Color

[Timothy]

Okay, so when I see a color as brown everyone else (excluding colorblind people) can also see that as brown because they learned that to be called brown. Except what if their brown is actually my green and my green is their brown? Everyone could be seeing things differently even though we all call it a certain color because we grew up with it. Black is a dark color and white is a bright color but white could be learned as dark and black as bright in my eyes but not in other peoples. What? 

[Alistair]

Well, nowadays we have means of measuring the wavelength of the electromagnetic radiation we call "light". The color of what we see depends on the wavelength of visible light... for instance green light corresponds to a wavelength of ~495-570nm. So, since we're capable of measuring it, we're pretty sure of what "green" is for everyone

If we don't all see colors exactly the same way, it's because our eyes are a bit different, not because there's some big misunderstanding about what, say, green is.

 

(I'm absolutely not an expert of the light spectrum. What I said above is the result of old high school memories and a quick wikipedia research. My apologies if the terminology used is somehow incorrect.)

 

[Timothy]

Well, um, okay then thanks i'll look into some of that

 

Edited October 18, 2017 by Timothy

[Youmu9]

Color has many meanings. Try finding out yourself. Bye.

[NickCrash]

> If colour is meant in the context of light, then what you see is what is emitted and filtered. You are more sensitive towards some colours anyway.

> If colour is meant as the appearance of an object, then you perceive the light wavelengths not absorbed by that material. 

> If you have 3 types of functional cones in your retina, you will be able to discern the same colours as everyone else, possibly with minor difference.

> If you suffer from protanopia, deutanopia, tritanopia or colour-blindness, you won't. It will become apparent with tests that check colours of similar light wavelengths.

> There already is some difference in how men and women, young and old, white and black people perceive colours. It's general, and not that significant.

> The difference lies in colours similar to each other that some people identify as the same colour. Big difference hints at cone malfunction.

> Colour perception also takes into account light intensity, hue, texture, as well as depth of the object. 

> This part of colour perception lies in the occipital lobe of your brain and is as such independent from what your retina perceives.

> In form of an example, your green will not be my red, unless one of us has Daltonism. However, my fuchsia can be your purple and vice versa.

[Candy]

So far we have to assume that if we have structurally similar cone cells and similar optical nerve connection to the brain, we must have similar color perception.

However this is actually impossible to ensure with current technology, much like we don't yet know what color dinosaurs were back in prehistory.

Theres a rather old vid I recommend watching:

 

[HughJ]

If it's a 1 to 1 correlation it doesn't matter

 

This extends beyond color

 

What if what other people see and recognize as a human face looks like a Picasso to you? All the content is there, and they'd be able to point to the right parts if asked

 

What if someone saw the entire world mirrored? Left and right would still correlate for them, so there wouldn't be any way to distinguish

 

What if another person perceived the entire human range of hearing inverted? So long as they always heard bass as you'd hear soprano, and vice versa, they'd be consistent in distinguishing pitch

 

The idea is that we define colors and sound, and a lot of other sensations by their distinction from one another. Experiences aren't cardinal, they're ordinal.

[Alaris]

13 hours ago, Candy said:

much like we don't yet know what color dinosaurs were back in prehistory.

This is a radically different issue.

 

I mostly agree with the others; as colours are defined by certain wavelenghts, and our light-sensitive cells are essentially equivalent, we should se approximately the same colour unless you have any alteration in your light-sensitive cells, nerves connecting them to the brain, or the part of the brain in charge of processing that itself.

 

But with extinct species' pigmentation... that's another story. We don't know the colour of the dinosaurs, first of all, because the pigments are not usually preserved. And when they are, it's usually only melanine, which is usually the most resilient. So... if we find a very very very well-preserved fossil we can somewhat infer the colour pattern, but not the colours themselves. But anyway that's a matter of quality of the information, not the information itself: we don't know the colour of the dinos because our organism does not "work properly", but because we simply don't have the means to discern it.

[Candy]

Yep, the problem with both is that we don't have the means to discern the truth. We can't see through another person's eyes, so we have to make assumptions (that since number of cones and rods is mostly the same, we must have similar vision), much like we must assume dinosaurs were dull colors so they could escape predators.

However, cells have some minor variations even within one person, so it's no wonder there's even more variability between people. Why should DNA code the amount of pigment on your skin, but not the signals triggered through seeing colors?

[Alaris]

I'm still thinking that those two things are not comparable. We can't see through anybody else's eyes, I agree. And we must make assumptions in order to state that every person should see the world in a similar way. But, first, it is not comparable to our melanosomes. First of all, the DNA codes only part of the pigment on our skins. Of course, if you get enough exposition to sunlight, you will get tanned, and that's a reflection of the adaptative nature of skin pigmentation. Depending on where each ethnicity historically lived, the amount of pigmentation (and/or body hair) was correlated (coded by DNA) to solar radiation incidence. That is, people with dark skin lived near the equator, whereas people with lighter shades lived in higher latitudes (apart from inuits, but because of other reasons).

 

Our eyes, on the other hand, possess a very conservative structure apart from changes in colour of the iris, which are in part due to the general pigmentation of the body, therefore correlated to an adaptative variability to prevent excessive light from entering the eye and damaging the cells. Such cells, and optical nerves, etc. don't have a reason to vary (a lot) among people from different regions or within a same population because, to begin with, it would be counter-productive in terms of ecological fitness. I don't rule out the possibility that minor variations may occur between you and me, but not in such a scope (e.g., you see yellow where I se red).

 

The thing with dinosaurs... that's because of the preservation quality. In some extremely well-preserved fossils (such as the one described here), colour and even iridescence can be inferred. In modern humans you don't have such biases, everyone is "perfectly preserved", so to speak.