File:Golden spiral, Fibonacci spiral, nature at work.jpg

Image courtesy of Massimo

Secret Code of Nature

• https://en.wikipedia.org/wiki/Golden_spiral

Rabbits and Math:

In 1202 Leonardo of Pisa published the massive tome "Liber Abaci," a mathematics "cookbook for how to do calculations," Devlin said. Written for tradesmen, "Liber Abaci" laid out Hindu-Arabic arithmetic useful for tracking profits, losses, remaining loan balances and so on...

In one place in the book, Leonardo of Pisa introduces the sequence with a problem involving rabbits. The problem goes as follows: Start with a male and a female rabbit. After a month, they mature and produce a litter with another male and female rabbit. A month later, those rabbits reproduce and out comes — you guessed it — another male and female, who also can mate after a month. (Ignore the wildly improbable biology here.) After a year, how many rabbits would you have?

The answer, it turns out, is 144 — and the formula used to get to that answer is what's now known as the Fibonacci sequence. (Via LiveScience)