This question may have been asked here but I didnt see it.

This is a classic question from the ABC science forum in australia and the question also made its way to england infected the BBC science forum

ha ha ha ....................attempt to answer it at your own peril :)

Welcome to Sciforums.

Question: Is it a transgenetic orange?

If so, a pale green glow.

well theres a few points to this:

how dark is it? If it's night time and you can only just make out a silhouette, then the orange has no colour, because for it to have colour it would have to be subjected to light, (white light or a light that carries a colour that the orange reflects)

Since Orange is a mixture of Red and Yellow, the light sources it could reflect are White light (which in the dark wouldn't be existant), or it could be Infra-Red which is present at night from the fluctuation of free floating atoms and molecules.

Of course infra-red is just before the eyes visual spectrum, otherwise we would be able to see at night.

Green would be within our visual spectrum of light and wouldn't occur at night (of course I'm going ont he assumption that it's pitch black)

The questions you could then ask are:
Is the orange moving? If so is it moving away or towards you?

I mention this because in normal light if something is travelling towards you, it has a higher frequency of light stemming up to ultraviolet, while if it's travelling away it will be more towards the infra-red end of the scale.

Of course you wouldn't be able to notice this unless you used particular types of equipment like a Spectrophotonmeter.

This would mean also that if the orange was travelling towards you (or you towards it) it might have a perception of green.
Of course I can't apply the speed you need to be approaching the orange, or the orange approaching you.

The answer given is not for the question asked. It is the classic question of "If a tree falls in the forest and nobody is around to hear it, does it does it make a sound?" Its a deeper kind of question then that. ME THINKS:p

By the way.. has anyone ever read, The Hichhikers Gude to The Galaxy.....:D

Makes you think on some of the same type of questions....

It is very dark....

hmmm...

Well if the orange is ripe, then it will be orange..

if it isn't ripe, then it will be green..

well that is my experience of oranges anyway :)

orange

and ive read hitch hickers 1- 5.5

Peter/Peter,

The answer is correct, it's just the question isn't right.
A classic "42" conundrum.

I believe it would be helpful to understand why an orange is orange when illuminated. Light waves enter our eyes and set off a reaction in the optic nerve that is associated with the external phenonoma of frequencies that are consistant with the physical properties of the orange. That is to say that the inherent properties of an orange are a constant, and that an organisms ability to recognize said properties using the interpretation of external stimuli such as light is variable. Raising the question of the colour of an orange in the dark is almost like raising the question of whether or not an orange CAN exist in the dark.

Do you like cheese?

It's black of course:-)

<<...What colour is an orange in the dark...>>

Since color is a subjective visual quantization of available light (Orange is a specific range of colors falling within the visually perceptible portion of the spectrum of electro-magnetic wavelengths), and vision requires the eye to receive and absorb visible wavelength photons in sufficient quantity to induce chemical activity, in the dark Orange will have no color at all.

Colour is a horse of a different color.

I smiled when I saw this, it also reminded me of the tree in the forest. The answer is slightly darker than its surrounding darkness, I think!!:confused: :rolleyes: :rolleyes:

orange

It can be.

Color is a property of the orange, yes ?
Then it's still orange in the dark. We just can't perceive it.

The chemical composition of the outer margins of the orange reflects light predominantly of wavelengths that we perceive as 'orange'.
The chemical composition is still there in the dark, only very few photons reflect off it.

"in the dark ___" "what" ?

what is it that it is in that is dark ?

You can't have colour in the absence of light. The orange will only have colour when exposed to light- basic physics.

You can't have colour in the absence of light. The orange will only have colour when exposed to light- basic physics.

ah ha !
yes and no
all matter IS light or it would not be colour.
thus colour IS matter and matter IS colour.

In the dark, the orange will simply cease to exist.

What pitch is a violin in a vacuum?

It's orange.

Is it not orange if we shine an artificial light on it and make it purple. No, because that same light on a banana would affect it's color as well.

In normal light it is orange to us. The color is it's own, just like a green apple is green.

If a tree falls in a forest it does make a sound even if it was to far away from us to hear, a dog sitting next to you probably did.

The orange is orange and the tree falling makes a sound we know this from experience.

It's orange.
No.


Is it not orange if we shine an artificial light on it and make it purple. No, because that same light on a banana would affect it's color as well.
In normal light it is orange to us. The color is it's own, just like a green apple is green.
Define "normal light".
We call it "orange" because that's what shows under the light we're used to.
If the sun gave out a different range of frequencies (and we'd evolved under that) what colour would we consider the orange to be?
The colour is NOT the colour of the orange at all. It's a combination of the orange, the frequency of ambient EM radiation and our receptors.

In the dark, the orange will simply cease to exist.

In the absense of light the color is black.
It's composition doesn't change.
It's presence doesn't change.

It's still there...It's still an orange but it's color is unpercievable.

But this sounds like a bad joke.

No.


Define "normal light".
We call it "orange" because that's what shows under the light we're used to.
If the sun gave out a different range of frequencies (and we'd evolved under that) what colour would we consider the orange to be?
Isn't the color of something established using 'normal' light i.e. sunlight ?


The colour is NOT the colour of the orange at all. It's a combination of the orange, the frequency of ambient EM radiation and our receptors.
Hmm I beg to differ.
Colors are defined by wavelength alone.
Light with a wavelength of 700nm, for example, is defined as red light.
And what wavelengths an object reflects is entirely based on what the object is made of.

It's still there...It's still an orange but it's color is unpercievable.

Yes, it's imperceivable. Are you saying that if something is imperceivable, it doesn't exist ?

Isn't the color of something established using 'normal' light i.e. sunlight ?
Hmm I beg to differ.
Colors are defined by wavelength alone.
Light with a wavelength of 700nm, for example, is defined as red light.
And what wavelengths an object reflects is entirely based on what the object is made of.
I think I may have expressed that badly (going out with family soon and keeping an eye on a certain thread ;)).
Orange is a human term used for our experience of the "colour".
If we'd evolved under a different sun what would be "normal" for us?
Meh, it mad sense to me before I started typing :o
I'll go and have a couple of pints of Guinness, that way it'll either make more sense or I won't care either way.:D

I think I may have expressed that badly (going out with family soon and keeping an eye on a certain thread ;)).
Orange is a human term used for our experience of the "colour".
If we'd evolved under a different sun what would be "normal" for us?
Meh, it mad sense to me before I started typing
I'll go and have a couple of pints of Guinness, that way it'll either make more sense or I won't care either way.:D

I think I see what you're saying, but I don't think it has much relevance though.
Anyway, have a good time! And have one on the Dominion ;)

Oli,


“ Is it not orange if we shine an artificial light on it and make it purple. No, because that same light on a banana would affect it's color as well.
In normal light it is orange to us. The color is it's own, just like a green apple is green. ”

Define "normal light".
We call it "orange" because that's what shows under the light we're used to.

Exactly, and before we had artificial lights that we could create we had sunlight. And that is normal light IMO as a baseline.

Artificial light affects all colors, ever put paint on a wall and it looked good with sunlight and then turn on an incandesent or flourescent bulb, it changes. Sometimes looks like crap.


If the sun gave out a different range of frequencies (and we'd evolved under that) what colour would we consider the orange to be

But it doesn't. If it did, it would be a different color or hue. Who came up with the color orange I don't know but it's orange. What if the sun were green ?


The colour is NOT the colour of the orange at all. It's a combination of the orange, the frequency of ambient EM radiation and our receptors.

In our perception it is orange correct. What color is a lime in our perception with the above. Green.

In the absense of light the color is black.
It's composition doesn't change.
It's presence doesn't change.

Because we can't see it, we might as well ask is there an orange there at all ?

But the question is what color is an orange in the dark. Since by experience we know what color the orange is in the light, then unless we are suggesting that in the dark the orange itself changes it's color to blue for example, then it is still orange.

Once the light reveals the orange we then say or there's an orange. And what color is the freaking "orange".

Oli,
Exactly, and before we had artificial lights that we could create we had sunlight. And that is normal light IMO as a baseline.
Artificial light affects all colors, ever put paint on a wall and it looked good with sunlight and then turn on an incandesent or flourescent bulb, it changes. Sometimes looks like crap.
But it doesn't. If it did, it would be a different color or hue. Who came up with the color orange I don't know but it's orange. What if the sun were green ?
In our perception it is orange correct. What color is a lime in our perception with the above. Green.
You're missing the point: (or I'm looking too deeply).
The colour "orange" is a confluence of our perception and the prevailing conditions: "orange" is the interaction between us and an orange - not necessarily a property of the orange itself.

You're missing the point: (or I'm looking too deeply).
The colour "orange" is a confluence of our perception and the prevailing conditions: "orange" is the interaction between us and an orange - not necessarily a property of the orange itself.

I understand where you are coming from but I think on these types of questions we over think it.

In the end, it doesn't matter what the cause of the orange being orange is, it just is. Even if the properties of the orange is debated as to what causes it to have it's color, we still see it as orange.

So I wasn't disagreeing or discussing why it is orange just that it is.

We could ask, what causes an orange to appear orange ?

That would be different.

What pitch is a violin in a vacuum?

nice one !

colour is a state of material physics.
just like pitch.

problem is society has become soo egocentric that they fail to grasp such concepts.

Color is a property of the orange, yes? Then it's still orange in the dark. We just can't perceive it. The chemical composition of the outer margins of the orange reflects light predominantly of wavelengths that we perceive as 'orange'. The chemical composition is still there in the dark, only very few photons reflect off it.I think this is the crux of the question. What defines the color of an object? Is it A) The color we would observe if it were in normal solar-spectrum light, or B) The color we actually observe in the current conditions? If A, then the orange is always orange, but if B, then it's color varies and it is currently black--or perhaps very dark grey, depending on what you meant by "in the dark."

I tend to go with B. There are too many things on this planet--especially man-made things--that change in appearance depending on the spectrum of the ambient light. I was instructed to wear black pants to a Christmas choir performance, and my wife (women are ALWAYS right about colors) picked out a pair from my closet. When I got to the company cafeteria under its peculiar lighting, they turned greenish-brown. Artificial dyes can be phosphorescent, absorbing light of one frequency and "reflecting" it back in another.
"in the dark ___" "what" ? What is it that it is in that is dark?The customary definition of "the dark" is "a space with so little solar-spectrum light that only the rods in the eyes react to the light and send signals through the optic nerve." It is the cones that discern color. The rods present a monochrome image in which everything is shades of grey.

Of course "in the dark" can also refer to an area that is literally without light. That didn't seem like the correct interpretation of the question in the O.P., since in absolute darkness we would not even know the orange was there.

The customary definition of "the dark" is "a space with so little solar-spectrum light that only the rods in the eyes react to the light and send signals through the optic nerve." It is the cones that discern color. The rods present a monochrome image in which everything is shades of grey.

Of course "in the dark" can also refer to an area that is literally without light. That didn't seem like the correct interpretation of the question in the O.P., since in absolute darkness we would not even know the orange was there.

our perception does not change the physics principals at work to define the "orange" as "orange" in colour.

just as much as one might define radioactive waste(etc) as being not there while it is killing you.

colour may be a witnessable product of spectral analysis however it does not stop it from being what it is and does not change it from being what it is.

thus observation is completely pure and the actual state has not changed.

the orange is a poison to something that is poisoned by it.
yet is is also defined as food to us.
reasonable doubt as far as perceptive interpretation surely cant go past basic physics as we currently understand them ?

it will be dark orange haha

I think this is the crux of the question. What defines the color of an object? Is it A) The color we would observe if it were in normal solar-spectrum light, or B) The color we actually observe in the current conditions? If A, then the orange is always orange, but if B, then it's color varies and it is currently black--or perhaps very dark grey, depending on what you meant by "in the dark."

I tend to go with B. There are too many things on this planet--especially man-made things--that change in appearance depending on the spectrum of the ambient light. I was instructed to wear black pants to a Christmas choir performance, and my wife (women are ALWAYS right about colors) picked out a pair from my closet. When I got to the company cafeteria under its peculiar lighting, they turned greenish-brown. Artificial dyes can be phosphorescent, absorbing light of one frequency and "reflecting" it back in another.
I go with A, because it makes sense to establish an objects color in the presence of light of all wavelengths. Otherwise, what's the point ? You have to have a standard.
Also, the chemical composition of the orange determines what wavelengths will be reflected off it. If you shine a light composed of just one color on it, the orange will not reflect all the wavelengths it normally could. So the colored light only lets us see one aspect of the oranges appearance. Only the molecules that reflect the used wavelength will now reflect light, so it's not the whole picture.

"Orange" is just a reference to a specific wavelength of light we perceive as the color orange. The spectrum of light hitting the object does not change this specific wavelength reference in any way.

If we are assuming it is completely dark and there is no light, then there can be no color. Color cannot exist without light transmitting that information. Hence my "pitch in a vacuum" analogy, if there are no sound waves there is no pitch.

Color cannot exist without light transmitting that information.
So if there were to be no light there wouldn't be any colour?
So orange isn't actually a property of the orange, it's only orange because light "says" it is?

So if there were to be no light there wouldn't be any colour?
So orange isn't actually a property of the orange, it's only orange because light "says" it is?I would go further and say it's only orange because it appears that way to us.

Forty years ago, when many old-fashioned men still wore plain white shirts to work, manufacturers were adding phosphorescent dyes to laundry detergent. Under sunlight and fluorescent office lights the dyes would absorb certain frequencies and reflect them back as extra blue light. This was culturally perceived as extra cleanliness, since white shirts tend to turn slightly yellow over time after absorbing body oils. Some of the advertisements called this new color "whiter than white." One of the brands of detergent was even honestly named "Rinso Blue."

Of course household incandescent lights did not provide the right spectrum so there was no phosphorescence and the shirts continued to look yellow.

“ Originally Posted by Oli
So if there were to be no light there wouldn't be any colour?
So orange isn't actually a property of the orange, it's only orange because light "says" it is? ”

I would go further and say it's only orange because it appears that way to us.

Either way it's orange.

"Orange" is just a reference to a specific wavelength of light we perceive as the color orange. The spectrum of light hitting the object does not change this specific wavelength reference in any way.

If we are assuming it is completely dark and there is no light, then there can be no color. Color cannot exist without light transmitting that information. Hence my "pitch in a vacuum" analogy, if there are no sound waves there is no pitch.

Of course there is, in the strings of the violin.

Color is a property of the orange, yes ?
Then it's still orange in the dark. We just can't perceive it.

The chemical composition of the outer margins of the orange reflects light predominantly of wavelengths that we perceive as 'orange'.
The chemical composition is still there in the dark, only very few photons reflect off it.
I agree completely. Our inability to perceive something doesn't alter reality. You want to know what color the orange is in the dark? Bring a flashlight.

What pitch is a violin in a vacuum?

you can still figure the pitch by measuring a vibrating string.. Optical pickups actually do this

isnt an orange actually the inverse of that colour on the spectrum?? Due to the other colours being absorbed and orange being the only one bouncing back??

isnt an orange actually the inverse of that colour on the spectrum?? Due to the other colours being absorbed and orange being the only one bouncing back??

black hole sun etc...

funny ol universe n all.
sheeple are soo dumb

So if there were to be no light there wouldn't be any colour?

Yes, unless there is an alternate way of perceiving colors other then light.


So orange isn't actually a property of the orange, it's only orange because light "says" it is?

Orange is a reference to a specific wavelength band of light. Orange is a property of orange (god couldnt we have done yellow/banana? lol). My point is that without light reflecting off the orange at specific wavelengths, no color exists. The information of "orange" is carried in light. No light = no information = no color. The property of orange remains unchanged there is just no light.

-=-

Orange color requires certain properties of the object, the type(s) of light which carries that color, eyes that receive that light & a brain to interpret it & produce the image.
Dark is the absence of light. No light = no color. No light receptor = no color. No brain = no color. Different enough properties of the object = different color. Different type of light = different color. Different eyes = different color. Different brain = different color.
Color is 1 aspect of the brain's interpretation of the signals the eyes receive. The signals are light reflected from the object & are such as they are due to the properties of the light & the properties of the object.
The OP presupposes the orange is there. The orange can be touched, held, squeezed, rolled about, tossed into the air & caught in the dark. There may be sound as it is squeezed or rolled & will be sound as it is caught. It can be smelled & tasted. And eaten.
There is a difference between this & the tree falling in the forest. Color requires an observer. Sound does not.
Technically, it is correct that the orange is not orange colored. It is the color(s) of the light it absorbs. If it were a simple matter of an object absorbing blue light & reflecting orange & another object absorbing red light & reflecting green & if we could know this of each object we see, I'd probably persist in calling the former blue & the latter red. As things are tho, it is much too impractical thus we refer to the reflected color.

Yes, unless there is an alternate way of perceiving colors other then light.

Orange is a reference to a specific wavelength band of light. Orange is a property of orange (god couldnt we have done yellow/banana? lol). My point is that without light reflecting off the orange at specific wavelengths, no color exists. The information of "orange" is carried in light. No light = no information = no color. The property of orange remains unchanged there is just no light.

Is it possible that you are speaking of color-perception instead of color ?

You can't have colour in the absence of light. The orange will only have colour when exposed to light- basic physics.

You are correct soulstar.
That's why what you said was completely ignored.

You are correct soulstar.
That's why what you said was completely ignored.

Then color doesn't exist.
How can you assign a construct of the mind to an object as a characteristic of that object ??

The colour we perceive as the colour of an object is the reflected light which is not absorbed as energy by the object.
Thus, when white light hits a leaf, the light which is not used by the leaf in photosynthesis is reflected. This appears to us as the colour green.

http://hyperphysics.phy-astr.gsu.edu/Hbase/biology/imgbio/phorate.gif


If you lit a plant with green light, it would barely keep alive.

The colour we perceive as the colour of an object is the reflected light which is not absorbed as energy by the object.
Thus, when white light hits a leaf, the light which is not used by the leaf in photosynthesis is reflected. This appears to us as the colour green.

If you lit a plant with green light, it would barely keep alive.

And ?
What causes only the green light to reflect ?

And ?
What causes only the green light to reflect ?

The material that the object is made of.

The material that the object is made of.

Exactly. The rest is just interpretation. Case closed.

The material that the object is made of.

True.
In the case of a plant, the organelles which change non green light into useable energy.

Enmos, you need to rethink this.

True.
In the case of a plant, the organelles which change non green light into useable energy.

Enmos, you need to rethink this.

I don't think so Captain :p

What is your definition of 'color' ? In your own words please (no dictionary definitions).

The wavelength of light you receive depends on the object and the light that hits it.

The wavelength of light you receive depends on the object and the light that hits it.

The objects ability to reflect certain wavelengths doesn't change with the different colors of light that shine on it.
In other words, it's characteristics don't change. Not when you shine a different color light on it and not if some other animal looks at it either.
The characteristics of the object determine its color.

The objects ability to reflect certain wavelengths doesn't change with the different colors of light that shine on it.

Yes, however, it isn't strictly correct to say the object *is* orange because if no light of that wavelength hits the object then none will reflect off it.

The wavelength of light you receive depends on the object and the light that hits it.
Correct. Plus the sensory capability of the observer.

Enmos. When people start asking for definitions of simple words, it is the time to stop arguing.
The opponent is digging trenches, and trench warfare is long lasting.

Yes, however, it isn't strictly correct to say the object *is* orange because if no light of that wavelength hits the object then none will reflect off it.

(I edited that post)

Why not ? You can shine a light on it periodically to see if its still orange :D

Correct. Plus the sensory capability of the observer.

Enmos. When people start asking for definitions of simple words, it is the time to stop arguing.
No, it's not correct. Neither the light nor the perceptions of the observer have any impact on the objects characteristics.

The observed colour isn't simply a property of the object because it also depends on another factor, the light hitting the object.

The observed colour isn't simply a property of the object because it also depends on another factor, the light hitting the object.

Well, I disagree. I explained in one of my posts above.

Enmos, imagine a universe in which there is no light.
In the middle is an orange, physically, atom for atom, exactly the same as an orange in our universe.


Does that Orange have the colour orange?

Well, I disagree. I explained in one of my posts above.

Well, I will agree that what colour you observe if you expose the object to white light is a property of the object.
Similarly for every other wavelength or combination of wavelengths, however, it still isn't strictly correct to say that the colour of the object is the colour that is observed if the object is exposed to white light.

Well, I will agree that what colour you observe if you expose the object to white light is a property of the object.
Similarly for every other wavelength or combination of wavelengths, however, it still isn't strictly correct to say that the colour of the object is the colour that is observed if the object is exposed to white light.

I think it is. The object still reflects the wavelengths it would normally reflect, only one or more are missing.
The way I see it, the color of an object is directly related to its chemical makeup. In fact, it's color IS the chemical makeup.

I can easily falsify your claim that perception has got anything to do with what color an object is. I'm colorblind.. I guess that should tell you enough ;)

Enmos, imagine a universe in which there is no light.
In the middle is an orange, physically, atom for atom, exactly the same as an orange in our universe.


Does that Orange have the colour orange?

If we say that those characteristic are called orange, then yes.

Well, I will agree that what colour you observe if you expose the object to white light is a property of the object.


Are you sure.
I've already shown that the observation of the colour green is made because the colours blue and yellow are not used by a leaf's chloroplasts.


Do you think that what an object does not do is a property of an object?
Is being President of the United States one of my properties because that is something that I do not do?

Are you sure.
I've already shown that the observation of the colour green is made because the colours blue and yellow are not used by a leaf's chloroplasts.


Do you think that what an object does not do is a property of an object?
Is being President of the United States one of my properties because that is something that I do not do?

Of course not absorbing certain wavelengths is a characteristic. Exactly the same as not reflecting certain wavelengths is a characteristic.

Are you sure.
I've already shown that the observation of the colour green is made because the colours blue and yellow are not used by a leaf's chloroplasts.


Do you think that what an object does not do is a property of an object?
Is being President of the United States one of my properties because that is something that I do not do?

Not being the president of the US would be a property of you by that definition, just as not reflecting red light is a property of the leaf.

I can't quite decide on whether not being able to do something can be a characteristic of an entity. If I tried, I could probably think of some instances, but I think they would be exceptions. I think that it would be if by necessity, that that was the case. I can't see that the inability of a leaf to absorb blue and yellow can validly be said to be a property of that leaf.
In common usage, which is what I would prefer to stick to, we define things by what they do rather than what they do not do.

In common usage, which is what I would prefer to stick to, we define things by what they do rather than what they do not do.

That's arbitrary :D

[deleted- explained in next post]

I can't see that the inability of a leaf to absorb blue and yellow can validly be said to be a property of that leaf.
You are calling it green because of those 'non-characteristics'!

Look, what is the difference between:
- absorbing all wavelengths but some.
- only reflecting some wavelengths.

No difference.

Damn, you deleted a patsy argument:D
I'll work on what's left.

The difference between something that a thing does being a property of that thing, and something that that thing does not do being a property of that thing, is, in the example of the leaf, the presence of a whole system within that leaf to absorb and use light of specific wavelengths, and the absence of the ability to absorb other wavelengths.

I think that what a thing does, rather than what is does not do, is what we would generally accept to be characteristic of that thing.
Don't you?

I think it is. The object still reflects the wavelengths it would normally reflect, only one or more are missing.
The way I see it, the color of an object is directly related to its chemical makeup. In fact, it's color IS the chemical makeup.

I see your point, but the fact remains color cannot exist without light transmitting that information.


I can easily falsify your claim that perception has got anything to do with what color an object is. I'm colorblind.. I guess that should tell you enough ;)

Im partially colorblind as well. High five :cheers:

I see your point, but the fact remains color cannot exist without light transmitting that information.
Im partially colorblind as well. High five :cheers:

personal perception has nothing to do with core physics principals/laws.

light exists as does matter.

hypothetically speaking (an example of absolutism);

just because you may have been blown up by a suicide bombing Bonita banana deathly yellow bang squad...
does that mean all the earth disappears also because you can no longer perceive it ?(and that all human rights laws are now null and void).

Damn, you deleted a patsy argument:D
I'll work on what's left.

The difference between something that a thing does being a property of that thing, and something that that thing does not do being a property of that thing, is, in the example of the leaf, the presence of a whole system within that leaf to absorb and use light of specific wavelengths, and the absence of the ability to absorb other wavelengths.

I think that what a thing does, rather than what is does not do, is what we would generally accept to be characteristic of that thing.
Don't you?

No, both are part of the same characteristic. Logic dictates that you can't have one without the other.
Did you read my last post ?

I see your point, but the fact remains color cannot exist without light transmitting that information.
The fact remains that color perception cannot exist without light transmitting that information.
Although.. that's not entirely true either :p


Im partially colorblind as well. High five :cheers:
I'm red/green colorblind. I assume you are as well ?

No, both are part of the same characteristic. Logic dictates that you can't have one without the other.
Did you read my last post ?

Mmmmh.......
Read posts before replying to them.
I might try that.

I can easily falsify your claim that perception has got anything to do with what color an object is. I'm colorblind.. I guess that should tell you enough ;)
So doesn't colour-blindness indicate that perception IS part of the problem?
I recall the story of one kid at school who persistently painted his grass as black in art class.
Because he was colour blind he couldn't tell that there was any difference at between green and black.
Hence, if we all colour-blind, we wouldn't know that grass is green and funeral clothes are black.
And before you start: what colour are most flowers (especially the "interesting" ones) to bees? They see into UV (I think), so all humans are colour-blind as far as bees are concerned.
Simply because science can show us what colours a bee sees does not mean that we're going to change our description of flowers.
But is our description more real than a bee's?
The colour orange is a human "concept" and definition, based on what WE see through our (limited) eyes - not the orange itself.

The fact remains that color perception cannot exist without light transmitting that information.
Although.. that's not entirely true either :p


I'm red/green colorblind. I assume you are as well ?

surely the test is

will it still happen when we are not present ?

and that would be a yes.

So doesn't colour-blindness indicate that perception IS part of the problem?
What problem ?
I don't understand what perception has to do with what color an object is or, to put it more general, what perception has to do with the characteristics of the perceived object.


I recall the story of one kid at school who persistently painted his grass as black in art class.
Because he was colour blind he couldn't tell that there was any difference at between green and black.
Hence, if we all colour-blind, we wouldn't know that grass is green and funeral clothes are black.
This is what you were getting at earlier. I don't see what relevance perception has. It doesn't matter if you see orange as green or if I see it as blue. An orange might look green to me, but that doesn't change its chemical composition. It doesn't even change the wavelengths that hit my retina.


And before you start: what colour are most flowers (especially the "interesting" ones) to bees? They see into UV (I think), so all humans are colour-blind as far as bees are concerned.
Yep, but we still know what kind of molecules reflect ultra-violet light. That we happen to be unable to perceive it doesn't change that fact.


Simply because science can show us what colours a bee sees does not mean that we're going to change our description of flowers.
But is our description more real than a bee's?
No. Color names are just that, names. And they indicate (whatever you decided upon calling them) the chemical composition of the object.


The colour orange is a human "concept" and definition, based on what WE see through our (limited) eyes - not the orange itself.
Of course. Names are just names. That's all the more reason to define color the way I do as opposed to what it might look like at the moment (highly subjective) ;)

It doesn't seem that anyone has mentioned "memory color" yet. It's well documented that humans allow their perception of a color to be influenced by what may be called the "characteristic" color of an object (say the color it would have under a noonday sky).

If you buy a white car, you see it as a white car, even if it is sunset and the car is (from a more objective standpoint) light orange due to its reflecting the dwindling sunlight. What color is the car in that example? Well, if "color" is the descriptiuon of the light that is reaching your eye from the object, the car is orange. If "color" is a property of the car that describes how it interacts with light of various shades, the car is white. In the latter case, though when you see an orange car at sunset it may not be possible for you to describe its "color", as the most you could say is that it appears to be orange, but it's true color can only be determined under more optimal lighting conditions.

I think a case could be made for either definition. The latter definition seems to be the one that describes how memory color interprets the world, of course. Interestingly there are a few examples of cases in which memory color does not work. For example, steak viewed under blue light tends to look blue (and a bit putrid), no matter how many steaks one has seen.

It doesn't seem that anyone has mentioned "memory color" yet. It's well documented that humans allow their perception of a color to be influenced by what may be called the "characteristic" color of an object (say the color it would have under a noonday sky).

If you buy a white car, you see it as a white car, even if it is sunset and the car is (from a more objective standpoint) light orange due to its reflecting the dwindling sunlight. What color is the car in that example? Well, if "color" is the descriptiuon of the light that is reaching your eye from the object, the car is orange. If "color" is a property of the car that describes how it interacts with light of various shades, the car is white. In the latter case, though when you see an orange car at sunset it may not be possible for you to describe its "color", as the most you could say is that it appears to be orange, but it's true color can only be determined under more optimal lighting conditions.

I think a case could be made for either definition. The latter definition seems to be the one that describes how memory color interprets the world, of course. Interestingly there are a few examples of cases in which memory color does not work. For example, steak viewed under blue light tends to look blue (and a bit putrid), no matter how many steaks one has seen.

White balance ;)

When you go through a traffic light, can you claim that the lights were on green even if the lamp was not on?

When you go through a traffic light, can you claim that the lights were on green even if the lamp was not on?

lol :rolleyes:

When I first saw the question of the OP I saw in it the same problem as the "Schrodinger's cat paradox". Bsically, it can be anything in the dark, unless we decide to observe it by using instruments. But then some of you started saying that it's color is merly a property of the compsition of the outer layer of the orange; which is absolutely right. So I turned towards that answer also. But after a while, I thought about that too, how do we know the properties of the orange? We would of needed to mesure them, wich is also part of the paradox, therefore I stand with my first idea, it could be anything in the dark.

--------

Thinking about it (this is another completly different route), color is light. In the dark there is no llight so there is no color, therefore the orange has no color (unless it emits it's own light).

But then some of you started saying that it's color is merly a property of the compsition of the outer layer of the orange; which is absolutely right. So I turned towards that answer also. But after a while, I thought about that too, how do we know the properties of the orange? We would of needed to mesure them, wich is also part of the paradox, therefore I stand with my first idea, it could be anything in the dark.
Why is it part of the paradox ? Do you think that in the dark the composition of the orange could change to anything and then magically revert back the moment the light is turned back on ?
If so, please explain the mechanism behind this.

Why is it part of the paradox ? Do you think that in the dark the composition of the orange could change to anything and then magically revert back the moment the light is turned back on ?

The second line there is similar to electrons in QM going through every possible path of potentials, until the observation is made, or in this case the "light" gets turned on and it selects just one path.

If the orange does not change in the dark, how do you know that? There is no proof until the light comes back on...

By claiming the orange remains an orange is claiming to have knowledge of the orange you can only know when the light is on. Light itself may change the properties of our orange, we literally have no way of knowing other than through thought experiments.


If so, please explain the mechanism behind this.

Quantum mechanics.

The second line there is similar to electrons in QM going through every possible path of potentials, until the observation is made, or in this case the "light" gets turned on and it selects just one path.

If the orange does not change in the dark, how do you know that? There is no proof until the light comes back on...

By claiming the orange remains an orange is claiming to have knowledge of the orange you can only know when the light is on. Light itself may change the properties of our orange, we literally have no way of knowing other than through thought experiments.
The thing is, you need to prove (or at least provide evidence) that the orange indeed can change in the dark.


Quantum mechanics.
Quantum mechanics is about subatomic particles, not oranges.
Besides, naming a field of science is hardly an explanation.

The thing is, you need to prove (or at least provide evidence) that the orange indeed can change in the dark.

Quantum mechanics is the evidence. It shows us directly potentials change based on observation. Its been experimentally confirmed many times over. In our case "light" is the observation.



Quantum mechanics is about subatomic particles, not oranges.
Besides, naming a field of science is hardly an explanation.

They have recently made "buckyballs" (fullerene with 60 carbon atoms) behave in exactly the same way as the electron in the original double slit experiment, so no it is not just limited to subatomic particles.

Besides what do you think oranges are made of? A giant particle called "orange"? :D

It's nonsense and you know it.

This question may have been asked here but I didnt see it.

This is a classic question from the ABC science forum in australia and the question also made its way to england infected the BBC science forum

ha ha ha ....................attempt to answer it at your own peril :)

not enough info for complete answer.

It's nonsense and you know it.

actually his quantum particle explanation is true.

After all you could analyze an orange in darkness with other quantum particles...by bombarding it and seeing what reflects and not.

actually his quantum particle explanation is true.

After all you could analyze an orange in darkness with other quantum particles...by bombarding it and seeing what reflects and not.

And you'd also be able to determine the chemical composition of the orange in the dark. Which would prove that it didn't change.
But then, some quantum dimwit would just say that it's chemical composition reverted the moment it was tested :shrug:

And you'd also be able to determine the chemical composition of the orange in the dark. Which would prove that it didn't change.
But then, some quantum dimwit would just say that it's chemical composition reverted the moment it was tested :shrug:

You guys miss the point.

Tell me how is bombarding an orange with quantum particles any different that bombarding it with light for information? It isnt. Fundamentally it is an observation being made, which alters the "normal" wave-function we call orange.

For a forum where science is defended, right or wrong, I must say QM still draws alot of apprehension from people simply because its ideas are so strange. But this is not news either, "For those who are not shocked when they first come across quantum theory cannot possibly have understood it." -Niels Bohr

EndofLight, there are quantum particles than interact with photons, their interaction can be analyzed for data and recorded to judge for presence of photons in that orange in the dark.

EndofLight, there are quantum particles than interact with photons, their interaction can be analyzed for data and recorded to judge for presence of photons in that orange in the dark.

The whole point of "in the dark" is that there are no photons.

The whole point of "in the dark" is that there are no photons.

that remains to be tested! By other quantum particles whose lack of interactions with photons and thus lack of emission of sub-quantum particles would mean lack of photons alltogether.

I guess what I am trying to say really is that: "Not all darkness is dark"

In essence there might still be a photon there. and what about other forms of radiation, UV light...infrared...?

You guys miss the point.

Tell me how is bombarding an orange with quantum particles any different that bombarding it with light for information? It isnt. Fundamentally it is an observation being made, which alters the "normal" wave-function we call orange.

For a forum where science is defended, right or wrong, I must say QM still draws alot of apprehension from people simply because its ideas are so strange. But this is not news either, "For those who are not shocked when they first come across quantum theory cannot possibly have understood it." -Niels Bohr

So what happens to beta-carotene in the dark that no one is aware of but you ?
How does it break down (and form other molecules perhaps) and then reassemble again instantly when the light is turned on ?

Interestingly there are a few examples of cases in which memory color does not work. For example, steak viewed under blue light tends to look blue (and a bit putrid), no matter how many steaks one has seen.I think the difference there is that we know that the color of a car doesn't ordinarily change, and even if it does, no big deal. So our mind doesn't devote much "processing power" to an accurate determination of color in such a situation. On the other hand, if meat appears putrid, that's valuable information that shouldn't be ignored, so we pay attention.

Consider some alternative examples. When in the dark, we often see monsters or various other threats that aren't there. Why? In a situation where the lighting is poor, our mind assumes the worse and interprets the available data so as to minimize the risk of missing a real threat because failure to do so might get us killed. Alternatively, when we see a woman approaching we often overestimate her attractiveness and are dissapointed when she gets a little closer or enters an area with good light. Why? Again, our minds don't want us to miss an opportunity to mate with an attractive female, so in the absence of complete information, it assumes the best.

But a car, is it white or is it orange..............who cares. Glance at it, assume it's the same as before. Then concentrate on more important issues.

An orange has no color regardless if it is in the dark or the light.

Color is a quale, a subjective quality of conscious experience and does not exist outside of the consciousness experiencing it.

An orange (the fruit) may reflect light waves that can stimulate such experiences but color is not a property of an orange, or indeed any object.

~Raithere

I guess what I am trying to say really is that: "Not all darkness is dark"

In essence there might still be a photon there. and what about other forms of radiation, UV light...infrared...?

well, infrared is hardly orange. I agree with you however that "not all darkness is dark". There is a non-zero probability that any substance above 0 K will emit a photon anywhere in the visible spectrum, or beyond. Of course, this may happen only once every 1000 years, but its still going to happen sometime.

An orange actually does not emit orange light very well. It bounces back orange photons, meaning it is an orange-mirror; a mirror to the color orange. A mirror of any color is a poor emitter of that color due to Kirchoff's law, which states that emission=absorption. Clearly, a mirror does not absorb, and hence it does not emit.

You can think of this as an 'emission coefficient'. An orange has a low emission coefficient for orange.

So, if you place an orange across from a photomultiplier tube, you will notice two things:
- the detector will trigger itself since the detector itself, just like the orange, has a non-zero probability of emitting orange photons (this is known as noise)
- the orange will not emit orange very much.

so, if you take your data from two photomultiplier tubes stationed in the dark at the same temperature, the one without the orange across from it should actually detect slightly more orange photons than the photomultiplier across from the orange. In this case you would indeed have some experimental proof that the orange is still orange. The problem is that the experiment may take several thousand years to complete :(