base spirals icon png download

Some say that the "golden spiral" can be found all around in the nature, which can be constructed as a Fibonaccy spiral. Contrary I could hardly find any snail shell images with those proportions. This image shows three other logarithmic spirals next to the well known "golden spiral", that I could find way better. One of them has the proportion of the nautilus shell discussed here: https://www.goldennumber.net/nautilus-spiral-golden-ratio/. The other two also have systematic proportions. However the bottom left one has quite a natural look, its proportions were not constructed upon the golden ratio. Mathematical functions are included in the file, if you want to plot them as parametric curvers.