Probably the Gateway prospectors should have taken it for granted that hospitable, Earth-like planets were bound to be a lot rarer than malignant ones. Their own solar system made that much clear. Anyway, all those years of listening to Project Ozma radio signals should have taught them that much.
What they found out was that there was a myriad different kinds of hostile environments. There was Eta Carina Seven; it was the right size, it had air, it even had water-when it wasn"t frozen, anyway. But Eta Carina Seven had a highly eccentric orbit. It was pretty well iced over, though still on its way to its frigid aphelion, and there were terrible storms. One lander never came back at all. Three of the others were damaged, or lost at least one crew member.
Mendoza was not the only one to find a planet that looked nice but turned out to be poison. One pleasing-looking planet was well vegetated, but the vegetation was all toxicodendrons. They were far worse than Earth"s poison ivy. The slightest touch meant blisters, agonizing itching pain, and anaphylactic shock. On the first mission to it everyone who landed on its surface died of allergic reactions, and only the crew member who stayed with the ship in orbit was able to get back to Gateway.
But once in a while-oh, very seldom-there was a good one.
The happiest of all, in the first decade of Gateway"s operation, was the mission of Margaret Brisch, usually called "Peggy."
Peggy Brisch went out in a One. She found what was really another Earth. In fact, in some ways it was nicer than Earth ever was. Not only were there no toxicodendrons to kill anyone who touched, or any nearby star with lethal radiation, there were not even any large, dangerous animals.
There was only one thing wrong with Peggy"s Planet. It would have been an ideal place to take Earth"s overflow population, if only it hadn"t been located a good nineteen hundred light-years away.
There was no way to get to it except on a Heechee ship. And the largest Heechee ship carried only five people.
The colonization of Peggy"s Planet would have to wait.
First and last, the Gateway prospectors found more than two hundred planets with significant life. It drove the taxonomists happily crazy. Generations of doctoral candidates had dissertation material that could not fail to win their degrees, and hard work simply to find names for the thirty or forty million new species the prospectors found for them.
They didn"t have that many names to spare, of course. The best they could do was a.s.sign cla.s.sification numbers and note the descriptions. There was no hope of establishing genera or even families, although all the descriptions were fed into the databanks and a lot of computer time went into trying to discover relationships. The best descriptions were generic; DNA, or something like it, was pretty nearly universal. The next best were morphological. Most living things on Earth share such common architectural features as the rod (indispensable for limbs and bones in general) and the cylinder (internal organs, torsos, and so on), because they provide the most strength and carrying capacity you can get for the money. For the same reasons, so did most of the galaxy"s bestiary. Not always, though. Arcangelo Pelieri"s crew found a mute world, full of soft-bodied things that had never developed bones or chitin, soundless as earthworms or jellyfish. Opal Cudwallader reached a planet where, the scientists deduced, repeated extinctions had kept knocking off land animals as they developed. Its princ.i.p.al creature, like Earthly pinnipeds and cetaceans, was a former land-dweller returned to the sea, and nearly everything else was related. It was as though Darwin"s finches had colonized an entire planet.
And so on and so on, until the explorers began to think they had found every possible variation on water-based, oxygen-breathing life.
Perhaps they almost had.
But then they found the Sluggards-the same race the Heechee had known as the Slow Swimmers-and took another look at the hitherto unimagined possible flora and fauna of the gas giants.
So they had been wrong in their basic a.s.sumption that life required the chemistry of a solid planet to evolve. That was a shock to their scientists . . . but not nearly the shock that came a bit later, when they discovered that life didn"t require chemistry at all.
Planets were nice, and pictures of stars were nice, but what everyone really wanted were some more samples of Heechee technology. There wasn"t any doubt that there was some of the stuff waiting to be found-somewhere. The ships proved that. The little morsels picked up in the tunnels of Venus had proved it even earlier. But they just whetted the human appet.i.te for more of these wonders.
Fourteen months after the program officially started, a mission got lucky.
Their ship was what was generally called a Five, but the system had not yet begun to operate in a standardized way. This time only four volunteers went along. They were officially chosen by the four Earth powers that had established the Gateway Corporation (the Martians took an interest later), and so they were an American, a Chinese, a Soviet, and a Brazilian. They had learned from the experience of Colonel Kaplan and others who had gone before. They brought along enough food, water, and oxygen to last them for six months; they were taking no chances this time.
As it happened, they didn"t need all those provisions. Their ship brought them back in forty-nine days, and they didn"t come back empty-handed.
Their destination had turned out to be an orbit around a planet about the size of the Earth. They had managed to make the lander work, and three of them had actually used it to set foot on the surface of the planet.
For the first time in human history, men walked on the surface of a heavenly body that was not part of the Sun"s entourage.
First impressions were a bit disappointing. The four-power party discovered quickly enough that the planet had had some bad times. Its surface was seared, as though by great heat, and parts of it made their radiation detectors squeal. They knew they could not stay there long. But a mile or less from the lander, down a barren slope from the mountaintop mesa where they had landed, they found some rock and metal formations that looked artificial, and poking around them they dug up three items they thought worth bringing home. One was a flat tile with a triangular design still visible on its glazed surface. The second was a ceramic object about the size of a cigar, with thread markings-a bolt? The third was a yard-long metal cylinder, made of chromium and pierced with a couple of holes; it could have been a musical instrument, or part of a machine-even a Hilsch tube.
Whatever they were, they were artifacts.
When the four-power crew proudly displayed their trophies back on the Gateway asteroid, they created an immense stir. None of the three looked like a major technological breakthrough. Nevertheless, if such things could be found, then there were certainly others-and no doubt things that would be of a lot more practical value.
That was when the interstellar gold rush began in earnest.
It was a long time before anyone got that lucky again. Overall, the statistics on missions out of the Gateway asteroid showed that four out of five trips came back with nothing to show but some pictures and instrument readings. Fifteen percent never came back at all. It was only one ship out of twenty that brought back any tangible piece of Heechee technology, and most of those things were only curiosities-but the very few that were more than curiosities were treasures beyond price.
They were few and far between, to be sure. The exploration of Venus had shown that was probable, for in all the hundreds of miles of Heech~e tunnels under the surface of the planet Venus no more than a dozen gadgets had been found.
To be sure, some of those meant big profits for those who learned to copy them. The anisokinetic punch was a marvel. Hammer it on one end, and the force of the blow came out at the side. What was even more marvelous was that scientists managed to figure out how it worked, and its principle had applications in every area of construction, manufacture, and even home repair. The fire-pearls were a mystery. So were the so-called prayer fans.
Then, of course, humans reached the Gateway asteroid, and that fleet of ships was the biggest treasure trove of all. But all there was on the asteroid were the ships themselves. The ships were empty of anything but their operating gear. The whole asteroid was empty, almost surgically clean . . . as though the Heechee had deliberately left the ships but removed everything else that could be of value.
Over a period of twenty years and more the Gateway explorers went out to seek whatever could be found. They came back with pictures and stories, and kinds of living things and minerals; but of Heechee artifacts they found very few.
That was why so many Gateway prospectors died poor-or just died.
MISSION TOOLBOX.
Some also died rich, without knowing they had become rich. That was the case in one of the biggest finds. Unfortunately, it did three of its five discoverers little good, because they did not survive the trip.
The mission started with three Austrians, two brothers and an uncle, using the last of an inheritance to pay their way to Gateway. They were determined to ship out only in an armored ship. As the only such vessel available was a Five, at the last minute they recruited a South American, Manuel de los Fintas, and an American, Sheri Loffat, to go with them.
They reached a planet; they landed on the planet; they found nothing much there. But their instruments showed Heechee metal somewhere around, and they tracked it down.
It was a lander. It had been abandoned there, heaven knew when. But it was not empty.
The biggest thing they found in the lander was a stack of Heechee metal hexagonal boxes, not more than half a meter across and less than half that tall, weight twenty-three kilograms. They were tools. Some of the items were familiar, and useless as far as anyone had been able to tell: almost a dozen little prayer fans of the kind that littered so many Heechee tunnels and artifacts. But there were also things like screwdrivers but with flexible shafts; things like socket wrenches but made out of some soft material; things that resembled electrical test probes but turned out to be spare parts for other Heechee machines.
It was a grand success. They wound up millionaires-or, at least, the survivors did.
That find was lying right on the surface of the planet. But before long the Gateway prospectors learned that planet surfaces were not the most likely places to look for examples of Heechee treasures. Under the surface was much, much richer.
One thing was clear early on about the vanished Heechee: they liked tunnels. The Heechee tunnels that honeycombed parts of the planet Venus weren"t unique. As explorations retraced the old interstellar trails they found examples of them everywhere the Heechee had gone. The inside of the Gateway asteroid was a maze of tunnels; so were the "other Gateways" that turned up as the explorations progressed. Nearly every planet the Heechee had left any signs on at all had tunnels dug into it, lined with Heechee metal. Where the surface conditions were unpleasant (as on Venus), the tunnels were extensive and complex. But even so fair a world as Peggy"s Planet had a few of them. The anthropologically trained scientists called Heecheeologists, trying pa.s.sionately to figure out what these vanished people were like, supposed that they came from a burrowing race, like gophers, rather than an arboreal one, like people. The Heecheeologists turned out to be right ... but it was a long time before any of them were sure of it.
All the tunnels looked pretty much alike. They were lined with a dense, hard, metallic substance that glowed in the dark: it was called Heechee metal. In the first tunnels humans encountered, on Venus and on the Gateway asteroid itself, the glow was a pale blue. Blue was by far the commonest of Heechee-metal colors, but inside the Heechee ships there were some parts that were made of a golden Heechee metal, and later on the explorers found Heechee metal that glowed red or green.
No one really knew why Heechee metal came in different colors. The Heecheeologists were not much help. All they could tell about the occasional variation in the color of Heechee metal was that it seemed clear that the tunnels of bluish metal were generally the ones poorest in Heechee artifacts: Gold, red, and green almost always had more treasures to be found by the explorers.
Of course, until men and women began to learn how to explore the galaxy in the Heechee ships, they were limited to the blue-glowing tunnels of Gateway and Venus. And in them the treasures to be found were spa.r.s.e, though sometimes of great value. In the tunnels found on the most productive planets, the metal walls started out blue, and then became another color just where the largest collections of useful tools were located. No one knew why ... but then, no one knew much about the Heechee at all, just then.
MISSION HEATER.
Wu Fengtse had chosen to ship out in a One. That had its advantages, and its faults. The biggest advantage was that if there was nothing to land on, and the only reward would be some kind of science bonus for observations, he could keep it all himself.
It didn"t happen that way, though. When he came out of FTL drive, he found himself in orbit around a more or less Earth-type planet.
So Wu had to face the problem of every single prospector: If he took his lander down to the surface of the planet, no one would be left in the ship. If anything happened to him on the surface, no one would be there to rescue him. He was completely on his own.
His other problem was that "Earth-type" was only a very approximate description of the world he had to explore. "Earth-type" meant that the planet was about the right size, and that it had an atmosphere and a temperature range that permitted water vapor in the air, liquid water in its shallow seas, and frozen water on its colder parts. It wasn"t heaven, though. Its colder parts included nearly all of the planet. Its best zone was around the equator, and that was not much unlike Labrador.
If there ever had been anything on any other part of its surface, it was now covered with thousands of feet of ice. There was no point in landing on a glacier; Wu had no way of digging down to whatever lay under it. After a lot of searching Wu found a bare outcropping of rock and landed there. By then he wasn"t very optimistic anymore. The environment did not look promising-but his instruments gave him better news than he had expected.
There was a tunnel.
Wu had practiced tunnel entry. He even had the necessar~y equipment. Sweating the big power drills into place and erecting the bubble shelter that would protect it from the outside air took all of his strength, and enough time to use up the bulk of his supplies. But he got in.
It was a blue-lined tunnel.
That was discouraging, but as he moved along it he caught glimpses of other colors. When he got to a red segment he found a huge machine-later on, experts decided from his description that it had been a tunnel digger-but he didn"t have the strength to lift it, or the equipment (or the courage, for that matter) to try to hack pieces off it. In the green part of the tunnel were bolts of what Wu first took to be cloth but turned out to be the crystalline sheeting the "prayer fans" were made of. In the gold was-the gold.
There were stacks and stacks of little hexagonal Heechee-metal boxes, all sealed. All heavy.
Wu couldn"t carry them all, and his energy was running out. He managed to get two of them back to the lander and then took off, with every intention of coming back in a Five.
Unfortunately, when he was safely back on Gateway it turned out that no Five would accept the program that had brought him there. Neither would any of the Threes or Ones that were lying in their docks, waiting for crews.
It seemed that only the One he had found the planet in would take him back.
That didn"t work, either. Before he could requisition it and ship out again someone else had taken his One-on a one-way trip.
All Wu had, then, was the two little boxes, but it was their contents that bought him a home in Shensi province. One of them contained heater coils. They weren"t operating, but they were close enough to working condition so that human scientists managed to tinker them going. (Later on better and bigger ones were found on Peggy"s Planet, but Wu"s were still the first.) The other box contained a set of gauges for measuring microwave flux.
Scientists puzzled over the gauges very diligently, but they asked the wrong questions. What they labored to ascertain was how they worked. It did not occur to any of them, just then, to wonder why the Heechee were so curious about millimeter microwave flux. If it had it might have saved a lot of people a lot of unnecessary confusion.It was in a tunnel on an otherwise unprepossessing planet that one prospector found the first specimen of the Heechee tunneling machine. It was in a tunnel on the Luna-like satellite of a distant gas giant planet that another found the "camera" that the so-called "fire-pearls" served as "film." And it was in a tunnel that Vitaly Klemenkov found the little device that sparked a whole new industry-and earned him only a pittance.
Klemenkov"s is a kind of hard-luck story. What he found was what human scientists came to call a "piezophone." Its main operating part was a diaphragm made out of the same material as the "blood-diamonds" that had littered the tunnel of Venus and many others. The material was piezoelectric: when squeezed it produced an electric current, and vice versa. Of course, there were plenty of blood-diamonds around, though no one had known before Klemenkov that they were basically raw material for piezoelectric devices. Klemenkov had visions of untold riches. Unfortunately, the main communications laboratories on Earth, subsidiaries of the cable and telephone and satellite corporations, developed the Heechee model into something they could manufacture themselves. Klemenkov took it to court, naturally-but who could fight the lawyers of the biggest corporations in the world? So he settled for a small royalty-hardly more, in fact, than an average emperor"s income.
There was one other splendidly productive variety of place to find Heechee treasures. But no one knew that at first, although if they had thought of the example of Gateway itself they might have deduced it, and certainly no one knew that these rich lodes were, actually, traps. A woman named Patricia Bover was the first Gateway prospector to report finding one-and, as was so often the case, it did her little good.
MISSION FOOD FACTORY.
Patricia Bover set out in a One. She had no idea where she was going. She was pleased that it was a relatively short trip-turnaround in seven days, destination in fourteen-and astonished when her instruments told her that the tiny, distant star that was the nearest to her was actually the old familiar Sun.
She was in the Oort cloud of comets, far beyond the orbit of Pluto, and she was docking on what was clearly a Heechee artifact. A big one: it was eight hundred feet long, she estimated, and it was like nothing anyone had ever before reported finding.
When Bover got into the thing and looked around, she realized she was rich. The thing was absolutely stuffed with machines. She had no idea what they did, but there were so many of them that she had no doubt at all that some of them, maybe many of them, would be as valuable as any heater or tunneler or anisokinetic punch.
The bubble burst when she found out she couldn"t get back to Gateway. Her ship wouldn"t move. No matter what she did to the controls it remained inert. It not only would not automatically return her to her port of origin, it wouldn"t go anywhere at all.
Patricia Bover was stuck, some billions of miles from Earth.
As it turned out, the artifact was still operating; in a part of it that Pat Bover never saw, it was actually still producing food, half a million years after it was left there by the Heechee, out of the raw materials of the comets themselves-carbon, hydrogen, oxygen, and nitrogen, the basic elements that make up most of human diet and body. If Pat had known that-if she had forced herself to investigate the thing-she might have lived quite long while there. (Though not long enough for anyone to get there to rescue her, of course.) She didn"t know that, though. What she knew was that she was in serious trouble. What she did was send a long radio message to Earth, twenty-five light-days away, explaining where she was and what had happened. Then she got into her lander and launched it in the general direction of the Sun. She took a knockout pill and crawled into the freezer . . . and died there.
She knew the odds were against her. She wasn"t properly frozen for any hope of revival, and anyway the chances were small that anyone would ever find her frozen body and try to revive it. And, as a matter of fact, no one ever did.
The Food Factory wasn"t the only Heechee artifact in s.p.a.ce which doubled as a trap for the unwary. There were altogether twenty-nine of these large objects-they were called "collection traps"-somewhere in the galaxy.
Patricia Bover"s ill-fated find in the Oort cloud wasn"t the only artifact the Heechee had left up and running. It wasn"t even the only one to which a Gateway s.p.a.ceship had a preprogrammed course. There was that other orbiting parking garage for s.p.a.ceships that the Heechee had left around another star, far away-almost as big as Gateway; humans called it Gateway Two.
And then there was Ethel"s Place.
Ethel"s Place was discovered by an early one-woman mission. (The woman"s name was Ethel Klock.) Then it was rediscovered by a group of Canadians in an armored Three; and re-rediscovered by another One, whose pilot was a man from Cork, Ireland, named Terrance Horran. The Canadians didn"t just discover the artifact. They also discovered Ethel Kiock, because she was there when they arrived. When Horran arrived he discovered them all, and later parties kept on discovering those who had come before, because they all stayed right there. As with Pat Bover on the Food Factory, it was a one-way destination for them all. There wasn"t any return. The boards on all the ships nulled themselves on arrival.
They had no way of getting off the artifact.
That was a great pity in the minds of all of them, because Ethel"s Place was a wonder. It was an object about the size of a cruise liner, but without any engines of any kind that they could discover. Ithad food machines, and air and water regenerators, and lights; and they were all still operating, even after all the millennia that had pa.s.sed. The Heechee machines were built to last. Morever, there were a lot of astronomical instruments on Ethel"s Place, and they were working, too.
The castaways had plenty of time to investigate their new home. They had nothing else to do. The food machines fed them; their lives were not threatened. They actually made quite a self-sufficient little colony. They might even have made it a permanent one, with generations of settlers coming along, if Klock had not been past the age of childbearing by the time the Canadians got there, or if the later arrivals had included any females.
They realized early that Ethel"s Place was a kind of astronomical observatory.
What the observatory had been put there to observe was obvious at once. Ethel"s Place was in orbit at a distance of about a thousand AU (which is to say, about five light-days) from a rather spectacular pair of astronomical objects. Binary stars weren"t particularly interesting. This pair was unique. One of them was a fafrly standard kind of star, though a rarish one-a hot, pulsating, super-giant specimen of the young and violent cla.s.s called type F. That by itself would have been worth a little bonus money-if they had had any way of reporting it-but its companion was a lot stranger. The type-F star had a tilted ring of hot gas around it, suggesting that it was still in the process of reaching its final stage of starhood. The companion was all gas, and not very hot gas, at that-an immense, nearly transparent disk of the stuff.
The more they looked at it, the stranger it got. Stars were supposed to be spheres. They weren"t supposed to be disks. The diskshaped companion was hard to observe anyway, even with Heechee optics. Visually, it looked like nothing more than a faint scarlet stain on the sky. It was too cool to radiate much. The Heechee instruments couldn"t tell them its temperature, because the Heechee had not been thoughtful enough to provide conversion tables into Cel sius or Kelvin or even Fahrenheit scales. Klock"s own best estimate was that it ran to maybe five hundred K-far cooler than the surface of Venus, for instance; cooler even than a log burning in a fireplace on Earth.
The best time to see it, they discovered, was when it was eclipsing the type-F companion star. Because the orbit of Ethel"s Place was retrograde with respect to the disk, such eclipses happened more often than they would have if their artifact had somehow been stationary in the sky. They still did not happen very often. Ethel Klock had observed one eclipse alone, shortly after she landed. By the time of the next eclipse she had the Canadians and Horran to share the sight with, but that was more than twenty years later.
The story of Ethel"s Place did finally have a happy ending for its captives-well, fairly happy. Ultimately human beings did learn how to make Heechee ships go where they wanted them to go. Shortly thereafter an exploring party in better command of its ship found the five castaways, and they were rescued at last.
It was a little late. By then Ethel Klock was in her seventyeighth year, and even Horran was nearly fifty. They didn"t even get their science bonuses, either. The Gateway Corporation had long since stopped issuing them, because the Gateway Corporation no longer existed.
They would have been out of luck anyway, they found, because even if they"d gotten back early they would not have collected much in the way of financial rewards. That binary star system was unfortunately not a new discovery. Indeed, it turned out to be a system that had been very familiar to astronomers on Earth, because of those very puzzling characteristics. The name of the star was Epsilon Aurigae, and its mysteries were no secret. They had been unlocked by human astronomers with conventional instruments when the binary"s cool orbiting disk had pa.s.sed between Earth and its type-F primary in the eclipse of the year A.D. 2000.
It was more than fifty years between the time the first Gateway prospector landed on one of those "collection traps" and the time the last of them was discovered. As many as eight separate missions might converge on one of them. When they did, they couldn"treturn. Most had food factories, either built in or supplied with shipments of food by automatic s.p.a.cecraft from an independent factory nearby, so the castaways didn"t starve, nor did they lack for water or air. A few did not have these amenities-not in working condition anymore, at least. In those cases all that was found were the abandoned Heechee ships and a few desiccated corpses.
Heecheeologists grew to believe that these "collection traps" served some purpose-maybe several purposes, though they could not be really sure what any of them were. None were accessible to planet dwellers; there were no tunnels on inhabited planets, nor were there any treasures where they could be reached without the use of s.p.a.cecraft.
It seemed to be a sort of intelligence test posed by these vanished aliens. It was almost as though the Heechee, when they went to wherever they had gone, had deliberately left clues to themselves. But even the clues were hard to find. No intelligent race could find one until it had first mastered at least primitive interplanetary travel on its own.
And the greatest prizes were even more thoroughly concealed.
As a matter of record, it wasn"t exactly a Gateway prospector who made the first round-trip expedition to the Food Factory. Pat Bover"s was only one way. The expedition that made it possible for the Heechee carbon-hydrogen-oxygen-nitrogen (or "CHON") food to do something to help out hunger on Earth arrived there in an Earthly chemical rocket, spiraling out into the outer reaches of the solar system.
And they did more than that, because it was through the Food Factory that the second big discovery came along. It was called Heechee Heaven. It was the largest Heechee-made artifact ever discovered, more than half a mile long, twice the size of an ocean liner. It was shaped like a spindle (a familiar Heechee design), and it was not uninhabited. It held the descendants of the breeding group of australopithecines the Heechee had captured on Earth"s surface, half a million years before; it held one living human, the son of a pair of prospectors who had reached Heechee Heaven in their Gateway ship-and been trapped there. And it contained the stored minds (poorly stored, but the machines that did the job had never been designed for human beings; humans had not yet evolved when those machines were built) of more then twenty Gateway prospectors who had come there on one-way trips.
All that was wonderful It was more than wonderful, though. For the first time, Heechee technology was not only on hand but accessible. At last some of it could be understood ... and copied ... and even improved! Those treasures were not just satisfying scratches for the scientists" itch of curiosity, or wealth for a few lucky discoverers. They meant a better life for everyone.
And Heechee Heaven was not simply a s.p.a.ce station. It was a ship. A vast one. A ship big enough to transport human colonists in quant.i.ties sizable enough to begin to make a dent in human misery-3,800 emigrants at a time, anywhere they chose to go-and keep on doing it, once a month, indefinitely.
And the colonization of the galaxy by the human race was possible at last.
The biggest "science" bonus the Gateway Corporation ever offeitd its prospectors wasn"t really scientific. It was emotional. It proved that even the Gateway Corporation had some human feelings. The bonus was waiting there for any explorer who discovered a living, breathing Heechee, and it wasn"t tiny. It came to fifty million dollars.
That was the kind of bonus any desperate Gateway explorer could dream about, but hardly any of them ever expected to claim it. Maybe the corporate masters didn"t expect ever to pay it out, either. They all well knew that every sign of the Heechee anyone had ever found was hundreds of thousands of years old. They also suspected, very likely, that there might not be much chance that anyone who did discover a live Heechee would be allowed to come back and tell the human world what he had found.
But there were other bonuses in that same emotional area. They were lesser but still very worthwhile. The biggest one was the stand- ing ten-million-dollar offer for the discovery of any intelligent race of aliens. After a while, that was made a little easier. You could earn it by finding any living aliens at all who showed the faintest signs of smarts. You could even earn money for dead ones. There was a flat million posted for the discoverer of the first non-Heechee artifact found, and half a million or so for the discovery of any one of a variety of "signatures"-that is to say, of such unmistakable signs of intelligence as a clearly coded radio transmission, or the detection of synthetic gases in some planetary atmosphere somewhere.
It stood to reason, Gateway prospectors told each other as they bought each other drinks in Gateway"s Blue h.e.l.l, that it was just about certain that somebody would find some of that kind of stuff somewhere, sometime. They had to. Everyone knew that there ought to be other intelligent races around. The Heechee couldn"t possibly be the only other intelligent beings in the universe. Could they?
That wasn"t a new idea. As far back as the middle twentieth century scientists had been listening for signals from other civilizations in s.p.a.ce and trying to calculate the probability of ever hearing one. A fellow named Stephen Dole had calculated that there ought to be some 63,000,000 life-sustaining planets in the galaxy; later scientists, on tougher a.s.sumptions, cut the expected number down much lower-but hardly any of them were willing to put it at zero. Almost everybody agreed there ought to be some-and, in fact, Gateway prospectors did keep turning up planets where things did live. And if there was life of any kind, it seemed a reasonable bet that sooner or later some of that life would evolve toward intelligence . .
But where were they?
Ultimately a couple of lucky breaks did begin to turn up a few such interesting discoveries, though they were very spa.r.s.e and slow in coming.