
Did Vikings navigate by polarized light? - binarymax
http://www.nature.com/news/2011/110131/full/news.2011.58.html
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pdx
Thankfully, we'll never have to wonder how river boats navigated the
Mississippi without depth finders and radar.

<http://www.classicreader.com/book/2886/7/>

The Vikings may very well been similarly observant of their world, without
resorting to sunstones.

~~~
eru
They would have probably resorted to all tricks they could find.

------
huxley
Or alternatively, the Viking picked up a stone, said it was magical, that it
told him the sun was "that a-way" and if he was wrong, they died, never to be
heard of again.

If he was right, they lived and he got a pretty sweet saga out of the deal.

~~~
sophacles
Ah yes, because people in the past were just plain stupid, we as a species
didn't gain the ability to intentionally take advantage of our surroundings or
question those having dubious advice until 325 years ago, when Newton
presented the Royal Society with his Pricipia Mathematica volume 1, thus
bestowing critical thought on humanity.

All evidence to the contrary is simply coincidental. For instance, the
cathedrals and churches contemporary to the vikings: They were not planned
even a little. They are simply the result of some guy saying "lets build a
cathedral" and piling stones until one of the piles resulted in a cathedral
that didn't fall over. Every last one is like this. And swords and armor?
Those guys just put funny rocks in the fire sometimes, and hit them for the
heck of it, and occasionally when things cooled off, there would be a sword
there!

~~~
dkarl
In the past? Launching ventures on intuition is common to this day. (Otherwise
nobody would start a business: no amount of effort will turn it into an exact
science.) In the past, people were just more apt to ascribe intuition to magic
or divine guidance. It wasn't that long ago in the United States that a farmer
could hire a diviner to tell him where to dig a well, using a divining rod to
find underground water.

People who succeed through luck are more often than not credited with insight.
They believe in their own skill and have no problem finding people who admire
them, trust them, and follow them. If you can believe what you read, it
happens on Wall Street all the time.

~~~
sophacles
So, because some people are stupid and follow slightly less stupid people for
idiotic plans, the entire history of Norse navigation via Sunstones must be
this! Due to the fact that some people had claimed the Sunstone magic worked,
and they had the evidence of being alive, all Vikings everywhere _completely
ignored the large number of ships out navigating with sunstones that
dissapeared_. That must be it, as large numbers of Wall street investors are
still hawking derivatives even tho they are shown to be a bad deal now.

It is highly likely that you are guilty of the exact same sort of confirmation
bias you are deriding with your diviner example. See you are going back and
cherry picking a few (not at all commonplace after better alternatives
existed) choice ideas, calling them good evidence, and ignoring the whole
confirmation bias issue.

Edit: also intuition is also very frequently the result of lots of observation
and experience on the intuiter's part. This may not be formally laid out, yet
is still pretty valid. Do intuition launched ventures have a track record that
is at all different (in a statistically meaningful way) than other ventures?
If not, it is a valid methodology for venture creation.

~~~
dkarl
_So, because some people are stupid and follow slightly less stupid people for
idiotic plans, the entire history of Norse navigation via Sunstones must be
this!_

Your comment seemed to say that it was implausible that success in a risky
enterprise might have been entirely due to luck yet attributed by many
observers to skill. All I pointed out was that it isn't just plausible, it
happens all the time.

~~~
sophacles
In the short term yes, this happens. In the long term? You all seem to not
realize that several centuries of navigation successes attributed to luck
stretches the credibility a bit. It's not like this was one case of luck, it
was a long running thing. All the luck cases in your examples rarely last
longer than years, let alone centuries.

Doubly so considering the whole society built itself on the spoils of the
raiders who went out on trips. Such things are not possible on just luck,
there has to be an amount of repeatability there. Strongly suggested by the
fact that viking raiders were so successful at returning that the ideas,
treasures and people (slaves and whatnot) that they brought back fundamentally
changed their society.

------
earle
The jet stream was by far a bigger factor in the successful crossing of the
Atlantic during those times.

~~~
kjhugthujk
For the flying long ships ?

~~~
eru
They do have sails.

------
jackfoxy
tl;dr If I recall correctly Will Durant writing in _The Story of Civilization_
stated this as a fact many decades ago. Since his work was based on a lot of
research, he must have read it somewhere.

~~~
kjhugthujk
It was suggested in the 60s and shown to be possible then - not sure what this
group have added.

~~~
Someone
1\. They did an experiment to see how well modern subjects can estimate the
position of the sun (answer: very badly)

2\. They measured the polarization patterns under similar conditions to check
whether there could be sufficient information there to do this better. They
think there is.

3\. they didn't yet ask subjects to estimate the position of the sun from the
'sky through a polarization filter'.

Guessing at the results of #3: I think that humans will do slightly better
looking through sunglasses, and expert users could use that in navigation.

In the end, I expect that the Vikings used as many cues as they could find to
navigate, just like carrier pigeons do (for carrier pigeons, the tricks
mentioned in the literature include detecting the magnetic North, using
polarization cues to detect the location of the clouded sun, and olfactory
cues. They also have a good map of their surroundings that helps them home in
on the last 30 miles or so. Because of that, a flight from say 100 miles away
need not be dead-accurate in direction to hit that 30-mile radius circle where
they know how to get home.

~~~
pbhjpbhj
>I think that humans will do slightly better looking through sunglasses, and
expert users could use that in navigation

I actually do this, not the sunglasses bit (must try!), the other bit.

I'm not very good at navigating in the car. I look at a map of a city before I
set out but can't remember road numbers and things. I'll see some landmarks
and know from a semi-pictorial memorisation the relative location; I'll look
for the sun and use that to navigate. It [mostly] works but only just - I grew
up in the country where this sort of thing works better (crossing large
fields, navigating woodlands, etc.).

I do estimate the location of the sun based on apparent sky brightness when it
is overcast. Obviously this doesn't always work (thick cloud, heavy rain, snow
on the ground). Also I've never actually done this by the stars though I
reckon I could in a pinch.

DAE (does anyone else) use sun location to establish compass direction and
navigate across cities by dead reckoning??

