Vi Hart’s phyllotaxis – with googly eyes! and glitter!

You guys know about Vi Hart, right? Check out her videos on “Spirals, Fibonacci, and Being a Plant”:

(And something you don’t see too often on youtube: notes and references, in video form, for the preceding three videos. If you like your phyllotaxis in text form, read “The Mathematical Lives of Plants” by Julie Rehmeyer.

“Are there spirals on other things that start with pine?”

Seriously, this is based on the usual observation that if the angle between leaves is 1/\phi rotations, where \phi=(1+\sqrt{5})/2, then leaves tend to be arranged in such a way that they don’t cover each other up. I actually hadn’t known that Lucas numbers show up in phyllotaxis as well — the relevant angle is 1/(2+\phi) of a circle. And the whole thing comes from the mutual repulsion of the growing leaves.

Less seriously, there are plants with smiley faces. And glitter.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s