A beautiful persian illumination, designed by the prolific [url=anitachowdry.com]Anita Chowdry[/url], boasting a splendid spiral. Let's investigate it. It is indeed a logarithmic spiral. Is it a golden spiral?

You can move the golden point parametrizing the golden spiral.[br]You can as well move the points and see the associated [math](\theta,\ln \bigl(r(\theta)\bigr)[/math] and the linear regression. This now leads to the blue spiral that fits this data.