This undated photo shows a spruce cone with a marked fibonacci number sequence. A numbers sequence thought up by the 13th century Italian mathematician known as Fibonacci plays out in plants, from ...

Though the Fibonacci sequence shows up everywhere in nature, these young mathematicians were surprised to find it in the answer to a variation of the pick-up sticks problem⁠—a nearly two-century-old f ...

One set rises gradually, another moderately and the third steeply. Count the number of spirals and you’ll find eight gradual, 13 moderate and 21 steeply rising ones. Fibonacci numbers again.