A 2-knot will be a 2-sphere embedded into R locally flatly. Although we cannot see a 2-knot directly with our eyes, there are several ways to visualize it. A motion picture is one of the ways. Roughly speaking, a motion picture is a CT scan (Computed Tomographic scan) of a 2-knot. It is a one-parameter family of slices of a 2-knot, that are 0or 1-dimensional objects in R. The n-twist-spun trefo...