It is generally accepted that travel to the past is impossible, at least because of the “grandfather paradox” – a hypothetical situation in which the time traveler goes back in time and kills his grandfather, which leads to the fact that the traveler is not born.
However, scientist Tim Maudlin believes that the “grandfather paradox” only creates restrictions for temporary travelers, but does not exclude the possibility of such travel in itself, reports Popular Mechanics.
Classic sci-fi plot – someone travels to the past and does something there that leads to catastrophic consequences for the present. The Grandpa Paradox is one example of such a plot.
Tim Maudlin, philosopher of science, researcher of the metaphysical foundations of physics and logic, tried to understand the “grandfather paradox”, and to understand whether this idea interferes with time travel to the past.
“The argument runs like this, if you could ‘go back in time’ then you could go back to a time before your grandfather had had any children and murder him,” Tim Maudlin, a philosopher of science who investigates the metaphysical foundations of physics and logic, explains to Popular Mechanics.
“But if that happened, then one of your parents would not have been born, so you would not have been born, so there would be no you to go back in time. Contradiction.”
“The grandfather paradox is usually presented as a reductio ad absurdum, or a refutation of the proposition that time travel is possible,” Maudlin says. “So the hypothesis must be impossible because of the grandfather paradox; time travel — or reverse causation — is not possible.”
Time travel, as the scientist added, contradicts the fundamental idea of causality, if considered only in the context of the “grandfather paradox”. However, Maudlin believes that the paradox still does not prevent travel into the past by itself.
“The grandfather paradox does not prove that you can’t go back in time, just that you can’t go back in time and kill your grandfather,” he says.
“There would be nothing logically wrong with going back in time and, say, saying ‘Hello’ to your grandfather.”