Are there some horrible details in the movie Interstellar?

Five-dimensional creatures I want to talk about my humble opinion on the point that "five-dimensional creatures can't go back to the past but can cross the future"

First of all, Cooper, as a three-dimensional creature living in a four-dimensional space, must have the characteristics of a three-dimensional creature, that is, he cannot cross the time dimension. Then, when the three-dimensional creature suddenly descended to the five-dimensional space, it was found that it could see Mufu at every time point from small to large and could manipulate it at will, so it transmitted quantum information in the black hole and saved mankind.

So the point is, who is going back to the past or crossing the future? If compared with the Mufu, Cooper really crossed into the future, because 126-year-old Cooper can still see the Mufu when he was a child, but Cooper can't go back. This is because Mufu never returned to the study after he got the watch, so in theory he can also go back to the past.

But if we look at Cooper objectively, it is absolutely impossible for Cooper to cross the time dimension. No matter how Cooper moves in that five-dimensional space, he still maintains the same nature as before. So three-dimensional creatures still can't travel through the time dimension, even in the five-dimensional space. This is also the question that Brand explained to Cooper after the play came out from Planet Miller.

Three-dimensional creatures live in four-dimensional space, and the uncontrollable time dimension restricts the world and enhances the rationality of the existence of this world. If one day there are four-dimensional creatures in the world we live in, or we evolve into four-dimensional creatures, then there will be a paradox of "you go back to the past and kill your grandfather."

Manipulating Time My idea is that if one day we all evolve into four-dimensional creatures and can manipulate time, then there must be a higher dimension to limit the world, which makes the sentence "You crossed the past and killed your grandfather, but you still exist" more reasonable. For example, compare the world and the underworld to the fifth dimension.

Four-dimensional creatures live in this world, only to find that the world is actually a five-dimensional space. One day they will evolve into eight-dimensional creatures, the world will be regarded as a nine-dimensional space, and the ninth dimension will naturally be found out. Unfortunately, what we three-dimensional creatures can really feel is only the time dimension.

In other words, Cooper didn't actually cross the past and the future.