, that some of the factors may be extremely small. I mentioned RNA and multi-cellular. And we can’t really know how unique our solar system is, or what role any putative uniqueness played, but I do see conditional evidence that suggests such factors make us all the more rare.
We may have debunked the idea of mining Earth for gold, but it’s likely heavy elements do play a role in the rise of intelligent life on Earth. Those require a nearby neutron star collision, so if heavy elements do play a crucial role, this further constrains the Drake Equation.
Secondly, the point of the blog post: We’re not just separated by vast differences in space; we’re separated by vast differences in time (which the D.E. also considers).
Science fiction galactic empires aside, how long can any civilization be expected to last? The center, famously, does not hold.
Let’s say we’re the first in this galaxy, and we get our act together and take it on the galactic road. In a few million years, at sub-light, we’ve expanded to fill the galaxy. But how many millions can we last? It took 10 billion for us to arrive (about four billion to cook us). Can we hold out until the next group arrives?
Perhaps more poignantly, can our (and by extension any) civilization last long enough to actually get off the planet and out of the star system? Based on the only examples we have, that seems unlikely.
How many civilizations on Earth have managed even 1000 years? (Depending on how you define a civilization, arguably none.) How long does a civilization have to last to fill the star system (let alone beyond)?
On the very presumption that we’re not special, there is no god, and we’re certainly not the center of it all, if we’re the product of evolution, it’s not looking that great for evolution. We may be a very brief blip in the scheme of things.
If we’re being realistic, the idea of a thriving solar system, let alone a thriving galactic empire, seems very science fictional. Given the available evidence, the various dystopic SF futures seem more likely.
Indeed, these days I’m thinking a creditable answer to Fermi’s Paradox is that intelligent life isn’t intelligent enough. (I really do believe our civilization is facing a Great Filter right now.)
Don’t get me wrong, CLB, I would LOVE to live in a crowded universe. I just don’t see any particular evidence for it. Yet. Here’s hoping.
@104 & 105: The point is, we don’t know either way. So assuming that absence of evidence is evidence of absence is premature. It’s just always seemed to me that the “Rare Earth” contingent was ignoring obvious counterarguments and exaggerating the arguments in their favor (e.g. interpreting “less likely” as “effectively nonexistent,” even though “less likely” out of hundreds of millions of chances is still pretty likely). It always felt biased to me, based more on some strange desire to be alone than actual objective science.
And the other point is, no matter how you slice it, there is a huge conceptual chasm between “We can’t find aliens” and “There are no aliens.” The former should not be discussed as if it were synonymous with the latter. The reason our lack of detection of aliens is called the Fermi Paradox is because it’s so staggeringly improbable that there aren’t aliens. So to glibly go around talking about “why there are no other inhabited planets” as if that were already the settled answer to the question is getting absurdly ahead of oneself, especially now that we’re actually discovering potentially habitable exoplanets by the truckload. The real answer for why we haven’t been contacted or visited by aliens will probably turn out to be something we haven’t even thought of yet.
wyrdsmythe @@@@@ 86:
I have yet to hear a convincing explanation of how chemistry evolved to RNA.
Well, it certainly seems possible to form some of the building blocks out in space.
And the the jump to multi-cellular life is another amazing, even fantastic, event.
Probably not, since it seems to have happened independently several dozen times in the Earth’s history.
@@@@@ 104:
It’s likely heavy elements do play a role in the rise of intelligent life on Earth. Those require a nearby neutron star collision, so if heavy elements do play a crucial role, this further constrains the Drake Equation.
I don’t see how “heavy elements play a role in the rise of intelligent life” except that you assert it. Which elements, and what is the depency?
In any case, the Sun isn’t at all unusual in terms of its heavy element content. There are billions of stars which are richer in heavy elements than the Sun. (The neutron-star collision may be required for efficient production of some heavy elements, but these get dispersed into the interstellar gas and mixed over hundreds of millions of years; there’s no requirement that a NS collision has to be “nearby” to a given star.)
@106: “The point is, we don’t know either way.”
Yep. Emphasis on “we.”
@107: “Well, it certainly seems possible to form some of the building blocks out in space.”
Yes, and it’s a very long way from the chemistry of (“some of the”!) building blocks to functioning RNA.
@107: “[Multi-cellular] seems to have happened independently several dozen times in the Earth’s history.”
Yes, sorry, more explanation required. I use “multi-cellular” as short-hand for the symbiotic event that led to mitochondrion, which allowed various multi-cellular forms to arise. If you read further in that link you provided, under The symbotic theory, it mentions how rare this is.
@107: “I don’t see how “heavy elements play a role in the rise of intelligent life” except that you assert it.”
I should have said “possible” (I got carried away). We don’t know to what extent traces of heavier elements might play a role in biology — certainly larger amounts of many of them are toxic — but if life evolved with these elements present, it’s possible they play a biological role. Certainly some of the lesser metals do.
There is the radiogenic heat produced by decaying radioactives in the Earth’s core. Without that core, we’d be a dry, dead planet. Perhaps all the heavy metals play a role in helping retain that heat.
I also wonder about social effects of a ductile, malleable, very attractive, biologically inert, non-corroding, relatively rare metal. It’s been used as coinage since recorded history.
I agree this is pure speculation on my part, and I’m not leaping to any conclusions. My analysis of what facts I know causes me to be very skeptical we’ll ever encounter alien life or that we ever could.
This is based on my analysis of the Drake Equation and, as the blog post suggests, doing the math about coincidence in time. And further that 1.38 billion years is only 19 minutes into a one-trillion-year “day.” (And beyond that, lack of any evidence “intelligent” life is smart enough to get out of their own star system.)
Here’s a new mathematical model assessing the mathematical parameter space we’d have to search for alien signals — not just physical space, but other parameters like signal bandwidth, frequency, repetition rate, and the sensitivity necessary to pick them up:
https://www.technologyreview.com/s/612232/the-8-dimensional-space-that-must-be-searched-for-alien-life/
According to it, the searching we’ve done to date has covered less than 6 quintillionths of this volume (5.8 x 10^-18). Which just goes to show how very, very early we are in the search and how very, very far we are from being able to assume there are no aliens out there.