I can provide some information on the different time travel models depicted in "Back to the Future" and "Avengers: Endgame" and discuss their conceptual frameworks.
"Back to the Future" presents a version of time travel that follows a single timeline or timeline preservation model. According to this model, altering events in the past can have immediate effects on the future, leading to changes in the present. This is depicted through the "butterfly effect," where small changes in the past result in significant alterations in the future. In the trilogy, the characters aim to fix disruptions caused by time travel to ensure a consistent timeline.
On the other hand, "Avengers: Endgame" introduces a different time travel model that involves multiple timelines or branching realities. In this model, when characters travel to the past and make changes, they create new branches or parallel realities instead of altering their own past. The film follows the idea that altering the past does not change the future of the time traveler's original timeline. Instead, it creates separate timelines that can potentially be visited or interacted with.
Both models have their own logical frameworks and implications. The single timeline model, as depicted in "Back to the Future," maintains a sense of a consistent timeline and the potential for causal loops. The multiple timeline model, as shown in "Avengers: Endgame," allows for coexistence of different timelines and potential for alternate realities.
It's important to note that both movie franchises take artistic liberties and present fictional versions of time travel. They do not necessarily align with current scientific understanding or theories. Time travel is still a subject of debate and exploration in the scientific community, and we do not have definitive evidence or established models for its possibility or mechanisms.
Ultimately, the choice of which time travel model makes more sense is subjective and can vary depending on personal preferences, interpretations, and the specific rules established within each fictional universe.