As you walk from Klyde Warren Park to the Dallas Museum of Art, you will pass by the Hunt Oil building. Its facade features the intersection of two cylinders, a narrower vertical one and a much larger-radius horizontal one. The curve where the two surfaces intersect is highlighted in silver trim. This is a beautiful, sweeping curve that does not lie in any one plane in space. It does not correspond to any familiar, simple curve; it’s not an ellipse or parabola or helix, etc. Such curves have been studied by mathematicians, however, and are called Steinmetz curves. It’s wonderful how math shows us that beautiful complexity can arise even from simple combinations of very simple shapes, such as these cylinders.