Novikov self-agreement principle

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The Novikov self-agreement principle is a conjecture made by Russian astrophysicist Igor Novikov in the 1980s to eliminate the paradoxes of time travel theory . This is achieved by assuming that an event which would imply a paradox is wholly unlikely.

The scenario

Instead of common notions of time travel paradoxes, such as the grandfather paradox , Novikow used a mechanical model that would be more accessible from the mathematical point of view. He envisioned a billiard ball being thrust precisely into a wormhole in such a way that it would travel back in time and collide with an earlier version of itself, thereby distracting itself from the orbit that allowed it to enter it in the first place to fall said wormhole - and thus to force the entire process into non-existence.

Novikov found that there were many trajectories that resulted from the same starting conditions. For example, the ball could only touch itself slightly, and thus only slightly influence its course, but only touch itself exactly the same in the next round. This process was self-contained (a so-called causality loop ) and not a paradox. The likelihood of such a phenomenon would be higher than zero, while the likelihood of self-extinction of the event would be zero, and hence Novikov concluded that no matter what a time traveler might do, he would never create a paradox.

Possible effects on free will

An episode of the Twilight Zone provides another example: A person travels back in time to investigate the cause of a famous fire. She is in the building while the fire is about to break out, but in the process accidentally knocks over a lantern, causing the fire that years later prompted her to travel back in time. The scenario completes itself completely - through the time travel, the event that had already happened in the future comes true.

Here the person had no influence on their free will - it was impossible for them to prevent the fire because they could not interrupt the event, because it had to agree with itself because it existed. Even if the person had known what was going to happen, they could never have prevented what on principle was supposed to happen. But even here alternative routes are possible - for example, the fire would never have broken out because the person would never have gone back in time. Here, too, the event completely coincides with itself, there is no interruption in causality.

So you can see that according to the principle of self-agreement there are many possibilities that are based on the same starting positions, and that one as well as the other leave the original event intact. Also, on closer consideration, free will is actually not curtailed, since only paradoxes become impossible, but all other decisions are free.

Judgment on the Novikov principle of self-agreement

The principle assumes certain circumstances that very narrowly limit the possibility of time travel. More precisely, it even assumes that there is only a single timeline that cannot be changed and thus completely denies the possibility of a many-worlds interpretation .

From this consideration the conclusion was drawn that the principle is nothing more than a tautology - which means that it has to be correct from its own definition and does not require verification .

Examples in literature and in film

The Novikov self-agreement principle was and is often used in fictional stories and narratives, which vary widely, but all essentially agree with Novikov's assumption:

See also

Web links