galactic geopolitics

If the star-thick center of our galaxy abounds with ancient civilizations, are they arrayed in empires, democracies, or . . .?

By Ben Bova

Many people have wondered why we haven't been contacted yet by an alien race. Let's assume, for the moment, that such a contact is inevitable. Sooner or later they will come to visit Earth, or we'll stumble into them somewhere out among the-stars.
It seems almost certain that we won't find another intelligent race among the planets of our own solar system. Mars and Venus have been blasted from our hopes by the pitiless advance of knowledge. Mercury, Pluto, and our own Moon were never really counted on as habitats for intelligent races. And the Jovian planets are too alien for us—more about that later.
If we find another intelligent race, it will be out among the stars. Assuming that brainy aliens are out there, what are the chances of having any meaningful, fruitful contacts with them? Not just radio chats; not an occasional awe-inducing visit. I mean long-term, continuous interaction, the way we interact with the other nations of Earth: trade, cultural interpenetration, tourism, war, politics.
This all depends, of course, on the realization of interstellar transportation. More than that, it's got to be fast, cheap interstellar transportation. Otherwise there can be no large-scale interactions, no politics, between us and them.
Look at a parallel from Earth's history.
Since at least Roman times, western Europeans knew that China and the Orient existed. In the Middle Ages, Marco Polo got there and back, spreading wondrous tales that grew each year. But Europe did not interact with China in any significant way. True, Europe engaged in trade with the Middle East, and obtained goods from the Orient through Arab middle-men. The Middle East was close enough for Europeans to reach on foot, if they had to. Europe traded with the Middle East, exchanged scholarly works, and engaged in the pious slaughters called the Crusades.
But there was no direct trade, and no conflict, with China. Once deep-ocean sailing vessels were perfected, though, Europe did indeed contact China directly and treated the Orient to western technology, trade, disease and war. Today, of course, with intercontinental rockets and instant communications, everybody on the globe can interact politically with everybody else.
The same rules could apply to interstellar politics. There may be glorious civilizations in the Orion complex, or even as close as Alpha Centauri. But we know less about them than Hannibal knew about China. No action.
Even today, however, it's possible to visualize a starship based on technology that's within our grasp. Almost. Nuclear fusion engines could provide the thrust for a starship; engineering papers have been published showing how a multi-staged fusion ship could attain a healthy fraction of the speed of light. Cryogenics and biomedical engineering are teaming to produce means of suspending animation, so that travelers need not age during their trip.
With these ideas, it's possible to envision trips to the nearest stars within a human lifetime. When that happens, we'll be in the Marco Polo stage of interstellar contact: adventure, strange tales and artifacts. But no lasting political relations—for better or worse—with the neighbors.
There would be little tourism—except of the scientific variety—when a person can visit the exotic land only once in his life. It's hard to picture trade relations based on one shipment per generation. That's more like a cultural exchange. And even the sternest, most fearless general might feel foolish mounting an attack when he knew that he could never see the outcome in his own lifetime.
But the importance of Marco Polo's adventure was the spur it gave to Prince Henry the Navigator and others, including Columbus. And the importance of the first interstellar contact will be the stimuli it gives to Earth.
Now, it you corner a theoretical physicist in a quiet place and feed him a few drinks, the chances are you can get him mumbling about tachyons and things that go faster than light. Einstein's light barrier is starting to look—well, not leaky, perhaps, but at least a little translucent. Perhaps one day ships will be able to zip among the stars at speeds far greater than light's. Then we can be just as close and chummy with our stellar neighbors as we are today with the Chinese.
But we've got to realize that there will be many races out there that we simply cannot interact with in any useful way, even though we may reach them physically.
For example, we may find races very much younger than our own, with a correspondingly simple technology and social development.
Aside from letting them worship us as gods, there's probably little that they could do for us.
Oh sure, we'd want to study them and learn more about how intelligence and societies evolve. But what could they offer us, aside from their own artifacts and bodies? The artifacts might be interesting as examples of alien art. And no matter how lopsided or gruesome they appear, there will arise at least one art critic who will explain the hidden aesthetic values that everybody else has missed, and sell the stuff at a huge markup.
And their bodies?
We wouldn't use them for meat, for a number of reasons. If their bodies contained some precious chemical substances that couldn't be found elsewhere—like the key to immortality—we'd be in a lovely ethical bind. But the chances for that sort of thing are vanishingly small. We wouldn't need muscular slaves in our technological society; electricity's cheaper. About the only remaining possibility would be the white slave market, and the girls would have to be damned good to be worth the freight charges back to Earth. (There's always the pervert market if the girls aren't lovely, or if they aren't really girls. But that's really a small market.)
And what could we offer our younger neighbors? Only the things that would destroy their culture as surely as western Europe destroyed the American Indians. Hopefully, by the time we reach such a race, we'll have learned to observe them invisibly, from orbit, without letting them know we're present.
If we tried to meddle with a race only slightly younger than we are, their reaction might very well be the same as the Indians'—they'd resist as strongly as they could, possibly with guerrilla warfare. We're finding out in Vietnam exactly what Custer learned nearly a century ago: that "unsophisticated" and "simple" people can use your own technology and weapons against you very effectively. However, the Indians were either killed or absorbed into our culture, and the Vietnamese are going through the same process—that part of the world will never again be a simple, unspoiled, isolated Asian backwater. The same thing would probably happen to a younger race that fights against us: the very act of resisting us will destroy their native culture.
What happens when we contact a race much more advanced than we are? Same situation, only in reverse. We'd have precious little to offer them, except curiosity value. And they'd be wise enough not to tamper with us. I hope. Playing cowboys and Indians is no fun when you're on the foredoomed side.
A really far-advanced race would most likely go its own way aloof and serene, even if we tried our hardest to make friends. The picture that comes to mind is a puppy dog chasing a monorail train.
That leaves us with races that are more-or-less at our own stage of development, intellectually, morally, and technologically. That's where the fun—and the danger—will be.
How much of a range is covered by "more-or-less" is rather hard to say. For a thumbnail definition, let's put it at this: we will interact strongly with races that have something to gain from us, and vice versa. Cavemen and angels have so little in common with us that we won't affect each other very much. But other humans, even if they're purple and have sixteen legs, will provide the interstellar action.
Further, the races we interact with will probably come from planets sufficiently like our own to make this Earth attractive to them. And their homeworlds will be similarly attractive—or at least bearable—to us. This is why, even if intelligent Jovians exist, we probably will interact with them about as much as we do with the denizens of the Marianas Trench. There's just no common meeting ground. We don't have political relations with the dolphins, even if they are as intelligent as we are. We've got nothing to trade or fight over.
So it boils down to this: Although we may meet many strange and marvelous races among the stars, if they are physically or intellectually far removed from us we will have little but the most cursory of contacts with them—except for scientific expeditions. But races that can stand on our Earth with a minimum of encumbrance, and have a technology of a roughly similar level as our own, will be the races that we will talk with, laugh with, trade with, and fight with.
It may be that intelligent life is scattered too thinly through the galaxy to expect to find a race close enough to us—in distance and dispostion—to make interstellar politics likely. There's an oft-used analogy to illustrate the point.
The whole history of the planet Earth, and man, can be illustrated by the Empire State Building. Let the height of the building represent the time since the creation of Earth, roughly five billion years. Man has existed for about a million years; his racial life span can be represented by a three-inch child's block standing atop the building. A dime balanced flat on top of the block stands for the ten thousand years of man's civilization. Pasted on top of the dime, a postage stamp represents the length of time that man's had a reasonably vigorous science and technology.
What are the chances of meeting another race at our own stage of development, within the few centuries represented by the postage stamp? Or even within the ten-thousand-year thickness of the dime?
Remember, below that dime are the cavemen. Much above it, and we're in the realm of highly-advanced civilizations that would regard us as cavemen.
The chances for meeting neighbors we can truly appreciate seem pretty slim, when you think about that postage stamp. But let's look around anyway, and see what the real world holds for us.
There are thirty-seven known stars within five parsecs of the sun. Twenty-seven of them are single stars, eight are doubles, and two triples. Four of these stars are known to have "dark companions"—bodies of planetary mass that are too faint and small to be seen. In fact, two of the nearest five stars have planets. Since planets are so damnably difficult to detect, you might suspect that there are plenty of them orbiting the farther stars, but we just can't find them from here.
If the population of stars maintains about the same density as we go farther away from the sun, then there should be something like 300,000 stars within 100 parsecs of us; and 300 million stars within 1,000 parsecs. The Milky Way galaxy, as a whole, is estimated to contain some 100 billion stars.
We have no way of knowing how rare intelligence is. But in every cosmological test that's been applied to Earth and the solar system so far, we find utterly no evidence for our own uniqueness. Quite the opposite.
The sun is a rather average star. It appears that planets form around stars naturally. Planets at our temperature range should turn out to look roughly like Earth. Life on those planets should be carbon/water based—that makes use of the most abundant available material and the most energetic chemical reactions they can produce. Given sufficient time, the natural forces that led to the evolution of intelligence on Earth should lead to similar results on similar worlds.
The real question, then, is this: What are the ages of the stars around us? If they are about the same age as the sun, we might reasonably expect to find interesting neighbors.
The sun's age has been pegged at roughly five billion years. This is based chiefly on estimates of how much of the sun's original hydrogen fuel has been converted to helium in the thermonuclear fusion process that makes the sun shine.
Many of the stars around the sun are clearly much younger. Table 1 shows the spectral classes of typical stars, together with estimates of their stable life spans. By "stable life span" we mean the length of time that the star is on the Main Sequence. Stars go through an evolutionary path.
1. A protostar condenses out of clouds of interstellar gas and dust. The protostar, a dark clump of mostly hydrogen, is about a light-year wide. It contracts rather rapidly, falling inward on itself under the gravitational force of its own mass. As it contracts, density and temperature at the core rise steeply.
2. When the density and temperature at the core reach high enough values for hydrogen fusion to begin, the star becomes a stable member of the Main Sequence. Its size and surface temperature remain stable as long as hydrogen fusion provides the star's energy source.

3. The bigger and more massive the star is, the hotter it is, and the faster it runs through its hydrogen fuel supply. When the hydrogen runs low, the star begins burning the helium "ash" that's left in its core. Helium fusion runs hotter than hydrogen fusion. The star's core temperature soars, and the outer layers of the star are forced to expand. The star leaves the Main Sequence and becomes a Red Giant. Helium fusion creates carbon, oxygen and neon. When the helium runs low, the star turns to burning these heavier elements. The star continues to create and then burn constantly-heavier elements; all the while its core is getting hotter, and its outer envelope is swelling enormously.
4. Eventually the star reaches a critical point. It explodes, either with the relative mildness of a nova, or with the star-shattering fury of a supernova. The eventual result is a white dwarf star or, in some cases, an even smaller, denser neutron star—or pulsar.
As you can see, the star remains stable only for a certain period of time, depending on its mass and surface temperature. After that, things get pretty dramatic for any planet-dwelling life nearby.
Hot blue giants such as Rigel and Spica won't be stable for more than 400 million years; the life span of a stellar gnat, despite their brilliance—or, really, because of it. By extrapolating backwards, moreover, we can see that these stars can't possibly be more than 400 million years old. Probably they're a good deal younger. Perhaps the dinosaurs never saw Rigel.
We know that it took about five billion years for intelligent life to develop on Earth. As a rule of thumb—lacking any better information—we can say that we shouldn't expect to find intelligent life on planetary systems of stars less than five billion years old. Thus, stars such as Rigel, Spica, and probably even Sirius and Vega, might be ruled out as possible abodes for intelligent life.
The stars that are smaller and cooler than the sun, such as the K and M dwarfs, have enormously longer life expectancies. But are they older than the sun? There's no easy way to tell.
We might be able to get some clues to their age by looking further afield. Consider the "geography" of the Milky Way galaxy.
The Milky Way is, of course, a spiral galaxy much like the beautiful spiral in Andromeda. The core of our galaxy is presumably thick with stars, but we never see them because they're hidden behind dust clouds. However, by looking at other spirals, and comparing their structure to the optical and radio-telescope evidence we have about the Milky Way, astronomers have made a reasonable picture of how our galaxy is built.
The core of our galaxy is rich with stars. These stars are predominantly much older than the sun; red giants are common. There is very little interstellar dust in the galaxy's central region, if any.
Out in the spiral arms, where we are, there is much dust. As we've already seen, this dust is the budding—ground for new stars. And, indeed, we see blazing young giants such as Rigel and Achernar and Spica only in the spiral arms.
Because the two regions of the galaxy seem to have different stellar constituencies, astronomers refer to the types of stars found in the spiral arms as Population I and those found in the core as Population II. Population I stars are young, the brightest members tend to be blue giants and supergiants, and they have a relatively high proportion of heavy elements in their make-up. Although the amount of heavy elements in them is never more than one per cent, the Population I stars are said to be metal-rich. Population II stars are old, the brightest members are red giants, and they are mostly metal-poor.
The metal content of a star is an important clue to its age. But before we go into that, we should note that cosmologists have estimated the Milky Way galaxy to be between 10 and 20 billions years old. That is, from two to four times the age of the sun. The universe, as a whole, is presumed to be of approximately the same age as our galaxy.
Now then, why are the stars in the galaxy's core metal-poor and the stars in the spiral arms metal-rich? Because the elements heavier than hydrogen have been created inside the stars. It works like this:
Consider the Milky Way before there were any stars. An immense dark cloud of gas, at least 30,000 parsecs across. The gas might have been entirely hydrogen, or it might have been a hydrogen/helium mixture. The Steady State cosmology leans toward all-hydrogen; the Big Bang would produce maybe 10 per cent helium.
The first stars to form, then, had no heavier elements. From lithium to iron, the heavier elements were cooked inside these stars as they went from hydrogen-burning to helium-burning to heavier-element burning. Some of these stars went supernova. In those titanic explosions, even heavier elements were created, beyond iron, all the way up to uranium and even beyond. There's some evidence that the so-called "man-made" element, Californium 254, was present in the supernova of 1054, which we know today as the Crab Nebula.
So the first generation of stars in the Milky Way began with only hydrogen—and maybe some helium. But they produced heavier elements and spewed them back into space to form part of the building material for the next generation of stars.
Most astrophysicists believe that the sun is at least a third-generation star. Beware of a clash of jargon here. Population I stars are late-generation, younger stars. Population II stars are older, early generation. II came before I, historically.
What's all this got to do with meeting the neighbors?
Just this: The first-generation stars could not produce life. At least, nothing we'd readily recognize as life. There was no carbon, no oxygen, nothing but hydrogen and perhaps helium. If those first stars had planets, they'd all be gas giants like Jupiter and Saturn, only more so; there'd be no methane or ammonia or any other heavier element or compound. Second-generation stars? It's possible that they'd have most of the heavier elements, including the carbon, oxygen, nitrogen, potassium, iron and such that we need for biochemistry. Planets of such stars might be able to support life—even our own kind of life—if these heavier elements are present in sufficient quantities. And if life has appeared on such planets, there's no reason to suppose it wouldn't eventually attain intelligence. Certainly the long-lived red dwarfs provide plenty of time for intelligence to develop: five billion years plus.
Let's grant that an intelligent race could arise on a second-generation star's planetary system. Could such a race develop a high civilization and technology? It all depends on the abundance of natural resources. Fossil fuels should be plentiful. But what about metals? Our technology is built around metals. Even our history rings with the sounds of the Brass Age, the Iron Age, the Steel Age, the Uranium Age.
The astronomical evidence is indistinct here. Astrophysical theory shows that second-generation stars should have a lesser abundance of heavy metals than we third-generation types do. But certainly there should be some metals, spewed out by first-generation stars.
In fact, if the first-generation stars included the same ratio of very-short-lived supergiants that we see in the heavens today, and these supergiants ended their brief (10 million years) lives in heavy-metal-producing supernova explosions—then there could be some favored second-generation stars that have a high percentage of metals in their make-ups. But on the whole, it would seem that the chances of finding a metal-rich second-generation star are rather poor. Certainly astronomical observation shows that these older stars tend to be metal-poor.
But how much metal is enough? There's no way to tell. Planets of second-generation stars might have iron mountains and gold nuggets lying on the open ground. Or they might have very little available heavy metals. Availability is the key, of course. Our own Jupiter might easily have more iron in it than Earth does. But if it's there, it's mixed in with 317.4 Earth masses of hydrogen, helium, methane, ammonia, and whatnot. Try to find it! And use it!
If there are planets of second-generation stars where heavy metals—iron, copper, silver, tin, gold—are abundant and available, those planets could be sites for highly advanced civilizations. But suppose intelligent races arise on planets where heavy metals are not available? What then?
First, we should clearly realize that intelligence per se doesn't depend on heavy metals. Mankind rose to intelligence with only wood, clay, rock and animal products as his natural resources. In a way, man went through a Ceramics Age—clay, mostly—before he discovered metals. In fact, it was wood and ceramics that allowed man to handle fire safely and usefully. Only after fire had been tamed did metals become possible and useful.
The history of man's technology shows that once metals became available, the race took a giant leap forward. And our own history is the only evidence we have to go on. Metals allowed men to build effective plows. And swords. And chariots. Even today our skyscrapers and computers and engines and spacecraft and weapons and refrigerators are made of metals. Metals are strong, tough, and cheap. And they are easily found and easily worked, with low-grade fire.
Could a race build skyscrapers and spacecraft without metals? Well, today there are many "space age" materials such as plastics and boron-or carbon-fiber composites. But take a look at the machinery that produces them: stainless steel, copper, brass. Modern technology is showing that there are nonmetallic materials that can outperform metals in strength, weight, and many other parameters. But these materials could not have been developed before an extensive Metal Age of technology. Cavemen, or even the ancient Greeks, could not have produced boron-fiber materials or modern plastics or ceramics—because they didn't have the metals to produce them with!
Would a race on a metal-poor, second-generation planet be stymied in its attempts at technology? Who can say? All we know for sure is that our technology depends on metals, and until metals were available, we had no civilization or technology beyond that of the Neolithic.
And another vital point. Again, we have nothing but the history of our own race to go on, but it looks very sure that without metals such as iron and copper, we would never have discovered the world of electromagnetic forces.
Man's discovery of magnetism depended on the abundance of iron on this planet. And from the beginning, man's experiments with electricity have needed lead, zinc, copper, et cetera. It's hard to see how the whole chain of study and use—from Volta and Faraday and Hertz on through to radio telescopes and television and superconducting magnets—could have happened in a metal-poor environment. And where would our technology be without electromagnetics? Early Nineteenth Century, at best. (Unless psionics had been legitimized, found to work, and filled the gap.)
So where does that leave our metal-poor, second generation races? It just might be possible to build a complex technology completely out of nonmetals; but tribes on Earth that never had easy access to heavy metals have never developed a high technology. Coincidence? Maybe. Could a strong technology be built around the lighter metals, such as lithium, beryllium or boron? Ironically—pardon the pun—these metals are much less abundant in the universe than the heavier—iron and up—metals. And for good reason: they make excellent "fuel" for the nuclear fusion reactions that power the stars. So the chances of having a sophisticated civilization based on light metals seem slim indeed. If our own history is any criterion, it's the heavy metals that lead to high technology. And they form a natural gateway to the world of electromagnetic forces and the whole concept of "invisible" forces that act over a distance: magnetism, electricity, gravity, nuclear forces. You can trace a direct line from man's use of heavy metals to electromagnetics, nuclear power, and—eventually, I hope—antigravity.
It looks, then, as if the oldest stars in the Milky Way, those first-generation members that are still around at the galaxy's core, have always been lifeless.
For the second-generation stars the situation is much cloudier: either they have enough metals to develop high civilizations or they don't. If they do, their races are so much older—and hopefully wiser—than we are that they won't interact with us at all. We'd probably bore them to whatever they have for tears. If they don't have metals, then they're probably gamboling innocently through some local version of Eden, and we should leave them strictly alone.
There goes the long-standing vision of an immense galactic empire, run by the older and wiser races of the Milky Way's ancient core. Like the steaming jungles of Venus and the bone-chess cities of Mars, the empire at the center of the galaxy doesn't exist. Either the older races are so far advanced that empires are meaningless trivialities to them, or they're so metal-starved that they never got past the "Me Tarzan" stage of development.
Remember, the first empires on Earth, in the Tigris-Euphrates plain, didn't get started until the local heroes had bronze swords, metal-shod horses and chariot wheels and gold helmets—at least, for the captains of the winning team.
It's a shame. It would have been pleasant to talk to them—those incredibly ancient, benign, understanding super-beings from the galaxy's core. It's sort of shattering to realize that, if they exist, they wouldn't want to be bothered with our chatterings any more than a crotchety grandfather wants to put up with a squalling baby.
On the other hand, we've all seen plenty of stories in which a race only slightly advanced over us—say a few centuries, technology-wise—does a very ruthless job on Earth and its people. So maybe we should be glad if there's no one older who's interested in us.
Now then, where do we stand? There may be older, second-generation races out there, but they just don't care about us. As far as they're concerned, we're on our own. There may be third-generation races closer to us, both geographically and intellectually. If they're ahead of us by even as much as a mere century or two, they could be decidedly dangerous. Imagine the job we could do with today's technology against Napoleon!
Of course, an older race might be benign. If so, it would probably not reveal its presence to us, for fear of damaging irreparably our pscyhes and culture, until we were ready to meet them on a more equal footing. The "equality" point might come when we've achieved an interstellar drive for ourselves.
If an older race is not benign, but aggressive, it would probably want to gobble us up before we had reached the interstellar flight stage. That way, we'd be more or less alone and defenseless against them. So, if we get visited by aliens from another star before we go star-roving ourselves, my hunch would be that their intentions might be far from pleasant—no matter what they say!
But the chances of meeting another race that's even within a few centuries of our present stage of development seem extremely remote. And remember, the sun is one of the oldest third-generation stars around this part of the galaxy. There might not be any older races within many kiloparsecs of us.
Could it be that we are the oldest, wisest, farthest advanced race in this neck of the stellar woods?
Now that's a truly sobering thought!