The Nothing Equation, Tom Godwin, Amazing Stories, December 1957. Note: The copyright for this magazine short fiction has expired in the United States and was not renewed, thus, The Nothing Equation now resides in the public domain.

The next day he thought he felt the hook to which the exerciser spring was attached crack loose from where it was welded to the wall. He inspected 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 not leaking yet but it could commence doing so at any time. He looked out the windows at the illimitable void that was waiting to absorb his pitiful little supply of air and he thought of the days he had hauled and jerked at the springs with all his strength, not realizing the damage he was doing.

There was a sick feeling in his stomach for the rest of the day and he returned again and again to examine the hairline around the hook.

The next day he discovered an even more serious threat: the thin skin of the bubble had been spot-welded to the outside reinforcing girders.

Such welding often created hard, brittle spots that would soon crystallize from continued movement—and there was a slight temperature difference in the bubble between his working and sleeping hours that would daily produce a contraction and expansion of the skin. Especially when he used the little cooking burner.

He quit using the burner for any purpose and began a daily inspection of every square inch of the bubble's walls, marking with white chalk all the welding spots that appeared to be definitely weakened. Each day he found more to mark and soon the little white circles were scattered across the walls wherever he looked.

When he was not working at examining the walls he could feel the windows watching him, like staring eyes. Out of self defense he would have to go to them and stare back at the emptiness.

Space was alien; coldly, deadly, alien. He was a tiny spark of life in a hostile sea of Nothing and there was no one to help him. The Nothing outside was waiting day and night for the most infinitesimal leak or crack in the walls; the Nothing that had been waiting out there since time without beginning and would wait for time without end.

Sometimes he would touch his finger to the wall and think, Death is out there, only one-sixteenth of an inch away. His first fears became a black and terrible conviction: the bubble could not continue to resist the attack for long. It had already lasted longer than it should have. Two million pounds of pressure wanted out and all the sucking Nothing of intergalactic space wanted in. And only a thin skin of metal, rotten with brittle welding spots, stood between them.

It wanted in—the Nothing wanted in. He knew, then, that Horne and Silverman 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. Not until that happened, not until the Nothing filled the bubble and enclosed his hideous, turned-inside-out body would it ever be content ...

He had long since quit wearing the magnetized shoes, afraid the vibration of them would weaken the bubble still more. And he began noticing sections where the bubble did not seem to be perfectly concave, as though the rolling mill had pressed the metal too thin in places and it 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 the danger was rapidly increasing because whenever he pressed his ear to the wall he could hear the almost inaudible tickings and vibrations as the bubble's skin contracted or expanded and the Nothing tapped and searched with its empty fingers for a flaw or crack that it could tear into a leak.

But the windows were far the worst, with the Nothing staring in at him day and night. There was no escape from it. He could feel it watching him, 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 blanket and he used that together with all his spare clothes to make a tent stretching from the table to the first instrument panel. When he crawled under 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 much better then, hiding there in the concealing darkness where the Nothing could not see him.

He did not mind going naked—the temperature regulators in the bubble never let it get too cold.

He had no conception of time from then on. He emerged only when necessary to bring more food into his tent. He could still hear the Nothing tapping and sucking in its ceaseless search for a flaw and he made such emergences as brief as possible, wishing that he did not have to come out at all. Maybe if he could hide in his tent for a long time and never make a sound it would get tired and go away ...

Sometimes he thought of the cruiser and wished they would come for him but most of the time he thought of the thing that was outside, trying to get in to kill him. When the strain became too great he would draw himself up in the position he had once occupied in his mother's womb and pretend he had never left Earth. It was easier there.

But always, before very long, the bubble would tick or whisper and he would 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. But they were very nice to him and helped him put on his clothes. Later, in the cruiser, everything was hazy and they kept asking him what he was afraid 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?" the voice demanded insistently.

"I told you," he said. "Nothing."

They stared at him and the haziness cleared a little as he saw they did not understand. He wanted them to believe him because what he told them was so very true.

"It wanted to kill us. Please—can't you believe me? It was waiting outside 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 the doctor took his hand to lead him away ...

The bubble was carefully inspected, inside and out, and nothing was found. When it was time for Green's replacement to be transferred to it Larkin reported to Captain McDowell.

"Everything is ready, Larkin," McDowell said. "You're the next one. I wish we knew what the danger is." He scowled. "I still think one of my roustabouts from the engine room might give us a sane report six months from now instead of the babblings we'll get from you."

He felt his face flush and he said stiffly, "I suggest, sir, that you not jump to conclusions until that time comes."

The cruiser vanished back into hyperspace and he was alone inside the observation bubble, ten thousand light-years beyond the galaxy's outermost sun. He looked out the windows at the gigantic sea of emptiness around him and wondered again what the danger had been that had so terrified the men before him.

Of one thing he was already certain; he would find that nothing was waiting outside the bubble to kill him ...