SDW: maths and drain covers

I am a mathematician and I am used to looking at “everywhere-maths“: the geometry of what you happen to look at while walking, the sound patterns you hear in what people say, the non-derivability of Dali’s mustaches… This is the approach I tried to convey also to my students. During these months I worked with some 2nd grade students on isometries and we collected many pictures of drain covers (yes, the metal top cover of manholes for beams and water supplies, for instance): they are great examples of wallpaper groups, that are ways to fulfill the two-dimensional plane with repetitive patterns (see They are literally symmetries under our feet and during SDW we are going to share with other students of our school (an Italian vocational technical high school) the magic of the unique 17 groups. We shall use pictures, drawing material and the great Symmetries section on

Stay tuned and… look just under your feet!