About the thread "The color that doesn't exist"

[tulamide]

@KBrown
I saw your two newest remarks/questions and answered them extensively. It took me quite some time. Unfortunately, a bad accident happened. There were like hundreds of spam posts in "offtopic" and in the process of deleting them, somehow three non-spam posts got deleted as well. I don't have a copy of what I wrote and I don't think I find the motivation to write it again. Unless you insist on it. For now, just the keyword you mentioned:

Perceptual illusion: Yes, that's close to what it is. It's a combination of physical and biological processes that lead to contradicting results. Our brain literally fills the hole between red and violett (the wavelengths we can't perceive), and magenta is what it came up with.

IT's basically an error state rather than a color. Define magenta as what happens to the brain, when green is absent but blue and red fire both.

[Spogg]

I have to hold my hand up. It was I who, according the moderator logs, deleted 3 valid topics. I was mortified when tulamide told me what had happened, especially so because I loved that thread myself; it was really interesting.

When I mark topics for deletion I always re-scan them to make sure before I hit delete. Clearly I missed all three it would seem (unless it was a board software glitch, which I doubt somehow).

I apologise profusely to all who posted and were following that topic.

May I suggest that any post that even vaguely relates to what we do and are interested in goes into General?
The problem with Off Topic is that every day we get pages and pages of spam, so if you post something of interest and someone logs on before we clear it out, they may not be bothered to look through it and see your post. This is quite apart from any accident that I or even trog might make while deleting literally hundreds of spam posts every day.

Cheers

Spogg

[trogluddite]

Don't feel too bad Spogg - I had to PM an apology to LeAttol last week for accidentally deleting one of his threads. It's all too easy to see what you expect to see and for the muscle memory to take over when there are so many threads and posts to delete in a single session. I agree with your advice; I hate having to do it, but it's probably for the best to treat "Off Topic" as redundant now (unless/until DSPr can sort out some proper spam filtering tools, which doesn't seem likely).

[Spogg]

Oh trog, you’ve made me feel a whole lot better mate!

Thank you!!

Spogg

[k brown]

This seems to discuss what tula is talking about.
http://www.biotele.com/magenta.html
This puts it well too:
https://arstechnica.com/science/2009/02 ... a-magenta/
And on qualia in general:
http://www.biotele.com/qualia.htm

Also, as I mentioned before, Edwin Land's Retinex theory is also relavant to this.
https://en.wikipedia.org/wiki/Color_constancy (scroll down to "Retinex Theory")
https://sciencedemonstrations.fas.harva ... experiment
Land's 1977 paper:

8f151a52afa3c1e80505ddb09b8624162e35.pdf.zip

(1.92 MiB) Downloaded 811 times

For those living near the San Francisco Bay Area, the Exploratorium has a fascinating simplified Retinex demo set up, so you can see the seeming impossibility of it with your own eyes.
Similar to the one described here:

1de5c1d9d5388c528fcfb25bdacbdda6cc78.pdf.zip

(1.73 MiB) Downloaded 798 times

And here:
http://www.greatreality.com/Color2Color.htm

I guess I'd sum up by saying that any color that anyone can see certainly exists (for that person) because color isn't a 'thing' - it's pure perception; only exists in the brain of the perceiver. ..tree falls in the woods... always a dumb question because sound is a physical thing - vibrating air; it doesn't need someone to hear it for it to exist. However color isn't a physical thing, it's entirely something the brain concocts for us based on certain inputs from the retina. Colors trogg dreams 'exist' simply because he perceives them, even with no input from the retina at all. In other words, a color doesn't need to have a wavelength to 'exist'.
So, would Shepard tones be considered a kind of auditory qualia?

That's what's so fascinating about the simpler Retinex demonstration (not the Mondrian one) - all one's eyes are presented with are two superimposed B/W photos shot through different filters, with a red filter over the lens of one of the projectors, and a (muted) full color scene is perceived - even though all the eyes are getting are white and red light.

[tulamide]

I guess I'd sum up by saying that any color that anyone can see certainly exists (for that person) because color isn't a 'thing' - it's pure perception; only exists in the brain of the perceiver. ..tree falls in the woods... always a dumb question because sound is a physical thing - vibrating air; it doesn't need someone to hear it for it to exist. However color isn't a physical thing, it's entirely something the brain concocts for us based on certain inputs from the retina. Colors trogg dreams 'exist' simply because he perceives them, even with no input from the retina at all. In other words, a color doesn't need to have a wavelength to 'exist'.
So, would Shepard tones be considered a kind of auditory qualia?

That's what's so fascinating about the simpler Retinex demonstration (not the Mondrian one) - all one's eyes are presented with are two superimposed B/W photos shot through different filters, with a red filter over the lens of one of the projectors, and a (muted) full color scene is perceived - even though all the eyes are getting are white and red light.

This is the part where I strongly have to disagree.

Psysical colors are a physical thing, as they are light of a certain frequency. Light is as physical as can be, is part of every current physic theory from relativity over string to quantum, is part of photovoltaic and photoelectric tech, even the age and distance of planets and stars are measured through redshift (which btw is measured without any human eye looking at it). Light of certain frequencies exists, it doesn't need someone to see it for it to exist. Actually you are the first to deny the physicality of light.

The issue is that you don't make a distinction between physical colors and the error states that our brain reacts to by making up colors that don't exist. For example, in my dreams I often hear people speak. The sound they make doesn't exist, no air is vibrating, it's just my brain making it up. But that doesn't mean there is no physical sound. For example, when you go to space you can't hear sound, but that doesn't mean the objects don't produce sound. The same is true for light of all frequencies. That you can't see light in a black hole doesn't mean there is no light.

The last example is very important, as it reveals what I'm talking about the whole time: You say "even though all the eyes are getting are white and red light." That is more than enough, because white light is what we perceive if the whole spectrum exists - all physical colors are in white light, filtering it and adding red light to confuse our eyes (since red receptors are already firing to the fullest from white light) of course can produce all kinds of colors.

Roentgen, another physical color from the spectrum, can only be made viewable by shifting the frequencies to a range we can perceive. That doesn't mean it doesn't exist physically, as many people who died from this aggressive light emission prove. The infrasound elephants make and the ultrasound dolphins make can only be heard by shifting the frequencies to the range humans can perceive. That doesn't mean they don't physically exist.

I hope I gave enough examples, as to why there is a difference between physical colors and things our brain makes up.

[k brown]

Well, I still maintain that you're confusing light and color - of course light is physical, I didn't say it wasn't. it's color that isn't 'physical' - it's only a perception that our brains create based on the physical wavelengths of physical light.

And no - there IS no sound in space, because there is no air to vibrate; that doesn't mean things don't vibrate in space, just that there's no air to be moved by those vibrations, so no sound. You hear people speak in your dreams simply because your brain remembers what people speaking sounds like and can provide that pure perception for you. There's no air vibrating you're eardrums while you're dreaming, so no sound. Just because your brain 'hears' something doesn't mean there is sound - sound and hearing are not the same thing; sound is physically vibrating air (whether there's someone around to hear it not), hearing is a perception in the brain that can be triggered by sound or generated on it's own in a dream - from memory. Just as wavelengths of light and color are not the same thing - color is just a groovy sensation that our brains do for us.

As to Roentgen (not a 'thing' in itself, just a unit of measurement), all electromagnetic radiation is of course physical, but X-rays and gamma rays don't have a color because they don't produce a sensation color in our brains - again there is no such thing as physical color. Different wavelengths of light/radiation are just that: different wavelengths - a given frequency of radiation will produce different sensations of color in different species. If there was a species that perceived X-rays and gamma rays as a color then it has a color for them, but not to us. Why? because color is not a physical thing, just a mental reaction to a physical thing, and that reaction can vary from person to person and species to species.

The main point of your original post is proof of all this - there is no wavelength of light to represent magenta; the brain doesn't like this 'gap' in the spectra between red and violet, so it 'makes up' the sensation/color magenta for us. A wavelength for magenta doesn't physically exist, but it does as a sensation of color (for humans; there many animals that don't perceive colors that we do and vice-versa), because color is a purely mental process triggered by different wavelengths of light.
I think the items I included explain this pretty clearly - or do think they are in error?

I feel we're just going to go 'round in circles on this, so it's probably time for others to weigh in.

[trogluddite]

It seems to me that in terms of the physical and perceptual processes, we're pretty much all agreeing with each other!

I think it's the semantics of the word "colour" (and colour names) that is causing the confusion. In other words; do we reserve the word "colour" only for the perceptual experience, or can we extend the meaning to also describe qualities of the electromagnetic radiation which causes that experience? Or to put it another way; when we say "red light", are we saying that "redness" is a property of the light, or are we only saying "light which makes us perceive redness"? Although it may not be immediately obvious, we are potentially using two different glosses of the same word.

In everyday speech, there no problem with saying e.g. "red light", of course - we all know what is meant. But in a more technical discussion like this one, it may be much more ambiguous; so I do feel that reserving the "colour" words only for the perceptual phenomena, and using only technical terms like "wavelength"/"frequency" for the electromagnetic phenomena can be beneficial, even though it's rather more cumbersome.

[tulamide]

Well, I still maintain that you're confusing light and color - of course light is physical, I didn't say it wasn't. it's color that isn't 'physical' - it's only a perception that our brains create based on the physical wavelengths of physical light.

And no - there IS no sound in space, because there is no air to vibrate; that doesn't mean things don't vibrate in space, just that there's no air to be moved by those vibrations, so no sound. You hear people speak in your dreams simply because your brain remembers what people speaking sounds like and can provide that pure perception for you. There's no air vibrating you're eardrums while you're dreaming, so no sound. Just because your brain 'hears' something doesn't mean there is sound - sound and hearing are not the same thing; sound is physically vibrating air (whether there's someone around to hear it not), hearing is a perception in the brain that can be triggered by sound or generated on it's own in a dream - from memory. Just as wavelengths of light and color are not the same thing - color is just a groovy sensation that our brains do for us.

As to Roentgen (not a 'thing' in itself, just a unit of measurement), all electromagnetic radiation is of course physical, but X-rays and gamma rays don't have a color because they don't produce a sensation color in our brains - again there is no such thing as physical color. Different wavelengths of light/radiation are just that: different wavelengths - a given frequency of radiation will produce different sensations of color in different species. If there was a species that perceived X-rays and gamma rays as a color then it has a color for them, but not to us. Why? because color is not a physical thing, just a mental reaction to a physical thing, and that reaction can vary from person to person and species to species.

The main point of your original post is proof of all this - there is no wavelength of light to represent magenta; the brain doesn't like this 'gap' in the spectra between red and violet, so it 'makes up' the sensation/color magenta for us. Magenta doesn't physically exist, but it does as a sensation of color (for humans; there many animals that don't perceive colors that we do and vice-versa), because color is a purely mental process triggered by different wavelengths of light.
I think the items I included explain this pretty clearly - or do think they are in error?

I feel we're just going to go 'round in circles on this, so it's probably time for others to weigh in.

Since you persist on ignoring the scientific world because they see color as physical, as a result of light being reduced to certain wavelengths and that eyes from insects to humans have physical/biological receptors to react to those physical colors, it sure is difficult to convince you of the error in your thought process.

The same is true for sound. You seem to think that sound only exists because of air. Pretty easy to disprove as more than enough sound is produced on a daily basis in -wait for it- water-! I'm glad scientists didn't know of your definition of sound, and instead invented the sonar. And those dolphins communicating with each other per sound under water, they must be a perceptional illusion, for sure.

Of course there is sound produced in space. An explosion blows with a bang, it doesn't care if there is a matter of sound transportation system like gas or liquid.

Interesting that you see roentgen as part of electromagnetic radiation and therefore as physical, although it is just a part of the light spectrum as green, blue, red, or microwaves. So you say, yes there is a spectrum of wavelengths, but only those that are convenient for my personal view of things are physical, while colors (for whom physical receptors exist, even for ultraviolet) specified through their wavelengths just as microwaves or roentgen (I have no clue what the term is in English, in German it is called "Röntgenstrahlung" and IS a thing!!!) are the great exception.

I wonder what else you deny a physical existence. Maybe electricity? It sure does only exist, when it is moving through a copper line to your PC, right?

But I understood that I won't reach you. It is sad that you as an artist lack the understanding of color, but maybe art and science really don't go well alongside.

It seems to me that in terms of the physical and perceptual processes, we're pretty much all agreeing with each other!

I think it's the semantics of the word "colour" (and colour names) that is causing the confusion. In other words; do we reserve the word "colour" only for the perceptual experience, or can we extend the meaning to also describe qualities of the electromagnetic radiation which causes that experience? Or to put it another way; when we say "red light", are we saying that "redness" is a property of the light, or are we only saying "light which makes us perceive redness"? Although it may not be immediately obvious, we are potentially using two different glosses of the same word.

In everyday speech, there no problem with saying e.g. "red light", of course - we all know what is meant. But in a more technical discussion like this one, it may be much more ambiguous; so I do feel that reserving the "colour" words only for the perceptual phenomena, and using only technical terms like "wavelength"/"frequency" for the electromagnetic phenomena can be beneficial, even though it's rather more cumbersome.

And not true.
We have receptors for red, green and blue! Holy shit a monitor wouldn't work if we hadn't discovered it, as it is using the very same system, but to display color instead of sensing it.
And guess what, without light you won't see a color. Test it by waking up at 3 am and watch your favorite colors that do have to be seen, because they are just a product of your brain, instead of being physical specifications!

Of course "redness" is a property of red light, it's so well a property that it is used to measure distance and size of planets and stars (via redshift)!!! How much more physical can it be?

[k brown]

You still haven't answered my question about whether you actually read any of the materials I provided, if you had, it's bewildering that you still maintain this position.

You definitely have me on the point about water; I shouldn't have been so specific - there has to be a material substance that can be physically moved, be it air, any other gas, oil, aftershave, whatever. With no substance to move and create vibrations, there IS no sound (for humans at any rate - infrasonic sound can happen in space [since it's not a complete vacuum], so any lifeform that can percieve frequencies that are too low for us to hear would hear something). Yes, Virginia, an explosion in space, for us humans is a SILENT one. If a tree falls in space does it make a sound? - NO, because there ain't enough air, water, gas, oil or aftershave in space to make an audible sound. Technically, any cyclical vibrations of a compressible material can be called sound, but if we are talking about only frequencies we can hear, if there's an explosion in space, a human won't hear anything.

Again, Google Roentgen - it's just a unit measurement, just like an ounce isn't a physical thing either. Roentgen is a unit of measurement for X-rays and Gamma rays. Maybe the word is used differently in other countries, but Wikipedia doesn't seem to be aware of that.

Thanks, trog for attempting create a 'neutral zone' (shoulda been a diplomat ), but I fear 'twas to no avail.

Since this has now degenerated into personal insult ("It is sad that you as an artist lack the understanding of color..." , I leave the discussion to others (if they dare).