Pondering about Purple . . . .

[foursixand2]

Or violet, i dont think there is a major difference, but the former term allows an alluring alliteration.

 

So i realized something very simple, which makes me wonder, but i am not a physicist so i fear the assumptions i make may be inaccurate. And i know there are differences in mixing colors of tangible substance, such as paint, and mixing or splitting colors in light.

 

Purple comes from a mixture of red and blue. Now the part of the electromagnetic spectrum that is visible to our optic equipment goes ROYGBIV.

 

My interpetation of this : there are three primary (or indivisible) colors : Red, Yellow, Blue. Orange is the blending of Red and Yellow, Green is the blending of Blue and Yellow. Im not sure why indigo would be distinctive, so i guess thats another question but not the main one im concerned with in this thread, what is the physical definition of indigo? Is it just an anomoly in our perception? an expanded sensitivity to the section between blue and violet? Assuming it is just that (its the simplest solution, but correct me if im wrong, thats why i create this thread) i'll throw it out of the set for my purposes.

 

This section of the spectrum becomes R OYG B. I also subtracted violet from the set because according to my reasoning it is merely a blend of the first and the last primary, indivisible colors.

 

Now i submit my insight derived from this realization : perhaps our system of visual perception is analogous to our system of audio perception. An 'octave' is double the frequency of a note. In our ears they are perceived as similarly resonating, we consider doubles and halves of any audible frequency to be the same note. So if we could extend our perception of the electromagnetic spectrum might we perceive each octave as red? If A is Red, would G be violet? And then that includes eight notes, (seven distinctive, until you return to A-Red) thus including indigo, again raising the question, what is indigo and why does it have a place?

 

I suppose this post could have been boiled down to a question of the correlation of frequencies of the colors of the spectrum.

 

I guess thats all i have to say on this subject until some sheds more light on my ponderings.

[YT2095]

RGB for Additive color synthesis.

 

RYB for Subtractive color synthesis.

 

it`s important to distinguish between you modes.

[foursixand2]

i guess i'll look up those terms to see what their pertinence to my post are. I did find some information that may confirm my insight as valid, rather than misguided. Red is 625–740 nm and Violet

380–420 nm when indigo is recognized, or more commonly 380–450 nm. Thats from wikipedia. So the measurement system of spectral color is inverse to the systems of audio frequency. Sound frequency per something of the wavelength, and nm is the length of the wave. The very middle of normally perceivable red is 682 and half. So an octave above it is 341 and a fourth. a shorter wavelength than is perceptible to our eyes.

 

So my conclusion is i should have labeled this thread 'indigo included?' (and my answer is no) and the rest was more or less a waste of words. All i needed to set out to find out was if our perceivable section of the spectrum either grossly exceeded or fell short double the wavelength of red. It does not so it appears my analogy of colors to notes can stand. Except to be a more fitting representation the traditional division of notes would need alteration, because i do conclude indigo obsolete. It is just bluish-purple.

 

So im now off to found the anti-indigo society. Try and stop me.

[swansont]

Supposedly it's Newton's fault that there are seven colors, which he chose because there are seven notes in a major scale and seven days in a week. Indigo is there to fill out the roster, as it were. (Orange as well, according to wikipedia http://en.wikipedia.org/wiki/Roy_G._Biv )

 

It's important to note that color synthesis mentioned by YT is a perception. Spectrally pure colors have individual wavelength ranges, and are not mixtures, and some colors (like brown and silver) are not represented in the spectrum.

[Daecon]

Blue and red light combines to make magenta, I think blue and magenta light combine to make purple.

 

[edit] Checking in MSPaint, it would appear that blue and magenta make lilac, purple is just half-strength magenta.

[YT2095]

in Music the same applies, only it`s called Harmonies or cords.

in the case of Magenta or Lilac it can be likened to say A Maj or A Minor or even Dim or Dim 7 etc...

 

shift the Frequency up several orders of magnitude from audio to the Light band and you have color "Cords".

[Klaynos]

To add, our eyes do not detect and mix colours in the true form... An orange photon is always an orange photon, but if our eyes get a red and a yellow photon we will interperate this as being orange... But it is not.

[YT2095]

same as our ears hear 3 notes at the same time in a Cord, but only one distinct sound.

 

A Major is 3 notes but one distinct sound for example.

 

an Oscilloscope and Spectrum analiser will say differently though

[swansont]

To add, our eyes do not detect and mix colours in the true form... An orange photon is always an orange photon, but if our eyes get a red and a yellow photon we will interperate this as being orange... But it is not.

 

And if the background isn't approximately white, we may not perceive the orange photon to be orange. I have laser goggles that filter out red and IR, and when I take them off, everything looks pink — somewhere in the optic sensing network it has filled in the missing color it assumes must be there.

[Daecon]

And if the background isn't approximately white, we may not perceive the orange photon to be orange. I have laser goggles that filter out red and IR, and when I take them off, everything looks pink — somewhere in the optic sensing network it has filled in the missing color it assumes must be there.

 

That's intriguing... could that imply that everyone's brain interprets colour in a slightly different way.

 

For instance, if I looked at the sky through your eyes and your mind, it might look the colour that I've always associated with the word 'teal', but each of us individually would recognise 'sky blue' as a definite, universally acknowledged colour.

 

Does that make sense? I'm not sure how to explain what I mean.

[A Fool]

yes there are variations to the interpretation of colors in the human brain, but generaly the majority of people see a similar color, hence our rationality of calling colorblindness a malformity. Also the primary colors of pigments are yellow, magenta, and cyan whereas the primary colors of light are red, green, and blue. I can see the argument of light as being scaled similar to music, but in light you just get into ultraviolet and infrared if you try to jump octaves, in a manner of speaking. Is the question you are asking about whether to recognise these higher frequencies as multiples of the visible light spectrum? (in that case you would be right)

[Edtharan]

My interpetation of this : there are three primary (or indivisible) colors : Red, Yellow, Blue. Orange is the blending of Red and Yellow, Green is the blending of Blue and Yellow.

Firstly Additive and Subtractive colour mixing.

 

The colours you described are subtractive colour mixing. Subtractive colour mixing occures becuase the substances you are interested in are absorbing certain frequencies of light.

 

If you have a white light (made up of all frequenceies) and shon it on some red paint, then that magenta paint (most people mistakenly call it red paint) absorbes blue light and reflects both green and red light.

 

If you then had cyan paint (again often called green paint), then it reflects blue and green light and absorbs Red light.

 

If you then mix these two paints together you can predict the final colour that you see by Subtracting the colours that both paints absorb from white light (that made up from all colours).

 

The Cyan absorb Red light and the Magenta Paint absorbs Blue light. This leaves only Green light. Mixing Magenta Paint and Cyan Pain will give you Green paint.

 

This is subtractive colour mixing is all about. You look at what light frequenceies are absorbed and remove (subtract) them from white light.

 

what is the physical definition of indigo? Is it just an anomoly in our perception? an expanded sensitivity to the section between blue and violet

Actually, you might call it "True Blue".

 

Typically our eyes have 3 types of colour receptive cells in them (ok some people have abnormalities that give them two in the case of colour blindness or even 4 types, but I am talking about the typical here). Each of these cells has a chemical that reacts to a range of frequencies of light (with a peak in the specific frequenciy that we call the primary colours).

 

So the cells that have the chemical that reacts strongly to longer wavelengths of light, we call Red. Those that react to the highest frequency we call blue, and the one in the middle we call green.

 

Our brain has evolved to be able to tell different combinations of activation of these cells so that the Red/Blue cells being activated is different from the Green cell activating. This means that whenever we get a combination of colours activating it is an interperetation of what reaches our eyes rather than just a pure colour based on wavelengths of light.