Tenho certeza de que este é o "Diário dos 100 anos-luz" de Greg Egan, que você pode encontre na coleção Axiomatic . Resumo (com alguns spoilers) aqui :
Another story from early in Egan’s career, “The Hundred Light-Year Diary” (Interzone, 1992), hints at the tack taken almost twenty years later in the Orthogonal trilogy. In this rather depressing short, a time-reversed star has been found—the light we receive from it comes from the future, not the past as with other stars. By setting up a shutter system between the Earth and the star, messages can be conveyed from the future to the past (the present of the story). Due to limited bandwidth, every citizen is allocated a certain number of bytes per day of messaging that they can send back in time to themselves. The narrator is a political operative who marries his wife based on both their messages about each other but then embarks on an affair that he had not written to himself about. His lover picks him up by telling him that she knows that he’ll come with her and of course he believes her, because everyone has knowledge about the critical days of their lives. But it turns out that she’s been ignoring the messaging system and living her life spontaneously, something he finds exotically attractive. In the end, his marriage dissolves into bitterness, none of which is reflected in his cheerful, positive messages to his past self. He finds that he can’t change what he’s writing—he can’t deviate from the script of the messages he’s already received. But the messages increasingly bear no resemblance to the life he’s actually living.
Note que a premissa da história parece ser baseada em um modelo de física teórica real (mas muito especulativo) física pelo astrofísico Thomas Gold , no qual a entropia mudará de crescente para decrescente no futuro, à medida que o universo muda da expansão para a contração-- O filósofo da ciência Huw Price discute a possibilidade de que as mudanças na direção da mudança de entropia possam acontecer em diferentes momentos para diferentes galáxias, e que isso permitiria um sistema de comunicação retrógrado semelhante ao descrito por Egan, em páginas 18-22 do este artigo , e em maior extensão em seu livro A seta do tempo e o ponto de Arquimedes .