Inevitability Sphere

By Jeff Duntemann K7JPD

A hyperspace tube can only be anchored on one end. If the tube is eleven light years long, just try to catch the other end!

"Thatís my ship up there," said the young captain with undisguised bitterness.

Old Tom Hoyt tugged thoughtfully at his beard, and looked up. A brilliant silver point was crawling across the sky, dimmed and sometimes hidden by a scramble of late summer clouds crawling in from the east. The alien air was sharp with its own hint of thunderstorms. Eveningís smoky yellows and pinks still hung in the west, but the gray east held flashes of distant lightning.

The captain went on. "The orbit wonít decay for another sixty-two thousand years. The computer told me that as though it mattered."

"Somebody will come after it, sooner or later."

"Not me. The junkman maybe. Iíve got a desk job now."

"When the next Earth-normal world turns up, your ship will fly again," Hoyt said.

"Only until they poke another Low Road through."

The simple truth, that. Hoyt had nothing to say. They stood beside his torchwing, which glinted silver in the cold blue light of the airstrip marker lamps. Aerodynamically, it was ancient. The fuselage was thicker, the wings stubbier than those of the Twentieth Century jet aircraft that had spawned it. The basic lines were the same.

Inside the silver skin was very little but torch and ignition capacitor. The airborne fusion tube had been born with the third millennium A.D., and Hoyt knew of little that would change it in the future.

The captain squeezed in through the tiny hatch, Hoyt climbing after. Hoyt settled both of them into their webs, then pulled a tight fitting helmet over his head. The captain began to done his own helmet, emblazoned with the silver galaxy of Earthís Star Service. Hoyt stopped him. "Cover your ears with your hands. They donít build Star Service helmets nearly soundproof enough for torch work."

Hoyt started the torch sequence. The torchwingís wings were tanks filled with heavy hydrogen. For half a minute the turbine burned the hydrogen in air, turning a generator with ever increasing speed. The resultant shreik was painful, even through Hoytís own helmet. The captain was hunched over, thumbs pressed hard into his ears. When the turbine had charaged the capacitor bank to capacity, the capacitors fed their entire accumulated charge to the ignition laser, for one star-hot pulseó


For the thousandth time, Hoyt felt as though it would shake his teeth loose. The turbine sank back to a dull whine, not feeding hot deuterium to the rising burble of the fusion torch. The noise faded from painful to merely maddening.

"How old is this thing?" the captain called over the racket.

"Hundred and forty years."

"They should have scrapped it a hundred and thirty nine years ago."

Hoyt shrugged. "Itís what Iíve got."

They taxied to the edge of the airstrip, waited for clearance, and let the torch go. They left the town at two Gs. Graveltown was lost beneath the thickening clouds before they ever saw its tiny scattering of lights. Hoyt punched in a familiar course on the autopilot and turned to look at the young captain. His uniform, crisp and spotless, was hung with brass and ribbons. His face was Celtic and a touch craggy, and very proud. His eyes were humorless and intelligent. Hoyt was troubled by the bitterness and anger he sensed. "You were about to say that this is the crudest thing you ever rode in," observed Hoyt.

"It is."

"Do you know what a tailgunner is, son?"

The captain nodded. "A suicide who shot steel slugs at other suicides in some twentieth century war. I saw one in a video years ago."

"Youíre looking at another."

The captainís eyebrows rose. "So when did they stop your clock, old man?"

"1996. Iíll be seventy-two forever. Time gives you perspective; crude is whatís ten years older than what youíre used to. Iíve known men who fought on horseback. But they did it well. Thatís what counts."

The captain remained silent. Hoyt looked ahead toward the advancing thunderstorm. True Gritís atmopshere was thinner than Earthís, but much deeper. The squall line was a churning black wall rolling out of the east, easily five miles high. Hoyt leveled off at twenty thousand feet and recovered control from the autopilot. That high, the sun had not quite set. The storm flashed purple from within.

The captain was peering ahead, suddenly interested. "I tried to spot it from space. Thought it would be easy. But the weatherís been lousy."

Hoyt grunted.

"You fly like youíve been a pilot for a long time."

Hoyt felt the younger man groping for a reason to respect him. "Quarter of a millennium. More."

"So why didnít you ever get into space?"

Hoyt shrugged. "Iím too oldóand too dumb. When I was young space was a kidís dream. Flying a wing is nothing like flying a starship. That takes real brains. Lots of things to keep straight, all at one time, but it goes slowly enough to let you stop and think. A supersonic wing you have to fly with your reflexes. Thereís no time to sit back and ask a computer questions. Old habits are hard to break. I never developed space brains."


Hoyt looked where the captain pointed. True Gritís end of the Low Road had just burst through the face of the nearest thunderhead. The Road darted erratically along the squall line for a mile or so, then shot straight up and was lost to sight. It was a thousand-foot sphere of velvet blackness, without feature or reflection.

Moments later it returned from their left, jigging and jogging and doubling back on its path. Hoyt watched the captainís eyes darting back and forth, trying to follow it. It would slow for a heartbeat, jitter almost in place, then dart off in mile-long straight lines to quickly to see at all. The captain shook his head.

"Nothing can move that fast!"

"Right. And nothing is just what it is. It occupies the same space as the air molecules it seems to cover. There is no interaction between it and the atmosphere, or anything else massing less than fifty pounds in one lump."

"So how in hell do you expect to catch it?"

"Instinct," Hoyt said, and grinned. "Iíve got good instincts."

Hoyt was swinging the torchwing in a wide arc, keeping the bounding sphere below and to their left. Instantaneous star travel indeed! It was easy enough to anchor one end of the Low Road a mile over the Mohave Desert. But the other endóHoyt thought of holding a twelve-foot fiberglass fishing rod in one hand and trying to follow a fly creeping randomly across the opposite wall with its tip. Then he imagined a fishing pole twelve light years long, and put it out of his head.

It wasnít entirely random motion, though it seemed random enough to him. The Low Road was slightly flexible in ways that gave Hoyt headaches to think about. Noise in the control circuits, changing solar wind pressures on the Earth, even minor temblors a thousand miles from the Mojave were multiplied by a seventy trillion mile lever. A man who followed that darting black ball could develop a feel for its wanderings; not enough to predict it exactly, but enough to improve his odds at catching it. Improving those odds was what Tom Hoyt did for a living.

Hoyt kept his eyes on the sphere. At last he chose to play his hunch, and without warning threw the torchwing into a power dive toward a point just ahead of advancing clouds. The Road hurtled toward the spot, jumped back, and came on again. The captain pressed himself back into his seat and cringed when the wing missed the black sphere by a few hundred feet. Then it was gone, into the clouds, and moments later the storm closed around them.

Hoyt swore under his breath. The torchwing bucked in the stormís rough air. Hoyt glanced aside and saw the young captain breathing rapidly.

"Things seldom happenÖthis fastÖin space," he said.

"Relax. They usually donít happen this fast dirtside either. Thatís most of the problem. Itís also the only reason I got this job. I have a reputation as a fast flier."

The young man laughed bitterly. "So do I. My ship is a premium speed courier. Too small for cargo, and rather spartan for passengers. I handled all government traffic in documents, credit transfers, and important people. The government never trusted the Low Road with things like thatóuntil now. They want me back on Earth in a bad way. So bad my own ship isnít even fast enough. You have my job now, old man."

Hoyt began wishing for a change of subject. He made a badly planned dive and missed the sphere by several miles. The captain watched it plummet into the clouds and vanish. Lightning glared around them.

"What happens if it hits the ground?" the captain asked.

"The Road tries to suck the whole planet through to Earth. It doesnít get too far before the breakers blow and the Road vanishes. It takes three months of calculation and a billion kilowatts of power to poke it through again. Theyíre careful. Believe me."

"They should have kept it in space."

Hoyt was searching the dark clouds for the Road. It was getting very dark. "It had to be in space, back when the damned ting wandered through a volume of space a million miles in diameter. Graveltown came through loaded in one-shot re-entry vehicles made of foam lined with brick. One of the unmanned ones burned up in the atmosphere with a fortune in farm machinery aboard. Entering a planetary atmosphere from orbit is dangerous.

"Control systems improved over the months. The volume of space in which the Road wanders is called its Ďprobability sphere.í Finding the thing when it was out in space was like finding an electron in an orbital. They knew it couldnít be in space forever, but they couldnít bring it down until they brought the probability sphere tighter than ten miles. Itís down to about three now, and getting a little tighter every week."

"Itís crazy," the young captain said.

"It took me to the stars," Hoyt said, "and I was the first man ever to ride it back to Earth again."


Night had fallen completely now. The front had passed, and the bulk of the storm was retreating into the west, beyond them. The sphere had risen from the writhing clouds below, black and invisible. In an instant it flickered and ignited to a warm yellow-green.

"Iím glad they can do that," Hoyt said. "I donít like chasing black cats through coal bins at midnight. At night itís just me and that big green ball, and no distractions to make things difficult."

Twice more Hoyt dove at the glowing green sphere. Each time he missed by almost a mile. Each time the captain went pale from the acceleration and the sudden, gut-wrenching turns and dives.

"This is worse than crazy," he said at last while Hoyt circled, resting. "Weíve been up here for two hours now and gone nowhere but around in circles."

"What was your fastest geodesic through paraspace from tau Ceti to Earth?" Hoyt asked.

"Eleven days."

"Then my slowest trip is still ten days faster than your best. Itís inevitable, son."

"Then itís mighty sloppy engineering, to have to chase your hyperspace tube around the sky like a feather blown in a windstorm."

"The tiniest noise pulse we can measure sends the thing skittering across a thousand feet of sky. Then thereís the little matter of matching velocities between two planets rotating on skew axes while revolving around stars moving in two very different directions. No easy job."

"But the same job one good starship captain can do without half trying."

The captain sounded frightened, despite his arrogant words. Hoyt looked closely at the siny buttons and medals. He saw the youth, pale and naked, beneath the awesome uniform. "What sort of job did they find for you? Civilian?"

"Yes." The captain kept his eyes straight forward. "Plotting geodesics in paraspace involves solving systems of equations of a large number of variables. They said jobs for starship captains were ĎuncertainíÖbut that I could have a solid future as senior analyst for the sociometric department of a very large processed food distributor. My first assignment is waiting for me: I am to solve the system of equations that should yield the parameters for selling the most breakfast cereal to the largest number of North American eight-year-olds."

Hoyt understood. He dropped the subject, and there was silence in the cabin of the wing for some time.

It was a bad night. Ten more times Tom Hoyt dove for where he thought his course might intersect that of the Low Road. Each time the sphere chose to move in the opposite direction. Hoyt knew his job was as much a matter of luck as anything else, but knowing what his passenger was leaving behind and knowing what he was going toward kept Hoyt from concentrating.

"Give up, Hoyt," the captain said after they had been aloft for nearly five hours.

Hoyt frowned. "Give up? Think of where Iíve been, son. When I was born space travel was fiction, childrenís fiction. I had a little telescope and I wanted to go to the stars, but I took what I could get. I tailgunned in the War and learned flying when it was over. After retiring from soldiering I flew a cargo jet for an air express company until they made me retire. I was middle aged when we landed on the Moon for the first time. I was old by the time MIT let slip that it had a twenty-year-old hamsterówhich ate its millionth sunflower seed last year, by the wayóand I was almost dead when I volunteered to undergo a clock stopping. I knew damned well that the process killed two people for every one it made immortal, but I had damned little to lose. Funny that it takes a suicide to become immortal. But it does. And I did.

"So I waited it out. And when space travel arrived in a big way, I couldnít get in because of my physiological age. So I did what Iíve always done: I flew. One day a friend of mine got me a rather odd job with the Low Road project. It took me two hundred eighty-eight years to get to the stars, but Iím here. I never give up. And nobodyís ever going to take the stars away from me!" Hoyt deliberately turned his last statement into a challenge and threw it in the younger manís face.

"Donít preach at me. Iím through. You finished me. Now leave me alone."

Hoyt bit his lip and dove once more at the dancing luminous sphere. He missed by a hundred feet. The captain choked off a cry of surprise as the mammoth ball lit the cabin with a sickly green light. Angry now, Hoyt threw the wing into a tight turn and followed. It went high. Hoyt went after it, straight up, and broke soundspeed with a dull thump. The sphere bounced like a childís ball for a second, and plummeted. Hoyt cursed and followed in a power dive that took them nearly to Mach three. The ball darted to one side and disappeared. Hoyt pulled out of the dive and began to circle idly again. The captain looked nauseated from the constant furious changes in speed and direction. Hoytís worst night. Perhaps the captain would get one more starship ride.

"Okay. Weíll try again tomorrow. The weatherÖ"


The captain swore in surprise. They were plunging straight down at the mottled barrenness of the Mojave Desert at seven hundred miles per hour. Hoytís reflexes took over, and he jerked the stick back. The wing pulled out a thousand feet above the ground.

"What happened?"

Hoyt shrugged. "Dumb luck. The ball hit us. We went through. Never happened before."

It was a brilliant cloudless afternoon over California. Fixed a mile high above the ground was solid ink-black ball a thousand feet in diameter. It was quite immobile.

For no apparent reason, the captain began to laugh. "Youíre an ass, Hoyt. The three-mile-wide volume of space with that big green ball bouncing through it isnít a probability sphere. Itís an inevitability sphere. Sit still in it long enough, and the ball has to hit you. Youíd save a lot of time and hydrogen in the long run sitting in the basket of a hot air balloon and just waiting for it."

Hoyt grinned, and threw the challenge back. "Iíll bet we could. I think we might be able to ship cargo that way, with a tethered balloon and some patienceÖand Iíd be glad to have you as a partner in the venture. Balloons to the stars! Jules Verne would have loved it!"

Hoyt turned the torchwing toward the Low Road airfield. They flew wide around a wing of slender concrete towers rising hundredds of feet above the desert rock. Each was surrounded by anÖaura? Not precisely, Hoyt thought. More a distortion. Light did not travel in straight lines around those towers.

The captain laughed again, more bitterly than before. "Forget it, old man. Youíre finished too. Give them another year. Theyíre going to shrink that probability sphere more and more, until the True Grit end just sits there and shivers a little. Hell, theyíll make it stand stock still! Theyíll pull it all the way down to the ground. Theyíll build an approach, like a bridge approach without a bridge, and thereíll be a stinking superhighway that starts out in California and ends up on Tau Ceti. Then youíll be out of a job too. How will you get to the stars then, old man?"

Ahh, the stars, the stars, may they soon belong to all, not only proud young soldiers and strange old menÖHoyt smiled.

"Iím not above driving a truck, son. Are you?"