Fibonacci

Today is Fibonacci Day. I'm excited about that, because some of the most beautiful things I know of in nature--my all-time favorite one being the design of the chambered nautilus shell--are based on the mathematical phenomenon of Fibonacci numbers.

Fibonacci numbers start with 0 and 1, and each following number is the sum of the two previous ones.  So the sequence of Fibonacci numbers goes like this: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, and so on. If you graph that out on block paper, that looks like this:

Do you see the similarity in that growing spiral to the chambered nautilus design?

It's amazing to me to see all the places where this sequence of numbers shows up in the design of nature.  So, in celebration of Fibonacci Day, here are some lovely examples of natural Fibonacci numbers (and not every spiral is a Fibonacci spiral, for the record):

A rose...

A gathering hurricane ...

A fiddlehead fern ... 

Some galaxies...

And, surprisingly, a budgie!

Any more you can think of?