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The Color of Snow: CR4 Challenge (01/12/10)

Posted January 11, 2010 5:01 PM

This week's Challenge Question:

If you are lucky enough to be enjoying Winter and you live in a snowy area, try this experiment. First, at around 10:00 AM, look at the fresh snow in your yard. What you probably will see is white snow. Now, dig a hole in the snow, and look at the snow inside, what color is the snow? Why?

And the Answer is...

When you look at the fresh snow without the hole, you see the reflection of white sunlight from the crystals at the surface. The reflected light retains the wavelength of the incident light, because there is not absorption of light.

If you dig a hole in the snow (not at noon), the sunlight rays reaching the hole travel through the overlying snow. By passing through many crystals to reach the hole, the light undergoes a small amount of absorption at the of the spectrum (red wavelength). This makes the reflected light somewhat blueish. So, the light coming from the hole tends to be blue rather than true white.

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#1

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/12/2010 11:32 AM

Blue.

Since the snow absorbs in the infra-red and red regions and the bluish lights comes back filtered off the red tinge.

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#2

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/12/2010 2:36 PM

Yellow. Huskies.

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#3
In reply to #2

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/12/2010 10:36 PM

Watch out where the huskies go....... But perhaps you could be Movin to Montana soon.....

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#4
In reply to #3

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/12/2010 10:58 PM

Your showing your age...Zappa fan!

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#5
In reply to #3

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/12/2010 11:20 PM

A Classic!

http://www.youtube.com/watch?v=Ws5Xeu3BEQk

Enjoy!

Joe

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#18
In reply to #5

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 10:22 AM

'

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#19
In reply to #18

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 10:31 AM

No happy new year for you,

You are the third who just waste space and time without any opinion. It's better for us to not have your opinion but why you are in?

Oh, your picture indicate! OK, now I catch it!

You have a year to make some improvement, Gil.

NB: You see, everyone can collaborate to the subject. Why not you?

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#21
In reply to #19

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 12:03 PM

Hi Gil,

There is a check box you should use for posts like this one. You can find it just before "Yes, this comment is very likely to be considered to be 'off-topic'." in the post editor.

Your comment has a certain self-referential quality that is vaguely funny - in other words, you are obviously "the pot calling the kettle black". Stevem's comment was concise and to the point but yours was meandering drivel, and completely unrelated to the topic, blue snow. In one character, he says more than you do in hundreds of characters.

Also, I've noticed that a large percentage of your posts seem to do nothing other than criticize the posts of others. Here, such behaviour is not the norm, and such behaviour is not supported. It can end up getting you expelled from CR4.

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#25
In reply to #21

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 3:32 PM

Dear Blink,

I have an opinion as everyone can, which can differ from others but I never criticize people's comments, attitude or character. When is meaningless, I answer. Point!

You are frustrated because someone told you: You have to collaborate or open your blog with any subject of your choice.

Never forget, actually the war is not on the "Internet"! If someone is querrelsome, , bellicose or warlikely aggressive, I suggest to not show it. Communication should not hurt, it should be helping.

Finally, your comment's volume means something. Keep it that way and you will be able to collaborate to some subject. Knowledge mixed with "helpfulness" is positive and cooperative. Thanks for your long and explicative comment, Gil.

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#35
In reply to #25

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 10:19 PM

Maybe 2 Valiums

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#24
In reply to #19

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 2:14 PM

In case you didn't get the reference Gil the above one character is an apostrophe.

Apostrophe is the name of the Frank Zappa album that has the lyrics being recited by others.

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#26
In reply to #24

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 4:03 PM

Hi Stevem,

Sorry for the misunderstanding of (') but I never heard Zappa's songs or never noticed just when he became a promoter of freedom of speech and was against censorship. As musician, I was and still a fan of Django Reinhardt and Les Paul.

Thanks for the words and believe me I went to "wikipedia" and learn lots about all three. This is your collaboration, not to the subject, to my personal improvement.

Next time as your comment, write the same number of letters and characters and you will be fine, Gil.

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#36
In reply to #26

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 10:23 PM

and possibly a dose of self reflection and humility

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#34
In reply to #19

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 10:17 PM

Valium

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#12
In reply to #3

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 8:21 AM

I don't go out in the cold. It messes with my Camarillo Brillo.

But if I did, I know that there is an ancient Eskimo legend wherein it is written, on whatever it is that they write it on up there. . .

-A-

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#20
In reply to #3

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 11:53 AM

ONLY IF YOU WANT TO BE A DENTAL FLOSS TYCOON

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#30
In reply to #3

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 4:59 PM

going to be a dental floss tycoon?

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#32
In reply to #30

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 5:56 PM

Zappa song "Moving to Montana"

Watch out for those zircon encrusted tweezers!!

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#6

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 12:29 AM

Seein as its now 35degC outside at present (that's 95degF for some of you guys) here in Oz, I CAN'T ANSWER THIS QUESTION!!!

Where's all the snow gone???

I must be in a parallel universe?

Or is it just too hot in summer for snow... actually here where I live it's even too hot in winter for snow! Oh well someone has to live here :)

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#7
In reply to #6

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 2:24 AM

The lowest temperature here is about 15ºC. No way the experiment can be performed.

If in the open the hole will be the colour of the sky at that moment. If under a tree with genn leaves, green. If under autumn colour leaves, the colour of the leavrs - yellow orange.

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#39
In reply to #7

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/14/2010 6:24 AM

i am agree your opinions

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#31
In reply to #6

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 5:14 PM

Happy New Year OTNToys,

Don't experiment, just read what other write down and learn about snow and its colourations. This is a fantastic world! We communicate and we learn something every day or so, isn't it? Stay with us and you will get cold being in Toronto. No! I just joke. It's cold here, around -10*C every day for two weeks but we survive like you with 35*C. This is summer for us but imagine when we get our summer with 35*C, Gil.

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#8

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 4:50 AM

It is especially noticable if there is a crack or crevice where the light reflects multiple times. Why shouldn't it be blue, water is blue as is obvious if you fill a white bottomed swimming pool.

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#9

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 7:32 AM

I am not sure this is what you are looking for but here goes. While I was in Alaska we had the chance to look at glaciers. Below the snow they are bright blue, but not exactly snow in my backyard.

Ice exists as a solid state which is a crystal, the crystal is actually less dense than the liquid (that is why ice floats). As the snow falls on a glacier it begins to compress the ice from a crystal to a none crystal. Thus when you are looking at the bright blue in the glacier, its actually compressed back to a liquid state. Even though you will never be able to get it to flow due to atmospheric conditions.

How did I do? Close, no cigar, what?

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#10
In reply to #9

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 8:13 AM

I dont know if that was correct or not, but you convinced me.

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#11
In reply to #9

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 8:15 AM

Sounds good to me, but I'm just a humble Engineer.

What I want to know is if snow is frozen water, why is it white when it falls out of the sky? and not clear.

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#14
In reply to #11

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 8:57 AM

Perhaps "off target", but I was amazed to hear from "a humble engineer". I didn't know such a thing existed.... Sorry, I couldn't resist.

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#22
In reply to #11

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 12:05 PM

I read once (waiting to recall where) that snow is white because it has sulfur in it. I am skeptical of this but it should be verifiable. anyone?

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#28
In reply to #11

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 4:24 PM

Happy New Year Merlin,

Go to www.wikipedia.org and you get the information about "snow". All the best, Gil.

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#29
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Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 4:26 PM

It's me again Merlin,

Also, check one of my comments concerning the whiteness of snow. By, Gil.

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#27
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Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 4:20 PM

Happy New Year GHO Goat,

Yes, compressed cristals of water without air is blue. Air between cristals whitening the colour of the snow. Imagine, density of snow could be 13 times ligther than water. Imaginw the air in between the cristals! Also, direct light is whiter than indirect light. We experience this phenomenon every year in Canada.

The question was posed by someone working at "wikipedia"? Why, because they don't have one single word about the colour of snow. Wait for scientific explanations, Gil.

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#13

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 8:24 AM

Everyone seems to agree it's blue. The question is why. I disagree with Guest, who says it's because snow absorbs at the red end of the spectrum. If that were the case, we would walk around knowing that snow is blue. But we walk around knowing that snow is white. It's white because it reflects ALL the colors of the spectrum, absorbing virtually none. I think the reason it looks blue in shadow is that most of the ambient light from the sun and from all the objects reflecting sunlight is blocked, leaving the snow illuminated only by sky light. Sky light really IS blue, because the atmosphere really DOES absorb at the red end and scatter to the blue end. So just as shining a blue light onto a white surface produces a blue-looking surface, shining blue sky light on white snow produces blue-looking snow.

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#15
In reply to #13

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 9:02 AM

When the snow falls (this is the same guest) - almost all the light is reflected / scatterred off- and that's why what you see is the white light, there is no preferencial treatment here .

It is like if you grind coloured glass fine, it will be white.

When you go deep, as is mentioned in a previous post, which portion I didn' elaborate, is the ice compresses into solid chunks. Still no problem, since the light passes and reflects back from the end with negligible portion of the red end of spectrum absorbed.

However if the size of the chunk (call it depth) is large enough, you do see the effect since in forward path and the reverse way, it loses significant amount of the red and the longer wavelengths.

Just as a proof had to search out with "blue ice" googled.

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#16
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Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 9:18 AM

So is it just coincidence that (referring to the photo in the link you posted) the blue starts right at the line where the crevasse casts a shadow? Or is there something about sunlight that creates air bubbles in ice?

I contend that if I climbed down into the snow hole I dug in the Original Post, and turned on a bright white light, the snow would look white, not blue. (But I'm just wingin it here, I've never actually tried this.)

I agree that thick glass tends to look green, and for the same reason it makes sense that thick homogeneous ice would look blue, but a hole dug in the snow is not solid ice devoid of air bubbles -- it's snow.

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#38
In reply to #16

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/14/2010 2:50 AM

Forcing me to check web for something i know ?

Wiki ,here ,

here : and their ice turns blue because all its air bubbles are squeezed out.

It is a common misconception that the blue color exhibited by glaciers, old sea ice, or even holes poked into a snow bank is due to the same phenomenon that makes the sky blue--light scattering (Rayleigh scattering) ...

When light passes through ice, however, the red light is absorbed while the blue is transmitted. Were the operating process scattering as in the atmosphere, then the transmitted light would be red, not blue. However, because of the large size of snow grains and ice crystals, all wavelengths of visible light are scattered equally. Scattering therefore does not play an appreciable role in determining the color of the transmitted light.

It takes an appreciable thickness of pure ice to absorb enough red light so that only the blue is transmitted.

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#23
In reply to #13

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 1:05 PM

Some of what you say maybe true. The snow is blue though the H²O molecule passes most colors of the spectrum it reflects some of the blue. It takes 25 meters for water to reflect all the blue out. That is why the earth's water bodies appear blue. Snow appearance of being white is do to the shape of the crystal and how it scatters the light. Most of the color spectrum is reflected back so that it appears white. Even the white of the snow has a soft blue tint to it as more of blue spectrum is reflected near the surface then the others. Some of the light passes into the snow what you see is the blue being reflected by the H²O in its solid state.

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#40
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Re: The Color of Snow: CR4 Challenge (01/12/10)

01/14/2010 3:45 PM

Happy New Year Ozzb,

Thanks! Finally, we start to get some explanations about why the sea appears blue from the sky or why the glaciers' ice is blue? It's good to have some knowledgeable input. The white colour of the snow is the air between cristals.

In the industry is work for decades, we use a plastic type ball filled with air, called opacifier, replacing TiO2 white pigment. You have to be careful because when the plastic balls collapse, efficiency is gone too.

Thanks again, Gil.

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#42
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Re: The Color of Snow: CR4 Challenge (01/12/10)

02/02/2010 9:23 PM

Yes ... but how does it change the color to yellow and make it taste different!

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#41
In reply to #23

Re: The Color of Snow: CR4 Challenge (01/12/10)

02/02/2010 1:23 AM

You answer appears correct...the color of an object depends on the light source (a specific spectrum of frequencies), some absorbance (according to Beer's law) of some frequencies by the substance, and the resulting spectrum transmitted/reflected.

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#17

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 9:27 AM

Snow acts like a bunch of billions of optic fibers in a random array wich refracts and scatters incomming light in all directions, this mixes all visible colors into white (thus its appearence), but underneat, snow is compressed and acts more like a lens that collects all incomming light from outer snow layers and shows the apparent color of the sky at that moment.

Have you dug into snow under a bright red sunset?.

Yahlasit

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#43
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Re: The Color of Snow: CR4 Challenge (01/12/10)

02/02/2010 9:57 PM

Hello Guest,

After Johannes Innes from Bauhaus, Germany before the "Big Calamity", we have only three colours, red, yellow, and blue, and black and white are not colours. It's late and I am hungry, Gil.

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#33

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/13/2010 9:08 PM

The snow is blue. Here's why. When you dig a hole, even in snow, the hole is going to be dark. The only light that can easily get in comes from above; the sky. Notice that the questions states 'around 10:00 AM'. Usually the sun is low in the winter at 10am and this also prevents any direct sunlight from getting in; which contains longer wave length light (red) which can then mix with the blue light and wash out the effect. We have a blue sky because the air scatters the shorter light waves (blue) much easier than than longer waves (red). This is why the moon turns red during an eclipse since the red rays get through the atomsphere and the blue rays are blocked or scattered. Any light then reaching into the hole comes from the blue sky. If you illuminate snow with blue light it will look blue. If our sky was red or orange, then the snow would look red or orange. You could dig a hole in the summer and put a white sheet in and get the same effect.

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#37

Re: The Color of Snow: CR4 Challenge (01/12/10)

01/14/2010 12:06 AM

Each snowflake is crystallized around a particle, the same particles that through refraction make the sky blue from their effect on sunlight. The denser 'atmosphere' of snow is effected the same way.

To paraphrase Hermes Trismestigus; 'As above, so below, to the accomplishment of all things.'

Just guessing.

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