Sobre o 2005-10, li uma história em uma antologia. Não se lembre do título da antologia, história ou autor. Envolveu o protagonista fazendo repetidas viagens ao passado. A cada volta, ele achava o mundo um pouco diferente, mas as pessoas ficavam dizendo: "Viu? Nada mudou." No final, houve inúmeras alterações cumulativas
humanity are now intelligent lobster-like arthropods, still maintaining that time travel does not alter history.
Isso pode ser "Projeto Brooklyn"de William Tenn (pseudônimo de Philip Klass), identificado em ID da história curta: Viagem no tempo com bola quicando
"See," cried the thing that had been the acting secretary to the executive assistant on public relations. "See, no matter how subtly! Those who billow were wrong: we haven't changed." He extended fifteen purple blobs triumphantly. "Nothing has changed!"
Como me lembrei de ter visto esse antes neste site, fiz uma pesquisa no Google por site: scifi.stackexchange.com "viagem no tempo" "história curta" nada aconteceu e encontrou essa pergunta / resposta entre os resultados.
Não corresponde exatamente à sua descrição, mas você pode estar pensando em "Assim frustramos Carlos Magno", uma breve história de RA Lafferty, que foi a resposta para essa velha pergunta e (inaceitável) para este; publicado pela primeira vez em Galaxy Magazine, Fevereiro 1967, disponível no Internet Archive. Algum dos estas capas Parece familiar?
Nenhum protagonista viaja para o passado. Em vez disso, um comitê de cientistas se senta em seu Instituto e faz com que sua máquina de IA envie um Avatar ao passado para efetuar as mudanças desejadas, que eles esperam observar no presente:
"We have perfect test conditions," the machine Epikt said as though calling them to order. "We set out basic texts, and we take careful note of the world as it is. If the world changes, then the texts should change here before our eyes. For our test pilot, we have taken that portion of our own middle-sized city that can be viewed from this fine vantage point. If the world in its past-present continuity is changed by our meddling, then the face of our city will also change instantly as we watch it.
"We have assembled here the finest minds and judgments in the world: eight humans and one Ktistec machine, myself. Remember that there are nine of us. It might be important."
[. . . .]
From his depths, Epiktistes the Ktistec machine sent out an Avatar, partly of mechanical and partly of ghostly construction. Along about sundown on the road from Pamplona to Roncesvalles, on August 14 of the year 778, the traitor Gano was taken up from the road and hanged on a carob tree, the only one in those groves of oak and beech. And all things thereafter were changed.
Mas é claro que os cientistas não estavam cientes das mudanças:
"Did it work, Epikt? Is it done?" Louis Lobachevski demanded. "I can't see a change in anything."
"The Avatar is back and reports his mission accomplished," Epikt stated. "I can't see any change in anything either."
"Let's look at the evidence," Gregory said.
The thirteen of them, the ten humans and the Ktistec, Chresmoeidec and Proaisthematic machines, turned to the evidence, and with mounting disappointment.
[. . . .]
"No, there is not one word of the text changed," Gregory grumbled. "History followed its same course. How did our experiment fail? We tried, by a device that seems a little cloudy now, to shorten the gestation period for the new birth. It would not be shortened."
"The town is in no way changed," said Aloysius Shiplap. "It is still a fine large town with two dozen imposing towers of limestone and midland marble. It is a vital metropolis, and we all love it, but it is now as it was before."
Depois de uma segunda tentativa, eles são pessoas da idade da pedra, não lagostas:
"Did it work, Epikt? Is it done?" Aloysius asked.
"Let's look at the evidence," said Gregory.
The four of them, the three humans and the ghost Epikt, who was a kachenko mask with a speaking tube, turned to the evidence with mounting disappointment.
"There is still the stick and the five notches in it," said Gregory. "It was our test stick. Nothing in the world is changed."
"The arts remain as they were," said Aloysius. "Our picture here on the stone which we have worked for so many seasons is the same as it was. We have painted the bears black, the buffalos red and the people blue. When we find a way to make another color, we can represent birds also. I had hoped that our experiment might give us that other color. I had even dreamed that it might appear in the picture on the rock before our very eyes."
"There's still rump of skunk to eat and nothing else," said Valery. "I had hoped that our experiment would have changed it to haunch of deer."
Na terceira tentativa, eles desfazem as mudanças e restauram o mundo ao seu estado original,
Sinto-me obrigado a mencionar o artigo de RA Lafferty "Frustramos, portanto, Carlos Magno"conforme referenciado em uma resposta a Título e autor da curta história do SF sobre uma máquina de 'melhoria' aparentemente quebrada. Ele também tem alguém fazendo mudanças na história sem que ninguém perceba, mas falta as transformações desumanas.
"I hope the Avatar isn't expensive," Willy McGilly said. "When I was a boy we got by with a dart whittled out of slippery elm wood."
"This is no place for humor," Glasser protested. "Who did you, as a boy, ever kill in time, Willy?"
"Lots of them. King Wu of the Manchu, Pope Adrian VII, President Hardy of our own country, King Marcel of Auvergne, the philosopher Gabriel Toeplitz. It's a good thing we got them. They were a bad lot."
"But I never heard of any of them, Willy," Glasser insisted.
"Of course not. We killed them when they were kids."
....
The four of them, the three humans and the ghost Epikt who was a kachenko mask with a speaking tube, turned to the evidence with mounting disappointment.
"There is still the stick and the five notches in it," said Gregory. "It was our test stick. Nothing in the world has changed."