Mysterious Patterns: Finding Fractals in Nature by Sarah C. Campbell (review)

Campbell, who introduced young audiences to Fibonacci number sequences in Growing Patterns (BCCB 5/10), returns with a similar approach to recognizing fractals in the natural world. She begins with an illustrated discussion of perfect shapes, such as a circle, cone, or cylinder, and demonstrates how objects in nature approximate these shapes. Then she moves toward Benoit Mandelbrot’s observation that natural shapes, although not perfect, often appear in a particular self-similar pattern, or, as Campbell puts it, “Every fractal shape has smaller parts that look like the whole shape,” using a leafless tree and a diagram of complex branching to demonstrate. The remainder of the text and images provide further examples, from broccoli to bronchioles, and a couple of examples of non-fractal patterns, such as pineapple husk and caterpillar markings. The definition of fractals is annoyingly late in arriving, though, and it is buried amid text that makes it easy to miss. Moreover, selected images vary in their efficacy for revealing fractal patterns: it’s far easier to recognize structural similarities in lung airways than in the aerial photo of the Colorado River. A Make Your Own Fractal activity, with simple directions and diagrams for constructing a Sierpinski triangle, goes a long way in providing clarity, and Yale mathematician Michael Frame’s closing notes on Mandelbrot and the practicality of his observations extends the view of fractals beyond natural phenomenon.