O conto "Hindsight" por Jack Williamson corresponde perfeitamente à sua descrição. (A história foi publicada pela primeira vez em Astounding Science-Fiction , maio de 1940 , disponível no Arquivo da Internet . Você pode ter lido em um arquivo georgiano tradução da antologia editada por Asimov-Greenberg As Grandes Histórias de Ficção Científica, Volume 2, 1940 qualquer um dos outros conteúdos parece familiar?) Tomando ponto por ponto:
Um homem criou uma Super arma para um império.
O império é a Astrarquia, fundada por piratas espaciais, baseada no cinturão de asteroides, e empenhada em conquistar todo o sistema solar:
His voice was injured and defiant. "But, so far as I'm concerned, the Astrarchy is just as respectable as such planet nations as Earth and Mars and the Jovian Federation. And it's a good deal more wealthy and powerful than any of them."
Tense-faced, the Martian girl shook her dark head. "Don't blind yourself, Bill," she begged urgently. "Can't you see that the Astrarch really is no different from any of the old pirates? His fleets still seize any independent vessel, or make the owners ransom it with his space-patrol tax."
She caught an indignant breath. "Everywhere—even here on Mars—the agents and residents and traders of the Astrarchy have brought graft and corruption and oppression. The Astrarch is using his wealth and his space power to undermine the government of every independent planet. He's planning to conquer the system!"
A super arma é uma autosight para armas de naves espaciais:
Beneath those thrusting eyes, Brek Veronar flinched. "Thank you, Gorro," he gulped—he was among the few privileged to call the Astrarch by name. "Later, perhaps. But the torpedo guide isn't finished. And I've several ideas for improving the autosight. I'd much prefer to stay in the laboratory."
For an instant, the short man's smile seemed genuine. "The Astrarchy is indebted to you for the autosight. The increased accuracy of fire had in effect quadrupled our fleets." His eyes were sharp again, doubtful. "Are further improvements possible?"
Brek Veronar caught his breath. His knees felt a little weak. He knew he was talking for his life. He swallowed, and his words came at first unsteadily.
"Geodesic analysis and integration is a completely new science," he said desperately. "It would be foolish to limit the possibilities. With a sufficiently delicate pick-up, the achronic detector fields ought to be able to trace the world lines of any object almost indefinitely. Into the future—
He paused for emphasis. "Or into the past!"
Mas, um dia, outra batalha, antes que ele aperte o botão, algo acontece. Quando ele acorda, o navio está danificado, o império perdido, todos em choque.
"The Queen is disabled. Reaction batteries shot away, and main power plant dead. Repair is hopeless. And our present orbit will carry us far too close to the sun. None of our ships able to undertake rescue. We'll be baked alive."
"How were we beaten?" demanded Brek. "I can't understand!"
:"Marksmanship," said the tired Astrarch. "Tony Grimm has something better than your autosight. He shot us to pieces before we could find the range." His face was a pale mask of bitterness. "If my agents had employed him, twenty years ago, instead of you—" He bit blood from his lip. "But the past cannot be changed."
Brek was staring at the huge, silent bulk of the autosight. "Perhaps"—he whispered—"it can be!"
Ele se lembra e decide que um evento em seu passado afetou essa batalha. Anos atrás, aquela garota escreveu uma carta para ele e o convidou para uma festa (ou encontro). Assim, seu amigo teve mais tempo para aprender e desenvolveu uma arma semelhante, porém mais poderosa, que ajudou os rebeldes a vencer a batalha. Ele sugere usar a energia deixada para fazer uma mudança no passado e fazer com que aquela garota escreva uma carta para seu amigo, não para ele, dando-lhe uma vantagem a tempo.
"What's this?" rasped the anxious Astrarch. "A schoolgirl writing a note—what has she to do with a space battle?"
Brek scanned the fiery symbols. "She was deciding the battle—that day twenty years ago!" His voice rang with elation. "You see, she had a date to go dancing in Toran with Tony Grimm that night. But her father was giving a special lecture on the new theories of achronic force. Tony broke the date, to attend the lecture."
As Brek watched the motionless image in the cube his voice turned a little husky. "Elora was angry—that was before she knew Tony very well. I had asked her for a date. And, at the moment you see, she has just written a note, to say that she would go dancing with me."
Brek gulped. "But she is undecided, you see. Because she loves Tony. A very little would make her tear up the note to me, and write another to Tony, to say that she would go to the lecture with him."
The Astrarch stared cadaverously. "But how could that decide the battle?"
"In the past that we have lived," Brek told him, "Elora sent the note to me. I went dancing with her, and missed the lecture. Tony attended it—and got the germ idea that finally caused his autosight to work better than mine.
"But, if she had written to Tony instead, he would have offered, out of contrition, to cut the lecture—so the analyzers indicate. I should have attended the lecture in Tony's place, and my autosight would have been better in the end."
The Astrarch's waxen head nodded slowly. "But—can you really change the past?"
Brek paused for a moment, solemnly. "We have all the power of the ship's converters," he said at last. "We have the high-frequency achronic field, as a lever through which to apply it. Surely, with the millions of kilowatts to spend, we can stimulate a few cells in a schoolgirl's brain. We shall see."
Mas no último segundo antes de prosseguir, ele olha para um relógio que seu velho amigo e aquela garota (amor do passado) o presentearam há muito tempo. Seus sentimentos não permitem que ele faça isso. Então ele deixou seu passado intocado.
Two minutes! Brek looked down at the jeweled chronometer on his wrist. For a moment he had an odd feeling that the design was unfamiliar. Strange, when he had worn it for twenty years.
The dial blurred a little. He remembered the day that Tony and Elora gave it to him—the day he left the university to come to Astrophon. It was too nice a gift. Neither of them had much money.
He wondered if Tony had ever guessed his love for Elora. Probably it was better that she had always declined his attentions. No shadow of jealousy had ever come over their friendship.
"Minus one—"
This wouldn't do! Half angrily, Brek jerked his eyes back to the screen. Still, however, in the silvery sodium clouds, he saw the faces of Tony and Elora. Still he couldn't forget the oddly unfamiliar pressure of the chronometer on his wrist—it was like the soft touch of Elora's fingers, when she had fastened it there.
Suddenly the black flecks in the screen were not targets any more. Brek caught a long gasping breath. After all, he was an Earthman. After twenty years in the Astrarch's generous pay, this timepiece was still his most precious possession.
His gray eyes narrowed grimly. Without the autosight, the Astrarch's fleet would be utterly blind in the sodium clouds. Given any sort of achronic range finder, Tony Grimm could wipe it out.
Brek's gaunt body trembled. Death, he knew, would be the sure penalty. In the battle or afterward—it didn't matter. He knew that he would accept it without regret.
No final, ele diz aos almirantes do Império que eles não podem fazer mais nada, porque a perda deles permaneceu refletida no tempo e não pode ser mudada.
"Once you told me, Veronar, that the past could be changed. Then I wouldn't listen. But now—try anything you can. You might be able to save yourself from the unpleasantness that my men are planning."
Looking at the muttering men, Brek shook his head. "I was mistaken," he said deliberately. "I failed to take account of the two-way nature of time. But the future, I see now, is as real as the past. Aside from the direction of entropy flow and the flow of consciousness, future and past cannot be distinguished."
"The future determines the past, as much as the past does the future. It is possible to trace out the determiner factors, and even, with sufficient power, to cause a local deflection of the geodesics. But world lines are fixed in the future, as rigidly as in the past. However the factors are rearranged, the end result will always be the same."