This is the floor of the butterfly house rotunda at the Detroit Zoo. When we entered the building, a zookeeper began chatting with us, and when he found out I was a math teacher he got very excited: “You are going to like this!” The zookeeper then told me that the pattern was based on the Fibonacci numbers.
I didn’t think much about the substance of his claim, and I generally don’t think much about claims involving the golden ratio that aren’t related to diagonal lengths of pentagons or rhombuses. But after posting this under the original title Fibonacci Flooring, John Sharp’s comments made me realize that I may be unwittingly perpetuating the mythology of the golden ratio.
Following John’s lead, I checked to see if the above spiral was really a golden spiral by loading it into Desmos and seeing if I could fit a golden spiral to it.
Doesn’t look like it! Thus, I have officially changed the title of this photograph to Non-Fibonacci Flooring, and I apologize if I in any way contributed to the cult of the golden ratio. As penance, I will link readers to George Hart’s excellent video debunking of the myth of the Nautilus shell as a golden spiral.