
Crystals That May Have Helped Vikings Navigate Northern Seas - petethomas
https://nytimes.com/2018/04/06/science/vikings-navigation-sunstones.html
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durkie
Neat tangent: the article refers to polarization of light being "practically
indiscernible to the human eye."

You can in fact see the polarization of light, and can train yourself to
notice it in various situations. The phenomenon is known as Haidinger's Brush
([https://en.wikipedia.org/wiki/Haidinger%27s_brush](https://en.wikipedia.org/wiki/Haidinger%27s_brush))
and one of the easiest ways I've found to see it is to look at an LCD monitor
(i'm using a very old macbook pro). Stare at a mostly-white part of the screen
and tilt your head from side-to-side while maintaining your gaze at a single
area on the screen. When you tilt one way, you should see a weird yellow and
blue blob pointing one direction, and when you tilt the other way that blob
should be shifted 90 degrees.

The effect is -super- subtle.

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pipio21
_Vikings, who “were brilliant” despite popular perception of them as brutes._

Well, you can be smart and brutal at the same time. Vikings had a brutal
culture because they needed it for survival, as they did starve over some
periods of the year without it.

Even in Spain, with a much mild climate, Romans reported local people in the
mountains pillaging the valleys in Winter as they got short of food. Romans
forced those people to live in the valleys and gave them land to work.

~~~
ramzyo
Definitely agree with your primary point. I think the author is using a less-
used definition of the word brute here..."one who lacks intelligence,
sensitivity, or compassion : a brutal person"

[https://www.merriam-webster.com/dictionary/brute](https://www.merriam-
webster.com/dictionary/brute)

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barking
There's at least one vendor selling calcite crystals on amazon.com for about
$15 or so and they say they can be used for this purpose.

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toomanybeersies
You could also buy a circular polarising filter for a camera for $5 that would
do the trick:
[https://www.bhphotovideo.com/c/product/972392-REG/bower_fp67...](https://www.bhphotovideo.com/c/product/972392-REG/bower_fp67cc_67mm_digital_hd_circular.html)

~~~
barking
that's a good idea

~~~
tk75x
Or go see a 3D movie and take the glasses home with you. The lenses are
polarized 90 degrees in relation to each other. Pop the plastic lenses out and
experiment by overlaying the two pieces then rotating one while keeping the
other still.

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zw123456
What did they do when it was cloudy at night ? I get it the polarizer crystal
lets you see the sun during cloudy weather, but you won't see any stars that
way, maybe a full moon if the clouds are thin enough. Just wondering...

~~~
INTPenis
I'm just a layperson but I doubt it was one thing that helped them navigate.

It was more like a lifestyle, to navigate the waters. Just like today some
people are born next to waters and are very comfortable there. Norwegian kids
sometimes get a boat as a present when they're 10-12 years old. Still today.

So it was more likely a combination of skills like using sight, sound, feel,
smell, birds, crystals and whatever else they knew that wasn't written down. I
recently read that in the south pacific natives were navigating by sticking
their body into the water and feeling the currents.

The human has a lot more than 5 senses after all.

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anotheryou
Why is there no pictures of this thing held up to the sky on an overcast day?

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Luc
Oh this again.

There's no indication the Vikings ever used sunstones in navigation, but they
_could_ have done (in a very theoretical sense, because I know of no one who
used it effectively in actual navigation), so the idea gets trotted out about
yearly, because it's fun alternative history.

~~~
bcraven
[https://phys.org/news/2016-07-experimentation-vikings-
sunsto...](https://phys.org/news/2016-07-experimentation-vikings-
sunstone.html)

"Some historical evidence such as Icelandic legends have mentioned travel
under snowy skies using sunstones and a study of a Viking wreck conducted in
2002 revealed that a crystal (Icelandic spar) had been onboard that was found
near other implements used for navigation."

~~~
TheSpiceIsLife
My _alternative_ explanation for this sort of thing is always something like:

Maybe the navigator was a hipppie and had crystals and bird feathers on
her/his dashboard, probably a mini dream catcher hanging from the rear vision
mirror.

I think it’s a plausible explanation for a lot of things.

Imagine future archeologists unearthing a car found in s remote location and
trying to explain the crystals and bird feathers and dream catchers.

Are we supposed to believe that no one had _trinkets_ back then.

I imagine this is one of those scenarios where people well versed in the field
of archeology do an eye-roll when they read a _news article_ pertaining to
their expertise. What’s the term for that?

~~~
OscarCunningham
The term is "Gell-Mann Amnesia". More specifically it refers to rolling your
eyes as you read an article about your domain of expertise, and then turning
the page and assuming the other articles aren't also garbage.

~~~
barking
Another variant of this is the type of 'shock' opinion columnist who at least
once a week criticises some interest/business sector/profession and has all
the answers. It's only when he hits on yours that you realise how maddeningly
clueless he is

