The spacing for the horizontal lines on this and the main links page was created using the Fibonacci Series, after the Italian mathematician Leonardo Pisano Fibonacci (approx. 1179-1250, Pisa, Italy). Liber Abaci was published in 1202, and was based on the arithmetic and algebra that Fibonacci had accumulated during his travels. The book, which went on to be widely copied and imitated, introduced to Europe the Hindu-Arabic place-valued decimal system, the use of Arabic numerals, and simultaneous linear equations. Many of the problems that Fibonacci considers in Liber Abaci were similar to those appearing in Arab sources. The second section of Liber Abaci contains a large collection of problems aimed at merchants. They relate to the price of goods, how to calculate profit on transactions, how to convert between the various currencies in use in Mediterranean countries, and problems which had originated in China. A problem in the third section of Liber Abaci led to the introduction of the number sequence for which Fibonacci is best remembered today: A man put a pair of rabbits in a place surrounded on all sides by a wall. How many pairs of rabbits can be produced from that pair in a year if it is supposed that every month each pair begets a new pair which from the second month on becomes productive? The resulting sequence is 1, 1, 2, 3, 5, 8, 13, 21, 34, 55,.... This sequence, in which each number is the sum of the two preceding numbers, has proven to be extremely fruitful and appears in many different areas of mathematics and science (the Fibonacci Quarterly is a modern journal devoted to studying mathematics related to this sequence). The series can be found in nature, as in the increasing volumes of the spiraling chambers of a Nautilus shell. It was also used by composer Béla Bartók as a basis for pitch selection and overall musical design. The series encompasses all numbers, starting with zero and one (zero representing both "nothing" and, by its inclusive circular shape, "everything," and one—the individual), then proceeds onward thusly: 0+1=1, 1+1=2, 1+2=3, 2+3=5, 3+5=8, etc. The lines on both this and the links page were spaced one pixel apart, two pixels apart, three pixels, five, eight, thirteen, twenty-one, thirty-four, fifty-five, eighty-nine, and finally, 0ne-hundred-forty-four pixels apart. For more information, go to: Fibonacci Back