Does Light Actually Illuminate?

[FrumiousBandersnatch]

If colour is purely a human perception then how do you explain cameras producing colour images?

They're designed to produce images that reflect the same frequencies as the original scene.

The simple fact that two identical areas, i.e. reflecting identical frequencies, can be perceived as different colours even in the same image, by the same individual at a single viewing with unchanging uniform illumination, tells us that colour is not an intrinsic property of those areas.

 

[Tinker Grey]

This sounds like a tree falling in the forest. If you define sound as vibrations in a medium, the tree makes a sound even when no one is there. If you define sound as the perception of the vibration then it doesn't.

It seems to me that that is what this conversation is about. If color is defined as what is reflected by an object, then that is intrinsically part of the object. It has the property of reflecting a wavelength. If you define color as the perception of the wavelength, then the object doesn't have that.

I would guess that most of us don't take these semantics under advisement when someone tells you their car is red.

For me, I tend to go with the former in each example. It doesn't seem very useful to say a car doesn't have color when no one is looking at it.

 

[partinobodycular]

It doesn't seem very useful to say a car doesn't have color when no one is looking at it.

But I don't think that's the question that's really being asked. We probably all agree that the car will reflect a certain wavelength of light whether or not anyone is looking at it. The question isn't what wavelength is that light...that we can objectively measure...rather the question is, what color is it? Is it red or is it yellow? Or does it even have a color? Most wavelengths don't.

Consider synesthesia, where an individual can perceive numbers or letters as being a certain color. Now if we all had synesthesia then we might all agree that the number three is green, for example. But that doesn't mean that the number three is green just because we agree that it's green. In fact it doesn't mean that it's any color at all. And being as most of us don't have synesthesia we probably understand that seeing numbers as colors is just a trick our mind is playing on us.

The same concept applies to wavelengths. We all agree that a certain wavelength will appear red...most of the time. But does that mean that it's actually red, or is it like the number three...it's just a trick our mind is playing on us, representing wavelengths as colors.

 

[Subduction Zone]

For me, I tend to go with the former in each example. It doesn't seem very useful to say a car doesn't have color when no one is looking at it.

My car is colorless.

 

[Landon Caeli]

This sounds like a tree falling in the forest. If you define sound as vibrations in a medium, the tree makes a sound even when no one is there. If you define sound as the perception of the vibration then it doesn't.

It seems to me that that is what this conversation is about. If color is defined as what is reflected by an object, then that is intrinsically part of the object. It has the property of reflecting a wavelength. If you define color as the perception of the wavelength, then the object doesn't have that.

I would guess that most of us don't take these semantics under advisement when someone tells you their car is red.

For me, I tend to go with the former in each example. It doesn't seem very useful to say a car doesn't have color when no one is looking at it.

I'm still convinced there's a difference between what's biologically practical, and what's universal. I think it's truly a kind of hard problem.

 

[Subduction Zone]

I'm still convinced there's a difference between what's biologically practical, and what's universal. I think it's truly a kind of hard problem.

That is true. Biological systems have to be limited. There is no way that one being can see the whole spectrum of light for example. Many insects see into the ultraviolet so what they "see" is going to be different from what we see. Even some people are partially color blind and have a limited appreciation compared to others of what we can see out there. There are special sunglasses that work by taking out specific frequencies of light that allow these color blind people to see actual colors. There are quite a few videos of people putting on those glasses for the first time.

 

[Tinker Grey]

But I don't think that's the question that's really being asked.

But we have those in this thread wondering if their perceptions are part of the properties of the object they are perceiving.

We probably all agree that the car will reflect a certain wavelength of light whether or not anyone is looking at it. The question isn't what wavelength is that light...that we can objectively measure...rather the question is, what color is it?

It's red. We named the wavelength red. Having determined the wavelength, we've determined the color because we named the wavelength.

Or does it even have a color? Most wavelengths don't.

That's right. We named only the wavelengths we perceive.

Consider synesthesia, where an individual can perceive numbers or letters as being a certain color. Now if we all had synesthesia then we might all agree that the number three is green, for example. But that doesn't mean that the number three is green just because we agree that it's green. In fact it doesn't mean that it's any color at all. And being as most of us don't have synesthesia we probably understand that seeing numbers as colors is just a trick our mind is playing on us.

Synesthesia is an interesting topic but I don't know how that is relevant to whether an object is red. We can measure wavelengths.

The same concept applies to wavelengths. We all agree that a certain wavelength will appear red...most of the time. But does that mean that it's actually red, or is it like the number three...it's just a trick our mind is playing on us, representing wavelengths as colors.

It's red because it reflects the wavelength we named red. The fact that our brains sometimes play tricks on us is an explanation as to why we didn't see it as red when in fact it is red.

 

[FrumiousBandersnatch]

This sounds like a tree falling in the forest. If you define sound as vibrations in a medium, the tree makes a sound even when no one is there. If you define sound as the perception of the vibration then it doesn't.

It seems to me that that is what this conversation is about. If color is defined as what is reflected by an object, then that is intrinsically part of the object. It has the property of reflecting a wavelength. If you define color as the perception of the wavelength, then the object doesn't have that.

I would guess that most of us don't take these semantics under advisement when someone tells you their car is red.

For me, I tend to go with the former in each example. It doesn't seem very useful to say a car doesn't have color when no one is looking at it.

I guess it's a metaphysical point - colour isn't considered intrinsic to objects any more than taste or smell. They are 'secondary' qualities:

"Primary qualities are properties objects have that are independent of any observer and include such properties as solidity, extension, motion, number and figure. They exist in the thing itself, can be determined with certainty, and do not rely on subjectivity. Secondary qualities are properties that produce sensations in the observer, such as colour, taste, smell, and sound. They are effects things have on people. Knowledge that comes from secondary qualities does not provide objective facts about things." Philosophy Explained: Primary and secondary qualities

 

[Tinker Grey]

I guess it's a metaphysical point - colour isn't considered intrinsic to objects any more than taste or smell. They are 'secondary' qualities:

"Primary qualities are properties objects have that are independent of any observer and include such properties as solidity, extension, motion, number and figure. They exist in the thing itself, can be determined with certainty, and do not rely on subjectivity. Secondary qualities are properties that produce sensations in the observer, such as colour, taste, smell, and sound. They are effects things have on people. Knowledge that comes from secondary qualities does not provide objective facts about things." Philosophy Explained: Primary and secondary qualities

I should think that an object's molecular makeup that entails that it reflects a wavelength is primary and objectively true (or false). Otherwise, almost nothing is primary. Perhaps that's the point. But I don't find the distinction useful.

 

[Landon Caeli]

It may be that the crux of the confusion altogether is whether we're observing nature in terms of what's useful for people, or what's accurate in the universe.

Which is the better objective, will depend on who one asks.

 

[FrumiousBandersnatch]

I should think that an object's molecular makeup that entails that it reflects a wavelength is primary and objectively true (or false). Otherwise, almost nothing is primary. Perhaps that's the point. But I don't find the distinction useful.

It could be useful to explain why two areas of an image that have identical properties can have different colours.

 

[FrumiousBandersnatch]

It may be that the crux of the confusion altogether is whether we're observing nature in terms of what's useful for people, or what's accurate in the universe.

Which is the better objective, will depend on who one asks.

I think it's just a matter of the subjective vs the objective. I think it can be useful to know the difference.

 

[Tinker Grey]

It could be useful to explain why two areas of an image that have identical properties can have different colours.

Does an optical illusion tell us about the object or the perceiver?

 

[FrumiousBandersnatch]

Does an optical illusion tell us about the object or the perceiver?

The perceiver, by definition. That's why colour is called a 'secondary quality'.

 

[Tinker Grey]

The perceiver, by definition. That's why colour is called a 'secondary quality'.

Cool. Agreed. However, I thought this thread was more about what reality works than about how we perceive it. An object reflects certain wavelengths regardless of our perception of it. A tree falling in the forest perturbs a medium regardless of an observer. A wavelength is reflected regardless of an observer.

I'm perfectly willing to say that different individuals experience reality differently, but I'm not willing to say that the reality external to them is, in fact, different.

And, inasmuch we can successfully communicate, it's almost moot.

 

[sjastro]

They're designed to produce images that reflect the same frequencies as the original scene.

The simple fact that two identical areas, i.e. reflecting identical frequencies, can be perceived as different colours even in the same image, by the same individual at a single viewing with unchanging uniform illumination, tells us that colour is not an intrinsic property of those areas.

If colour is not an intrinsic quality of light then colour imaging is impossible.
The production of a photoelectron signal is based on the photoelectric effect which depends on the colour or wavelength of light.
Using potassium as an example;

The image sensor in your camera is a monochrome chip and is unable to differentiate light of different colours which is why a Bayer colour array is applied to the sensor.

If two identical areas are perceived as different colours then it is the processing of the red, green and blue light by the brain or camera software which is the variable.
The intrinsic colour information of the photons is determined by their wavelengths and does not change.

 

[FrumiousBandersnatch]

If colour is not an intrinsic quality of light then colour imaging is impossible.
The production of a photoelectron signal is based on the photoelectric effect which depends on the colour or wavelength of light.
Using potassium as an example;

The image sensor in your camera is a monochrome chip and is unable to differentiate light of different colours which is why a Bayer colour array is applied to the sensor.

If two identical areas are perceived as different colours then it is the processing of the red, green and blue light by the brain or camera software which is the variable.
The intrinsic colour information of the photons is determined by their wavelengths and does not change.

Perhaps we're using different definitions of colour.

 

[SelfSim]

I'm perfectly willing to say that different individuals experience reality differently, but I'm not willing to say that the reality external to them is, in fact, different.

The 'reality external to them' is still a model perceived by someone.

 

[Ophiolite]

The 'reality external to them' is still a model perceived by someone.

Your illogic is consistent, I'll give you that.

 

[Ophiolite]

And, inasmuch we can successfully communicate, it's almost moot.

I clicked agree for the rest of your post. On this point, however, I note that not all members can successfully communicate.