Alfred S. Posamentier, Ingmar Lehmann

The Fibonacci sequence is mathematics’s most common and possibly most fascinating numerical pattern. Each number following the first two ones in this straightforward pattern is the sum of the two numbers that came before it (1, 1, 2, 3, 5, 8, 13, 21, ad infinitum). This pattern appears again in natural formations all throughout the world, from the arrangement of the whorls on a pinecone to the branches of specific plant stems. All of which provide stunning proof of the natural world’s intricate mathematical foundation. Two seasoned math lecturers led us on a fascinating tour of the Fibonacci numbers’ numerous applications with outstanding clarity. They start with a brief biography of a renowned Italian explorer who, among other things, was in charge of making Arabic numerals widely used in the West. Turning to botany, the authors illustrate the astounding relationships between Fibonacci numbers and organic forms through illustrated graphics (pineapples, sunflowers, and daisies are just a few examples). They cite a large number of instances of the Fibonacci sequence and its derivative, the “golden ratio,” in different spheres of society and culture, including art, architecture, the stock market, and others. And, of course, there are practically endless applications in mathematics, as the authors amply show, in areas like probability, number theory, geometry, algebra, and Pascal’s triangle, to name a few. This enjoyable and educational book enables the reader to understand the elegance of mathematics and its wonderful applications in both natural and cultural environments. It is approachable and appealing to even the most math-phobic person.