[Coral-List] Coral reefs and etnomathematics

[Douglas Fenner]

       Stick charts are maps of where atolls are and which way waves move,
used by the Micronesian people of the Marshall Is.
https://en.wikipedia.org/wiki/Marshall_Islands_stick_chart   They appear to
be unique to the Marshall Is and so were likely invented there, long ago.
Fascinating.  You can buy stick charts in shops in the Marshall Is.  Today,
people in the Marshall Is. sail very fast outrigger canoes made of local
materials to go across the lagoons to tend their gardens and/or coconuts on
islands they don't live on (the lagoons are often like large lakes).  The
hulls are asymmetrical, and the outrigger, etc flex with the waves.  They
zip around in them like race cars.  They still build them.  A superior
design.  Pretty cool.  The peoples of the Pacific were the world's greatest
navigators for about 2000 years, and discovered the last bits of land left
in the world that were uninhabited, across vast open ocean distances.  I go
out with people in a modest size western motor boat and once out of sight
of land it starts to get scary if the waves build up, it can be extremely
dangerous, and they were in tiny little flImsy outrigger canoes, living by
catching rainwater and fish, for weeks or months, at least for exploring
(in many cultures they built larger catamarans for voyaging to settle,
re-created by the Hawaiian voyaging catamaran Hōkūleʻa that has now circled
the  globe https://en.wikipedia.org/wiki/Polynesian_Voyaging_Society).  And
they did it all without a compass or star chart or formal instruction.
They knew where they were at using a wide variety of acute observations of
nature, like waves, stars, clouds, seabirds, seaweed, etc.  The canoes were
built without any nails, entirely with lashings holding them together (no
nylon ropes, only sennit fibers from coconuts).  We know that people went
back and forth between archipelagoes periodically, knew how to find them
and knew what was there.  There are stone adzes in French Polynesia that
have stone that came from an island in Hawaii, as far away as London is
from New York.  Today, flying in a commercial jet at over 500 miles an
hour, that takes about 5 hours to get there, and they did it in tiny canoes
with no compass.  Tonga ruled the Samoas for a while.  There are stone axes
from the Samoas scattered around the Pacific, we know because the chemical
composition of the rock differs slightly between archipelagoes and islands
(atolls don't have the basalt volcanic rock that is hard enough to make
adzes with, all they have is soft coral rock, though shells were hard
enough to make cutting tools and fish hooks).  Madagascar was first settled
by people from Indonesia, on the other side of the Indian Ocean
https://en.wikipedia.org/wiki/Madagascar.  Most of the peoples of the
Pacific, including Indonesia, the Philippines, original groups in Taiwan,
and first settlers in Madagascar, Micronesians and Polynesians are all
"Austronesian" people, all speaking Austroneisan languages thought to
originate from Taiwan (because all four basal branches of the language
family are there and three are only there).  People in the Cook Is.
discovered and settled the last large land on earth that was uninhabited,
between about 1280 and 1350, we call it New Zealand today
https://en.wikipedia.org/wiki/New_Zealand.  The oral history tells who
discovered it, how many trips they made to it, how many voyaging catamarans
went to settle it, and the amount of genetic variation in the Maori people
today is consistent with that number of initial settlers.  The Polynesian
wave of island discovery and settlement started about 3000 years ago, the
Micronesian wave perhaps a bit earlier (both likely from the
Philippines-Indonesia area).  Melanesian people are from a much earlier
wave of people, at least 35,000 years ago.  The presence of people in
Australia as long as 65,000 years ago is the first hard evidence of some
kind of floating vessel, maybe a raft or dugout canoe, because there is one
gap in Indonesia of deep water 50 miles wide that never has had a land
bridge, and few if any humans can swim that far without help from a boat.
Many Melanesian people New Guinea and nearby island coastlines speak
Austronesian languages they surely picked up from the relative newcomers.
There are about 1000 Austronesian languages.  Incredible.
  Cheers, Doug

On Sun, Feb 28, 2021 at 4:10 AM David Blakeway via Coral-List <
coral-list at coral.aoml.noaa.gov> wrote:

> Hi Vassil,
> I didn't know what ethnomathematics was so looked it up. A concise
> definition is "the study and presentation of mathematical ideas of
> traditional peoples" (Ascher 1991. Ethnomathematics: A Multicultural View
> of Mathematical Ideas).
> So that could get interesting with respect to reefs. Polynesian stick
> charts for navigating between atolls seem quite mathematical, like a
> Cartesian graph. And the layout of building foundations indicates an
> understanding of rules for squaring things up, probably 'equal diagonals'.
> All reef cultures would have a good understanding of cyclical time and
> temporal patterns in reef biota. But I don't know of reef-specific
> mathematical concepts. People must have wondered about the rules underlying
> geometric patterns in corals and reefs... why are you asking, did you come
> across something?
> One sure thing is that most of this precious knowledge is gone. As one of
> the early 19th century naturalists put it: "*...sunk in the sea of oblivion
> just at the moment when they were placed into our hands*."
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