We forgot about PHI!

Today I started reading The Da Vinci Code and I'm glad I finally decided to do so. It reminded me to measure things with D to show the ubiquity of PHI. He already loves PI so this one should be interesting to him - when I showed him before, he was quite surprised but then we forgot to do much with it. I wonder if the human body ratios remain intact through puberty? D is also interested in music, we can explore the presence of PHI in that as well as art. He hates art but if I can add math into it that may spark a bit of at least temporary interest!