It is one of the most cited examples to prove that travel back in time is impossible. This is what the famous grandfather paradox is
We have already dealt with time travel. Today we will try to explain in the clearest and simplest way possible what is the grandfather paradox and why it is related to .
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Let’s start from the assumption that it is more than a paradox an’antinomythat is, a preposition that indicates the simultaneous presence of two contradictory statements that can both be proven. It was the Frenchman René Barjavel the first to talk about the grandfather paradox in his book “The Careless Traveler”from 1943. This is an example that is often cited to say that going back in time is impossible. Let’s try to understand why.
The experiment that generates the grandfather paradox
Suppose for a moment that we could go back to the past with a time machine. Imagine meeting your grandfather as a young man and killing him, before he meets your grandmother. This would make your birth impossible. Consequently, it would also make your time machine journey impossible. This is where the so-called “grandfather paradox” arises.
They exist three possible solutions to the paradox. The first hypothesises that it is precisely the laws of physics that prevent closed timelines. He said this, claiming it is impossible to travel backwards in time, but only forward: in this way they would not be violated .
Then there is the possibility that every timeline generates a different future. They are the so-called ““a bit like those told in the Netflix TV series, ““. Let’s take an example.
If I, Valerio 1I went back in time to kill my grandfather 1I should travel from my universe (universe 1) to universe 2 (the past). Valerio 1, therefore, would kill his grandfather, who we will call grandfather 2. By doing so Valerio 2 will never be bornallowing Valerio 1 to return to the future and continue living his life.
Novikov’s self-consistency principle
The third and final solution to the paradox involves the impossibility of changing history, because it has already happened. It’s about the Igor Novikov’s self-consistency principleRussian physicist according to whom the past is immutable.
Let’s say Valerio goes back in time, meets his grandfather and kills him. Three possibilities arise from this event:
- That Valerio killed a person who in reality he is not his grandfather.
- That he really killed his grandfather, but only after having conceived his son/daughter, i.e. Valerio’s parents.
- Time travel might even be the reason for Valerio’s birth. This implies that the events themselves will prevent the grandfather’s murder.
Fascinating, don’t you think?
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Read the article “” on Space.com
