Heechee - The Gateway Trip Part 9

The greatest treasure the Heechee tunnels on Venus had to offer had already been discovered, though the first discoverers didn't know it. No one else knew, either-at least, no one except a solitary tunnel-rat named Sylvester Macklin, and he was not in a position to tell anybody what he had found.

Sylvester Macklin had discovered a Heechee s.p.a.ces.h.i.+p.

If Macklin had reported his find he would have become the richest man in the solar system. He also would have lived to enjoy his wealth. But Sylvester Macklin was as crotchety a loner as any other tunnel-rat, and he did something quite different.

He saw that the s.h.i.+p looked to be in good condition. Maybe, he thought, he could even fly it.

Unfortunately for himself, he succeeded.

Macklin's s.h.i.+p did exactly what any Heechee s.h.i.+p was designed to do, and the Heechee were marvelously great designers. No one knows exactly what processes of thought and experiment and deduction Macklin went through when he blundered onto the wonderful find. He didn't survive to tell anyone. Still, obviously at some point he must have gotten into the s.h.i.+p and closed its hatch and begun poking and prodding at the things that looked as though they ought to be its controls.

As people later well learned, on the board of every Heechee s.h.i.+p is a thing shaped like a cow's teat. It is the thing that makes the s.h.i.+p go. When it is squeezed it is like slipping an automatic-s.h.i.+ft car into "drive." The s.h.i.+p moves out. Where it goes to depends on what course was set into its automatic navigation systems.

Mackim didn't do anything about setting any particular cour~e, naturally. He didn't know how.

So the s.h.i.+p did what its Heechee designers had programmed it to do in such an event. It simply returned to the place it had come from when its Heechee pilot had left it, half a million years ago.

As it happened, that place was an asteroid.

It was an odd asteroid in several respects. Astronomically it was odd, because its...o...b..t was at right angles to the ecliptic. For that reason, although it was a fair-sized chunk of rock and not far from Earth's own orbit at times, it had never been discovered by human astronomers.

The other odd thing about it was that it had been converted into a sort of parking garage for Heechee s.p.a.cecraft. In total, there were nearly a thousand of the s.h.i.+ps there.

What there was not any of anywhere on the asteroid was anything to eat or drink. So Sylvester Mackim, who could have been the richest man in history, wound up as just one more starved-to-death corpse.

But before he died Macklin managed to get off a signal to Earth. It wasn't a call for help. No one could reach him in time to save his life. Mackim knew that. He accepted the fact that he would die; he just wanted people to know in what an unsuspected marvel of a place he was dying. And after a while other astronauts, flying the clumsy human rockets of the time, came to investigate.

What they found was the gateway to the universe.

Within the next decade the Gateway asteroid had become the center of mankind's most profitable industry, the exploration of the galaxy.

Macklin didn't own the Gateway asteroid, of course, in spite of the fact that he had discovered it. His luck wasn't that good. He didn't own anything, being dead.

Anyway, it soon became obvious that Gateway was much too important to be owned by any individual, or even by any single nation. The United Nations fought over the question for years, in Security Council and General a.s.sembly-and, more than once, almost with guns and aircraft outside the UN itself. What the world powers wound up with was the Gateway Corporation, a five-power consortium that was set up to control it.

The Gateway asteroid was not a very congenial place for people to live-of course, it had never been designed for human people. It had been designed for the Heechee, and they had stripped it bare before they left. It was a chunk of rock the size of Manhattan, laced through and through with tunnels and chambers and not much else. The thing wasn't even round. One Gateway prospector described it as shaped "more or less like a badly planned pear that the birds had been pecking at." Its internal structure resembled the layers of an onion. The outer sh.e.l.l was where the Heechee s.h.i.+ps were docked, their lander ports snuggled into hatch chambers. (Those chambers were the things that looked from the outside like bird peckings.) Then, inside, there were layers with great open s.p.a.ces which the humans used for storing supplies and parts, and for the large water reservoir they called "Lake Superior." Closer to the center were the residential tunnels, lined with small rooms like monastery cells, where the humans lived while they waited for their s.h.i.+ps. In the heart of the asteroid was a spindle-shaped cavern. The Heechee seemed to like spindle-shaped s.p.a.ces, though no one knew why. Gateway's tenants used this one for a meeting place-and drinking place, and gambling place, and a place to try to forget what lay ahead of them.

Gateway didn't smell good. Air was precious. It didn't feel good, either, at least not to fresh prospectors just up from Earth. The asteroid had a slow spin, so there was a sort of microgravity, but there wasn't much of it. Anyone who made a sudden move anywhere in Gateway was likely to find himself floating away.

Of course, no one ever looked at the Gateway asteroid as a resort paradise. There was only one reason why any human being would be willing to put up with its expense, its inaccessibility, its discomforts, and its stink, and the reason was the Heechee s.p.a.ces.h.i.+ps.

Flying a Heechee s.p.a.ces.h.i.+p took a lot of courage, and not much else. Each s.h.i.+p was like every other s.h.i.+p in its cla.s.s. The biggest of them, the Fives, were not very big-about the same volume of s.p.a.ce as a hotel bathroom, and that to be shared by five people. The s.h.i.+ps called the Ones (because they could hold only one person for any length of time) were not much bigger than the bathtub itself. Each s.h.i.+p contained a minimum of fittings, and most of the fittings were of unknown importance. There was always a golden coil that seemed to have something to do with the s.h.i.+p's drive, because it was observed to change color at start, finish, and turnaround of each trip. There was always a diamond-shaped golden box about the size of a coffin, too. In a few of the s.h.i.+ps there was an even more mysterious device that looked like a twisted rod of crystal in a black ebon base; it didn't seem to do anything at all (but, as it turned out much later, was capable of some truly astonis.h.i.+ng feats). No one knew exactly what was inside any of those things, because whenever anyone tried to open one it exploded. And then there was the control system, with a curious, painful forked bench to sit on before it. Knurled k.n.o.bs, flas.h.i.+ng lights, the go-teat-they were what made the s.h.i.+p go.

Of course, the s.h.i.+ps lacked a great many things that human beings really didn't want to get along without: the people who ultimately flew them had some human furnis.h.i.+ngs added, like freezers, more comfortable seats, bunks, cooking tools-and a whole catalogue of cameras, radio antennae, and scientific instruments of all kinds.

There was nothing hard about flying a Heechee s.h.i.+p. Anybody could learn as much as anybody else knew in half an hour: you fiddled around with the course-setting wheels, pretty much at random because no one knew what the settings meant. Actually (it was learned, much later and at great cost) there were some 14,922 separate destinations preprogrammed into the 731 operable s.h.i.+ps on the asteroid-there were about another 200 s.h.i.+ps that simply didn't work at all. But it took a lot of time, and a lot of lives, to find out what some of those destinations were.

Then, when you had set up some combination (and crossed your fingers, or yourself), you squeezed the go-teat. After that you were on your way. That was all there was to it.

For that reason, anybody could become a prospector. Anybody, that is, who was willing to pay his way to Gateway and then to jay the steep charges for air, food, water, and living s.p.a.ce while he was in the asteroid. .. and who was brave enough, or desperate enough, to take his chances on a highly likely and often very nasty death.

Over the years a great many human beings escaped from their Earthside poverty to take their chances in a Gateway s.h.i.+p. First and last, there were 13,842 of these gold-rush gamblers, in those chancy years before exact navigation of a Heechee s.h.i.+p became possible and the random exploration program was discontinued.

Quite a few of the prospectors survived. Many became famous. A few became vastly rich. And no one remembers the others.

When one of those bold, faintly crazy early prospectors set out in a Heechee s.p.a.cecraft, he didn't expect the s.h.i.+p to go exactly where he wanted it to go. He (or, almost as often, she) could never coun~ on that for many reasons, not least because none of those early prospectors had any idea what destinations were worth aiming for. But that ignorance carried no penalty, anyway. Since no Gateway prospector knew how to navigate a Heechee s.h.i.+p, the first s.h.i.+ps followed whatever destination settings had been left on the board by the last long-ago Heechee pilot.

Considering the risks, it was a good thing for those early Gateway prospectors that the Heechee had been so much like human beings in important ways. For instance, the Heechee had possessed the primate-human itch of curiosity-in fact, they had a lot of it. That meant that a lot of the preprogrammed destinations were to places that human beings also found interesting to look at. They were just as interesting to human beings as they had been to the old Heechee, and the particular branch of the human race that delighted most in what the first waves of Gateway explorers found was the astronomers. Those astronomical people had become very ingenious at teasing information from whatever photons landed in their instruments-whether those photons were visible light, X-rays, infrared, whatever. But photons couldn't tell them everything they wanted to know. The human astronomers sighed over their knowledge that there was such a lot of stuff out there that didn't radiate at all-black holes, planets, heaven knew what! They could only guess at such things.

Now, with the Heechee s.p.a.cecraft, someone could go out and see them firsthand!

That was a pretty wonderful break for astronomers. . . although often enough it turned out to be a lot less wonderful for the men and women who went out to look.

The trouble with astronomy, from the point of view of the prospector who had just risked his life on a shot-in-the-dark voyage on a Heechee s.h.i.+p, was that you couldn't sell a neutron star. What the prospectors were after was money. That meant that, if they were lucky, they might find some kind of high-tech Heechee gadgets that could be brought back and studied and copied and made into fortunes. There wasn't any commercial market for a supernova sh.e.l.l or an interstellar gas cloud; those things just didn't pay the bills.

To deal with that problem, the Gateway Corporation started a program of paying science bonuses to the explorers who came back with great pictures and instrument readings but nothing commercial to sell.

That was virtuous of the Gateway Corporation, to pay off for pure, noncommercial knowledge. It was also a good way of coaxing more hungry humans into those scary and often deadly little s.h.i.+ps.

By the time the Gateway Corporation had been in operation for two full years more than one hundred trips had set out, and sixty-two of them had returned, more or less safely. (Not counting the odd prospector who arrived dead, dying, or scared out of his wits.) The s.h.i.+ps had visited at least forty different stars-all kinds of stars: baby blue-white giants, immense and short-lived, like Regulus and Spica and Altair; yellow normal-sequence stars like Procyon A and their dwarf counterparts, like Procyon B; staid G-type stars like the Sun, and their giant yellow relatives, like Capella. The red giants, of the types of Aldebran and Arcturus, and their supergiant counterparts, like Betelgeuse and Antares . . . and their tiny red-dwarf relatives, like Proxima Centauri and Wolf 359.

The astronomers were thrilled. Every trip's harvest triumphantly supported much of what they thought they had known about the birth and death of stars-and demanded quick revisions of much else that they thought they had known, but hadn't. The masters of the Corporation were less delighted. It was all very well to expand the horizons of astronomical science, but the pictures of the twentieth white dwarf looked pretty much like the pictures of the first. The hungry billions of Earth could not be fed on astronomical photographs. They already had a number of astronomical observatories in orbit. They weren't pleased to see their once-in-alifetime treasure trove turned into just one more of them.

But even the Corporation had to be pleased at some of the things the prospectors brought back.

MISSION PULSAR.

The first big science bonus was paid to a man named Chou Yengbo, and he might not have earned it if he hadn't happened to have taken a few elementary science courses before he discovered that even a college degree couldn't get you a decent job, those days, in Shensi Province.

When Chou's s.h.i.+p came out of the faster-than-light drive, Chou had no trouble figuring out which objects the Heechee had set the controls for.

Actually there were three objects in view. They were weird. The first was wholly unlike anything Chou had ever seen before, even in the holograms of his astronomy course. It wasn't quite like anything any other human being had e'~er seen before, either, except in imagination. The object was an irregular, cone-shaped splash of light, and even on the viewscreen its colors hurt his eyes.

What the thing looked like was a searchlight beam fanning out through patches of mist. When Chou looked more carefully, magnifying the image, he saw that there was another beam like it, sketchier and fainter and fanning out in the opposite direction. And between the two points of the cones formed by those beams, the third object was something almost too tiny to see.

When he put the magnification up to max, he saw that that something was a puny-looking, unhealthily colored little star.

It was much too small to be a normal star. That limited the possibilities; even so, it took Chou some time to realize that he was in the presence of a pulsar.

Then those Astronomy 101 lessons came back to him. It was Subrahmanyan Chandrasekhar, back in the middle of the twentieth century, who had calculated the genesis of neutron stars. His model was simple. A large star, Chandrasekhar said, uses up its hydrogen fuel and then collapses. It throws off most of the outer sections of itself as a supernova. What is left falls in toward the star's center, at almost the speed of light, compressing most of the star's ma.s.s into a volume smaller than a planet-smaller, in fact, than some mountains. This particular sort of collapse can only happen to big stars, Chandrasekhar calculated. They had to be 1.4 times as ma.s.sive as Earth's Sun, at least, and so that number was called Chandrasekhar's Limit.

After that supernova explosion and collapse has happened, the object that remains-star heavy, asteroid sized-is a "neutron star." It has been crushed together so violently by its own immense gravitation that the electrons of its atoms are driven into its protons, creating the chargeless particles called neutrons. Its substance is so dense that a cubic inch of it weighs two million tons or so; it is like compressing the hugest of Earth's old supertankers into something the size of a coin. Things do not leave a neutron star easily; with that immense, concentrated ma.s.s pulling things down to its surface, escape velocity becomes something like 120,000 miles a second. More than that: its rotational energy has been "compressed," too. The blue-white giant star that used to turn on its axis once a week is now a superheavy asteroid-sized thing that whirls around many times a second.

Chou knew there were observations that he had to make- magnetic, X-ray, infrared, and many others. The magnetometer readings were the most important. Neutron stars have superfluid cores and so, as they rotate, they generate intense magnetic fields-just like the Earth. Not really just like the Earth, though, because the neutro1 star's magnetic field, too, is compressed. It is one trillion times stronger than the Earth's. And as it spins it generates radiation. The radiation can't simply flow out from all parts of the star at once- the lines of magnetic force confine it. It can only escape at the neutron star's north and south magnetic poles.

The magnetic poles of any object aren't necessarily in the same place as its poles of rotation. (The Earth's north magnetic pole is hundreds of miles away from the point where the meridians of longitude meet.) So all the neutron star's radiated energy pours out in a beam, around and around, pointing a little, or sometimes a lot, away from its true rotational poles.

So that was the explanation of the thing Chou was seeing. The cones were the two polar beams from the star that lay between them, north and south, fanning out from its poles. Of course, Chou couldn't see the beams themselves. What he saw were the places where they illuminated tenuous clouds of gas and dust as they spread out.

The important thing to Chou was that no Earthly astronomer had ever seen them that way. The only way anyone on Earth ever could see the beam from a neutron star was by the chance of being somewhere along the rim of the conical shape the beams described as they rotated. And then what they saw was a high-speed flicker, so fast and regular that the first observer to spot one thought it was the signal from an alien intelligence. They called the signal an "LGM" (for Little Green Men) until they figured out what was causing that sort of stellar behavior.

Then they called the things "pulsars."

Chou got a four-hundred-thousand-dollar science bonus for what he had discovered. He wasn't greedy. He took it and returned to Earth, where he found a new career lecturing to women's clubs and college audiences on what it was like to be a Heechee prospector. He was a great success, because he was one of the first of the breed to return to Earth. alive.

Later returnees were less fortunate. For instance, there was- MISSION HALO In some ways Mission Halo was the saddest and most beautiful of all. The mission had been written off as lost, but that turned out to be wrong. The s.h.i.+p wasn't lost. Only its crew was.

The s.h.i.+p was an unarmored Three. When it came back its arrival was a surprise to everyone. The s.h.i.+p had been gone over three years. It was a certainty that n.o.body could have survived so long a trip. In fact, no one had. When the hatch crews on Gateway got the ports open, recoiling from the stench inside, they discovered that Jan Mariekiewicz, Rolph Stret, and Lech Szelikowjtz had left a record of their experiences. It was read with compa.s.sion by the other prospectors, and with rejoicing by astronomers.

"When we reached two hundred days without turnaround," Stret had written in his diary, "we knew we were out of luck. We drew straws. I won. Maybe I should say I lost, but, anyway, Jan and Lech took their little suicide pills, and I put their bodies in the freezer.

"Turnaround came finally at 271 days. I knew for sure that I wasn't going to make it either, not even with only me alive in the s.h.i.+p. So I've tried rigging everything on automatic. I hope it works. If the s.h.i.+p gets back, please pa.s.s on our messages."

As it happened, the messages the crew left never got delivered. There was no one to deliver them to. The messages were all ~ddressed to other Gateway prospectors who had been part of the same s.h.i.+pment up from Central Europe, and that batch wasn't one of the lucky ones. Every one of them had been lost in their own s.h.i.+ps.But the pictures the s.h.i.+p brought back belonged to the whole world.

Stret's jury-rigging had worked. The s.h.i.+p had stopped at its destination. The instruments had thoroughly mapped everything in sight. Then the s.h.i.+p's return had been triggered automatically, while Stret's corpse lay bloating under the controls.

The record showed that their s.h.i.+p had been outside the Milky Way galaxy entirely.

It brought back the first pictures ever seen of our galaxy from outside. It showed a couple of fairly nearby stars and one great, distant globular cl.u.s.ter-the stars and cl.u.s.ters of the spherical halo that surrounds our galaxy-but most of all it showed our Milky Way galaxy itself, from core to farthest spiral wisp, with its great, familiar octopus arms: the Perseus arm, the Cygnus arm, the Sagittarius-Carina arm (with our own little Orion arm, the small spur that held the Earth, nearby), as well as the large, distant arm that Earthly astronomers had never seen before. They called it simply "Far Arm" at first, but then it was renamed the StretMariekiewicz-Szelikowitz arm to honor the dead discoverers. And in the center of it all was the great bellying octopus-body ma.s.s of core stars, laced with gas and dust clouds, showing the beginnings of the new growing spiral structures that might in another hundred million years become new arms themselves.

They also showed the effects of a structure more interesting still, but not in enough detail to be recognized just then-not until some other events had taught human beings what to look for in the core. All the same, they were beautiful pictures.

Since no one returned from Mission Halo alive, there wasn't even a science bonus due, but the Gateway Corporation voted a special exception to the rules. Five million dollars was voted for the heirs of Mariekiewicz, Szelikowitz, and Stret.

It was a generous gesture but, as it turned out, a very inexpensive one. The award went unclaimed. Like so many Gateway prospectors, the three who had manned the s.h.i.+p had no families that anyone could find, and so the Gateway Corporation's bursar quietly, and philosophically, returned the cash to the Corporation's general funds.

The first, best, and brightest hope of any exploration crew was to find a really nice planet with really nice treasures on it. Ultimately some of them did, of course, but it took a while. For a good many orbits after the systematic exploration program began the crews went out and came back with nothing but pictures and hard-luck stories-when they came back at all.

But some of the things they had seen were wonderful. Volya Shadchuk took a One into the heart of a planetary nebula, green-tinged with the radiation from oxygen atoms, and collected fifty thousand dollars. Bill Merrian saw a recurring nova system, red giant's gases being sucked onto a white dwarf; luckily not enough matter had accreted while he was there to blow off in a noval explosion, but he got the fifty thousand and ten percent more for "danger bonus." And then there were the Grantlands.

There were five of the Grantlands-two brothers, their wives, and the eldest son of one of the couples. They reached a globular cl.u.s.ter-ten thousand old stars, mostly red, mostly sliding toward the sunset at the lower right side of the Hertzspung-Russell diagram as they aged. The cl.u.s.ter was in the galactic halo and, of course, the trip was a long one. None of them survived. The trip took 314 days, and all of them were alive at the time of arrival (but existing on scant rations). They took their pictures. The last of them, the young second wife of one of the brothers, died thirty-three days into the return trip; but the pictures they had taken survived.

The three Schoen sisters were no luckier. They didn't come back at all, either. Again, their s.h.i.+p did, but thoroughly racked and scorched, and of course their bodies inside were barely recognizable.

But they, too, had taken a few pictures before they died. They had been in a reflection nebula-after a.n.a.lysis it was determined that it was the Great Nebula in Orion, actually visible to the naked eye from Earth. (American Indians called it "the smoking star.") The Schoen sisters must have known they were in trouble as soon as they came out of drive, because they weren't really in s.p.a.ce anymore. Oh, it was close to a vacuum-as people on Earth measure a vacuum-but there were as many as three hundred atoms to the cubic centimeter, hundreds of times as many as there should hav~ been in interstellar s.p.a.ce.

Still, they looked around, and they started their cameras-just barely. They didn't have much time.

There are four bright young stars in the Orion Nebula, the so-called Trapezium; it is in such nebulae that gas clouds fall together and are born as stars. Astronomers conjectured that the Heechee knew this, and the reason the s.h.i.+p had been set to go there was that Heechee astronomers had been interested in studying the conditions that lead to star formation.

But the Heechee had set that program half a million years before.

A lot had happened in those half million years. There was now a fifth body, an "almost" star, in the Orion Nebula, formed after the Heechee had taken their last look at the area. The new body was called the Becklin-Neugebauer object; it was in its early hydrogen-burning stage, less than a hundred thousand years old. And it seemed that the Schoen sisters had the bad luck to come almost inside it.

MISSION NAKED BLACK HOLE.

The crew was William Sakyetsu, Marianna Morse, Hal M'Buna, Richard Smith, and Irma Malatesta. All of them had been Out before-Malatesta had done it five times-but luck hadn't favored any of their ventures. None of them had yet made a big enough score to pay their Gateway bills.

So for their mission they were careful to choose an armored Five with a record of success. The previous crew in that s.h.i.+p had earned a "nova" science bonus in it, managing to come close enough to a recurring nova to get some good pictures, though not so close that they didn't live through the experience. They had collected a total of seven and a half million dollars in bonus money and had gone back to Earth, rejoicing. But before they left they gave their s.h.i.+p a name. They called it Victory.

When Sakyetsu and the others in his crew got to their destination they looked for the planet-or the star, or the Heechee artifact, or the object of any interesting sort-that might have been its target.

They were disappointed. There wasn't anything like that to be found anywhere around. There were stars in sight, sure. But the nearest of them was nearly eight light-years away. By all indications they had landed themselves in one of the most boringly empty regions of interstellar s.p.a.ce in the galaxy. They could not find even a nearby gas cloud.

They didn't give up. They were experienced prospectors. They spent a week checking out every possibility. First, they made sure they hadn't missed a nearby star: with interferometry they could measure the apparent diameter of some of the brighter stars; by spectral a.n.a.lysis they could determine their types; combining the two gave them an estimate of distance.

Their first impression had been right. It was a pretty empty patch of sky they had landed in.

There was, to be sure, one really spectacular object in view-the word Marianna used was "glorious"-a globular cl.u.s.ter, with thousands of bright stars interweaving their orbits in a volume a few hundred light-years across. It was certainly spectacular. It dominated the sky. It was much nearer to them than any such object had ever been to a human eye before. But it was still at least a thousand light-years away.

A globular cl.u.s.ter is an inspiring sight. It was a long way from Sakyetsu and his s.h.i.+p Victory, but by the standards of Earthly astronomers that was nothing at all. Globular cl.u.s.ters live on the outer fringe of the galaxy. There aren't any in the crowded spiral-arm regions like the neighborhood of Earth. There are almost none less than twenty thousand light-years from Earth, and here was one a twentieth as far-and thus, by the law of inverse squares, four hundred times as bright. It was not an unusually large specimen, as globular cl.u.s.ters go; the big ones run upward of a million stars, and this one was nowhere near that. It was big enough to be exciting to look at, all the same.

But it was neither big enough nor near enough for Victory's instruments to reveal any more than Earth's own orbiting observatories, with their far more powerful mirrors and optical systems, had seen long ago.

So there was very little chance that the instruments on Victory could earn them any kind of decent bonus. Still, those instruments were all they had. So the crew doggedly put them to work. They photographed the cl.u.s.ter in red light, blue light, ultraviolet light, and several bands of the infrared. They measured its radio flux in a thousand frequencies, and its gamma rays and X-rays. And then, one sleeping period, while only H~tl M'Buna was awake at the instruments, he saw the thing that made the trip worthwhile.

His shout woke everybody up. "Something's eating the cl.u.s.ter!"

Marianna Morse was the first to get to the screens with him, but the whole crew flocked to see. The fuzzy circle of the cl.u.s.ter wasn't a circle anymore. An arc had been taken out of its lower rim. It looked like a cookie a child had bitten into.

But it wasn't a bite.

As they watched, they could see the differences. The stars of the cl.u.s.ter weren't disappearing. They were just, slowly, moving out of the way of-something.

"My G.o.d," Marianna whispered. "We're in orbit around a black hole."

Then they cursed the week they had wasted, because they knew what that meant. Big money! A black hole. One of the rarest objects (and, therefore, one of the most highly rewarded in science bonuses) in the observable universe-because black holes are, intrinsically, un.o.bservable.

A black hole isn't "black," in the sense that a dinner jacket or the ink on a piece of paper is black. A black hole is a lot blacker than that. No human being has ever seen real blackness, because blackness is the absence of all light. It can't be seen. There is nothing to see. The blackest dye reflects a little light; a black hole reflects nothing at all. If you tried to illuminate it with the brightest searchlight in the universe-if you concentrated all the light of a quasar on it in a single beam-you would still see nothing. The tremendous gravitational force of the black hole would suck all that light in and it would never come out again. It can't.

It is a matter of escape velocity. The escape velocity from the Earth is seven miles a second; from a neutron star as much as 120,000 miles per second. But the escape velocity from a black hole is greater than the speed of light. The light doesn't "fall back" (as a rock thrown up from Earth at less than escape velocity will fall back to the ground). What happens to the light rays is that they are bent by the gravitational pull. The radiation simply circles the black hole, spiraling endlessly, never getting free.

And when a black hole pa.s.ses in front of, say, a globular cl.u.s.ter, it doesn't hide the cl.u.s.ter. It simply bends the cl.u.s.ter's light around it.If Victory's crew had wasted seven days, they still had five days' worth of supplies left before they had to start back to Gateway. They used them all. They took readings on the black hole even when they couldn't see it ... and when at last they got back to Gateway they found that one, just one, of their pictures had paid off.

They shared a five-hundred-thousand-dollar bonus simply for the pictures of the globular cl.u.s.ter. But the one picture that they hadn't even noticed when they took it-a split-second frame, taken automatically when no one happened to be watching the screen- showed what happened when the black hole occluded a bright B-4 star, a few hundred light-years away. That star hadn't moved up or down. By chance it had pa.s.sed almost exactly behind the black hole. Its light had spread to surround the hole, like a halo; and that gave them a measure of the hole's size .

And then, long after they were back in Gateway, the research teams that studied their results awarded them another half a million, and the information that they were very lucky.

Marianna Morse had wondered about that: Why had the Heechee used an armored Five to visit this harmless object? Answer: It hadn't always been harmless.

Most black holes are not safe to visit. They pull in gases in accretion rings, and the acceleration of the gases as they fall produces a h.e.l.l of radiation. Once this one had, but that was a long time ago. Now it had eaten all the gases in its neighborhood. There was nothing left to fall and so generate the synchrotron flux of energy that might fry even an armored Five if it lingered too long nearby .

and so the crew of Victory, without knowing it at the time, had had an unexpected stroke of luck. They arrived at the neighborhood of their black hole after its lethal feeding frenzy had ended, and so they had come back alive.

In its first twenty years the Gateway Corporation handed out more than two hundred astronomical science bonuses, for a total of nearly one billion dollars. It paid off on double stars and supernova sh.e.l.ls; it paid off on at least the first examples of every type of star there was.

There are nine members of the catalogue of star types, and they are easily remembered by the mnemonic "Pretty Woman, Oh, Be A Fine Girl, Kiss Me," which runs the gamut from youngest to longest-living stars. The stellar cla.s.ses from A down to the dim, small, cool Ms didn't earn any special science bonuses unless there was something truly remarkable about them, because they were too common. The vast majority of stars were dim, small, and cool. Contrariwise, the Os and Bs were hot young stars, and they always got bonuses because they were so few. But the Gateway Corporation awarded double bonuses on the P and W cla.s.ses: P for gas clouds just condensing into stars, W for the hot, frightening Wolf-Rayet type. These were new stars, often immense ones, that could not be approached safely within billions of miles.