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Author Topic: Why does hair look darker when it's wet?  (Read 2395 times)

Offline thedoc

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Why does hair look darker when it's wet?
« on: 14/03/2015 16:51:50 »
Why is it that, even though I have light brown hair, when I get into the shower or hot spring my hair turns darker?
Asked by Brian in Nagoya


                                        Visit the webpage for the podcast in which this question is answered.

 

« Last Edit: 14/03/2015 16:51:50 by _system »


 

Offline thedoc

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Why does hair look darker when it's wet?
« Reply #1 on: 14/03/2015 16:51:50 »
We answered this question on the show...

Hair is light when it's dry for the same reason that ice is clear when it's a sheet on a pond, but white and opaque when it's in the form of snow particles.
In dry hair, and in small particles of snow, light bounces - or reflects - off all the surfaces, returning a range of wavelengths - or colours - of light to your eye. This makes the reflected light look a lighter and brighter hue.
But when hair is made wet, this smooths the surfaces and brings the hair strands closer together. The result is that more light is guided deeper into and around the hair, rather than being reflected back towards you. Less reflected light makes the hair look darker. In the case of a sheet of ice, less light being reflected back results in greater transparency and hence it looks less white.
« Last Edit: 14/03/2015 16:51:50 by _system »
 

Offline lightarrow

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Re: Why does hair look darker when it's wet?
« Reply #2 on: 14/03/2015 17:14:06 »
ls it also because water on the hair surface decreases its index of refraction and so the reflection coefficient? A lot of things become darker when wet.

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lightarrow
 

Offline yor_on

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Re: Why does hair look darker when it's wet?
« Reply #3 on: 17/03/2015 19:23:43 »
Heh :)
You're unfailingly polite LightArrow.

Think you will like this one. Darkerwhenwet.
 

Offline lightarrow

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Re: Why does hair look darker when it's wet?
« Reply #4 on: 20/03/2015 18:05:10 »
Heh :)
You're unfailingly polite LightArrow.

Think you will like this one. Darkerwhenwet.
I should have imagined that you were an expert of Angstrom works  :)
I gave a look to that document and I realized how little I know even of the "simplest" things!  [:-'(]
Thank you.

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lightarrow
 

Offline yor_on

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Re: Why does hair look darker when it's wet?
« Reply #5 on: 21/03/2015 18:27:28 »
No expert, just thought you would like it :)

 

Offline Michael28

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Re: Why does hair look darker when it's wet?
« Reply #6 on: 17/05/2015 09:18:31 »
I also felt the same that my hairs look darker after a wash. You know I just make a hairstyle with best curling iron (oops! how did that URL sneak in there? mod) that I have in my wet hair. My hairs really look amazing after a wash. I love my wet hair and a lovely hairstyle in them.
« Last Edit: 17/05/2015 11:09:31 by evan_au »
 

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Re: Why does hair look darker when it's wet?
« Reply #6 on: 17/05/2015 09:18:31 »

 

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