The paper linked to in this post is math-light and fun (or, if you prefer, math-light but fun), esp. the discussion of the golden ratio in human anatomy (ratio

The paper linked to in this post is math-light and fun (or, if you prefer, math-light but fun), esp. the discussion of the golden ratio in human anatomy (ratio of height to height of navel): "we're not told why this is important. The navel is a scar of no great importance in an adult"; and, having tested the hypothesis on his family: "there is some ambiguity about the precise location of the navel since it has a nontrivial length."