Linking Trees’ Fibonacci Sequence to Solar Power

Linking Trees’ Fibonacci Sequence to Solar Power Wins Student A Young Naturalist Award
Friday, August 12, 2011
http://www.amnh.org/news/2011/08/linking-trees%E2%80%99-fibonacci-sequence-to-solar-power-wins-student-a-young-naturalist-award

When 13-year-old Aidan took a winter hike through the Catskill Mountains, he noticed something spectacular about the bare trees. “I thought trees were a mess of tangled branches,” he would later recall, “But [then] I saw a pattern in the way the tree branches grew.”

Armed with a protractor, Aidan measured the angles of the branches and discovered they grew in a Fibonacci sequence—a mathematical pattern that can be observed throughout nature, from the curve of nautilus shells to the spirals of galaxies. In this famous sequence, each number is the sum of the previous two: 0, 1, 1, 2, 3, 5, 8, continuing infinitely. Could this branch pattern help trees absorb more sunlight? Aidan’s pursuit of that question in his essay The Secret of the Fibonacci Sequence in Trees earned him a 2011 Young Naturalist Award.

To test his hypothesis, Aidan constructed a model tree based on the Fibonacci sequence of an oak, using PVC pipes as branches and PV solar panels as leaves. After testing his prototype against a flat solar panel, Aidan confirmed that trees outperformed the traditional model—in winter, by as much as 50 percent.

As it turns out, this distribution of branches minimizes the extent to which limbs shade the leaves below them. And unlike a flat solar panel—which must be mechanically readjusted to follow the Sun’s moving path—a Fibonacci-sequence tree can still absorb light when the Sun sits low in the sky. “Collecting the most sunlight is the difference between life and death,” wrote Aidan, who thinks humans can put treelike solar panel designs to use, especially in urban spaces where sunlight is scarce. He has already applied for a patent for his PV solar panel tree.

For his next project, Aidan plans on comparing the Fibonacci sequences of different trees to see if one species’ branch arrangement is more efficient than another. He knows he’ll find another secret in nature if he just keeps looking up.

The Young Naturalist Awards is a nationwide, science-based research contest for students in grades 7 through 12 presented by the Museum. To learn more and to submit your own project, visit amnh.org. The deadline for the 2012 contest is March 9, 2012.

The Young Naturalist Awards are proudly supported by Alcoa Foundation.