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Did the Vikings use crystal ‘sunstones’ to discover America?
- dang 11y agoUrl changed from http://www.universal-sci.com/headlines/2016/2/9/did-the-vikings-use-crystal-sunstones-to-discover-america http://www.universal-sci.com/headlines/2016/2/9/did-the-viki..., which points to this.
- 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.
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- 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...
- rusanu 11y ago- Icelandic rocks could have steered Vikings (2011) [0] - 'Viking sunstone' found in shipwreck (2013) [1] - Crystals 'helped Viking sailors' (2007) [0] http://www.bbc.com/news/science-environment-15523520 http://www.bbc.com/news/science-environment-15523520 [1] http://www.bbc.com/news/world-europe-21693140 http://www.bbc.com/news/world-europe-21693140 [2] http://news.bbc.co.uk/2/hi/europe/6338535.stm http://news.bbc.co.uk/2/hi/europe/6338535.stm
- halviti 11y agoThey were described reasonably well in multiple sagas, listed on inventory sheets, and they actually found one in a shipwreck. https://en.wikipedia.org/wiki/Sunstone_(medieval) https://en.wikipedia.org/wiki/Sunstone_(medieval) IMHO, I think is sufficient evidence to say that it is reasonably likely they were using these.
- Luc 11y agoI'm sure people have found all kinds of stuff described reasonable well in myths. Isn't there books written about UFO sightings in the bible? Churches and monasteries had them in their inventories, but how does that prove they were used for navigation? It would be like churches keeping sextants under the altar. It doesn't make sense. The shipwreck that contained the calcite was found far away in the Channel and dated 500 years after the vikings. And there's no record of it in any navigation books of the time. It's myths and internet memes, being propagated over and over again. I don't doubt it'll be on HN again 3 months hence.
- empath75 11y agoI think there's a different level of skepticism needed for ufos and fairly simple piece of technology. While I don't think the case has been proved its certainly one of those things where there's a reasonable chance of it being true.
- Luc 11y agoNah, it doesn't pass the sniff test once you start looking at the details. I don't have time now, but you could look in the archives of NavList at fer3.com for more info.
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- will_walker 11y agoI recently started designing and making jewelry. I'm particularly fascinated by Iolite. [Iolite]("https://en.wikipedia.org/wiki/Cordierite" https://en.wikipedia.org/wiki/Cordierite") is commonly referred to as "water sapphire" or "viking's compass". This is because it changes in tone depending on it's angle to the sun. Historically it would have been useful because the effect works regardless of cloud cover and even when the sun is below the horizon. I'm not sure if the nickname is a historic remainder or attached during modernity (the jewelry industry is both ancient and opaque) but the effect is real, and could potentially be of concrete utility during navigation.
- dalke 11y agoThis article says that the three likely possibilities for 'sunstone' (if it really was used for navigation) are calcite, tourmaline, and cordierite. It was Thorkild Ramskou who made this hypothesis in the 1960s. I strongly suspect it didn't gain the poetic moniker 'Viking's compass" until afterwards. Moreover, if it were used in the jewelry industry before the 1960s then it would be strong supporting evidence for the hypothesis.
- GeorgeRichard 11y ago"... it changes in tone depending on it's angle to the sun ... the effect works ... even when the sun is below the horizon." This sounds like magic. Have you observed this effect yourself and do you have an explanation for it or a reference to one?
- analog31 11y agoI'll have to check it out, next chance I get, with a polarizer. One thing that could be exploited is that the sunlight scattered by the ionosphere (why the sky is blue) is polarized, so the polarization axis could be the clue.
- dalke 11y agoAccording to your link, that's the case. It only works when the sun is just below the horizon so there is still scattered light in the sky.
- kayman 11y agoI know tv is not a source of truth, but an interesting side note, in the Netflix series, Vikings, they used a sunstone.
- toomanybeersies 11y agoGetting slightly off topic, but Vikings is a History channel production, not a Netflix show.