Get rid of such nonsense concepts as time and space that don't hold water here. What we call the universe is a synthesis of physical behaviors.

We say that the universe is finite, because infinite physical actions will produce paradoxes, but obviously, we exist and paradoxes do not produce. So the role of physics is limited, and so is the universe.

But since it is limited, where is the boundary? Body movements can't reach or work, and that's the boundary.

But human cognition or all other detection or anything physical, so we won't find the boundary, we can't reach it.

In other words, the boundary will become non-boundary with physical action.

We even say that we coexist with the border. Just like 0+ 1= 1, although 0 is 0, 1 is 1, there is still 0+ 1= 1.

This question, and ask "What can't we know?" Again, the answer can only be "impossible to know".

In addition, our understanding of physical effects cannot be complete.

Then the problem of "outside" is simpler. As long as the concept of "nothingness" is used, it can be perfunctory.

There is a "non-physical effect" outside, and there is no "physical effect" between the two. For physical actions, it is "nothingness".

As for whether there will be any strange "functions"? There's no point.

Because our "universe" and "physical interaction" are mutually defined.

As for the "universe" outside this definition, the same reason is meaningless.

Meaningless, that is, there is no intersection, or to use a popular phrase "parallel universe"