The question I want to ask is about flying through time and space. In the third level of the movie Harry Potter and Back to the Future levels 1 to 3, there was a time-traveling plot.

But what I saw Harry Potter do when he went back in time was exactly what he did in the future. Then, the current him went back to the past, and the current him saved the past him in that place (note that the current him is the center). Then, is this time-traveling a continuous cycle? It was fate. So the history was fixed?
However, I didn't see this situation in episodes 1-3 of Back to the Future. (The protagonist's mother said that she met her father in a car accident.) Once, the protagonist took a time machine to travel back in time. In the end, the person in the car accident was not his old father, but himself. Then history would naturally change, and if that was the case, the protagonist would slowly disappear. (Note that his mother and father met in a car accident, but now they have become the main characters.) According to the Harry Potter cycle. His mother should have said that the person she met in the car accident was not his father, but the main character. According to the law of the cycle, before the current protagonist returned to the past, there should be a future protagonist who returned to the past first. So, according to the original plot, traveling through time and space could change history without the effect of a cycle (but it could also be said that there was. Although there was no future him, what he did now caused the past him to do the same, forming a cycle later on.) If we look at him from the perspective of the past, the present him is the future him (the pioneer of the whole thing), and there is a cycle. If that was the case, then Harry Potter was in the past, following the so-called pioneers. But this explanation is a little forced. You can ignore the previous explanation.
The final question is, is what I'm doing now following what I'm doing in the future?
What he did (whether it was a continuous cycle)(whether he had a future), or whether he had no future, only the present and the past. History could be changed, but could the process not be a cycle?
I hope you can help me answer it. I hope you can understand it. If you don't understand, you can watch these two movies.

Answer 1

Thank you very much for your reminder! The plot you mentioned is one of the important elements in the Harry Potter series. I also saw a time-traveling plot in the Back to the Future series. My answer to your question is that both Harry Potter's level 3 and the Back to the Future movies have time-travel plots. In these movies, the ability to travel through time and space was seen as a form of magic, and through the use of this magic, people could explore the past, present, and future. In Harry Potter, Harry and his friends used magic to cross the time barrier into the Forest of Curses and Hogwarts Castle. In the Back to the Future movie series, the protagonists used time machines to travel through time and change the direction of history and the future.