GIRL
Say you're me in your math class and your teacher's talking about… Well, who knows what your teacher's talking about. Probably a good time to start doodling, and you're feeling spirally today, so, yeah. Oh, and because of overcrowding in your school, your math glass is taking place in Greenhouse No.3 — plants.
Anyway, you've decided there's three basic types of spirals. There's the kind where as you spiral out you keep the same distance. Or you can start big but make it tighter and tighter as you go around, in which case the spiral ends. Or you could start tight but make the spiral bigger as you go out.The first kind is good if you really want to fill up a page with lines or you want to draw curled up snakes. You can start with a wonky shape to spiral around, but you've noticed that as you spiral out it gets rounder and rounder. Probably something to do with how the ratio between two different numbers approaches one as you repeatedly add the same number to both. But you can bring the wonk back by exaggerating the bumps, and it gets all optical-illusiony.Anyway, you're not sure what the second kind of spiral is good for, but I guess it's a good way to draw snuggled up slug cats, which are a species you've invented just to keep this kind of spiral from feeling useless.This third spiral, however, is good for all sorts of things. You could draw a snail or a Nautilus shell, an elephant with a curled up trunk, the horns of a sheep, a fern frond, a cochlea and an inner ear diagram, an ear itself. Those other spirals can't help but be jealous of this clearly superior kind of spiral. Better draw more slug cats.Here's one way to draw a really perfect spiral. Start with one square and draw another next to it that is the same height. Make the next square fit next to both together — that is, each side is length two. The next square has length three. The entire outside shape will always be a rectangle. Keep spiralling around, adding bigger and bigger squares. This one has side length… one, two, three, four, five, six, seven, eight, nine, ten, 11, 12, 13, and now 21. Once you do that, you can add a curve going through each square, arcing from one corner to the opposite corner. Resist the urge to zip quickly across the diagonal if you want a nice, smooth spiral.
She takes out a pine cone
GIRL
Have you ever looked at the spirally pattern on a pine cone and thought, 'Hey, there sure are spirals on this pine cone'? I don't know why there's pine cones in your greenhouse. Maybe the greenhouse is in a forest. Anyway, there's spirals and there's not just one either, there's… one, two, three, four, five, six, seven, eight going this way. Or, you could look at the spirals going the other way and there's… one, two, three, four, five, six, seven, eight, nine, ten, 11, 12, 13. Look familiar? 8 and 13 are both numbers in the Fibonacci series — that's the one where you start by adding one and one to get two, then one and two to get three, two and three to get five. Three plus five is eight, five plus eight is 13, and so on.
Some people think that instead of starting with one plus one you should start with zero and one. Zero plus one is one, one plus one is two, one plus two is three, and it continues on the same way as starting with one and one. Or, I guess you could start with one plus zero and that would work too. Or, why not go back one more to negative one and so on?Anyway, if you're into the Fibonacci series, you probably have a bunch memorised. I mean, you've got to know one, one, two, three, five. Finish off the single digits with eight and, ooh, 13, how spooky! And once you're memorising double digits, you might as well know 21, 34, 55, 89, so that whenever someone turns a Fibonacci number you can say, 'Happy fib-birthday!' And then, isn't it interesting that 144, 233, 377? But 610 breaks that pattern, so you'd better know that one too. And, oh, my goodness, 987 is a neat number, and, well, you see how these things get out of hand.Anyway, 'tis the season for decorative scented pine cones, and if you're putting glitter glue spirals on your pine cones during math class, you might notice that the number of spirals are five and eight, or three and five or three and five again. Five and eight. This one was eight and 13. And one Fibonacci pine cone is one thing, but all of them? What is up with that?
She takes out another small pine cone
GIRL
This pine cone has this lumpy weird part, maybe that messes it up. Let's count the top. Five and eight. Now, let's check out the bottom. Eight and 13. If you wanted to draw a mathematically realistic pine cone, you might start by drawing five spirals one way and eight going the other. I'm going to mark out starting and ending points for my spirals first, as a guide, and then draw the arms — eight one way and five the other. Now I can fill in the little pine-coney things. So, there's Fibonacci numbers in pine cones, but are there Fibonacci numbers in other things that start with 'pine'?
She produces a pineapple
GIRL
Let's count the spiral on this thing. One, two, three, four, five, six, seven, eight. And, one, two, three, four, five, six, seven, eight, nine, ten, 11, 12, 13. The leaves are hard to keep track of, but they're in spirals too — of Fibonacci numbers. What if we looked up these really tight spirals going almost straight up? One, two, three, four, five, six, seven, eight, nine, ten, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21. A Fibonacci number. Can we find a third spiral on this pine cone? Sure. Go down like this. And… one, two, three, four, five, six, seven, eight, nine, ten 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21. But that's only a couple of examples.
She produces another plant
GIRL
How about this thing I found on the side of the road? I don't know what it is. It probably starts with 'pine', though. Five and eight. Let's see how far the conspiracy goes. What else has spirals in it? This artichoke has five and eight, so does this artichoke-looking flower thing and this cactus fruit does too. Here's an orange cauliflower with five and eight, and a green one with five and eight. I mean, five and eight. Oh, there's actually five and eight. Maybe plants just like these numbers though — doesn't mean it has anything to do with Fibonacci, does it? So, let's go for some higher numbers. We're going to need some flowers.
She produces a plant
GIRL
I think this is a flower. It's got 13 and 21.
She produces a daisy
GIRL
These daisies are hard to count, but they have 21 and 34. Now, let's bring in the big guns.
She produces another flower, with a detailed pattern in its centre
GIRL
One, two, three, four, five, six, seven, eight, nine, ten, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34. And… one, two, three, four, five, six, seven, eight, nine, ten, 11, 12… 53, 54, 55. I promise this is a random flower and I didn't pick it out specially to trick you into thinking that there's Fibonacci numbers in things, but you should really count for yourself next time you see something spirally.
There's even Fibonacci numbers in how the leaves are arranged on this stalk, or this one, or the Brussels sprouts on this stalk are a beautiful, delicious three and five. Fibonacci is even in the arrangement of the petals on this rose, and sunflowers have shown Fibonacci numbers as high as 144.It seems pretty cosmic and wondrous, but the cool thing about the Fibonacci series and spirals is not that it's this big, complicated, mystical, magical, super-math thing beyond the comprehension of our puny human minds that shows up mysteriously everywhere — we'll find that these numbers aren't weird at all. In fact, it would be weird if they weren't there. The cool thing about it is that these incredibly intricate patterns can result from utterly simple beginnings.