What does blue look like to a person who is colorblind

[Maia]

Speaking as someone who is *completely* colour blind, please try and convince me that colours actually exist at all.

Click on this link: https://youtu.be/HU6LfXNeQM4

It's a PBS documentary on how perceptions in the brain are often deceptions.

There's a segment that talks about color. And it notes that color is something that is created in the brain.

It wouldn't play. But I do know that anyway, though.

[Flannel Jesus]

Speaking as someone who is *completely* colour blind, please try and convince me that colours actually exist at all.

"Colours actually exist" has two facets:

Prove to me that light has different wavelengths, and prove to me that people who can see and who aren't colour blind perceive some sort of qualia in regards to that light that gives them information about the wavelengths.

The first statement, "light has different wavelengths", is just scientific fact. You can read textbooks on it or Wikipedia articles on it or whatever - if you aren't convinced by all that stuff, then there wouldn't be a way to convince you

As for the way sighted people perceive it, you could possibly be convinced by a certain amount of agreement between various people on the colour of a few different objects. Maybe something as simple as, grab a granny smith apple and a gala apple and ask as many different people as you can, "what basic colour is this?" (Basic colour meaning roygbiv) If there's a lot of agreement in answers, that should indicate that they're perceiving SOMETHING about these things that allows them to come up with a consistent answer. Figuring out exactly what that "something" is may be a bit tricky, but it's a good step I think towards proving to yourself that this thing we call colour really is being perceived.

[Skepdick]

"Colours actually exist" has two facets:

Prove to me that light has different wavelengths.

Color isn’t the wavelength of light. The wavelength of light is the wavelength of light.

Color is the consequence of light interacting with your visual system.I

[Maia]

I don't doubt that colours exist in the sense that the brain has evolved to assign certain colours to certain wavelengths of light. Is this just completely arbitrary, though?

[Flannel Jesus]

I don't doubt that colours exist in the sense that the brain has evolved to assign certain colours to certain wavelengths of light. Is this just completely arbitrary, though?

I don't know if anybody knows for sure if it's "completely arbitrary". There's still, I believe, a widespread acceptance of the idea that two people who are fully colour-perceptive might perceive colours in totally different ways - I like to describe it as a rotation of the colour wheel. If my colour wheel was rotated relative to my friends, then the qualia I see when I see something blue, he might see when he sees something red. And if that were the case, as far as I know there's no experiment we could do to find out that was the case, yet.

I could be wrong on both those counts, but if I'm not...

It's also my belief that rather than colour qualia being hard coded at birth, our brains quite possibly learn what qualia to assign to what sensory experiences. I'm by no means certain of that, but there are a few things leading me towards that direction. And if that's the case, colour wheel rotation is actually pretty likely

[Maia]

I don't doubt that colours exist in the sense that the brain has evolved to assign certain colours to certain wavelengths of light. Is this just completely arbitrary, though?

I don't know if anybody knows for sure if it's "completely arbitrary". There's still, I believe, a widespread acceptance of the idea that two people who are fully colour-perceptive might perceive colours in totally different ways - I like to describe it as a rotation of the colour wheel. If my colour wheel was rotated relative to my friends, then the qualia I see when I see something blue, he might see when he sees something red. And if that were the case, as far as I know there's no experiment we could do to find out that was the case, yet.

I could be wrong on both those counts, but if I'm not...

It's also my belief that rather than colour qualia being hard coded at birth, our brains quite possibly learn what qualia to assign to what sensory experiences. I'm by no means certain of that, but there are a few things leading me towards that direction. And if that's the case, colour wheel rotation is actually pretty likely

Does it even mean anything to ask if when one person "sees" red they are "seeing" the same thing that someone else does when they "see" red? I suspect it actually doesn't mean anything at all. But perhaps I'm a little biased.

[Skepdick]

Does it even mean anything to ask if when one person "sees" red they are "seeing" the same thing that someone else does when they "see" red? I suspect it actually doesn't mean anything at all. But perhaps I'm a little biased.

Not only is there no reason to believe that two people see the same thing when they see "red".

There's no reason to believe the exact same person sees the same thing when they see "red".

There are numerous experiments showing that the exact same person identifies different wavelengths as "red" given different lighting conditions e.g morning, afternoon and evening.

That's why "red" is an approximate range of frequencies: 550 to 750nm or thereabout, but since light is a consitnous spectrum it's inevitable that different people will draw the line at different places.

[Flannel Jesus]

Yeah I think it means something. I think there's enough correspondence between one person's mind and sensory experiences and qualia experiences that that question could feasibly be answered with a "yes" for some people, maybe even most people.

It's also vaguely possible that the qualia one person uses for colour, another person uses for sound or texture.

Or that people have maybe entirely unrelatable qualia to other people.

I personally don't think it's that extreme though, I think most likely people's "colour qualia" is at least in the same category of qualia as each other, even if the colour wheels are shifted around. I don't have anything more than intuition to back that up though, as someone who sees colour, and for whom colour plays an important role in enjoying the lushness of existence

[Maia]

Does it even mean anything to ask if when one person "sees" red they are "seeing" the same thing that someone else does when they "see" red? I suspect it actually doesn't mean anything at all. But perhaps I'm a little biased.

Not only is there no reason to believe that two people see the same thing when they see "red".

There's no reason to believe the exact same person sees the same thing when they see "red".

There are numerous experiments showing that the exact same person identifies different wavelengths as "red" given different lighting conditions.

That's why "red" is an approximate range of frequencies: 550 to 750nm or thereabout.

I don't think there's any reason to believe that when someone "sees" red they're actually seeing anything at all. It's just the brain firing neurons. There's nothing out there that corresponds to it. Wavelength of light don't exist in discrete bands but are just a continuum.

The latter point is a separate issue though, and while obviously true, is not what I was referring to.

[Skepdick]

I don't think there's any reason to believe that when someone "sees" red they're actually seeing anything at all. It's just the brain firing neurons. There's nothing out there that corresponds to it. Wavelength of light don't exist in discrete bands but are just a continuum.

Hence...

since light is a consitnous spectrum it's inevitable that different people will draw the line at different places.

I am indirectly speaking about the process of quantization. Turning continuous light into discrete colors.

https://en.wikipedia.org/wiki/Quantizat ... rocessing)

It's a fundamental problem with human reasoning, nothing specific to colors. A prism turns white light into a spectrum of colors.

So what makes the question "How many colors are there?" interesting is that the answer depends on the sensitivity of your measurement apparatus.

The spectrum is infinite, so there are as many colors as you can discern.

[Maia]

Yeah I think it means something. I think there's enough correspondence between one person's mind and sensory experiences and qualia experiences that that question could feasibly be answered with a "yes" for some people, maybe even most people.

It's also vaguely possible that the qualia one person uses for colour, another person uses for sound or texture.

Or that people have maybe entirely unrelatable qualia to other people.

I personally don't think it's that extreme though, I think most likely people's "colour qualia" is at least in the same category of qualia as each other, even if the colour wheels are shifted around. I don't have anything more than intuition to back that up though, as someone who sees colour, and for whom colour plays an important role in enjoying the lushness of existence

I've often wondered that myself, if the brain can assign something like colour to a completely different type of sensory input. I don't think it can, though, from my experience.

[Flannel Jesus]

I don't think there's any reason to believe that when someone "sees" red they're actually seeing anything at all. It's just the brain firing neurons.

But "firing neurons" would be what "seeing" is.

I mean, we could take your sentence and plug in some different words to undermine any mental experience, right?

Replace "see" with "hear", I don't think they're hearing anything at all, it's just the brain firing neurons.

Or feeling pain, I don't think they're feeling anything at all, is just the brain firing neurons.

Or having thoughts, I don't think they're thinking anything at all, it's just the brain firing neurons.

Either none of those things ever happen, OR the brain firing neurons IS those things happening

[Maia]

I don't think there's any reason to believe that when someone "sees" red they're actually seeing anything at all. It's just the brain firing neurons. There's nothing out there that corresponds to it. Wavelength of light don't exist in discrete bands but are just a continuum.

Hence...

since light is a consitnous spectrum it's inevitable that different people will draw the line at different places.

I am indirectly speaking about the process of quantization. Turning continuous light into discrete colors.

https://en.wikipedia.org/wiki/Quantizat ... rocessing)

It's a fundamental problem with human reasoning, nothing specific to colors. A prism turns white light into a spectrum of colors.

So what makes the question "How many colors are there?" interesting is that the answer depends on the sensitivity of your measurement apparatus.

The spectrum is infinite, so there are as many colors as you can discern.

And yet people who can see colours have a pretty good general agreement about them.

[Skepdick]

And yet people who can see colours have a pretty good general agreement about them.

Sure. Because it's an approximation. 550-750nm. +-5%

But this is a linguistic agreement. It doesn't mean that you and I are having the same experience when we use the word "red".

You are having whatever experience you are having when you see this color.
I am having whatever experience I am having when I see this color.

As long as we keep using the word "red" when we are having our respective experiences - we are all good.

[Wizard22]

I don't know if anybody knows for sure if it's "completely arbitrary". There's still, I believe, a widespread acceptance of the idea that two people who are fully colour-perceptive might perceive colours in totally different ways - I like to describe it as a rotation of the colour wheel. If my colour wheel was rotated relative to my friends, then the qualia I see when I see something blue, he might see when he sees something red. And if that were the case, as far as I know there's no experiment we could do to find out that was the case, yet.

I could be wrong on both those counts, but if I'm not...

It's also my belief that rather than colour qualia being hard coded at birth, our brains quite possibly learn what qualia to assign to what sensory experiences. I'm by no means certain of that, but there are a few things leading me towards that direction. And if that's the case, colour wheel rotation is actually pretty likely

That's not how light particulate matter moves though. Colors are based on wavelength. It doesn't matter which direction you move or rotate that wavelength, it's going to appear as 'red', 'green', 'blue' in any direction of perception. That's why the subject-object distinction is confusing to most people.