“Do Plants Know Math?”

What if, long before humans had discovered numbers or counting or the quadratic formula, plants had already figured out math? And what if their patterns helped humans puzzle out numeric mysteries?

These are some of the questions that Christophe Golé, professor of mathematical sciences, and his co-authors explore in their new book, Do Plants Know Math: Unwinding the Story of Plant Spirals, from Leonardo da Vinci to Now.

As Golé explains, plants “embody math. They're in a sense, little calculators, the biology, the biochemistry and biophysics of the system that produces those organs around the tip of the stem produces a little calculator of Fibonacci numbers.” Fibonacci numbers are created by adding each of the previous two digits. So 1+1 =2, 1+2=3, 2+3=5, 3+5=8, and so on. Many plants exhibit two sets of spirals going clockwise and counterclockwise and when you count their numbers, it is one Fibonacci number going one way, and the next going the other way: 8 and 13 in the pinecone or 13 and 21 in the African daisy shown in the exhibit, for example.

With the book, the co-authors (a physicist, a biologist, a mathematician, and a science writer) strike a difficult balance–appealing to a wide audience, from children to specialist mathematicians. They do that by including hands-on activities, vivid illustrations, and compelling historical stories alongside mathematical explanations.

The co-authors trace how people have been fascinated by plant spirals for centuries. For example, artist and inventor Leonardo da Vinci might have been one of the first to record allusions to this in writing in his now famous notebooks. Fast forward several centuries to when computer inventor Alan Turing attempted to discover the principles that make life possible by starting with modeling plant spiral patterns, even as his mental health suffered under intense homophobic persecution that led to his death by presumed suicide.

A specialized photographer, Victor Mozqueda, created illustrations of plant patterns from 25 layers of high quality photographs so that no part of the blossom, succulent, or fruit is out of focus. Large prints of some of the book illustrations are on display in the McConnell Hall foyer through December. This exhibit is sponsored in part by Golé’s participation in the Kahn Institute project, “Vegetal Forms: Knowing Place and Time Through Plants.” Further information about each illustration is available on the exhibit website.

In addition to vibrant historical stories and innovative geometry, the book and exhibit include hands-on activities, such as folding paper to resemble a maple leaf. Golé explains why they included these activities, “we wanted people to feel like it's not knowledge that came from above, but we wanted them to be active and present and feel like they had agency.” Smith students in the NASA funded MaRS program (lead by Golé and Shannon Audley, associate professor of Education & Child Study), adapted and ran some of these activities with middle school students in a summer camp in Springfield, MA.

With his exhibit and book, Golé invites viewers to “look closely. Count everything—petals, seeds, spines, scales. Open your eyes to these beautiful patterns.”