Hacker News Reader

Comment by davidw | Hacker News Reader

I've always wondered what the process was like for the people who made it to someplace like Rapa Nui (Easter Island), which is a tiny speck in the middle of a vast ocean. Was it some kind of shotgun approach where a lot of expeditions were launched, and a very few hit a target and the others either perished or turned around?

View on HN

Islands leave distinctive cloud formations in their wake, sometimes stretching many hundreds of miles. Here's an example from satellite photography: http://m.earthobservatory.nasa.gov/NaturalHazards/view.php?i...

A popular theory is that Polynesian navigators would hone in on these cloud patterns in the sky, treating them as the big arrows in the sky pointing to land that they essentially are.

Another navigation aid was birds. They knew the maximum flight time of certain types of bird, and therefore if you saw that species, you would know you were within a certain radius of land.

"Islands leave distinctive cloud formations in their wake"

Only islands with high peaks, which means most likely, volcanic islands. Which happens to be true for large islands in the pacific. As opposed to purely coral islands which rise just above the sea level.

Very true. However, flat, forested islands can reflect a greenish color onto whatever clouds might be above them.

The volcanic islands tend to form pearl-chains... one making a law from the faultlines, can follow that line

There's a lot of speculation on this. But the colonization ships were not accidents or lost fishing boats; they brought fully stocked large boats with plant seeds and breeding animals. Not to mention a mix of women and men. Most places like Hawai'i were regularly visited for hundreds of years. Rapa Nui is a bit more of an exception.

I've seen it suggested that some of the discoveries may have indeed been accidents . . . the losers in a conflict would be banished from the island, and the lucky ones would find somewhere new to go. The unlucky would perish.

However, Polynesian navigation was quite sophisticated. They followed the stars at night; they could read the ocean to tell where land was; they could follow sea birds to roosting places.

> they could read the ocean to tell where land was; they could follow sea birds to roosting places.

That enlarges your target some, but still... over those kinds of distances, to hit a speck of land like Easter Island seems pretty amazing.

It seems crazy but these people lived their entire lives on small islands and had nothing else to do but master what little information surrounded them.

I've heard stories of Islanders that could detect different types of fish from surface wave patterns.

I get their mastery of the environment they knew. Say, navigating between inhabited islands, or doing long fishing trips, or that kind of thing. What I don't get is how they bumped into stuff like Easter Island for the first time. The clouds mentioned in another comment seem kind of plausible, but even still, it seems pretty amazing.

This isn't as difficult as you think. When you know an area well, you know what species of fish are likely to be around - down to specific habitats like rocky vs sandy coastline, and even particular arrangements of rocks or sand formation. After a while you notice their behaviours and specifically behaviours distinct from other species (e.g. bottom feeding, surface hunting, swimming style etc). So it's more of a combination of inputs that gives you an educated guess as to the fish you can't see, based on what you know about the area as well as fish behaviour. Anecdotally, I have an avid fisher of an uncle (more than one actually...) who is able to tell what species of fish he's hooked before he can even see it.

Also, There were a lot more fish in the sea back then and thus it was easier to live off the land while sailing.

Those guys had to have been absolutely top-notch fishermen, too. I'd have to think drinking water might be a more limiting factor, although some parts of the tropics certainly have daily rains that would likely provide that.

More than anything, I just wonder how they managed to cross thousands of miles of open water and hit relatively tiny targets.

It's hard to imagine these days but back then you could catch so much fish, you could easily retrieve enough fluid (blood) from them that you wouldn't need any rain.

Don't forget that fish eyes are a good source of fresh water too!

Man, I hope I never need this information.

Many oceanic fish also have non trivial amounts potable fluid along their spines.

Reply on news.ycombinator.com