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Why are there no brown lasers?

NRGLite

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Hi guys, it's been a while.

So, I've been thinking about this very interesting question. Something that intrigues me a lot is the fact that red light and green light blended make yellow light, but the color red and the color green blended make...BROWN!

So, is it possible to make a brown laser?

EDIT: Even more intriguing: a simple search reveals that IT IS IMPOSSIBLE TO SEE RED AND GREEN SIMULTANEOUSLY! They are known as a forbidden color.

Now I'm really confused. :(
 

Cyparagon

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If you look at rgb values, brown is just a darker orange. You'd need something brighter adjacent to it to make the dark orange appear brown, of course. Just as you'd need a bright white next to a dim white for the dim white to appear grey.
 

NRGLite

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@BowtieGuy Umm, that's just a for fun poll...:)
@Cyparagon So you are saying that though the color brown is made from red and green, brown light is made from...dark orange?
 

Pman

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I've got some. Hosts that is;)
 
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Cyparagon

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@BowtieGuy Umm, that's just a for fun poll...:)
@Cyparagon So you are saying that though the color brown is made from red and green, brown light is made from...dark orange?
Dark orange is also red and green.
 

Encap

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"Color is a function of the human visual system, and is not an intrinsic property. Objects don't "have" color, they give off light that "appears" to be a color. Spectral power distributions exist in the physical world, but color exists only in the mind of the beholder. There is no physical significance in color names. It's all a matter of culture and culture depends on where you live, what language you speak, and what century it is. A given wave of light has the same frequency no matter who is viewing it, but the person perceiving the color will call it a word appropriate to their culture" From excellent article in The Physics Hypertextbook, here: http://physics.info/color/

Example: The spectrum of light coming from a brown object like a tree or some mud will contain all the frequencies of light in the visible spectrum, with different strengths for each frequency. You can examine this with a prism. But this broad spectrum of light is indistinguishable to our eyes from light which contains only red, green, and blue light in the appropriate mixture. If you were to look at mixtures of perfecty red, green, and blue light through a prism, you would get three sharp lines. The colors of mud and trees will give a rainbow pattern which is brigher towards red end and dimmer towards the blue end.

Found a clear explaination of what is perceived by normal human vision and called "brown" and shades of "brown" in Western English speaking world 2015:

"In Optics : Brown is a composite color, made by combining red, yellow and black.In the RGB color model, which uses red, green and blue light in various combinations to make all the colors on computer and television screens, it is made by mixing red and green light.
In terms of the visible spectrum, "brown" refers to high wavelength (low frequency) hues, yellow, orange, or red, in combination with low luminance or saturation. Since brown may cover a wide range of the visible spectrum, composite adjectives are used such as red brown, yellowish brown, dark brown or light brown."
"As a color of low intensity, brown is a tertiary color: a mix of the three subtractive primary colors is brown if the cyan content is low. Brown exists as a color perception only in the presence of a brighter color contrast.Yellow, orange, red, or rose objects are still perceived as such if the general illumination level is low, despite reflecting the same amount of red or orange light as a brown object would in normal lighting conditions."
From: https://en.wikipedia.org/wiki/Brown
 
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Surprisingly, light is different than the color of objects. I learned this in art class when I was a kid. Light can never be black or brown or anything like that but an object can.

 
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Laser Chick

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@ VisibleGreen Very interesting how the original of one is the combination of the other and vice-versa.
 

Encap

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Surprisingly, light is different than the color of objects. I learned this in art class when I was a kid. Light can never be black or brown or anything like that but an object can.
Yes that is simplified view that has been taught to kids for a long time as it is easy to comprehend -- Objects don't have color they reflect frequencies some of which the human eye/brain a percieves as color--black color is simply a color that does not allow any reflection.

Light is frequency/wavelength. Color is a function of the human visual system, and is not an intrinsic property. Objects don't "have" color, they reflect light that "appears" to be a color. Spectral power distributions exist in the physical world, but color exists only in the mind of the beholder. There is no physical significance in color names. . A given wave of light has the same frequency no matter who is viewing it.

From excellent article that everyone interested in light and color should read in The Physics Hypertextbook, here Color - The Physics Hypertextbook
 
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Yes that is simplified subjective view that has been taught little kids for a long time as it is easy to comprehend -- Objects don't have color they reflect frequencies some of which the human eye/brain a can percieve as color--black color is simply a color that does not allow any reflection.

Light is frequency/wavelength. Color is a function of the human visual system, and is not an intrinsic property. Objects don't "have" color, they give off light that "appears" to be a color. Spectral power distributions exist in the physical world, but color exists only in the mind of the beholder. There is no physical significance in color names. . A given wave of light has the same frequency no matter who is viewing it.

From excellent article that everyone interested in light and color should read in The Physics Hypertextbook, here Color - The Physics Hypertextbook
Encap I am well aware that is what "little kids" are taught. However saying that the object has no color is subjective and I don't appreciate you talking down to me as if I was still that "little kid".
What I've said was a fact and to help nrglite understand it because he himself is around 13-15.

@ VisibleGreen Very interesting how the original of one is the combination of the other and vice-versa.
It's quite something isn't it? Personally I feel that you can say that the object has color because in a way it's telling us that it is by reflecting the light it wants to be :)
 
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Encap

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Encap I am well aware that is what "little kids" are taught. However saying that the object has no color is subjective and I don't appreciate you talking down to me as if I was still that "little kid".
What I've said was a fact and to help nrglite understand it because he himself is around 13-15.
Wasn't meaning to talk "down" to you at all--sorry you took it that way--you're the one who mentioned kids in the first place "learned this in an art class when I was a kid" . That made me remember I was taught the same thing pretty much as a kid. I thought my comment was appropriate for a forum dedicated to lasers and light. Ok will delete the word "little".

What I was simply trying to point out the reality is that "color" is a function of the human visual system. Objects don't "have" color. Color only exists in the mind. Light has wavelength/ frequency no matter if or who is viewing it. Objects reflect frequencies of light --some not all of which the the human eye/brain can precieve and call "color". The distinction is a source of much confusion and misunderstanding about the nature of light, color, and related terms as we have just seen here.
That is why I put the exaample of brown in the earlier post as follows:
"The spectrum of light coming from a brown object like a tree or some mud will contain all the frequencies of light in the visible spectrum, with different strengths for each frequency. You can examine this with a prism. But this broad spectrum of light is indistinguishable to our eyes from light which contains only red, green, and blue light in the appropriate mixture. If you were to look at mixtures of perfecty red, green, and blue light through a prism, you would get three sharp lines. The colors of mud and trees will give a rainbow pattern which is brigher towards red end and dimmer towards the blue end."

Sorry if I confused you or NRG was not meaning to --that why I put the link to the really excellent and accurate article on color for anyone interested in the larger picture and details of what color has been in history, is, and is not Color - The Physics Hypertextbook

NRGlite--have a look at the article--am sure you will enjoy it given your interesting question. Hope it helps.
 
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Wasn't meaning to talk "down" to you at all-sorry you took it that way--you're the one who mentioned "learn in an art class when I was a kid" . That made me remember I was taught the same thing pretty much as a kid. I thought my comment was an appropriate point in a forum about lasers and light. Ok will delete the word "little".

What I was simply trying to point out the reality is that "color" is a function of the human visual system. Objects don't "have" color. Color only exists in the mind. Light has wavelength/ frequency no matter if or who is viewing it. Objects reflect frequencies of light --some not all of which the the human eye/brain call "color". The distinction is a source of much confusion and misunderstanding about the nature of light, color, and related terms as we have just seen here.
That is why I put the exaample of brown in the earlier post as follows:
"The spectrum of light coming from a brown object like a tree or some mud will contain all the frequencies of light in the visible spectrum, with different strengths for each frequency. You can examine this with a prism. But this broad spectrum of light is indistinguishable to our eyes from light which contains only red, green, and blue light in the appropriate mixture. If you were to look at mixtures of perfecty red, green, and blue light through a prism, you would get three sharp lines. The colors of mud and trees will give a rainbow pattern which is brigher towards red end and dimmer towards the blue end."

Sorry if I confused you or NRG ws not meaning to --that why I put the link to the really excellent and accurate article on color for anyone interested in the larger picture and details Color - The Physics Hypertextbook

NRGlite--have a look at the article--am sure you will enjoy it given your interesting question. Hope it helps.
I should have realized you weren't trying to be rude. Sometimes I feel that we over analyze things to the point of having little to no meaning. I'll have to give your links a look at since this topic is pretty interesting, light is interesting :)
 

Encap

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@ VisibleGreen Very interesting how the original of one is the combination of the other and vice-versa.
Laser Chick--yes is interesting, that. depends upon the starting point --- background black/no reflection of wavelengths or white reflection of all wavelengths.

In the additive primary color mixing you start with darkness/nothing called black, a color that does not allow any reflection i.e. black paper and add to it red, green and blue to get each one of those and by mixing them get :
nothing = black
red + green = yellow
green + blue = cyan
blue + red = magenta
red + green + blue = white

in subtractive color mixing the absence of pigment is white paper. Adding pigment to it(subtracting wavelength ranges) produces the primary subtractive colors:
white − red = cyan
white − green = magenta
white − blue = yellow
then mix them and get:
nothing = white
cyan + magenta = blue
magenta + yellow = red
yellow + cyan = green
cyan + magenta + yellow = black


Here is an interactive thingy where you can mix them on either background---specify the color with the key on keyboard and click spot onto the background box HTwins.net - Light Mixer

Have a look at the article here is very interesting: Color - The Physics Hypertextbook
 
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