What makes RG light and Y light the same color is how your human eyes react to these two spectra. RG light and Y light are metamers for the color we call "yellow". — InPitzotl

We're "color blind" to spectra; we can't even tell RG light from Y light. — InPitzotl

Yeah...

:roll:

I've certainly had enough discourse with you...

"Spectra"(capitalized for grammatical reasons only) IS a name. — creativesoul

Yes. Switching form, I'll quote you with quotation marks.

"It is used to pick out..." Yes."You said so yourself." I did. "Those distributions of intensities of light existed" Tense problem: "exist" is better. Other than that, spot on! "Those distributions are discovered." ...well, technically, yes. Because we have spectroscopes, prisms, rainbows, and brains, we discover the distributions. But as colors, we're seeing "equivalence classes of spectra". "Distributions of light do not require" ...yes.

"Colors are distinct from spectra." Yes; color is an equivalence class of spectra; spectra are the members. "Spectra map to the same color." Not necessarily; spectra that map to the same color map to the same color. "Metamers are the name given to distinct spectra..." yes. "That's not about our language use." Correct. "It's about color vision capability," ...correct; for example, for humans, it's about the human color vision capability. "It exists in it's entirety regardless ..." I'm interpreting this to mean that we don't have to know about spectra to see color; in that case, yes. "It most certainly" ...to me it sounds like you said the same thing twice, rephrasing it. "It requires colors" Yes, but, "colors require colors" is a tautology. "and spectra that map to them because it requires metamers" ...that works, but those aren't different things. "It does not require any of the language" correct.

"Color vision capabilities include" ...whole paragraph correct; but, it sounds like a repetition.

""Spectra" is a name." ...sure.

"It seems you're having a bit of trouble following along." ...no, you are having the trouble. "I've not talked about seeing a thing we've named red, as though that is the same as seing it's color as red." Well... you definitely said this:

Seeing red is the exact same thing as seeing the spectra we've named "red".

"You have. The earlier bits about seeing the crayons with the name on them and all that..."
...why does this confuse you so much? If I look at a box of crayons, I see colors. If a deuteranope looks at the same box, he also sees colors. But when I look at the crayon labeled red, I see red; when the deuteranope looks at it, he does not see red.

Neither I, nor the deuteranope, see spectral distributions; we're both incapable of doing so. I just see a crayon's membership in an equivalence class of spectra; that's red. Analogously, the deuteranope does not see "red"; he is incapable. He just sees a crayon's membership in a different equivalence class.
"Seeing red things is seeing things" ...yes.

Surely you are not asserting this. What are you doing with the word "so" here? So because "red" is a human word, it refers to a human group?

Again, what's confusing you? Humans created English. "Red" is a human word. So, human word? Check. Humans have human eyes; human color vision. Human color vision has particular properties. We made that word to talk about some equivalence class humans can see.

"Sorry, but I have to ..." ...okay, but it looks like the problem is that you're confused.

Using the term "red" in normal parlance is to pick out all things we've given the namesake to...

Huh? Which is it? Is it normal parlance or all things we've given the namesake to?

Spectra are not a human grouping. Color vision capability is not a human group. "Spectra" is a human word. "Color" is a human word. "Mt. Everest" is a human word. None of the referents of those words - which act as names - are human groupings. Human groupings are existentially dependent upon human language use. Spectra, colors, and Mt. Everest are most certainly... not.

Ah, you're choking on human grouping. Well, yes, humans invent language; and they make up stuff. That's not a bad thing; it's part of the human project. But, humans not only invent language and make up stuff; they are also animals of a particular type. We're primates, and we're mammals. We also have human eyes; human eyes tend to be equipped with trichromatic vision of a particular type. The particular kind of trichromatic vision humans have begins with the three cone types humans as a species have; the human species' L, M, and S cones. Those cones respond to spectra in particular ways; they are incapable of measuring spectra per se... rather, they measure equivalence classes of spectra. So there are equivalence classes of spectra that humans can see based on human physical properties. The equivalence classes are groupings. The properties are human. Therefore, these are human groupings, which means that, no, "human groupings" are not necessarily existentially dependent on human language use. This human grouping is "existentially" dependent on human cone sensitivities.

"All human groups are existentially dependent upon humans. Colors are not."

But human colors are; they are "existentially" dependent on human... cone sensitivities.

""Red" is a human word referring to that which existed in it's entirety prior to our naming and descriptive practices involving the term."

Red refers to equivalence classes of spectra that human cones resolve.

You said spectra are not colors, and also that green is a color... — creativesoul

"Even" is an equivalence class of integers. "Odd" is an equivalence class of integers. But "odd" is not an integer.

I think you're full of shit and you know it. Hence, you're all over the place, and now you've shown a pattern of feigning ignorance when I point out any of the problems with what you've been arguing here.

No longer interested in what you have to say here. Shame too, because it seems that you may be using current convention. If you're using it correctly... it's wrong.

Are you saying that no other animal perceives any of the sets of spectra that we call "red"?
No. I'm saying that no other animal perceives the set spectra that we call "red" as the same color. — InPitzotl

This is still the problem.

I can't believe that anyone is still arguing with you, when you are clearly completely correct.

I usually don't like to try to win arguments by pointing out that I have an MIT degree in Cognitive Science and consequently I'm well-educated on certain issues. But I will pull it out now to say that I'm well-educated enough to know that InPitzotl is correct, and anyone here who wants to actually understand what colors are, should read everything he says carefully.

That's if they want to actually learn something. Those who wish to remain ignorant should carry on as they are, I suppose.

|>ouglas

Nice. The cavalry has shown up.

:meh:

The more the merrier.

This is still the problem. — creativesoul

Thought you weren't interested?

Let's go back to this box of crayons. There are 96 crayons here; each is a distinct spectral distribution, and we see them as different colors. But that's kind of cheating, because these crayons were made for humans. Imagine our mantis shrimp has a box of crayons. There's 960 crayons in his box. When we open it up, we see one row in one compartment has crayons that all look like the same color yellow to us. Suppose one of these reflects only 700nm and 545nm light; call that crayon A; another reflects 570nm light only; call that crayon B. On the next row, however, we see orange crayons. Call one of these C.

So here's the key. Since each crayon reflects a single spectral distribution, then the two terms are pretty much analogous. So crayon=spectral distribution; crayons=spectra.

So, to the mantis shrimp, A, B, and C are different colors. To us, A and B are the same color; C is a different color. To Spot, who is a dichromat dog, A, B, and C are all the same color.

"Are you saying that no other animal perceives any of the sets of spectra we call 'red'"? Here, "are you saying that no other animal perceives any of the sets of crayons we call 'yellow'"? So let's get specific. We call crayon A and B yellow. There are two other animals; Spot, and the mantis shrimp. The mantis shrimp sees the set of crayons A and B. So does Spot. And why should this be surprising? The mantis shrimp and Spot both see; what has what they see to do with what we call things?

"No. I'm saying that no other animal perceives the set spectra that we call "red" as the same color."

Translation... no other animal perceives the crayons that we call 'yellow' as the same color. Again, we call crayons A and B yellow; and we call crayon C orange. Both the mantis shrimp and Spot see crayons A, B, and C (they see all of these spectra). But the mantis shrimp sees A and B as different colors. Spot sees A, B, and C as the same color.

This is still the problem. — creativesoul

Sounds good to me; yes, this is still the problem. If you don't get it now, I can do a "mathemagic" analog if you like next using numbers and equivalence classes as metaphors. But I can only explain this in so many ways; either you'll get it or you won't.

This is still the problem.
— creativesoul
Thought you weren't interested? — InPitzotl

I'm interested in what's true. Not everything you've said is bullshit.

Rhetoric does not impress me.

Let's talk about what we've both agreed is the problem. I quoted it once. You've mentioned it more than once.

Let's talk about it.

Are you saying that no other animal perceives any of the sets of spectra that we call "red"?
No. I'm saying that no other animal perceives the set spectra that we call "red" as the same color.
— InPitzotl

This is still the problem. — creativesoul

Let's go back to this box of crayons. There are 96 crayons here; each is a distinct spectral distribution, and we see them as different colors. But that's kind of cheating, because these crayons were made for humans. — InPitzotl

Stating the case - no matter how simply it may be stated - is never cheating.

I'll take the time to actually address what you've said here.

Imagine our mantis shrimp has a box of crayons. There's 960 crayons in his box. When we open it up, we see one row in one compartment has crayons that all look like the same color yellow to us. — InPitzotl

"The same color yellow to us"...

That's seems unnecessarily complex terminological use. I want to entertain the scenario of the mantis shrimp and the box of crayons, because I do believe that you know the names of all sorts of things, and as a result I've a certain amount of confidence that there's something to be gained by me individually as a result. I also entertain and still believe that there's something that others could gain as well, including but not limited to yourself.

Do you have any issue whatsoever agreeing that mantis shrimp have visual capabilities different to ours, as well as quite similar? They can distinguish between a greater number of spectral distributions than we can, and as a result, it makes perfect sense to say that they can see more colors than we can. Your earlier bit about all the different reds seems to be commensurate with all this as well. So...

I think we agree there. So... continuing on mantis shrimp, us, color vision capability and a box of crayons... Are you ok with the following, as it is stated?

We see one row in one compartment has yellow crayons. Not all of these crayons reflect the same spectra. We cannot distinguish between those spectra. And yet again... I think that we agree there. I want to see if our agreements can lead somewhere a bit more useful than our disagreements have led thus far.

Suppose one of these reflects only 700nm and 545nm light; call that crayon A; another reflects 570nm light only; call that crayon B. On the next row, however, we see orange crayons. Call one of these C.

So here's the key. Since each crayon reflects a single spectral distribution, then the two terms are pretty much analogous. So crayon=spectral distribution; crayons=spectra. — InPitzotl

Counting seems off.

"Crayon", "spectral distribution", and "spectra" are the terms in use. I count three. You use three and further talk as if you'd only used two.

This needs reconciliation.

If A=B and A=C then B=C.

If crayons are spectral distribution and spectra, then spectra are equal to spectral distribution. That can't be right.

Spectral distributions consist of a plurality of particular frequencies or a single one.

The spectra emanating from an object consists of virtually countless possible combinations thereof(spectral distributions).

Thus... the two are not equal.

There is no such trinity of equivalency to be had here. Strict adherence leads rather quickly to meaningless nonsense and the inherent incapability to draw and maintain the actual distinctions that those terms are best utilized for.

Crayons are certainly not equal to either. Colors consist of different sets of spectral distributions that we've attributed the same namesake to. I'm granting that based upon granting the earlier bits about "yellow" being more than one spectral distribution. There are a plurality of different spectral distributions that we've named "yellow".

The light reflected by each and every crayon is not equal to the color we see when viewing them. The color we see is - in part - the result of our perceiving particular spectral distributions within the overall spectra being emitted from the crayons.

We do not see the entire spectra. We see parts of it.

The spectra emanating from an object changes along with light conditions. Along with that change comes a change in the colors we see when viewing it.

I am hoping that most or all of this is agreeable for you. I'll check back later. Sorry I could not further consider the example until this bit is at least tentatively agreed upon.

Colours are electromagnetic impulses associated by the self to the objects that produce them.

What exactly is a color? In an ideal world, all colors would be true. That is, nothing more would be true than this. It is almost hard to imagine the number of problems this can cause.

However, no color exists, and we can construct fake color schemes, or color mixing schemes, to resolve the situation. The real problem with color is that the electromagnetic spectrum is deeply involved, involving colors of wavelengths that cannot be perceived.

Each wavelength of light falls off as it travels through a material. If you take a fiberglass prism, it becomes smaller as it moves towards the blue end of the spectrum. This is because each wavelength has less color in it as it moves to the far red end.

I've can't keep track of what the disagreement here is precisely anymore. Why don't we table the discussion on whether there are colors for a moment and address an easier question: Are there chairs?

Well, of course there are chairs. I'm sitting on one right now!

But providing necessary and sufficient conditions for what is and is not a chair is no easy feat. Certainly a chair is designed to be sat on. Except there are toy chairs which are not meant to be sat on. And maybe art chairs that are also not designed to be sat on, but which everyone would recognize as a chair. There are also artistic representations of chairs, that everyone might recognize as a representation of a chair. But in the case of a Picasso representation of a chair, it might be difficult to ascertain how people who might live in this represented world might sit in the chair.

Of course, representations of chairs are not chairs, so it doesn't directly address the issue of whether chairs exists, but it does address the issue of whether representations of chairs exists (they do!) and understanding this is, I believe, important to our understanding of what chairs are.

To make matters more complicated, not everything that is meant to be sat on is a chair. There are stools, sofas, benches, etc.

So how do we know what is and isn't a chair? Well most of us can tell just by looking at something whether or not it is a chair. How do we do this? There's a simple answer to this and a complex one. The simple answer is that we have complex brains and perceptual organs with sophisticated information processing abilities that allow us to classify things into chairs and non-chairs. The complex answer is a very detailed model of how this particular information processing works.

There are of course some complications. For some physical objects, we might not be able to decide whether something is a chair or not. For other objects, we might be sure that something is a chair, but we might be surprised to learn that other people completely disagree on the object's chairness. For such objects, there may be no fact of the matter on whether the object is a chair.

Now let us consider animals. Are there any animals that could be trained to identify chairs from non-chairs. E.g., we might try with dogs. E.g., we could train some dogs that it's okay for them to poop on chairs and only on chairs. We could then figure out what a dog's notion of a chair is from what it will and won't poop on.

I'm sure that we could successfully achieve this goal for chairs that sit squarely in the center of chairness. But I feel confident, that dogs would be thrown off of by more artsy chairs. And perhaps by things that are more like stools with arms than chairs, etc. Sure we might keep trying to train them using art chairs and chair-like stools, etc., but I feel pretty confident that they would ultimately not end up having the same conception of chairs that humans do. I believe that we would learn with enough effort that no real animal (other than the human animal) is ever going to be able to properly distinguish chairs from non-chairs, despite the fact that chairs exist.

Now let's suppose that some aliens visit the Earth, and they want to know all about us. In particular, they are really interested in our notion of chairs, because they are having a hard time fathoming that chairs really exist. To them, our classification seems completely arbitrary. Why is one thing a stool and not a chair, and another thing a chair, even though it's in a museum and is not something that any human could comfortably sit on at all? Maybe these aliens with enough effort will eventually be able to distinguish chairs from non-chairs almost as well as humans. Or maybe they won't because their senses and their brains just work too differently from ours to be able to do so.

If they are very clever aliens, they might reverse engineer our brains, figure out the software contained therein, and leave Earth happy knowing that they have solved the mystery of what a chair is and now convinced that they do exist. Even if they can't classify chairs from non-chairs themselves, they can now build machines to do this classification for them. Once they have done this, they return happily to their home planet and program their factories to churn out all sorts of different kinds of chairs so that they can give them to each other as cool novelty gifts during their celebrations of Zmas.

Now rerun this argument mutatis mutandis for colors, and you will readily see that colors exist too, even though it might be very problematic for other creatures to distinguish colors as we do.

How do colours exist to the blind? No. Does hate exist to someone who has never had problems with anything? No. Does anything exist to someone who has never existed? No. When one thing exists it allows another thing to exist. Eyes=>colour, problem=>hate, exist=>things exist. One thing creates two things and two things create three things and three things create everything. For some it exists and for others it doesn’t so colour isn’t objective. If it’s not objective but subjective does that make it fake? Who know haha. If a human was born with consciousness but not thinking or senses what would exist for them?

no other animal perceives the crayons that we call 'yellow' as the same color. Again, we call crayons A and B yellow; and we call crayon C orange. Both the mantis shrimp and Spot see crayons A, B, and C (they see all of these spectra). But the mantis shrimp sees A and B as different colors. Spot sees A, B, and C as the same color. — InPitzotl

Spectra are the light emitted from the crayon. Different animals perceive different spectral distributions - out of the spectra - than us. Some perceive more, some less, presumably some almost the same. Some spectral distributions cannot be distinguished between, although they are perceived. A and B for us. A, B, and C for Spot.

What color is seen depends upon both, the spectra emitted by the crayon and the creature's color vision capabilities.

We agree there.

How do colours exist to the blind? No. — Leviosa

That makes as much sense as saying that California doesn't exist for anyone who's never been there and is never going to go.

|>ouglas

So, it seems that we're not so much in disagreement aside from the claim you made that no other animal sees the frequencies that we call "red" as red. This seems odd to me because the red spectrum is not determined by us. Thus, if some other animal has similar visual capabilities perceiving and distinguishing the red spectrum from yellow and blue spectrum, there is no reason I can think of for them to not see red when frequencies along that spectrum are perceived by them.

've can't keep track of what the disagreement here is precisely anymore. Why don't we table the discussion on whether there are colors for a moment and address an easier question: Are there chairs? — Douglas Alan

We agree that there are colors. Our disagreement got clouded by all the jargon. Upon re-reading, had I understood then what I think I understand now, this conversation would have went differently. Much of the confusion rightly lands upon my own shoulders... although not all of it. My interlocutor has erred several times when speaking for me and when drawing analogies. However, I still have a modicum of respect for his/her opinion on the matter...

Chairs are not the same scenario though. Not at all. We - and only we - determine what counts as a chair. The same is not true with colors.

I've been a bit busy; but I'm just going to fast forward to this.

So, it seems that we're not so much in disagreement aside from the claim you made that no other animal sees the frequencies that we call "red" as red. — creativesoul

You're still confused over the same point. There are three completely distinct things here: (1) frequency, (2) spectral distribution, (3) color.

Photons hit spots on our retina; but they aren't confined to having single frequencies (1's); they have distinct frequencies. But there's some distribution of them depending on what you're looking at... more at some frequencies than others. Because each photoreceptor is sensitive to a range of frequencies, then it's the entire distribution (2) that matters, not individual frequencies. But a given photoreceptor is simply more sensitive to some frequencies than others... at the photopsin level, it either folds or doesn't, but just has a probability of folding per photon based on the photon's frequency. That means you can make it fold with a given probability in multiple ways; you can fire less photons at the more sensitive frequencies, or more at the less sensitive ones. Since what matters for detection is simply the raw number of photopsin events, and there's multiple ways of reaching that number, then we're not detecting (2)'s; we're detecting "numbers of events". This is like a math function; in goes the photons, out comes some result... but it's the output (3) of that function that matters... you cannot distinguish what you cannot discern. The function isn't one to one, so it loses information.

Your "frequency=color" theory is fundamentally flawed; that's a misconception. If you really care about truth, get rid of the false things you believe. Consider for example Mary, who has only one photoreceptor type; namely, L. As it happens, L cones are actually sensitive throughout our visual band; so she's going to "see" the same frequencies (1) as us, and she's going to "see" the same spectral distributions (2) as us. But she won't see color; the whole "point" of having multiple photoreceptor types is to see color... to make the distinctions I described in the last paragraph. Mary has one photoreceptor type. So, if Mary looks at a 700nm LED in a dark room, she will see it. If you look at a 700nm LED in a dark room, you will see it. But you see its color; Mary does not. But Mary does see a 700nm LED. Therefore, color isn't "seeing a frequency we call 'red'"; it's something else. Think that through carefully... as a hint, though, I've already told you what color actually is. It's an equivalence class of spectral distributions; it's the output of that function I described in the last paragraph.

This is really where you're choking, so spend time on it. Once you grasp it, you'll realize that every photoreceptor-type combination leads to a unique color gamut. Once you reach that phase, you should realize that whether or not other animals see what we call red is a function of whether or not they see the same equivalence class of spectra, which means they have photoreceptors with the same sensitivities we do, and that is the thing that, whereas possible, is unlikely.

Chairs are not the same scenario though. Not at all. We - and only we - determine what counts as a chair. The same is not true with colors. — creativesoul

I would argue that it is the same with colors. Color vision is far from only in the eyes. There is a lot of cognitive processing that is unique to humans that goes into our color vision. And even if it were the case that all of human color vision were determined only by our human eyes, the eyes of all animals and potential aliens are going to work differently and classify crayons differently.

|>ouglas

I would argue that it is the same with colors. ... Color vision is far from only in the eyes. — Douglas Alan

I should point out for clarity that Douglas's description of color here is different than the one I've been presenting to you. They are, however, both correct... they're just focused on different things. The color concept that I'm describing could be called "colorimetric color"; that is indeed only in the eyes. Colorimetric color is about what we can possibly discern; it's the principle subject of colorimetry. What Douglas is describing we could call "perceptual color", which we can say is in the brain (though really that starts in the eyes). Since I'm just trying to explain the fundamentals to you, I'm focusing entirely on colorimetric color. I defer to Douglas for the rest, since that's what he volunteered.

You're still confused over the same point. There are three completely distinct things here: (1) frequency, (2) spectral distribution, (3) color.

Photons hit spots on our retina; but they aren't confined to having single frequencies (1's); they have distinct frequencies. But there's some distribution of them depending on what you're looking at... more at some frequencies than others. Because each photoreceptor is sensitive to a range of frequencies, then it's the entire distribution (2) that matters, not individual frequencies. But a given photoreceptor is simply more sensitive to some frequencies than others... at the photopsin level, it either folds or doesn't, but just has a probability of folding per photon based on the photon's frequency. That means you can make it fold with a given probability in multiple ways; you can fire less photons at the more sensitive frequencies, or more at the less sensitive ones. — InPitzotl

Thanks for the reply.

I agree that frequency, spectral distribution, and color are not equivalent. So, that is not where my confusion lies, if I am still confused about some things.

I also agree that photons travel along the same wavelength from emission through detection(photons have distinct frequencies); that different objects emit/reflect a plurality of photons, and each one at it's own frequency; that a given photoreceptor is simply more sensitive to some frequencies than others. I agree that there are different ways to cause that event(folding) such as less photons at frequencies that it's more sensitive towards or more photons at the frequencies it's less sensitive towards. All photons detected by photoreceptors travel along wavelengths within the range of frequencies that that particular photoreceptor is sensitive towards(that it is capable of detecting).

Since what matters for detection is simply the raw number of photopsin events, and there's multiple ways of reaching that number, then we're not detecting (2)'s; we're detecting "numbers of events". — InPitzotl

This bit leaves me a bit confused though. When you say that "we're not detecting (2)'s; we're detecting numbers of events" are you referring to us or the photoreceptors under consideration?

I would argue that it is the same with colors. Color vision is far from only in the eyes. There is a lot of cognitive processing that is unique to humans that goes into our color vision. And even if it were the case that all of human color vision were determined only by our human eyes, the eyes of all animals and potential aliens are going to work differently and classify crayons differently. — Douglas Alan

Colors and color vision are not equivalent. I said that what chairs are is not the same as what colors are. The former is existentially dependent upon us, the latter is not.

I've never claimed that all of human color vision is determined only by our eyes, nor would I.

But that's another matter altogether... seeing chairs and seeing colors, and not what I'm currently focusing upon.

This bit leaves me a bit confused though. When you say that "we're not detecting (2)'s; we're detecting numbers of events" are you referring to us or the photoreceptors under consideration? — creativesoul

Sort of (changed from yes); I'm referring to the number of photopsin molecules (available for detection). (2) has a particular effect on our eyes. A different (2) could also have the same effect on our eyes. So call the former (2a), and the latter (2b). The effect is (3x); (2a) would have effect (3x), and (2b) would also have effect (3x). Since we can't distinguish (2a) from (2b), it doesn't make sense to say that we detect (2a). What we detect instead is (3x). 3x is "an equivalence class of spectra". 2a is just a member of that equivalence class. 2b is another member.

Colors and color vision are not equivalent. I said that what chairs are is not the same as what colors are. The former is existentially dependent upon us, the latter is not. — creativesoul

I don't consider chairs to be existentially dependent on us. Chairs could exist even if we didn't. There would just be no beings that had the concept of chairs or that could pick them out.

I.e., there are possible worlds in which there were never any humans, but in which there are chairs. And if there were never any humans in the actual world, there could still be chairs in the actual world, since there would be humans in possible worlds with the concept of chairs.

|>ouglas

I don't consider chairs to be existentially dependent on us. Chairs would exist even if we didn't. — Douglas Alan

When and where there have never been humans, there could not ever have been chairs. That's what existential dependency amounts to on my view... and it's my notion. It's about initial existence(emergence) not subsistence(continued existence).

Metamers.