The guy in figure 24 is a French mathematician called Étienne Ghys and somewhat known to the public for his commitment to the popularisation of mathematics. I guess he would love this sort of things. I wonder if this picture that chosen randomly on the internet or if this is some kind of homage.
If you have enjoyed the article and you have macOS, you will probably like the LotsaEscher [1] screensaver. Too bad it does not work since Sierra---the source code [2] is in the public domain, though, so hopefully <i>someone</i> can work around.<p>[1] <a href="http://wakaba.c3.cx/sup/kareha.pl/1118971388/" rel="nofollow">http://wakaba.c3.cx/sup/kareha.pl/1118971388/</a> (the original URL is gone, I guess that's because the program does not work now)<p>[2] <a href="https://bitbucket.org/WAHa_06x36/lotsaescher/" rel="nofollow">https://bitbucket.org/WAHa_06x36/lotsaescher/</a>
I love this article. Years ago I tried to find the formulas on my own and implement them in my own Complex function visualizator but failed :(
I have to retry !<p>Someone who succeeded : <a href="http://2008.sub.blue/projects/droste.html" rel="nofollow">http://2008.sub.blue/projects/droste.html</a>