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Avichal
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Since with the help of two different wavelength of light we can make every other wavelength of light why do we need three then - like red, green, blue or red, green, yellow? I guess red, blue or red, yellow will suffice.
Avichal said:Since with the help of two different wavelength of light we can make every other wavelength of light …
… why do we need three then - like red, green, blue or red, green, yellow?
To elaborate, suppose you have a white wall, a red laser, a yellow laser, and an orange laser. Aim the red and yellow lasers at the same spot on the wall and aim the orange laser at a different spot on the wall. Next tune the intensities of the red and yellow lasers so that the colors of those two spots is indistinguishable to the human eye.tiny-tim said:nopeAvichal said:Since with the help of two different wavelength of light we can make every other wavelength of light ...
you can't make a single wavelength out of any other wavelength(s)
And to add a little color to the thread :tongue2:D H said:... Just because those two spots are indistinguishable to the human eye does not mean that they have the same wavelength. That they appear to be the same color is just an optical illusion based on how the human eye works.
... there are three types of color-sensitive cones in the retina of the human eye, corresponding roughly to red, green, and blue sensitive detectors.
E.g., purple. Or white.NemoReally said:... and not forgetting that many colours don't have a "wavelength" at all as they don't exist on the spectrum.
D H said:E.g., purple. Or white.
Avichal said:Oh ok...its not the light or color. Its how our eyes work! So there is a possibility that some animals need only two colors i.e. they are dichromatic(or whatever it is called)?
Why is dichromatic colourblind?snorkack said:Yes.
Almost all mammals other than monkeys are dichromatic, like colourblind. Not monochromatic, though.
In a normally trichromatic (or better) species, it means that the animal lacks the ability to see the full normal colour "spectrum". A dichromatic human is regarded as colour blind (even though they can see some colours) but I'm not sure that a normally dichromatic species can be properly be regarded as colourblind. Using that definition, then you could probably make a case for humans being normally colourblind as they lack the colour range of a tetra- or penta-chromat. Indeed, we have no idea what colour really is and, consequently, what possible values it could take. I think a monochromat could be regarded as colourblind as there is no indication that they see "colour" at all.Avichal said:Why is dichromatic colourblind?
The 2 questions are not related. Stealing shamelessly from Wiki ..Alfi said:Why do we need four colours to make a map, if we can only see three?
Pink is a non-spectral color, but a rather boring one. The same goes with light green, light blue, light anything. Pink is just light red, basically a white spectrum but with a bit of a peak in the red. (BTW, white is also non-spectral.)1MileCrash said:Thought it was pink..
And what it does to make the linear range from red to violet wrap around to instead form the color circle is part of that "somehow". Purple is a pigment of our imagination.NemoReally said:Our brain then (somehow) combines the outputs from adjacent cones to construct "colour".
Ouch! If you send me your address, I'll arrange delivery of a smart bomb ...D H said:... Purple is a pigment of our imagination.
NemoReally said:In a normally trichromatic (or better) species, it means that the animal lacks the ability to see the full normal colour "spectrum". A dichromatic human is regarded as colour blind (even though they can see some colours) but I'm not sure that a normally dichromatic species can be properly be regarded as colourblind. Using that definition, then you could probably make a case for humans being normally colourblind as they lack the colour range of a tetra- or penta-chromat. Indeed, we have no idea what colour really is and, consequently, what possible values it could take. I think a monochromat could be regarded as colourblind as there is no indication that they see "colour" at all.
In principle, simply on the basis that there is an extra 'dimension' for colour to extend into (by analogy, consider the rooms available in a single story dwelling to those in a high-rise tower of the same footprint and rooms per floor). However, the colour discrimination might be lower in a particular trichromat than in a dichromat (back to the analogy, d = 30 by 30 rooms and t = 5 x 5 x 5 rooms) as a result of cone sensitivity and / or brain processing. In addition, the colour dimensions might not contribute equally (eg, a 5 x 20 x 10 block or even (5 x 20) and (10) or some rooms might cover more than one floor).Avichal said:So can you say that a trichromatic species sees more colors than dichromatic and similarly higher i.e. tetra or penta see even more.
I don't think anybody knows what colour actually is. However, we can develop mathematical models that allow us to functionally describe and model it. You might the following webpage of interest ... http://www.archimedes-lab.org/color_optical_illusions.html#Now I feel as if I don't know what exactly color is?
D H said:And what it does to make the linear range from red to violet wrap around to instead form the color circle is part of that "somehow". Purple is a pigment of our imagination.
Avichal said:Since with the help of two different wavelength of light we can make every other wavelength of light why do we need three then - like red, green, blue or red, green, yellow? I guess red, blue or red, yellow will suffice.
The reason why you need at least three colors to make every other color is because of the way our eyes perceive color. Our eyes have three types of cone cells that are sensitive to red, green, and blue light. When these three primary colors of light are combined in different proportions, they can create all the colors of the visible spectrum. Adding a third color allows for a wider range of shades and hues to be created.
No, black and white are not considered colors in the traditional sense. Black is the absence of light, while white is the presence of all colors. Mixing black and white will only result in shades of gray, but not the full spectrum of colors.
Having a wide range of colors is important for many reasons. It allows us to visually distinguish objects and perceive depth and contrast. Colors also play a significant role in our emotions and can evoke different moods and feelings. In addition, colors are used in various industries such as art, fashion, and marketing to convey messages and attract attention.
While digital technology has advanced greatly and allows us to create a wide range of colors, it still follows the same principle of needing at least three primary colors to create all the other colors. Additionally, natural light and pigments also play a role in color perception, making it necessary to have a variety of colors in physical form.
In theory, there is no limit to the number of colors that can be created by mixing different proportions of the three primary colors. However, the human eye can only perceive a certain range of colors, known as the visible spectrum. This range is approximately 7 million colors, but it varies from person to person. Therefore, while there may be an infinite number of colors, our eyes can only perceive a limited amount.