Name: TED-Ed】波利尼西亞人的航標是如何航行在太平洋上的？- Alan Tamayose和Shantell De Silva (【TED-Ed】How did Polynesian wayfinders navigate the Pacific Ocean? - Alan Tamayose and Shantell De Silva)
Uploaded: 2021-01-14T07:08:00.000Z
Duration: 5 min 32 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

Imagine setting sail  from Hawaii in a canoe.

Your target is a small island thousands of kilometers away

That's a body of water that covers more than 160 million square kilometers,

greater than all the landmasses  on Earth combined.

Polynesian navigators managed voyages  like this

without the help  of modern navigational aids.

and clouds as guides that allowed them to see the ocean as a series of pathways

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

Voyages became less frequent by around 1300 A.D.

as Polynesian societies became more rooted in specific locations.

successful journeys depended on  a number of factors:

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,

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

They used those to divide the sky into four quadrants,

So, for example, when they saw the star Pira‘atea rising from the ocean,

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

However, it's not visible  south of the Equator,

so navigators there could use a constellation called Newe,

and some mental tricks to estimate where south is.

For instance, draw a line through these two stars,

and draw another line  from there to the horizon.

But the sky also contains  navigational aids much closer to Earth,

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,

And high masses of clouds can indicate mountainous islands.

Once navigators neared their destination, other clues,

and types of fish in the area helped determine the proximity of land.

For example, the Manu-O-Ku had a known flight range of 190 kilometers,

Partially through evidence in petroglyphs,

written observations  of European explorers,

But also by trying them out for ourselves.

completed a worldwide voyage  using only these techniques.

If that seems remarkable, remember the ancient Polynesians,

who through close study  and kinship with nature,

an unfathomably vast,  vibrant living ocean.

TED-Ed】波利尼西亞人的航標是如何航行在太平洋上的？- Alan Tamayose和Shantell De Silva (【TED-Ed】How did Polynesian wayfinders navigate the Pacific Ocean? - Alan Tamayose and Shantell De Silva)