Time travel is a concept that is nearly impossible if not entirely impossible to accurately depict in movies, and will most likely be impossible to achieve in real life. Movie time travel is depicted in a way where it looks interesting and it causes people to think, but it is filled with several plot holes, which can ruin a movie if you think to much about them. Similarly, future real life time travel will have similar problems to that of movie time travel theoretically, but we have no way of knowing for sure whether or not it will work in the future.
In movies, time travel is usually portrayed poorly, which causes most time travel movies to be filled with plot holes. This does not mean that movies that portray time travel well have no plot holes, they just have less or try to explain the plot holes in the movie somehow. In time travel movies people go back in time to alter the future, and this is the start of the problem. First, the future can change drastically with one slight modification because one disturbance will grow exponentially worse as time passes. Secondly, changing the future makes no sense because if you go back in time to change something, nothing will happen. Nothing will happen because what you going back in time to modify has already happened, because its in the past and everything done in the past has led to the moment of you going back in time and alter the future, even you in the past trying to adjust the future. Lastly, time travel will never work because people will have needed to make the time machine without going back in time in the first place. Therefore, going back in time with a time machine and telling your past self how to make a time machine is impossible because of the same reason why changing the future in general is impossible. If you tell your past self how to build a time machine, it means it will have already happened, but this is impossible because the very first time machine you made came without the help of a future self, so it could not have already happened.
There are a few theories that could explain time travel, but I only believe one of them to be true because it is somewhat logical and easy to explain and understand. One, if we do invent a time machine and go back in time, we will not be changing our own future, because it has already happened, we are actually creating a new timeline. This new time line is much like a fork in the road, the road is a single road for a long period of time, but at some point it splits and creates two roads which grow increasingly distant from one another, never connecting again. The reason why simplicity plays a part in these theories is because if someone comes up with a unique theory with several complex components, that makes several more components that could potentially be false. On the other hand, the one I told you is simple and has few components with potential problems.
Time travel in both movies and real life is a complicated topic with several problems. The problems of time travel are based on two possible theories. First, what you go back in the past to change has already happened. Second, if someone manages to adjust the past the outcome will cause the future to change exponentially and cause for a future so different that the person who altered the future would not recognize where he was once he went back to his time. There is only one theory for explaining time travel that is reasonable and that is, every time someone changes the past they create a new timeline. However, no one understands time travel fully and even the best theories have there problems. The only way to understand the impacts of time travel is to do it ourselves and learn through experience, and who knows, maybe someone born today will someday invent a time machine and explain to the world how time travel actually works.
