Simple cubic curves enclose an area. This construction morphs as time goes by. The morphing causes an interesting problem, because begin and end point of the curve are typically not the corners of the area. Even if the curves are long enough and the point of intersection is a corner of the area for the bases of the morphing, this is not true within the interpolation of the morphing.

The aesthetics of simplicity is fascinating over and over. Whoever already tried to create without a sophisticated tool from a stone a perfect sphere, whoever already tried to carpenter from a pile of laths a perfect cube, knows about the difficulties and the excitement and interesting, lying in the details of the simplicity, knows what distinguishes the idea, the concept from the real construction of the later work.

There is no perfection in the realisation of our ideas, the approximation, the aspects of failing is the truth of our live. On the other hand our ideas, concepts and theories will never be a perfect description of the reality. But in many many case already our rough approximations provide a lot of useful applications.