
Fractal planting patterns yield optimal harvests, without central control - dnetesn
https://phys.org/news/2017-06-fractal-patterns-yeild-optimal-harvests.html
======
chrismealy
This reminds me of something from Sam Bowles's "Microeconomics":

 _Like the overnight train that left me in an empty field some distance from
the settlement, the process of economic development has for the most part
bypassed the two hundred or so families that make up the village of Palanpur.
They have remained poor, even by Indian standards: less than a third of the
adults are literate, and most have endured the loss of a child to malnutrition
or to illnesses that are long forgotten in other parts of the world. But for
the occasional wristwatch, bicycle, or irrigation pump, Palanpur appears to be
a timeless backwater, untouched by India’s cutting edge software industry and
booming agricultural regions. Seeking to understand why, I approached a
sharecropper and his three daughters weeding a small plot. The conversation
eventually turned to the fact that Palanpur farmers sow their winter crops
several weeks after the date at which yields would be maximized. The farmers
do not doubt that earlier planting would give them larger harvests, but no one
the farmer explained, is willing to be the first to plant, as the seeds on any
lone plot would be quickly eaten by birds. I asked if a large group of
farmers, perhaps relatives, had ever agreed to sow earlier, all planting on
the same day to minimize losses. “If we knew how to do that,” he said, looking
up from his hoe at me, “we would not be poor.”_

~~~
SagelyGuru
That story makes no sense. If those farmers of Palanpur can not agree to plant
all together at the right time, how come they manage it several weeks later,
or ever?

~~~
comicjk
At some point, the individual losses from planting later become larger than
the losses from birds. Then somebody plants, and then they all do. The first
farmer to plant loses more to birds than everyone else, but less than he would
by delaying more.

------
aetherspawn
I didn't understand:

1\. how they didn't have pest problems if they planted in fractal patterns

2\. but they did have pest problems if they didn't plant at the same time

Could someone kindly explain that in a little more depth?

~~~
oelmekki
> When farmers are planting at different times, pests can move from one field
> to another, but when farmers plant in synchrony, pests drown and the pest
> load is reduced.

The strategy is that if there are several fields planted for the same amount
of bugs, each field receive less bugs than if it was the only one planted (on
the contrary, if they were planted one after an other, the whole bug
population would just jump from field to field).

~~~
aetherspawn
Thanks, I thought when it said drown it literally meant something to do with
water but this makes a lot of sense now.

~~~
mamon
Yes, they meant literal drowning of bugs when the field is flooded with water,
which is one of the stages of growing rice. Bigger the area flooded at once,
lower the chance for the average bug to escape. Fractal pattern arises as a
trade-off because water supply is limited - if it wasn't for that they would
probably just flood ALL the fields at once.

------
jcoffland
I fail to see how the planting patterns are fractal. A fractal pattern is one
which repeats itself at different scales. I realize that the repetition does
not need to be exact but I don't see how there is any at all in this
situation.

~~~
FullMtlAlcoholc
Actually, that is only one type of fractals. Perfectly self similar patterns
like the Triforce or Sierpensky triangle are used as toy models for learning .
Typically, fractals in nature are not self similar(Branching of your blood
vessels for example) . Mandelbrot developed fractal geometry as a way to model
nature that captures roughness. It was kind of a rebellion against calculus,
where if you zoom in eventually you get smoothness. It's funny that many
people think that only self similar patterns are fractals when his desire was
to get away from idealized models towards more pragmatic ones

EDIT: I'm actually just learning about fractals, so I'm certainly no expert,
but I'm excited to share what I've learned so far.

Look at a line, square, and cube in 1, 2, and 3 dimensions respectively. If
you scale down each by 1/2 in all its dimensions, you need to look at how much
of the "mass" (for lack of a better term is scaled down

If you cut a line in 1/2, it's mass is scaled by 1/2 as it takes 2 one-half
length lines to make the original line.

If you scale a square down 1/2 along all its dimensions, you break into/scale
it down into 4 smaller squares, it's mass scaling factor is 1/4....scaling a
cube down 1/2 along all its dimensions (1/2)^2 breaks it into 8 smaller
cubes...it's scaling factor is 1/8 and you can see the progression here.
(1/2)^3. (I imagine a tesseract/hypercube has a scaling of 1/16 as it is the
4D analogue of a cube) The exponent represents the concept of dimension and
this is how you can have non-integer dimensions.

So, back to the Sierpenski triangle or triforce example. Let's scale it down
1/2\. When we do that, we know we get 1/3 the "mass" of the original since
there are 3 triangles contained in the larger triangle at each level. The
dimensionality is then (1/2)^x = 1/3 where x is the dimensionality. We rewrite
this as log 3 base 2 which gives it a dimensionality of ~1.585.

And that is the definition of a fractal, a shape with a non-integer dimension
which gives the shape roughness at every scale. I don't quite understand the
more technical definition, but hopefully this helps!

Note, you cannot use length or area as a measurment for a scaling factor, as
the length would be infinite and area would be 0. Also, I say mass because the
more correct concept is difficult for me to explain without a whiteboard, but
basically, it has to do with putting the fractal on a 2d grid, scaling it, and
seeing what the ratio of boxes touched is. See, told you I'm bad at explaining
it :D

~~~
FullMtlAlcoholc
I forgot to add that fractal dimensionality is a clear differentiator between
natural and man made things. So, it does make some sense to separate the
natural from the synthetic.

Off topic, but does anyone know how this would affect the Fermi Paradox if
aliens produce technology inherently fractal in nature?

~~~
jacobolus
You might enjoy
[https://www.youtube.com/watch?v=gB9n2gHsHN4](https://www.youtube.com/watch?v=gB9n2gHsHN4)

~~~
FullMtlAlcoholc
I did enjoy it, if you can't tell from the content of my original post. I
never quite knew what fractals were until yesterday afternoon. After 30
minutes of youtube, I'm explaining it to someone else, although at a 10 yr
old's level.

------
ggrothendieck
There is an agent-based model of Balinese irrigation written in NetLogo here:
[https://www.openabm.org/model/2221/version/3/view](https://www.openabm.org/model/2221/version/3/view)

------
chriswarbo
This looks very interesting from a regulation point of view, as a potential
way to bring greedy self-interest into alignment with national/international
social interest. I wonder what scenarios could be given a "pest tax", to alter
the dynamic from a tradgedy of the commons to a cooperative/competitive
optimum?

~~~
chiefalchemist
There's plenty of science against (20th century) top heavy / top down control.
The issue seems to be: the current power holders admitting their model is
flawed; and those being managed realized they'd be better off without
"leadership."

~~~
chriswarbo
> top heavy / top down control

Could you characterise what is meant by this?

I know that achieving some objective 'X' may not be amenable to regulation
which says 'you must do X'; but regulation may (in some circumstances, with
sufficient thought) alter the situation's dynamics such that greedy self-
interest in that environment just-so-happens to coincide with causing 'X'.

What better alternatives are there to "top down control"; do you mean a "vote
with your wallet" sort of 'bottom up' pressure?

~~~
chiefalchemist
Centralized, as opposed to decentralized. I would say these farms/farmers are
decentralized. There's no gov agency, with some academia pencil pusher in some
removed city overseaing them. They've figured it out. And they will continue
to do so.

p.s. Team of Teams (book) does a great job flying to decentralized flag.

------
kakarot
Now how can I apply this to Dwarf Fortress?

~~~
anigbrowl
That's an absolutely valid question that doesn't deserve to be downvoted.
Generalizing these insights for deployment is absolutely a problem worth
solving.

~~~
kakarot
Haha, people can be such assholes sometimes.

Dwarf Fortress doesn't currently have crop pests, but it's reasonable to
assume it will within a decade. Tarn plans to spend the rest of his life
working on it.

Dwarf Fortress is a game about decentralized, organized planning so once pests
are added we'll see pages and pages of discussion about the best way to plan
your fractal farm.

Sure, I was being half serious but c'mon people have a sense of humor.

------
abhinai
TLDR; Locally collaborative greedy planting strategy leads to globally optimal
results and looks like a fractal from above. Mind == Blown.

------
havella
this is very interesting, wondering the principle applies to societal
organization and current reversal trends on globalization (mono-culture) and
weakening of international 'controlling' organizations.

~~~
gumby
Actually this _depends_ on a monoculture as it is an adaptation to the life
cycle of the rice (paddy) plant and its water requirements. If different
farmers were growing different crops the requirements would vary.

------
marmshallow
Can anyone find sample satellite imagery that illustrates the fractal
patterns? I didn't see any in the article or with a quick google search.

~~~
DanBC
Fractal doesn't appear in the paper. I'm not sure where phys.org gets the word
fractal from.

Here's some figures which might help with satellite image searches.

[http://www.pnas.org/content/early/2017/05/31/1605369114.figu...](http://www.pnas.org/content/early/2017/05/31/1605369114.figures-
only)

------
chiefalchemist
Is this a form of emergence?

~~~
rubidium
Yes... both profs are external sante fe institute members. That's kindof their
chorus.

~~~
chiefalchemist
Can you recommend a book or two on emergence? I've seen it mentioned. It
intrigues me. But I haven't been able to find anything sold for going deeper.
TIA

~~~
rubidium
First read "more is different". Solid state physicists were first to pioneer
in this field:
[http://robotics.cs.tamu.edu/dshell/cs689/papers/anderson72mo...](http://robotics.cs.tamu.edu/dshell/cs689/papers/anderson72more_is_different.pdf)

There's a very light book by some modern author that's not terrible:
Emergence: The Connected Lives of Ants, Brains, Cities, and Software
[https://www.amazon.com/dp/0684868768/ref=cm_sw_r_cp_api_3Wxp...](https://www.amazon.com/dp/0684868768/ref=cm_sw_r_cp_api_3WxpzbP55A6WW)

If you want to really dig in though you need some math: Emergence of Dynamical
Order: Synchronization Phenomena in Complex Systems (World Scientific Lecture
Notes in Complex Systems, Vol. 2)
[https://www.amazon.com/dp/9812388036/ref=cm_sw_r_cp_api_.Yxp...](https://www.amazon.com/dp/9812388036/ref=cm_sw_r_cp_api_.Yxpzb925HPYX)

Final suggestion is most of the stuff is online at different professors
websites. Warning: the field is full of meaningless fluff too, and there's a
lot of qucks mixed in with genuinely interesting science.

~~~
chiefalchemist
Thanks.

------
anigbrowl
These insights will be useful for my political project.

------
Polarity
so: monolithic frameworks vs loose coupled components?

