The author of this lesson started a big movement on a small island.
Stick around after this episode to learn more.
Imagine setting sail from Hawaii in a canoe.
Your target is a small island thousands of kilometers away
in the middle of the Pacific Ocean.
That’s a body of water that covers more than 160 million square kilometers,
greater than all the landmasses on Earth combined.
For thousands of years,
Polynesian navigators managed voyages like this
without the help of modern navigational aids.
Ancient Polynesians used the Sun,
and clouds as guides that
allowes them to see the ocean as a series of pathways
rather than an obstacle.
Their voyages began around 1500 B.C.
when the people who would settle Polynesia first set sail from Southeast Asia.
Early Polynesians eventually settled a vast area of islands
spread over 40 million square kilometers of the Pacific Ocean.
Some historians believe the voyagers moved from place to place
to avoid overpopulation.
Others, that they were driven by war.
Voyages became less frequent by around 1300 A.D.
as Polynesian societies became more rooted in specific locations.
During the voyaging period,
successful journeys depended on a number of factors:
the skill of navigators,
and weather being some of the biggest.
Voyages relied on sturdy wa’a kaulua, or double-hulled canoes,
which were powered by sails and steered with a single large oar.
Canoe building involved the whole community,
bringing together the navigators,
and hula dancers.
Navigators were keen observers of the natural world.
They were abundantly familiar with trade wind-generated ocean swells,
which typically flow northeast or southeast.
By day, navigators could identify direction
by the rocking motion of their canoes caused by these swells.
But sunrise and sunset were even more useful.
The Sun’s position indicated east and west
and created low light on the ocean
that made it possible to see swells directly.
At night, navigators used something called a star compass,
which wasn’t a physical object, but rather a sort of mental map.
They memorized the rising and setting points of stars and constellations
at different times of the year.
They used those to divide the sky into four quadrants,
subdivided into 32 houses,
with the canoe in the middle.
So, for example, when they saw the star Pira‘atea rising from the ocean,
they knew that to be northeast.
They had some other tricks, too.
The Earth’s axis points towards Hokupa’a, or the North Star,
so called because it’s the one fixed point in the sky as the Earth rotates
and always indicates north.
However, it’s not visible south of the Equator,
so navigators there could use a constellation called Newe,
or the Southern Cross,
and some mental tricks to estimate where south is.
For instance, draw a line through these two stars,
extend it 4.5 times,
and draw another line from there to the horizon.
But the sky also contains navigational aids much closer to Earth,
Besides being useful weather cues,
under the right conditions, they can indicate landmasses.
For instance, the lagoons of Pacific atolls
can actually be seen reflected on the underside of clouds,
if you know what to look for.
And high masses of clouds can indicate mountainous islands.
Once navigators neared their destination, other clues,
such as the flight patterns of birds,
floating debris or vegetation,
and types of fish in the area helped determine the proximity of land.
比如 白燕鸥的飞行里程可达190公里 它也因此闻名
For example, the Manu-O-Ku had a known flight range of 190 kilometers,
and could be followed back to shore.
So how do we know all of this?
Partially through evidence in petroglyphs,
written observations of European explorers,
and Polynesian oral traditions.
But also by trying them out for ourselves.
In 2017, a voyaging canoe called Hokulea
completed a worldwide voyage using only these techniques.
If that seems remarkable, remember the ancient Polynesians,
who through close study and kinship with nature,
were able to forge these paths across
an unfathomably vast, vibrant living ocean.
The educator behind this lesson helps TEDEds Student Voice Program
find its way to Hawaii
Over 30 TEDEds Clubs have since formed in the Hawaii Islands,
and thousands more across the globe.
What if every educator and student subscribes to TEDEd,
follows Alan’s lead.
Navigate to ED.TED.COM/CLUBS
to be the founder of the first TEDEd Club at your school.
波利尼西亚的探险者如何驾驭太平洋？ - Alan Tamayose和Shantell De Silva