Logarithmic Spiral Regression Tool
Logarithmic spirals occur in more setting than any other shape: animal, plant, weather, water, astronomy, architecture (helix staircases viewed in perspective, for example). Use this applet to disprove the myth that the "Golden Spiral" is common.
Upload a picture of a Golden Spiral to see that it does not match the shell very well. Upload other spirals to compare (fiddlehead ferns, hurricanes,galaxies, sunflower heads, roses, snail shells, ...)