What is a good specific research topic to write about that relates to phi (the golden ratio)?

I need a good research question into something specific about phi (the golden ratio) that can get 4000 words+. Thanks.

What is a good specific research topic to write about that relates to phi (the golden ratio)?
It is the foundation of Biological Archetecture, I've inlcuded a few links.
Reply:Look up how the ancient Greeks used phi to design their buildings.
Reply:write about the relationship with the fibonacci numbers