Mathematics is studied for three reasons: calculation, application, and inspiration. It is the science of patterns, helping us to think logically, critically, and creatively. However, the inspirational aspect is often overlooked in education, with focus primarily on future tests or classes rather than the inherent fun or beauty of mathematics.
Arthur Benjamin introduces the Fibonacci numbers as an example of an inspirational mathematical concept. These numbers, starting with 1, 1, and each subsequent number being the sum of the two preceding ones (1+1=2, 1+2=3, 2+3=5, etc.), were introduced to the Western world by Leonardo of Pisa (Fibonacci) in his book "Liber Abaci".
Fibonacci numbers appear surprisingly often in nature. Examples include the number of petals on a flower or the number of spirals on a sunflower or pineapple.
Benjamin highlights the beautiful number patterns within Fibonacci sequences. For instance, summing consecutive squared Fibonacci numbers reveals a pattern related to other Fibonacci numbers (e.g., 1^2 + 1^2 = 2, 1^2 + 1^2 + 2^2 = 6 which is 2*3, 1^2 + 1^2 + 2^2 + 3^2 = 15 which is 3*5).
To explain why these patterns occur, Benjamin uses a geometric proof. By arranging squares with side lengths corresponding to Fibonacci numbers (1x1, 1x1, 2x2, 3x3, 5x5, 8x8) into a rectangle, the total area can be calculated in two ways: by summing the areas of the individual squares or by multiplying the rectangle's height by its base. This demonstrates that the sum of the squares of Fibonacci numbers (1^2 + 1^2 + 2^2 + 3^2 + 5^2 + 8^2) equals the product of the last Fibonacci number and the next one (8 x 13).
Continuing this process generates larger rectangles whose dimensions are consecutive Fibonacci numbers (e.g., 13x21, 21x34). The ratio of the larger side to the smaller side in these rectangles (e.g., 13/8 = 1.625) approaches approximately 1.618, which is known as the Golden Ratio, a number that has fascinated thinkers for centuries.
Benjamin concludes by emphasizing that while calculation and application are important, the beautiful and inspirational side of mathematics, often neglected in schools, is crucial. He stresses that mathematics isn't just about solving for 'x' but also about understanding 'why', fostering critical thinking skills.