Chaos theory is often used in the examination of the possible effects of time travel.
There was an episode of "The Simpsons," that springs immediately to mind, where Homer Simpson travels back in time to the age of dinosaurs, kills a giant mosquito, and by the time he returns to the present world, that one tiny change brought about an entirely different world from the one he was used to.
This is an interesting, and in principle, accurate view of "The Butterfly Effect," wherein one even minute change in a system can over time evolve and grow into very dramatic changes in the long run.
In an example such as time travel, it is not difficult to see how seemingly small changes could potentially bring about major long-run divergence from reality, just as a butterfly's wings flapping in one corner of the world can, potentially, affect whether patterns in other corners of the world (with its effects growing exponentially throughout time).
Scientists have been able to use the principles of chaos theory to help them to understand the universe in terms of the motions of objects through space, including the satellites which are constantly orbiting the Earth, and being jostled constantly by unforeseen forces, which cause dramatic long-term, chaotic changes in vector and velocity.
Whether systems, of course (variations of the butterfly effect), are best modeled using tools of chaos theory (which explains why they are so consistently difficult to predict), as well as any other "turbulent system," such as water flowing down a river, the motion of the air as a passing airplane causes turbulent vortexes, and the innerworkings of the human body.
Chaos theory has even found its way into such seemingly unrelated fields as the treatment of Epilepsy - for the siezures caused by this disease have been shown to display chaotic tendencies.
Chaos theory has also been shown to have potential as providing an accurate mathematical model for human behavior, as well.
In economic theory, in particular, it has proven useful to interprate the centuries of data through the lens of chaos theory - for as much as economics might be controllable to a certain extent by policies and politics, in the end, their constant fluctuations and long-term variability has been shown to adhere to a thoroughly chaotic system.
Population growth, as well, has been shown to show signs of chaos over the long term - both in human and non-human inquiries.
In all of these applications, however, research is still ongoing, as mathematicians continue to analyze the available data in order to model it using known tools for chaotic systems and to better understand the causes for the chaos. This, in turn, will help economists and social scientists to better understand the past, present and future of their given fields.
References:
"‘Chaos’ Theory Empowers VA And University Of Florida Researchers To Predict Epileptic Seizures."
Gleick, James. “Chaos: Making a New Science.” Penguin, 1988
Brown, Allison. "Has Chaos Theory Found Any Useful Application in the Social Sciences?"