Spira Mirabilis

I acquired a neat thing today - a tiny fossilized echinoderm, a sea biscuit of some sort. I haven't had time to hunt down what it is exactly yet, but I picked it up for three reasons:
-It's neato
-It will go nicely in my shadow-box shelf full of fossils, cast off shells, dried sponges, and dried bugs. Yes, bugs.
-It beautifully demonstrates the pentamerous symmetry that is characteristic of echinoderms.

Boy, that's a crappy picture - it's too late to stay up and take another one, though. Time to get a real camera, I think.

But you can see the star shape, it's so perfect. Pentamerous symmetry in echinoderms fills me with wonder - the star or flower shape is such a symbol to us humans, an image embedded in our psyche. And there it is on that sea critter (well, that rock that was once a sea creature).

Patterns like that in nature appeal to my senses; the whorls of certain shells, the curls of waves, honeycombs in beehives, but most of all the amazing and mathematically beautiful design of ammonites and the chambered nautilus. (click that link, the picture is stunning). Wikipedia has a great article on the reoccurring appearance of the logarithmic spiral in nature.

I think Spira Mirabilis, the miraculous spiral, is possibly my favorite thing in the world.