Recognition of what isn't there?

[setarcos]

Given an object that perfectly reflects all visible colors we would generally call this a white object.
Given an object that perfectly absorbs all visible colors, not all electromagnetic radiation like the fabled blackbody of physics, but all visible colors, what would we be able to see? What would the object look like within color reflective surroundings? Seems to me its too simple to say we'd see a black body since what ever reaches our eyes as black would involve an imperfect absorption of all visible colors but instead a gradient of reflection of some imperfectly absorbed colors.

 

[exchemist]

Given an object that perfectly reflects all visible colors we would generally call this a white object.
Given an object that perfectly absorbs all visible colors, not all electromagnetic radiation like the fabled blackbody of physics, but all visible colors, what would we be able to see? What would the object look like within color reflective surroundings? Seems to me its too simple to say we'd see a black body since what ever reaches our eyes as black would involve an imperfect absorption of all visible colors but instead a gradient of reflection of some imperfectly absorbed colors.

Nothing "reaches our eyes as black". That's the point.

Something that appears black does so because no visible light comes from it into our eyes. If it reflects a bit, then it is not totally black.

 

[Erebus]

Given an object that perfectly reflects all visible colors we would generally call this a white object.
Given an object that perfectly absorbs all visible colors, not all electromagnetic radiation like the fabled blackbody of physics, but all visible colors, what would we be able to see? What would the object look like within color reflective surroundings? Seems to me its too simple to say we'd see a black body since what ever reaches our eyes as black would involve an imperfect absorption of all visible colors but instead a gradient of reflection of some imperfectly absorbed colors.

The closest we've come to creating a black that absorbs all visible light is Vantablack. It isn't quite pure black but it should give you a decent idea of what that would look like.

This is Vantablack painted onto crinkled foil:

 

[Secret Chief]

The closest we've come to creating a black that absorbs all visible light is Vantablack. It isn't quite pure black but it should give you a decent idea of what that would look like.

This is Vantablack painted onto crinkled foil:

Ooooooooooooooooo

Like my new avatar?!

 

[exchemist]

Ooooooooooooooooo

Like my new avatar?!

As black as Hotblack Desiato's spaceship.

 

[RestlessSoul]

Ooooooooooooooooo

Like my new avatar?!

Bit shiny tbh. That could be my screen though...

 

[TransmutingSoul]

The closest we've come to creating a black that absorbs all visible light is Vantablack. It isn't quite pure black but it should give you a decent idea of what that would look like.

This is Vantablack painted onto crinkled foil:

You created a black hole!

Regards Tony

 

[Secret Chief]

As black as Hotblack Desiato's spaceship.

As intriguing as impossible colours, eigengrau and imaginary colours.

 

[setarcos]

Nothing "reaches our eyes as black". That's the point.

Something that appears black does so because no visible light comes from it into our eyes. If it reflects a bit, then it is not totally black.

Good response. Something to think about. Consider though that an interpretive response of color by the brain is initiated by the stimulation of the color receptors in the eye. This would include stimulus resulting in "color blindness" which is not equated to total blindness. The brain has been stimulated and concurrently initiates interpretation.
However, with total lack of stimulation the brain is still stirred to interpretive response at a particular frequency resulting in what we see as black and sometimes other "imagined colors". Why is that?
We don't just not see anything because the object absorbs all sensory stimulus to our sight, the brain delineates the object from its surroundings by seeing something right? Typically neurological response requires stimulation for action to be initiated. Our ability for sensory stimulation is quite limited when weighed against what exists and thank God since otherwise we would be quickly overwhelmed with sensory input given our capacities but basically this lack of stimulation is interpreted by the brain as invisible to us. Case in point would be ultraviolet and there has been case studies where individuals actually couldn't see certain things right in front of them even though they could identify other objects by sight. So why wouldn't an object which reflects no light simply be invisible to us as well?
Actually upon further reflection...everything we see and identify as black to my knowledge is actually the color we see with imperfect absorption not perfect absorption. Why should we assume the "color" scheme to continue on a gradient into what perfectly absorbs all color?

 

[setarcos]

As intriguing as impossible colours, eigengrau and imaginary colours.

Nothing makes us see something

 

[setarcos]

The closest we've come to creating a black that absorbs all visible light is Vantablack. It isn't quite pure black but it should give you a decent idea of what that would look like.

This is Vantablack painted onto crinkled foil:

I've heard of this and thought about its thermal properties used as a coating for a solar oven or water heater. I wonder though...is the reason we see the thing as black in the first place because the thing is not a perfect absorber of all color? Perhaps I'm just over thinking this thing and in the wrong direction?

 

[Stevicus]

The closest we've come to creating a black that absorbs all visible light is Vantablack. It isn't quite pure black but it should give you a decent idea of what that would look like.

This is Vantablack painted onto crinkled foil:

 

[exchemist]

As intriguing as impossible colours, eigengrau and imaginary colours.

I had to look up eigengrau. That's quite interesting - especially as I'm having trouble with my left eye at the moment (posterior vitreous detachment - which does not mean taking a piece of glass out of my arse).

 

[Erebus]

I've heard of this and thought about its thermal properties used as a coating for a solar oven or water heater. I wonder though...is the reason we see the thing as black in the first place because the thing is not a perfect absorber of all color? Perhaps I'm just over thinking this thing and in the wrong direction?

If we were able to create a paint that was absolutely pure black and reflected no light whatsoever, we would still see it as black. It would also make any 3D object painted in it appear completely 2D. Vantablack does that to an extent, though it's still possible to see some details of whatever's been painted with it from certain angles and with the right lighting.

 

[exchemist]

Good response. Something to think about. Consider though that an interpretive response of color by the brain is initiated by the stimulation of the color receptors in the eye. This would include stimulus resulting in "color blindness" which is not equated to total blindness. The brain has been stimulated and concurrently initiates interpretation.
However, with total lack of stimulation the brain is still stirred to interpretive response at a particular frequency resulting in what we see as black and sometimes other "imagined colors". Why is that?
We don't just not see anything because the object absorbs all sensory stimulus to our sight, the brain delineates the object from its surroundings by seeing something right? Typically neurological response requires stimulation for action to be initiated. Our ability for sensory stimulation is quite limited when weighed against what exists and thank God since otherwise we would be quickly overwhelmed with sensory input given our capacities but basically this lack of stimulation is interpreted by the brain as invisible to us. Case in point would be ultraviolet and there has been case studies where individuals actually couldn't see certain things right in front of them even though they could identify other objects by sight. So why wouldn't an object which reflects no light simply be invisible to us as well?
Actually upon further reflection...everything we see and identify as black to my knowledge is actually the color we see with imperfect absorption not perfect absorption. Why should we assume the "color" scheme to continue on a gradient into what perfectly absorbs all color?

I don't entirely follow what you are saying. You seem to be talking about visual perception, whereas I was talking about the physics of the situation. "Black" is the sensation we perceive, in the absence of light impinging on the retina.

A black object will not be invisible if it is surrounded by a background that is not black. That's fairly obvious. We will perceive an object-shaped absence of light, contrasted with the light received from the surroundings. So it looks black. If the surroundings are also completely dark, e.g. in a cellar with the light off, then we can't any longer the see the black object because everything is equally black.

As for perfect blackness, we can make objects that are almost perfectly black (i.e, reflect almost no visible light) and they look,er, black. So it is entirely reasonable to suppose that a perfectly black object will also look black. More detail here from the Wiki article on black bodies:

It has long been known that a lamp-black coating will make a body nearly black. An improvement on lamp-black is found in manufactured carbon nanotubes. Nano-porous materials can achieve refractive indices nearly that of vacuum, in one case obtaining average reflectance of 0.045%.[5][33] In 2009, a team of Japanese scientists created a material called nanoblack which is close to an ideal black body, based on vertically aligned single-walled carbon nanotubes. This absorbs between 98% and 99% of the incoming light in the spectral range from the ultra-violet to the far-infrared regions.[32]

Other examples of nearly perfect black materials are super black, prepared by chemically etching a nickel–phosphorus alloy,[34] vertically aligned carbon nanotube arrays (like VantaBlack) and flower carbon nanostructures;[35] all absorb 99.9% of light or more.

 

[Secret Chief]

I had to look up eigengrau. That's quite interesting - especially as I'm having trouble with my left eye at the moment (posterior vitreous detachment - which does not mean taking a piece of glass out of my arse).

Oo not heard of that. I've had cataract operations in both eyes but also have glaucoma.

 

[exchemist]

Oo not heard of that. I've had cataract operations in both eyes but also have glaucoma.

Bad luck.

What I've got is not as bad. So the optometrist says. But I'm seeing the consultant tomorrow to get it checked over and to find out the prognosis in more detail.

 

[Secret Chief]

Bad luck.

What I've got is not as bad. So the optometrist says. But I'm seeing the consultant tomorrow to get it checked over and to find out the prognosis in more detail.

Hopefully I'm controlling the pressure with my drops. Also, when I had the cataract ops the consultant implanted iStents. Incredible stuff.

What is iStent?