Doodling in Math Class: Spirals, Fibonacci, and Being a Plant [1 of 3]
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0:00 - 0:02Say you're me and you're in Math class
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0:02 - 0:03and your teacher's talking about-
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0:03 - 0:05Well, who knows what your teacher's talking about.
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0:05 - 0:06Probably a good time to start doodling
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0:06 - 0:08and you're feeling spirally today, so, yeah.
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0:08 - 0:10Oh, and because of over-cutting in your school
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0:10 - 0:12your Math class is taking place in Greenhouse #3:
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0:12 - 0:13Plants!
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0:13 - 0:16Anyway, you've decided there are three basic types of spirals.
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0:16 - 0:18There's a kind where as you spiral out,
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0:18 - 0:20you keep the same distance, or you could start big
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0:20 - 0:21and make it tighter and tighter as you go around,
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0:21 - 0:23in which case the spiral ends,
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0:23 - 0:25or, you could start tight but make it bigger as you go out.
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0:25 - 0:27The first kind is good
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0:27 - 0:28if you really want to fill up a page with lines
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0:28 - 0:30or if you want to draw curled up snakes.
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0:30 - 0:32You can start with a wonky shape to spiral around.
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0:32 - 0:33But you've noticed that, as you spiral out,
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0:33 - 0:35it gets rounder and rounder,
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0:35 - 0:36probably something to do with
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0:36 - 0:38how the ratio between 2 different numbers approaches 1
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0:38 - 0:39as you repeatedly add the same number to both.
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0:39 - 0:42But you can bring the wonk back by exaggarating the bumps
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0:42 - 0:44and it gets all optical illusiony.
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0:44 - 0:46Anyway, you're not sure what the 2nd type of spiral's good for
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0:46 - 0:49but it's a good way to draw snuggled up Slug Cats
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0:49 - 0:50which are species you've invented
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0:50 - 0:53just to keep this spiral from feeling useless.
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0:53 - 0:56This 3rd spiral, however, is good for all sorts of things.
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0:56 - 0:57You could draw a snail or a Nautilus shell,
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0:57 - 0:59an elephant with a curled up trunk,
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0:59 - 1:01the horns of a sheep, a fern frond,
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1:01 - 1:04a cochlea in an inner ear diagram, an ear itself.
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1:04 - 1:05Those other spirals can't help
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1:05 - 1:08but be jealous of this clearly superior kind of spiral.
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1:08 - 1:09Better draw more Slug Cats.
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1:09 - 1:11Here's one way to draw a really perfect spiral:
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1:11 - 1:14Start with 1 square, and draw another next to it
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1:14 - 1:15that is the same height.
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1:15 - 1:17Make the next square fit next to both together.
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1:17 - 1:19That is, each side is length 2;
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1:19 - 1:21The next square has length 3.
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1:21 - 1:23The entire outside shape will always be a rectangle.
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1:23 - 1:26Keep spiralling around, adding bigger and bigger squares.
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1:26 - 1:32This one has side length 1,2,3,... 12,13, and now 21.
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1:32 - 1:33Once you do that, you can add a curve
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1:33 - 1:35going through each square, arcing from one corner
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1:35 - 1:38to the opposite corner. Resist the urge to zip quickly
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1:38 - 1:41across the diagonal if you want a nice, smooth spiral.
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1:41 - 1:43Have you ever looked at the spirally pattern on a pinecone
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1:43 - 1:45and thought 'hey, sure are spirals on this pinecone'?
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1:45 - 1:47I don't know why there're pinecones in your Greenhouse.
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1:47 - 1:49Maybe the Greenhouse is in a forest.
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1:49 - 1:51Anyway, there're spirals, and there's not just one either.
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1:51 - 1:54There are 1,2,3,...8 going this way,
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1:54 - 1:55or you could look at the spirals going the other way,
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1:55 - 1:59and there are 1,2,3,...12,13.
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1:59 - 2:00Look familiar?
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2:00 - 2:038 and 13 are both numbers in the Fibonacci Series.
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2:03 - 2:05That's the one where you start by adding 1 and 1 to get 2
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2:05 - 2:07and 1 and 2 to get 3, 2 and 3 to get 5,
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2:07 - 2:113+5=8, 5+8=13, and so on.
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2:11 - 2:14Some people think that instead of starting with 1+1
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2:14 - 2:19you should start with 0 and 1; 0+1=1, 1+1=2, 1+2=3,
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2:19 - 2:21and it continues on the same way as starting with 1+1
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2:21 - 2:24or I guess you could start with 1+0,
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2:24 - 2:25and that would work too
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2:25 - 2:27or why not go back one more to -1, and so on.
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2:27 - 2:29Anyway, if you're into the Fibonacci Series
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2:29 - 2:31you probably have a bunch memorized.
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2:31 - 2:33I mean you've got to know 1,1,2,3,5,
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2:33 - 2:35finish off the single digits with 8
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2:35 - 2:37and oh, 13, how spooky!
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2:37 - 2:38And once you're memorizing double digits,
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2:38 - 2:41you might at well know 21,34,55,89,
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2:41 - 2:42so that whenever someone turns a Fibonacci number,
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2:42 - 2:44you can say 'Happy Fibirthday!'
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2:44 - 2:48And then, isn't it interesting that 144,233,377?
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2:48 - 2:51But 610 breaks that pattern,
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2:51 - 2:52so you'd better know that one too...
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2:52 - 2:54And oh my goodness, 987 is a neat number!
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2:54 - 2:56And, well, you see how these things get out of hand.
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2:56 - 2:58Anyway, 'tis the season for decorative, scented pinecones.
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2:58 - 3:00and if you're putting glitter glue spirals
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3:00 - 3:02on your pinecones, uh, during Math class,
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3:02 - 3:04you might notice the number of spirals are 5 and 8,
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3:04 - 3:08or 3 and 5, 3 and 5 again, 5 and 8.
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3:08 - 3:09This one was 8 and 13
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3:09 - 3:11and one Fibonacci pinecone is one thing,
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3:11 - 3:14but all of them? What is up with that?
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3:14 - 3:15This pinecone has this wumpy, weird part.
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3:15 - 3:17Maybe that messes it up. Let's count the top.
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3:17 - 3:205 and 8, now let's check out the bottom: 8 and 13.
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3:20 - 3:23If you wanted to draw a mathematically realistic pinecone,
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3:23 - 3:25you might start by drawing 5 spirals one way,
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3:25 - 3:27and 8 going the other. I'm going to mark out
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3:27 - 3:29starting and ending points for my spirals first
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3:29 - 3:31as a guide, and then draw the arms,
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3:31 - 3:328 one way, and 5 the other.
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3:32 - 3:35Now I can fill in the little pineconey things.
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3:35 - 3:37So there's Fibonacci numbers in pinecones,
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3:37 - 3:38but are there Fibonacci numbers
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3:38 - 3:39in other things that start with 'pine'?
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3:39 - 3:41Let's count the spirals on this thing.
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3:41 - 3:471,2,3,... 8, and 1,2,3,... 13.
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3:47 - 3:49The leaves are hard to keep track of,
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3:49 - 3:51but they're in spirals too, of Fibonacci numbers.
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3:51 - 3:53What if we look at these really tight spirals
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3:53 - 3:54going almost straight up?
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3:54 - 4:011,2,3,....21! A Fibonacci number.
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4:01 - 4:03Can we find a third spiral on this pinecone? Sure!
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4:03 - 4:05Go down like this, and...
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4:05 - 4:101,2,3,.... 21!
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4:10 - 4:12But that's only a couple examples.
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4:12 - 4:13How about this thing I found on the side of the road?
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4:13 - 4:16I don't know what it is, it probably starts with 'pine' though.
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4:16 - 4:195 and 8. Let's see how far the conspiracy goes.
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4:19 - 4:21What else has spirals in it? This artichoke has 5 and 8.
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4:21 - 4:23So does this artichoke-looking flower thing,
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4:23 - 4:25and this cactus fruit does too.
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4:25 - 4:27Here's an orange cauliflower with 5 and 8,
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4:27 - 4:29and a green one with 5 and 8. I mean, 5 and 8.
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4:29 - 4:31Oh, it's actually 5 and 8.
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4:31 - 4:33Maybe plants just like these numbers though,
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4:33 - 4:35doesn't mean it has anything to do with Fibonacci,
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4:35 - 4:36does it?
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4:36 - 4:37So let's go for some higher numbers.
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4:37 - 4:39We're going to need some flowers.
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4:39 - 4:41I think this is a flower, it's got 13 and 21.
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4:41 - 4:43These daisies are hard to count, but they have 21 and 34.
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4:43 - 4:45Now let's bring in the big guns.
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4:45 - 4:551,2,3,4,......34!
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4:55 - 5:03And 1,2,3,4,5,........ 55!
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5:03 - 5:04I promise this is a random flower
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5:04 - 5:06and I didn't pick it out especially to trick you into thinking
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5:06 - 5:08that there're Fibonacci numbers in things.
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5:08 - 5:10But you should really count for yourself
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5:10 - 5:11next time you see something spirally.
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5:11 - 5:13There're even Fibonacci numbers
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5:13 - 5:15in how the leaves are arranged on this stalk,
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5:15 - 5:16or this one,
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5:16 - 5:18or the brussel sprouts on this stalk
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5:18 - 5:19are a beautiful, delicious 3 and 5.
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5:19 - 5:22Fibonacci is even in the arrangement of the petals on this rose,
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5:22 - 5:26and sunflowers have shown Fibonacci numbers as high as 144.
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5:26 - 5:28It seems pretty cosmic and wondrous,
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5:28 - 5:30but the cool thing about the Fibonacci series and spiral
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5:30 - 5:32is not that it is this big, complicated,
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5:32 - 5:34mystical, magical super-Math thing,
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5:34 - 5:36beyond the comprehension of our puny human minds
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5:36 - 5:38that shows up mysteriously everywhere.
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5:38 - 5:40We'll find that these numbers aren't weird at all.
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5:40 - 5:42In fact, it would be weird if they weren't there.
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5:42 - 5:44The cool thing about it is
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5:44 - 5:46that these incredibly intricate patterns
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5:46 - 5:55can result from utterly simple beginnings.
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