_The space ships were miracles of power and precision; the men who manned them, rich in endurance and courage. Every detail had been checked and double checked; every detail except--_ THE NOTHING EQUATION By TOM GODWIN [Illustration] The cruiser vanished back into hyperspace and he was alone in theobservation bubble, ten thousand light-years beyond the galaxy'soutermost sun. He looked out the windows at the gigantic sea ofemptiness around him and wondered again what the danger had been thathad so terrified the men before him. Of one thing he was already certain; he would find that nothing waswaiting outside the bubble to kill him. The first bubble attendant hadcommitted suicide and the second was a mindless maniac on the Earthboundcruiser but it must have been something inside the bubble that hadcaused it. Or else they had imagined it all. He went across the small room, his magnetized soles loud on the thinmetal floor in the bubble's silence. He sat down in the single chair, his weight very slight in the feeble artificial gravity, and reviewedthe known facts. The bubble was a project of Earth's Galactic Observation Bureau, positioned there to gather data from observations that could not be madefrom within the galaxy. Since metallic mass affected the hypersensitiveinstruments the bubble had been made as small and light as possible. Itwas for that reason that it could accommodate only one attendant. The Bureau had selected Horne as the bubble's first attendant and thecruiser left him there for his six months' period of duty. When it madeits scheduled return with his replacement he was found dead from atremendous overdose of sleeping pills. On the table was his daily-reportlog and his last entry, made three months before: _I haven't attended to the instruments for a long time because it hatesus and doesn't want us here. It hates me the most of all and keepstrying to get into the bubble to kill me. I can hear it whenever I stopand listen and I know it won't be long. I'm afraid of it and I want tobe asleep when it comes. But I'll have to make it soon because I haveonly twenty sleeping pills left and if--_ The sentence was never finished. According to the temperature recordinginstruments in the bubble his body ceased radiating heat that samenight. * * * * * The bubble was cleaned, fumigated, and inspected inside and out. No signof any inimical entity or force could be found. Silverman was Horne's replacement. When the cruiser returned six monthslater bringing him, Green, to be Silverman's replacement, Silverman wascompletely insane. He babbled about something that had been waitingoutside the bubble to kill him but his nearest to a rational statementwas to say once, when asked for the hundredth time what he had seen: "Nothing--you can't really see it. But you feel it watching you and youhear it trying to get in to kill you. One time I bumped the walland--for God's sake--take me away from it--take me back to Earth . .. " Then he had tried to hide under the captain's desk and the ship's doctorhad led him away. The bubble was minutely examined again and the cruiser employed everydetector device it possessed to search surrounding space for light-yearsin all directions. Nothing was found. When it was time for the new replacement to be transferred to the bubblehe reported to Captain McDowell. "Everything is ready, Green, " McDowell said. "You are the next one. " Hisshaggy gray eyebrows met in a scowl. "It would be better if they wouldlet me select the replacement instead of them. " He flushed with a touch of resentment and said, "The Bureau found myintelligence and initiative of thought satisfactory. " "I know--the characteristics you don't need. What they ought to have issomebody like one of my engine room roustabouts, too ignorant to getscared and too dumb to go nuts. Then we could get a sane report sixmonths from now instead of the ravings of a maniac. " "I suggest, " he said stiffly, "that you reserve judgement until thattime comes, sir. " * * * * * And that was all he knew about the danger, real or imaginary, that haddriven two men into insanity. He would have six months in which to findthe answer. Six months minus-- He looked at the chronometer and saw thattwenty minutes had passed since he left the cruiser. Somehow, it seemedmuch longer . .. He moved to light a cigarette and his metal soles scraped the floor withthe same startling loudness he had noticed before. The bubble was assilent as a tomb. It was not much larger than a tomb; a sphere eighteen feet in diameter, made of thin sheet steel and criss-crossed outside with narrowreinforcing girders to keep the internal air pressure from rupturing it. The floor under him was six feet up from the sphere's bottom and thespace beneath held the air regenerator and waste converter units, thestorage batteries and the food cabinets. The compartment in which he satcontained chair, table, a narrow cot, banks of dials, a remote-controlpanel for operating the instruments mounted outside the hull, amicrofilm projector, and a pair of exerciser springs attached to onewall. That was all. There was no means of communication since a hyperspace communicatorwould have affected the delicate instruments with its radiations butthere was a small microfilm library to go with the projector so that heshould be able to pass away the time pleasantly enough. But it was not the fear of boredom that was behind the apprehension hecould already feel touching at his mind. It had not been boredom thathad turned Horne into a suicide and Silverman into-- Something cracked sharply behind him, like a gunshot in the stillness, and he leaped to his feet, whirling to face it. It was only a metal reel of data tape that had dropped out of thespectrum analyzer into the storage tray. His heart was thumping fast and his attempt to laugh at his nervousnesssounded hollow and mirthless. _Something_ inside or outside the bubblehad driven two men insane with its threat and now that he wasirrevocably exiled in the bubble, himself, he could no longer dismisstheir fear as products of their imagination. Both of them had beenrational, intelligent men, as carefully selected by the ObservationBureau as he had been. He set in to search the bubble, overlooking nothing. When he crawleddown into the lower compartment he hesitated then opened the longestblade of his knife before searching among the dark recesses down there. He found nothing, not even a speck of dust. Back in his chair again he began to doubt his first conviction. Perhapsthere really had been some kind of an invisible force or entity outsidethe bubble. Both Horne and Silverman had said that "it" had tried to getin to kill them. They had been very definite about that part. * * * * * There were six windows around the bubble's walls, set there to enablethe attendant to see all the outside-mounted instruments and dials. Hewent to them to look out, one by one, and from all of them he saw thesame vast emptiness that surrounded him. The galaxy--his galaxy--was sofar away that its stars were like dust. In the other directions theempty gulf was so wide that galaxies and clusters of galaxies were tiny, feeble specks of light shining across it. All around him was a void so huge that galaxies were only specks init. .. . Who could know what forces or dangers might be waiting out there? A light blinked, reminding him it was time to attend to his duties. Thejob required an hour and he was nervous and not yet hungry when he hadfinished. He went to the exerciser springs on the wall and performed awork-out that left him tired and sweating but which, at least, gave hima small appetite. The day passed, and the next. He made another search of the bubble'sinterior with the same results as before. He felt almost sure, then, that there was nothing in the bubble with him. He established a routineof work, pastime and sleep that made the first week pass fairlycomfortably but for the gnawing worry in his mind that somethinginvisible was lurking just outside the windows. Then one day he accidentally kicked the wall with his metal shoe tip. It made a sound like that from kicking a tight-stretched section of tinand it seemed to him it gave a little from the impact, as tin would do. He realized for the first time how thin it was--how deadly, dangerouslythin. According to the specifications he had read it was only one-sixteenth ofan inch thick. It was as thin as cardboard. He sat down with pencil and paper and began calculating. The bubble hada surface area of 146, 500 square inches and the internal air pressurewas fourteen pounds to the square inch. Which meant that the thin metalskin contained a total pressure of 2, 051, 000 pounds. Two million pounds. The bubble in which he sat was a bomb, waiting to explode the instantany section of the thin metal weakened. It was supposed to be an alloy so extremely strong that it had a highsafety factor but he could not believe that any metal so thin could beso strong. It was all right for engineers sitting safely on Earth tospeak of high safety factors but his life depended upon the fragile wallnot cracking. It made a lot of difference. * * * * * The next day he thought he felt the hook to which the exerciser springwas attached crack loose from where it was welded to the wall. Heinspected the base of the hook closely and there seemed to be a fine, hairline fracture appearing around it. * * * * * He held his ear to it, listening for any sound of a leak. It was notleaking yet but it could commence doing so at any time. He looked outthe windows at the illimitable void that was waiting to absorb hispitiful little supply of air and he thought of the days he had hauledand jerked at the springs with all his strength, not realizing thedamage he was doing. There was a sick feeling in his stomach for the rest of the day and hereturned again and again to examine the hairline around the hook. The next day he discovered an even more serious threat: the thin skin ofthe bubble had been spot-welded to the outside reinforcing girders. Such welding often created hard, brittle spots that would sooncrystallize from continued movement--and there was a slight temperaturedifference in the bubble between his working and sleeping hours thatwould daily produce a contraction and expansion of the skin. Especiallywhen he used the little cooking burner. He quit using the burner for any purpose and began a daily inspection ofevery square inch of the bubble's walls, marking with white chalk allthe welding spots that appeared to be definitely weakened. Each day hefound more to mark and soon the little white circles were scatteredacross the walls wherever he looked. When he was not working at examining the walls he could feel the windowswatching him, like staring eyes. Out of self defense he would have to goto them and stare back at the emptiness. Space was alien; coldly, deadly, alien. He was a tiny spark of life in ahostile sea of Nothing and there was no one to help him. The Nothingoutside was waiting day and night for the most infinitesimal leak orcrack in the walls; the Nothing that had been waiting out there sincetime without beginning and would wait for time without end. Sometimes he would touch his finger to the wall and think, _Death is outthere, only one-sixteenth of an inch away_. His first fears became ablack and terrible conviction: the bubble could not continue to resistthe attack for long. It had already lasted longer than it should have. Two million pounds of pressure wanted out and all the sucking Nothing ofintergalactic space wanted in. And only a thin skin of metal, rottenwith brittle welding spots, stood between them. It wanted in--the Nothing wanted in. He knew, then, that Horne andSilverman had not been insane. It wanted in and someday it would get in. When it did it would explode him and jerk out his guts and lungs. Notuntil that happened, not until the Nothing filled the bubble andenclosed his hideous, turned-inside-out body would it ever be content . .. * * * * * He had long since quit wearing the magnetized shoes, afraid thevibration of them would weaken the bubble still more. And he begannoticing sections where the bubble did not seem to be perfectly concave, as though the rolling mill had pressed the metal too thin in places andit was swelling out like an over-inflated balloon. He could not remember when he had last attended to the instruments. Nothing was important but the danger that surrounded him. He knew thedanger was rapidly increasing because whenever he pressed his ear to thewall he could hear the almost inaudible tickings and vibrations as thebubble's skin contracted or expanded and the Nothing tapped and searchedwith its empty fingers for a flaw or crack that it could tear into aleak. But the windows were far the worst, with the Nothing staring in at himday and night. There was no escape from it. He could feel it watchinghim, malignant and gloating, even when he hid his eyes in his hands. The time came when he could stand it no longer. The cot had a blanketand he used that together with all his spare clothes to make a tentstretching from the table to the first instrument panel. When he crawledunder it he found that the lower half of one window could still see him. He used the clothes he was wearing to finish the job and it was muchbetter then, hiding there in the concealing darkness where the Nothingcould not see him. He did not mind going naked--the temperature regulators in the bubblenever let it get too cold. He had no conception of time from then on. He emerged only whennecessary to bring more food into his tent. He could still hear theNothing tapping and sucking in its ceaseless search for a flaw and hemade such emergences as brief as possible, wishing that he did not haveto come out at all. Maybe if he could hide in his tent for a long timeand never make a sound it would get tired and go away . .. Sometimes he thought of the cruiser and wished they would come for himbut most of the time he thought of the thing that was outside, trying toget in to kill him. When the strain became too great he would drawhimself up in the position he had once occupied in his mother's womb andpretend he had never left Earth. It was easier there. But always, before very long, the bubble would tick or whisper and hewould freeze in terror, thinking, _This time it's coming in . .. _ * * * * * Then one day, suddenly, two men were peering under his tent at him. One of them said, "My God--_again!_" and he wondered what he meant. Butthey were very nice to him and helped him put on his clothes. Later, inthe cruiser, everything was hazy and they kept asking him what he wasafraid of. "What was it--what did you find?" He tried hard to think so he could explain it. "It was--it was Nothing. " "What were you and Horne and Silverman afraid of--what was it?" thevoice demanded insistently. "I told you, " he said. "Nothing. " They stared at him and the haziness cleared a little as he saw they didnot understand. He wanted them to believe him because what he told themwas so very true. "It wanted to kill us. Please--can't you believe me? It was waitingoutside the bubble to kill us. " But they kept staring and he knew they didn't believe him. They didn't_want_ to believe him . .. Everything turned hazy again and he started to cry. He was glad when thedoctor took his hand to lead him away . .. The bubble was carefully inspected, inside and out, and nothing wasfound. When it was time for Green's replacement to be transferred to itLarkin reported to Captain McDowell. "Everything is ready, Larkin, " McDowell said. "You're the next one. Iwish we knew what the danger is. " He scowled. "I still think one of myroustabouts from the engine room might give us a sane report six monthsfrom now instead of the babblings we'll get from you. " He felt his face flush and he said stiffly, "I suggest, sir, that younot jump to conclusions until that time comes. " * * * * * The cruiser vanished back into hyperspace and he was alone inside theobservation bubble, ten thousand light-years beyond the galaxy'soutermost sun. He looked out the windows at the gigantic sea ofemptiness around him and wondered again what the danger had been thathad so terrified the men before him. Of one thing he was already certain; he would find that nothing waswaiting outside the bubble to kill him . .. THE END Transcriber's Note: This etext was produced from _Amazing Stories_ December 1957. Extensive research did not uncover any evidence that the U. S. Copyright on this publication was renewed. Minor spelling and typographical errors have been corrected without note.