Sunstone Unearthed From Sixteenth Century Shipwreck

sciencehabit writes "In 1592, a British ship sank near the island of Alderney in the English Channel carrying an odd piece of cargo: a small, angular crystal. Once it was brought back to land, a few European scientists began to suspect the mysterious object might be a calcite crystal, a powerful 'sunstone' referred to in Norse legends which they believe Vikings and other European seafarers used to navigate before the introduction of the magnetic compass. Now, after subjecting the object to a battery of mechanical and chemical tests, the team has determined that the Alderman crystal is indeed a calcite and, therefore, could have been the ship's optical compass. Today, similar calcite crystals are used by astronomers to analyze the atmospheres of exoplanets—perhaps setting the stage for a whole new age of exploration."

Prime example of scientific tunnel-vision?

[the biologist]

I hope that by "battery of mechanical and chemical tests", they meant "showed it to a geologist for five minutes". There are a number of minerals which can mimic calcite to the untrained eye, but they're easy for the specialist to distinguish.

lost knowledge?

[k6mfw]

In a discussion I had with a friend the other day about how did Vikings navigate? Mostly poor weather (no star sightings) and very close to magnetic north pole (compass is useless), or they only traveled part of year when weather was not really bad. One story I heard is they used pressure as a means of navigation. Huh? don't ask me, that is what someone else said. But since that was 1000 years ago, that knowledge is lost so all we have is speculation. Interesting to consider What If... they continued further south and settled in sunny Florida?

In the book "From Vinland To Mars" published in 1970s it said many Scandinavian men were "landless sons" since first born son inherits the land, and there is not much farmable real estate in those areas. So these landless sons don't have much career opportunity except join the Viking Navy and plunder rest of Europe but there was also motivation to go west to find other places to settle.

Sadly, not that sunstone

[Aryeh Goretsky]

Hello

When I first saw the headline, I thought it was going to be a fossilized bioluminescent sunstone [wikispaces.com] from H [wikispaces.com]. Beam [wikipedia.org] Piper [gutenberg.org]'s Little [tvtropes.org] Fuzzy [wikipedia.org] series of science fiction stories.

Still, a fascinating read, albeit not one as exciting as if H. Beam Piper's fictional sunstones had been found to exist in real life.

Regards,
Aryeh Goretsky

Re:In a perfect world

[mcgrew]

That sounds like Vogon, anybody got a babelfish?

This interested the hell out of me, I'd never heard of it before. Wikipedia says it was used to find the sun on a cloudy day, which would indeed be very useful to navigators with no compasses.

It also said it's Oregon's official gemstone. No sun or magnets in Oregon?

THIS is why I love slashdot! Who knew? Not me!

Aah That's Clever!

[Greyfox]

I imagine that was "magic" back in the day. Just a little Viking sorcery! I suppose the reverse of the rule is also true; any sufficiently antiquated "magic" must seem like technology. Imagine the wonder of the first person to notice this. Did they closely guard their secret? Did this knowledge give them an edge over their neighbors?

By the time you get to 1767 [google.com], we're definitely leaning more toward "technology" (Though I didn't see this particular one mentioned in said document.) The math and devices are pretty well understood and the methods are shared openly. I'm sure I could find earlier documents if I were inclined to dig around a bit. This one actually popped up on a search for... something else I was looking for. Needless to say, I immediately decided I wanted to be a member of the Order of the Commissioners of Longitude. If they let me in I promise I'll sit in the back and be very quiet...

Re:In a perfect world

[Nidi62]

This interested the hell out of me, I'd never heard of it before. Wikipedia says it was used to find the sun on a cloudy day, which would indeed be very useful to navigators with no compasses.

I find the timing of this story rather interesting, because the History Channel's newest special miniseries Vikings just started up this past Sunday. In it, the main character reveals to his brother a sunstone that a wanderer had given him. He then proceeds to find the sun through the clouds for his brother, who did not believe that the stone would work.

Re:Iceland Spar

[An dochasac]

I've done a lot of sailing on the Great Lakes and Irish Sea and I can tell you that cold water often brings a kind of dense low fog. There are times when we can see the tops of masts and blue sky above but because the sun is often low at these latitudes, we can't see where the sun is. But sometimes the fog was so bright, I'd wear sun glasses and then I did notice that the zenith blue sky was polarized. What's more, the digital watch we used for sailing was an LCD watch-- which means it polarized display. And the display did darken noticeably when turned at certain angles, so the reflected sky polarization was also discernible. At the time I wondered whether it could be used as a practical form of navigation, but we had a compass. A few years later Loran-C became popular addition to the compass as and then GPS. But when I heard about the theory that an Iceland spar sunstone might have been used for navigation in the high arctic, I'd give it the nod of plausibility. No it isn't as good as a compass, unless you're above 70 degrees magnetic latitude. No it wouldn't work well under conditions of total cloud cover or rain, might not work at all. But I'm sure this kind of low fog is at least as common in the arctic as it is at my latitude and if I were lost without a compass, GPS, Loran-C on a foggy day, you'd better believe I'd break out the sunstone if I had one.

Re:Prime example of scientific tunnel-vision?

[Zyrill]

Actually, a crystal's basic physical and optical properties do not change even when it is eroded: one unit cell of the crystal has all the determining characteristics that a macroscopic sample would have. Given, it takes some training to tell a rough diamond apart from quartz, but that's what mineralogists and material scientists are for. Oh and one more thing: if it was at least a little transparent, the most readily distinguishable characteristic of calcite is that it's birefringent (check: Wikipedia [wikipedia.org] if you do not know what that means).

Re:lost knowledge?

[able1234au]

I don't think they went from Norway to Newfoundland. Instead they went Norway -> Orkneys -> Iceland -> Greenland -> Newfoundland. So while still an amazing achievement, it was more like one more hop, mostly west, so tracking the sun is useful for that. The vikings from Greenland that sailed down to L'Anse aux Meadows had already been sailing west from Greenland to trade with the natives (the Dorsets?) and just kept going further. L'Anse aux Meadows was a long way from Greenland and the Indians further south would have been tough to fight, given the population of Greenland was small. So you can see why they did not establish large settlements there. If word had gotten all the way back to Norway and the multiple hops were easier then perhaps more would have settled but it didn't look as attractive as it did for the rest of Europe 500 years later.