Some time travel stories in fiction simply ignore paradoxes. They focus more on the adventure aspect of time travel. For example, in 'Back to the Future', Marty goes back in time and there are some potential paradoxes like seeing his younger mother fall in love with him instead of his father, but the story just moves forward and finds ways to resolve the situation without getting too deep into the paradox.
In some time travel stories, the concept of fate or a fixed timeline is used to deal with paradoxes. For example, in '11/22/63' by Stephen King, there seems to be a force that resists the main character's attempts to change history. It's as if history has a way of righting itself and preventing paradoxes. The idea is that no matter what the time traveler does, certain events are meant to happen, which is a way to skirt around the complex issues of paradoxes in time travel.
There are also novels that embrace the paradoxes. They use them as a central plot device to create a mind - bending and complex story. For example, in some stories, a character might go back in time and cause the very event that sent them back in time in the first place, creating a never - ending loop of causality that the reader has to figure out.
Many time travel science fiction novels create rules within their own universes to deal with paradoxes. In 'A Wrinkle in Time', the idea of tessering (a form of time/space travel) has its own set of rules that prevent the characters from creating major paradoxes. The characters can't just go back and change everything willy - nilly. Another approach is seen in '11/22/63' where the universe seems to have a kind of elasticity. When the main character tries to change history, the universe tries to push back and correct itself to avoid a paradox.
Some sci fi time travel stories simply avoid dealing with paradoxes. They might create a kind of 'soft' time - travel system where changes in the past don't really create big problems. For example, in 'Star Trek', the time travel episodes often seem to have a sort of built - in fix for any potential paradoxes.
In some time travel novels, changing the past is impossible. For example, in 'The Time Traveler's Wife', the events are sort of pre - determined and the time traveler can't really change the past in a significant way. It's more about experiencing different times.
Well, in some magestic time travel novels, the idea of changing history is almost forbidden. Take 'Kindred' for example. The main character is more of an observer in the past, and any attempt to change the course of history in a major way seems impossible. It's as if history has its own momentum. But in novels like 'The Anubis Gates', the characters are constantly trying to manipulate history for their own purposes, yet they are always thwarted by the complex web of time and the unforeseen consequences that come with trying to change things.
Some stories use the concept of parallel universes. So when you travel back in time and change something, you create a new branch of the timeline, and the original timeline still exists. For example, in 'Sliders', the characters slide between different parallel universes, so any changes they make don't create a paradox in their original world. Another way is through self - consistency. The events are set up so that any time travel actions don't actually create a paradox. For instance, in '12 Monkeys', the time traveler's actions are all part of the events that already happened.
One common time travel paradox is the grandfather paradox. If you travel back in time and kill your grandfather before he has children, then you couldn't be born to go back in time in the first place. Another is the bootstrap paradox, like a person going back in time and giving Shakespeare the plays he wrote, but then where did the plays originally come from? And then there's the predestination paradox, where events in the past seem to be fated because of time travel, for example, a time traveler goes back to save someone, but it turns out that their very presence there was what caused the situation that needed saving in the first place.
Some fictional time travel books suggest that changing the past is impossible. For example, in 'The Time Machine', the past is set and the time traveler can only observe. Others, like '11/22/63', show that while it may seem possible to change the past at first, there are unforeseen consequences that ultimately keep the overall course of history the same. In this case, the protagonist tries to prevent Kennedy's assassination but realizes that the past resists being changed.
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Different types of fiction handle time travel rules in distinct ways. In hard science - fiction, time travel rules are usually more complex and try to adhere to scientific principles. There might be rules related to energy requirements, spacetime curvature, and relativity. In contrast, in soft science - fiction or pulp fiction, the time travel rules can be more flexible and used mainly for the sake of creating exciting stories. For instance, a character might be able to time travel just by stepping into a special machine without much explanation of the underlying physics. In horror - related fictions with time travel elements, the time travel rules might be used to introduce elements of dread. For example, a character might be trapped in a time loop where they are doomed to repeat a terrifying event over and over again.