Sir Arthur C. Clarke made a famous observation about space explorers discovering aliens: "If one considers the millions of years of pre-history, and the rapid technological advancement occurring now, if you apply that to a hypothetical alien race, one can figure the probabilities of how advanced the explorers will find them. The conclusion is we will find apes or angels, but not men."
Why? Consider the history of Planet Earth. Let the height of the Empire State building represent the 5 billion year life of Terra without Man. The height of a one-foot ruler perched on top would represent the million years of Man's existence. The thickness of a dime will represent the ten thousand years of Man's civilization. And the thickness of a postage stamp will represent the 300 years of Man's technological civilization. An unknown portion above represents "pre-Singularity Man", the period up to the point where mankind hits the Singularity/evolves into a higher form/turns into angels. Say another dime. Then they leave Terra to go to better things. Above that would be another Empire State building, representing the latter 5 billion years of Terra's lifespan without Man.
If you picked a millimeter of this tower at random, what would you most likely hit? One of the Empire State buildings, of course. So, assuming only one civilization develops on a planet, chances are the first-in-scout starship Daniel Boone will discover mostly planets that are currently empty of alien civilizations (but they might have an almost 50% chance to discover valuable Forerunner artifacts or other paleotechnology).
If you only use the section with an alien civilization, you have a ruler and two dimes worth of apes and angels, and a postage stamp edge worth of near Human civilization. If you pick a millimeter at random chances are you ain't gonna pict the edge of the postage stamp. Ergo: apes or angels, but not men.
For a further discussion of alien "angels", see the section Star Gods below.
Mark Alan Barner of Anaheim explains it this way:
If these figures do not suit you, this is your opportunity to play with the various values until more reasonable numbers appear. But you will be forced to live with the implications of any values you change.
In those science fiction novels that care about technical details, there are some solutions mentioned. They all rely upon some method to start all the alien species in a stellar region simultaneously. This means that they will all develop at roughly the same rate, and encounter each other at roughly the same technological level. Solutions include postulating some alien race at the dawn of galactic history seeding planets, or disasters like gamma-ray bursters destroying all life in a galactic zone, forcing the planets to start re-evolving life starting at the same point in time.
So what happens when our intrepid Terran star scouts discover a primitive intelligent alien species living with a tech level similar to Victorian England, or even as low as cave men? In a science fiction universe free of The Prime Directive, there will be a temptation to try and teach the aliens how to raise their tech level.
If the aliens are really primitive, the Terrans will find themselves doing that stale old "Chariots of the Gods" routine, playing the role of ancient astronauts. If the Terrans become extinct or suffer a new dark ages, they will be remembered in alien myth. And you can bet your last rocket that there is a TV Tropes page on the topic, though it is about the more common popular culture situation of aliens doing an uplift on us humans.
If the aliens are only somewhat behind Terran technology, idealistic members of the Galactic Peace Corps (or unscrupulous merchants who want to cash in on alien's lust for technology) can rapidly accelerate tech level advancement.
But there are a couple of pitfalls to this.
First off, an interstellar empire uplifting some aliens might find they have created a competitor. Do you want space barbarians? Because that's how you get space barbarians.
In Poul Anderson's Dominic Flandery stories the secret agent hero spends most of his time defending the decadent Terran Empire from the rival Merseian Roidhunate. Flandary's burden is due to the unfortunate fact that six hundred years prior do-gooder David Falkayn gave high technology to the Merseians so they could survive the radiation from a nearby supernova. No good deed goes unpunished.
On the other hand this might be a crippling influence on the alien culture. The concept was the subject of a 1899 poem by Rudyard Kipling called The White Man's Burden. This was a poem about Eurocentric racism and about the belief of the Western world that industrialisation is the way to civilise the Third World. In retrospect this policy has done far more harm than good. Science fiction writers are fond of the topic, ISFDB lists no less than five stories with the title of "Earthman's Burden".
Occasionally the Spaceman's Burden technique is done out of self defense. In Poul Anderson's Turning Point (see below) the Terran Survey discovers a race of primitive humanoids close enough to successfully breed with humans. They are light-hearted kindly race with about caveman-level technology but unfortunately with an average IQ of about 400. The Terrans freak out since the aliens are capable of becoming a threat to the galactic empire in a couple of hundred years, tops. Not because the aliens would harm the Terrans, they just out-class the Terrans so drastically that humans will be sidelined forever more.
Mercifully the Terrans find an option B, since option A involves saturation bombing the alien planet with enough nuclear warheads to turn it into a sphere of radioactive glass. Option B assimilates all the aliens into the galactic empire, scattering them into tiny groups within large populations of humans. There they will be dazzled by human culture and history, and have their own culture eradicated. A nasty example of Earthman's Burden, but is sure beats option A.
Forerunners are basically extinct angels. That is, they are a long-extinct star-faring alien civilization who left ruined cities and artifacts across the galaxy. In most science fiction they were somewhat more advanced technologically than the civilization the novel's protagonist come from, but not hyper-advanced Star Gods or something.
As a matter of terminology, they are commonly called "Forerunners", "Precursors", "Ancients", "Elder race", "Antecessors", "Progenitors", or "Predecessors".
Their thousand year old ruins are sobering, but their high-tech artifacts are generally far in advance of current tech levels and are of course both incredibly valuable yet incredibly dangerous. Archaeologists who stumble over such remains have a tendency to be killed by pirates, and their artifacts stolen.
And any forerunner installation that is still operating is insanely dangerous. It would be best to sell the rights to the site for lots of money, but do not go anywhere near it. Just ask Dr. Morbius.
In Arthur C. Clarke's The Fountains of Paradise he calls the first intelligence species who were born right after the big bang the Hunters of the Dawn. Ian Douglas (aka William Keith) in the Legacy Trilogy uses the same name for a currently exutant xenophobic species who is doing a Killing Star / Dark Forest Rule on the galaxy. They also are called the Xul, an old Sumerian word meaning "evil" or "great" but popular culture believes means "cosmic eldritch horror from the Necronomicon".
Now if a highly advanced alien civilization is extinct, the gold rush will be on as everybody realizes that incredibly valuable alien technology is literally just lying around for the taking. Xenoarcheologists will be busy excavating paleotechnology, then rushing to the patent office.
Actually alien technology is still quite valuable even if it is from a still living civilization whose tech level is on par with yours. In the real world corporations engage in industrial espionage of rival corporations all the time, even though the rivals are of more or less the same tech level. The value increases with the tech level of the alien stuff, regardless if the samples are paleotechnology from an archeological dig of a ten thousand year old Forerunner alien empire site or still-warm fragments of an alien warship that survived the most recent border skirmish.
Blue Tyson thinks the proper term is actually "xenopaleotechnology" and admittedly he does have a point.
Drawbacks will include quite a few unfortunate realities:
- The fact that everybody else has the same idea of harvesting paleotechnology and they probably have guns.
- The fact that "everybody else" includes other alien civilizations (some of which you have not encountered before) who probably also have guns.
- The tendency for the astromilitary to seize and classify as top-secret any paleotechnology you find in the name of national security, leaving you with nothing but the threat of their guns.
- The hazard that the Forerunner race you are looting may not be extinct but just mostly extinct. And who take a very dim view of tomb robbers. And have ultra-high-tech alien guns.
- The risk that abandoned alien installations could be guarded by still working deadly automatic defenses. Including computer controlled guns.
- The fact that monkeying around with such technology is insanely dangerous. Like an idiot child looking down the barrel and playing with the trigger of a gun.
Toying with alien technology can be very very dangerous. Especially if the aliens are more technologically advanced that you are. Even if the items are not deliberately booby-trapped, fiddling with, say, alien nanotechnology could result in the lab and most of the surrounding terrain melting into grey goo.
As an analogy, imagine an 1850's Victorian Era scientist dismantling a live nuclear reactor trying to figure out how it works. Radioactivity hadn't been discovered yet, much less nuclear fission. So they would be at a loss trying to explain the disaster that happened after they removed all the nuclear damper rods for closer examination.
Also in Larry Niven's short story A Relic of the Empire, the pirates learn the hard way about Tnuctipun stage trees. The Tnuctipun became extinct about one billion years ago, but living examples of their genetically engineered organic tech can be found on many planets. A stage tree looks like a tree, but can be used as a solid-fuel rocket booster. The pirates did not know about stage trees, so they tried to use one as firewood. The resulting explosion was most impressive.
In Algis Budrys novel Rogue Moon a still-working alien machine is discovered abandoned on Luna. The government expends hundreds of lives just trying to figure out how to walk through it without being killed in various weird ways. They figure once that has been done, they might be able to start investigating more important questions, like what the heck is the machine's purpose?
The legendary Gharlane of Eddore opined some precautions:
In the TV show Babylon 5, there was a corporation called Interplanetary Expeditions or "IPX". It was dedicated to researching the ruins of advanced civilizations that are now extinct, in the quest to find new technologies that they can patent and profit from. In other words: paleotechnology is their entire business model and revenue stream.
Jouni Pohjola notes that pretty much all of the above points are the reason for combat archeology (think Indiana Jones), as seen in Ken MacLeod's Newton's Wake. According to TV Tropes, combat archeology is mostly involved with jumping through wormholes and gunning down post-singularity alien robots.
In some of Andre Norton's space science fiction (noteably The X Factor) archeologists investigate wilderness planets looking for Forerunner artifacts. As with real-world archeologists they are focused on doing science, not on the fact that some of the artifacts will fetch a high price on the black market. Often when they discover some, they will abruptly be raided by "Jacks" (presumably short for "skyjacker") who will kill all the archeologists then plunder the site for anything valuable. Working Forerunner technology is valuable but rare, Jacks mostly rely upon the large number of mega-wealthy entitled individuals who will pay top dollar for unique Forerunner works of art and jewelry.
As far as technological advancement goes, there is a crude measure in the Kardashev scale.
|I||A civilization that is able to harness all of the power available on a single planet.||~1016|
|II||A civilization that is able to harness all of the power available from a single star.||~1026|
|III||A civilization that is able to harness all of the power available from a single galaxy.||~1036|
Carl Sagan estimated that humanity is currently around Type 0.7. A Type II would probably have some kind of Dyson sphere to harvest all the star's energy. Type III would probably be as far advanced from us as we are from one-celled amoebae. Terran space explorers would be wise to avoid areas where Type III civilizations are operating. Otherwise they might suffer a similar fate to that of an ant trying to cross an interstate highway. And for similar reasons: not because the Type III hates lower races, but because the lower races are so far beneath their notice that Type IIIs cannot be bothered to keep track of them. Do you ever think about the ants you run over in your automobile? Even with a Type II the situation might be analogous to a puppy-dog chasing a monorail.
Do check out this amusing article entitled Abusing the Kardashev Scale for Fun and Profit.
Things might get worse if a human explorer succeeded in attracting the attention of a Type III. They might react as you would, reaching for a cosmic spray-can of insecticide. Or use the explorer with the same lack of concern shown by cancer researchers to their laboratory rats. Maybe more like the lack of concern they show to the cells in their tissue cultures.In the Babylon 5 episode, "Mind War", surveyor Catherine Sakai's encounters a ship from a Type III civilization near the rim system Sigma 957. In a titanic display of cosmic force, the alien ship almost destroys hers like an automobile running over a beetle. She is rescued by Ambassador G'Kar. Later, she asks for answers.
Dr. Robert A. Freitas Jr. points out that it isn't just Type III civilizations that are dangerous, it is also Type III individuals. As civilizations technologically advance, members of that civilization have access to increasing amounts of energy. For example, your average medieval peasant could never hope to own something as destructive as an AK-47 automatic rifle or a few drums of fuel oil mixed with ammonium nitrate.
Imagine a family picnic. Some ants show up. Little Billy gets annoyed, tracks the ants back to their nest, dumps a cup of kerosene onto it and lights a match. The ant nest is annihilated. Billy gets called back to the picnic for ice cream.
Imagine a gathering of Type III entities. Some human starships show up. Little Beta-Lambda gets annoyed, tracks the starships back to Earth, and seeds it with five gigatons of neutronium antimatter. Earth is annihilated. Beta-Lambda gets called back to the gathering for euphoronic frequencies.
Once an alien species advances beyond us humans by say, oh, several hundreds of thousands or million years, they enter Charles Stross' classification of "Weakly Godlike Entities."
David Zindell's War in Heaven contains quite a few god-like entities who still occasionally notice humanity. However they are mostly concerned with efforts to circumvent the restrictions place upon them by the other god-like entities in the area.
A vaguely related concept is ultra-advanced civilizations that are not only so advanced they are god-like compared to us, but so advanced that we cannot interact with the civilization, only with its sub-systems, sub-sub-systems, or sub-sub-sub-systems.
In more detail: The Terran Empire might encounter an advance alien civilization, and engage in trade or battle with them. Only later they may discover that the "alien civilization" is the cosmic equivalent of a hyper-advanced entity's immune system. The entity would probably never become aware of the Terran Empire, much as you are never aware of the many tiny infections that are quietly taken care of by your immune system. The members of the "alien civilization" might be intelligent compared to the Terran Empire, but compared to the hyper-entity they are as unintelligent as your white corpuscles are compared to you.
Sub-systems make sense. After all, what sort of conversation could you personally have with an e. coli bacteria? It's not like you have a lot of common ground for a meeting of the minds. Or common communication, bacteria cannot hear speech and you are pretty blind to chemosensor messaging.
You'd need an intermediary. Probably several levels of intermediaries. An ant intermediary is closer to a bacteria but would still have a tough time talking to it.
The reassuring point is the fact that even though human being have a reasonably technologically advanced civilizations, amoebae still exist. So hopefully the weakly god-like entities will allow us to exist.
There is worse to come. It is possible that a hyper-advanced civilization could reach a state so advanced that we could not even detect their existence, much as amoebae could not detect us. Paul Hughes proposes a corollary to Clarke's Third Law: Any sufficiently advanced intelligence is indistinguishable from nature (see below).
There are such civilizations in Sir Arthur C. Clarke's 2001 A Space Odyssey, Greg Egan's Diaspora, and Paul J. McAuley's Eternal Light.
Most science fiction authors and many real scientists are of the opinion that any alien race that live underwater are going to have a real problem trying to advance out of the stone age and develop science. All that water is a problem. For one thing the water is most counter-productive if one is trying to discover fire and all the technology it enables.
The standard science fiction dodge is to postulate the aquatic aliens using organic technology, that is, doing radical genetic engineering on aquatic animals to make technology we would make with metal and electronics. Example: the Tyranids from the Warhammer 40,000 universe. Tyranid organic technology has the classic "warm, moist, skooshy and drips goo everywhere" along with a side order of "far too many sharp pointy bits." The shade of H. R. Giger approves of the design.
In the RPG 2300AD the alien species Pentapods are "an amphibious species with a preference for aquatic environments, with a biotechnological technical infrastructure (including starships that are massive living beings)". Their equipment works very well, but is usually damp and has to be regularly given food and water.
For computers and digital devices, slebetman and Journeyman Geek are of the opinion that the logical thing for an aquatic race to do is use Fluidics aka "fluid logic". This uses pneumatics and hydraulics instead of electronics to do analog and digital operations. Note that such devices are more or less immune to electromagnetic interference, ionizing radiation, and EMP; unlike electronic devices. Fluidics also will not suffer catastrophic electrical short circuits if immersed in sea water, also unlike electronic devices.
One of the main draw-backs of fluidic computers is the maximum clock frequency is only a tens of kilohertz, as compared to the gigahertz typical to computers such as the one you are using to read this website. This means an aquatic race using fluidics would try the parallel, multi-core approach much sooner than we did.
The second-most serious drawback is fluidics cannot be miniaturized anywhere near the scale of electronics. At a rough guess a halfway powerful computer will fill a room, much like old vacuum tube computers.
After the limits of fluidic computing were reached, it would be relatively easy to make the conceptual leap to optical computing.