
Haidinger's Brush: How to see polarization with the naked eye - nkurz
http://www.polarization.com/haidinger/haidinger.html
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carterschonwald
Huh. I've always seen this. Thought it was some optical phenomena related to
chromatic aberration in my glasses though.

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speeder
Can someone think about a practical purpose for this?

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tomwalker
I am not sure about a practical purpose, but I am completely fascinated by the
fact that our senses are curtailed and there is a lot more happening around us
that we can detect.

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NamTaf
Another notable sense that we completely lack is echolocation, which is common
amongst subterranean and underwater animals.

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speeder
We DO have echolocation.

What happen is that most people lose it because they don't use.

When I was younger (about 8 years old) I could do it very easily, back then I
had no idea how I did it, or how it worked, I only "knew" stuff happening
around me, and I thought it was something supernatural (since most people do
not had the same feelings I had).

After a while I stopped caring about it, got busy with other things, and it
faded away, then I learned that it was echolocation.

I want to get it back, but I don't have time to retrain myself... :(

But seriously, it was very nice, it made pratically impossible to sneak on me,
anyone moving near me while there are lots of sound, like in the middle of a
busy city or school, I would "feel" (it is very hard to describe) "movement"
behind me, and would look (startling whoever was sneaking).

Also we have that kid: <http://www.youtube.com/watch?v=G1QaCeosUmw>

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NamTaf
Oh wow, I'm stupid. In tiredness last night I meant to type electrolocation
[1] but ended up typing echolocation. Sorry about that.

You're completely right that we can develop echolocation quite functionally if
we throw ourselves at it, as some blind people have demonstrated readily. The
best examples are probably Daniel Kish [2] as well as Ben Underwood, who
famously was that kid shown rollerblading down the street using it.

Suffice to say, had I actually typed electrolocation I'd look less stupid
right now :) It's why I mentioned subterranean animals, e.g.: monotremes such
as the echidna and platypus, as well as underwater creatures which tend to
hunt in mud and silt. In both cases, echolocation isn't really effective since
dirt/mud doesn't tend to let sound created by an animal penetrate too well.

Now, if you guys have examples of where humans have shown electrolocation, I'd
certainly like to read about that!

[1] <http://en.wikipedia.org/wiki/Electrolocation> [2]
<http://en.wikipedia.org/wiki/Human_echolocation#Daniel_Kish>

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IvyMike
Don't do it!

Ignorance is bliss. I now see this visual flaw on LCD screens whenever there's
a white background. Ugh.

