Talk:1882: Color Models
This comic shows the trend of having a simple and satisfactory explanation for something, and the exasperation with repeatedly realizing the inadequacy of the explanation, making revisions, and having a more complex yet still inadequate model.
As Randall began his schooling, he learned that mixing the primary colours of pigment (red, blue, and yellow) together he could create almost any colour, so colour must be a combination of those 3 colours.
He also learned about rainbows, and that the colours in the rainbow were just different wavelengths of light. Somehow these different wavelengths created unique colours.
As Randall got older, philosophy and a discussion on perception came into play, and Randall came to the realization that his experiences are analogous to but not necessarily the same as his peers.
As he got older, Randall learned about colour spaces as used in pigments, light, and printing, possibly from computer science (Red, Green, Blue; Red, Yellow, Blue; Cyan, Magenta, Yellow, Key) as well as the physics of electromagnetic rays and the biology of vision, understanding that visible light is a small portion of the electromagnetic spectrum - one crudely interpreted by the 3 types of cones in our eyeballs.
Randall then learned about the opponent process model, wherein the signal from cones are not interpreted individually, but in difference to one another. "Responses to one color of an opponent channel are antagonistic to those to the other color. That is, opposite opponent colors are never perceived together – there is no "greenish red" or "yellowish blue"." (from wikipedia)
After that, Randall comes to understand the modeling of colour spaces and the design and limits of human visual perception - despite only having three cones, color space cannot be made into a triangle and still cover the gamut of human colour experience.
Klein manifolds are beyond me, you'll have to fill in something about that.
Eventually, the modeling becomes so complex (and yet still unsatisfactory) that Randall hopes it becomes someone else's problem. 184.108.40.206 15:50, 28 August 2017 (UTC)MagnusVortex
I'm familiar with klein manifolds, they're peculiar 4D dimensional topological objects related to mobius strips. I have no Idea how they might relate to color, and doing a search for "a hyperdimensional four-sided quantum Klein manifold" returned pictures of bicycles...
It might be good to point out in the explaination that he progresses from a dual nature of color (light, and paint) at the beginning and then trends to a unified explaination of color. 220.127.116.11 18:27, 28 August 2017 (UTC) Sam
- Yes those are great looking bikes and are called Klein Quantum racing bikes... so Google did its job of keyword matching. Rtanenbaum (talk) 20:40, 28 August 2017 (UTC)
- The beauty of explainxkcd
The explanation of this comment is a great example of why this site is delightful — and nigh-invaluable! Thanks, regulars, for doing the work to help us understand all this. 18.104.22.168 (talk) (please sign your comments with ~~~~)
I think the explanation of the text is missing an important point. It starts like it's about the philosophal question of "the same color for everybody", but ends with a very mundane explanation, which I think quite funny.
22.214.171.124 21:18, 28 August 2017 (UTC) Loïc
Yes, the description needs to include the fact that the top reference to color being unknowable is a reference to qualia. The brain of one individual may interpret colors differently than the brain of another individual, but since we would all use the same words for our interpretations of the same wavelengths, we can't really know if how I see blue is the same as how you see blue, hence that reference. But then in the tag, he has swapped out the reason for our different interpretations for the same color, blaming our browsers instead of our brains.
Exactly this. Although really that only relates to our experience of colour, so I'm not sure how much relevance it has to the colour mixing track, despite the arrow. 126.96.36.199 13:11, 29 August 2017 (UTC)
I added a comment about qualia, which could probably be improved upon. --188.8.131.52 14:52, 30 August 2017 (UTC)
"As the 4th dimension is time, the color space would probably change all the time."
...no. No. I'm removing that. Just... no.
- Just to explain to the people that aren't engineers, physicists, or mathematicians; while "the three dimensions" are commonly thought of as height/width/depth, with time often used as the 4th dimension, there is nothing that requires "dimensions" to refer to those properties. For example: a flat plane with a temperature distribution could be said to have three dimensions (height/width/temperature), or a cube could be said to have four (height/width/depth/temperature)184.108.40.206 17:00, 6 September 2017 (UTC)
I don't think Randall even scratched the surface. Ask "What is Yellow?"...it's the almost pure frequency of light given off by a sodium lamp at 589nm wavelength. Then, take a digital photo of a sodium lamp and look at the picture on an LED monitor. The color looks the same...but now you're looking at a mixture of red and green LED's - so you're seeing two frequencies at 660nm and 530nm...there is no yellow light. So, you ask yourself - is it the case that mixing two frequencies that the eye can see creates the illusion of a colour between the two?
Well, what color do you see when you mix red and blue? Magenta...right? But what color is midway between red and blue? That's Green. So the difference between Magenta and Green *should* be about the same as the difference between "Sodium lamp yellow" and "Picture of sodium lamp yellow".
The Mantis Shrimp can see 12 'primary colors' and is sensitive to the plane of polarization of the light. We see 3 primaries and have no clue about polarization.
- That's not true. We can see Haidinger's Brush. See https://en.wikipedia.org/wiki/Haidinger%27s_brush . 220.127.116.11 10:09, 30 August 2017 (UTC)
There is no mention of the RGB/RYB/CYMK issue in the explenation 18.104.22.168 06:13, 30 August 2017 (UTC)
What if, what you see as blue when you look at the sky in real life, I see as a slightly different blue, because the different web browsers we've been using have retrained our eyes to perceive meatspace differently? Promethean (talk) 20:57, 2 September 2017 (UTC)