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"But without magnetic compasses, like all ancient sailors they would have struggled to find their way once the clouds came over." "Struggled", certainly, but P
by dalke 11y ago
"But without magnetic compasses, like all ancient sailors they would have struggled to find their way once the clouds came over."
"Struggled", certainly, but Polynesian sailors crossed the Pacific without a compass or sunstone. Quoting https://en.wikipedia.org/wiki/Polynesian_navigation https://en.wikipedia.org/wiki/Polynesian_navigation :
> Polynesian navigators memorize important facts: the motion of specific stars, so where they would rise and set on the horizon of the ocean; weather and the seasons of travel; wildlife species (which gather at particular positions); the direction, size, and speed of ocean waves; colors of the sea and sky, especially how clouds would cluster at the locations of some islands; and angles for approaching harbours.
Quoting from https://en.wikipedia.org/wiki/Mau_Piailug https://en.wikipedia.org/wiki/Mau_Piailug concerning the master navigator Mau Piailug:
> Prudent navigation relies on no single technique, but instead synthesizes position from multiple inputs. Underway, this constant synthesis makes it easy to spot the navigator—he's the one with red eyes from sleep deprivation.
I see no reason why the Norse wouldn't have had some of the similar navigation skills.
That doesn't mean they couldn't have used a sunstone, but rather that it's not unreasonable to believe that they could have navigated with only 'landmarks, birds and whales, and little else'.
- theoh 11y agoSynthesizing position from multiple inputs sounds like a process analogous to a Kalman filter.
- eximius 11y ago... Or common sense. You know, don't put all your eggs in one basket, etc.
- theoh 11y agoActually I thought it might add value to the discussion by making the comparison. We're mostly computer engineers here, after all. But never mind.
- dalke 11y agoIt's very little if anything like a Kalman filter. Or rather, as much like a Kalman filter as it is a PID controller. For example, Nainoa Thompson described part of learning to be a navigator from Mau Piailug. The full account is at http://pvs.kcc.hawaii.edu/ike/hookele/locating_land.html http://pvs.kcc.hawaii.edu/ike/hookele/locating_land.html . In short: > The diurnal flights of such birds are the most useful signs for expanding landfall, since their flights to and from an island gives a fairly specific direction to the wayfinder. As the birds leave an island in the morning, the wayfinder can sail in the direction the birds are coming from to find land; as the birds return to an island in the late afternoon, the wayfinder can follow the birds to land. In this case: > The night before that we saw the birds flying south so how come late in the morning with the sun very high was this bird coming out of the north? That would suggest that we passed the island during the night. But this interpretation was wrong: > Mau had seen in the beak of the bird a little fish and he knew that the birds were nesting. They had flown out to sea before sunrise and were taking food back at mid-morning to feed their young, before they flew out to sea again to feed themselves. How is this meaningfully like a Kalman filter?
- fapjacks 11y agoRight. They read the ocean swells like a map (and still do, though it is a dying bit of wisdom). I'm glad someone mentioned this.
- Florin_Andrei 11y agoThis is great. They literally milked the environment for every bit of data that it could provide to them, and combined all the inputs. I'm sure a lot of trial and error went into figuring out which inputs were reliable in which context.
- sosborn 11y agoAnd there are still doing it: http://www.hokulea.com http://www.hokulea.com
- pedrosorio 11y agoYeah, in a sense they were practicing Sensor Fusion: https://en.wikipedia.org/wiki/Sensor_fusion https://en.wikipedia.org/wiki/Sensor_fusion
- dsp1234 11y agobut Polynesian sailors crossed the Pacific without a compass or sunstone. I wonder if the types of ocean weather present in the Polynesian triangle vs the viking routes would have made it easier or harder to navigate without additional aids.
- AReallyGoodName 11y agoWell, weather aside, the keeled Polynesian sailboats with tringular sails are basically the modern sailboat standard with excellent into the wind performance. Longboats had no keel and were not nearly as advanced.
- deleted 11y ago[deleted]
- Outdoorsman 11y agoThat's an interesting point... I think it's certainly worth considering that ocean weathers and, especially, temperatures factor in... I would expect survival rates, in the event of an accident--tipping over, developing a leak, blowing off-course for a time--would be higher in a warmer climate... Water temperatures cold enough to induce hypothermia for a man or crew overboard most likely meant death... In other words, unfortunate Polynesian explorers and sailors were probably more likely to live to sail another day...