Haidinger's Brush: How to see polarization with the naked eye | Hacker News Reader

Haidinger's Brush: How to see polarization with the naked eye

polarization.com

57 pointsnkurz13 comments

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Huh. I've always seen this. Thought it was some optical phenomena related to chromatic aberration in my glasses though.

Can someone think about a practical purpose for this?

When something is this cool, it no longer requires a purpose. :)

maybe 3D vision without glasses?

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.

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

Not really. Most of us just have no reason to practice it. If we lacked the ability, audio engineers wouldn't use reverb effects.

http://blogs.discovermagazine.com/notrocketscience/2011/05/2...

However if I recall correctly, whether this is actually innate ability in humans, of something that happens when you throw large neural network on a problem is still an open question. Seeing what even 100 neurons in artificial nerual network can learn, I'd guess the latter, but that's just a guess.

How would you distinguish between an innate ability and something our brains are capable of? Those seem like the same thing to me.

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

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

You can use it for navigation if a cloud is covering the sun but another part of the sky is clear.

Don't do it!

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

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