As a three-dimensional creature, it was almost impossible to cross the barrier of a high-dimensional world.
Just like how two-dimensional creatures couldn't perceive the existence of a three-dimensional world, if they didn't rely on scientific theories or special technical means, all they could observe was the projection of three-dimensional objects on paper with the help of light sources. The laws of physics were incomprehensible to two-dimensional creatures.
It was almost impossible to stand in the position of low-dimensional creatures and interact with high-dimensional space.
The four-dimensional space fragment and the existence of Z particles were somewhat similar.
But its existence was more complicated.
It was not a thing that existed in four-dimensional space; it was the space itself.
Therefore, it was theoretically impossible to cross this barrier.