A week ago I figured out that the evolute of an Euler spiral (Cesàro equation κ(s) = s) is another simple power law spiral, the Cesàro equation being κ(s) = -1/s³. The writeup is at: https://linebender.org/wiki/curves/euler-spiral-evolute/
None of the math for this was very hard, in fact I can see the result being obtained hundreds of years ago if anyone had bothered to look. A challenge for math enthusiasts: does the result generalize to other spirals with a simple power law?
