Why is the color white not a mirror?

  • Context: High School 
  • Thread starter Thread starter Loanzac
  • Start date Start date
  • Tags Tags
    Color Light
Click For Summary

Discussion Overview

The discussion revolves around the nature of the color white and its relationship to reflection and absorption of light. Participants explore why white is not considered a mirror despite reflecting all colors, and they delve into concepts of diffuse versus specular reflection, the properties of different surfaces, and the perception of color.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that while white reflects all colors, it does so in a diffused manner, which prevents it from conveying a clear image like a mirror does.
  • Others argue that the surface texture plays a significant role, noting that even smooth surfaces like car bumpers can still scatter light due to microscopic imperfections.
  • A later reply questions the uniformity of white surfaces, suggesting that different "whites" reflect various frequencies of light differently.
  • Some participants discuss the concept of primary colors and speculate about the existence of a fourth primary color, referencing how different species perceive color differently.
  • There is mention of tetrachromats, individuals who can perceive a broader spectrum of colors, which raises questions about subjective color perception among humans.

Areas of Agreement / Disagreement

Participants express a range of views on the nature of white and its reflective properties, with no consensus reached on whether white can be considered a mirror. The discussion includes various perspectives on color perception and the properties of light, indicating multiple competing views.

Contextual Notes

Participants highlight the complexity of color perception, including the influence of individual differences in retinal cone distribution and the effects of surface texture on light reflection. These factors contribute to the ongoing debate without definitive resolutions.

Loanzac
Messages
4
Reaction score
0
If the color black absorbs all colors and reflects none and the color red absorbs all colors but reflects the color red and the color white is made up of all colors no absorption and all reflection how come the color white is not a mirror?
 
Science news on Phys.org
For one thing, the reflected light is scattered in all directions and is therefore incapable of conveying an image.
 
As Danger says:

specularjavafigure1.jpg
 
So when we see the color white we are seeing all colors reflected in a chaotic ( diffused ) manner with no one color dominating on both the absorption and reflection sides of the coin?
 
In the picture of diffuse reflection you show an uneven surface but what about a smooth surface like a white car bumper?
 
Car bumpers are not smooth when you get down to nanometer sized scales. In addition, light is partially penetrating the material a small ways before being reflected back out, which can cause scattering and other effects.
 
Loanzac said:
In the picture of diffuse reflection you show an uneven surface but what about a smooth surface like a white car bumper?
You can have a smooth, but mostly transparent layer, which causes some specular reflection at the surface. But most light penetrates the surface and gets diffused below it.
 
Also, there are a lot of different "whites". Not all frequencies are reflected equally by most of them.
 
Loanzac said:
If the color black absorbs all colors and reflects none and the color red absorbs all colors but reflects the color red and the color white is made up of all colors no absorption and all reflection how come the color white is not a mirror?
It's interesting just how good a "mirror" some polished black flat surfaces are, such as the plastic case/cabinet of electronic gear.
 
  • Like
Likes   Reactions: Danger
  • #10
Since we're talking about light and color, I've always wondered: what would a fourth primary color look like? If our eyes could see far enough beyond infrared or ultraviolet would a fourth primary color likely show up?
 
  • #11
I think that it's purely a matter of semantics. Insects see ultraviolet, but I don't think that it's considered a "primary colour" even to them. There's some kind of shrimp or something that has about 9 different types of cones in its eyes. I have no idea what it "sees".
 
  • #12
riscoe said:
Since we're talking about light and color, I've always wondered: what would a fourth primary color look like? If our eyes could see far enough beyond infrared or ultraviolet would a fourth primary color likely show up?

Why don't you ask them? They're called tetrachromats - people with a fourth colour detector in their eyes.
 
Last edited:
  • #13
(It's not quite as awesome as it sounds. They don't really see new colours, but they can distinguish far finer gradients between existing colours than the rest of us can - mostly in the blue-green range.)
 
  • #14
DaveC426913 said:
mostly in the blue-green range
That area drives me nuts! I never know what to call something anywhere near the transition point. One of my favourite colours is teal. I know exactly what it looks like, but I have absolutely no idea as to whether it's blue or green. I see it as both at the same time.
 
  • #15
Blue? Green? Frequencies may be absolute; but I thought color is not, in other words each of us is genetically unique and perceive light in different ways
 
  • #16
gsal said:
perceive light in different ways
We all, if in normal health, perceive it the same way from a physical standpoint. How our brains interpret it might very well be unique to each individual. There is really no way to know. That would require telepathy, so as to "see" through someone else's eyes. Something red to me might very well be "seen" by you as what I think of as yellow. I just go by what I'm told they are.
That's why I always refer to my Pantone swatch kit when doing graphics. (Well, that and the fact that what shows on a monitor isn't what comes out on the printer.)
 
Last edited:
  • #17
What I meant to say is that while we all receive the same light, we do not perceive it the same way in as much as each of us may have different number of retinal cones of the various types... And then there are Colo blind people
 
  • #18
Danger said:
There's some kind of shrimp or something that has about 9 different types of cones in its eyes.
It's these guys:
170px-Mantis_shrimp_from_front.jpg

12 types of colour recognition photoreceptors. Sees polarization. Single eye depth perception. The coolest animal on the planet.
http://en.wikipedia.org/wiki/Mantis_shrimp
 
  • #19
gsal said:
Blue? Green? Frequencies may be absolute; but I thought color is not, in other words each of us is genetically unique and perceive light in different ways
Different ways yes, but not more ways. Tetrachromats can distinguish finer differences than others.

One woman, who had not known she was special, recounts stories where she would see people wearing clothes that they thought matched, but to her, it was obvious that they clashed - different shades of blue-green that no one else seemed to see.
 
  • #20
Bandersnatch said:
It's these guys:
That's the little bugger that I meant, alright! I've never seen that article before. They're even more impressive than I thought. (And frightening, given that I'm deathly allergic to shrimp... :D)
 

Similar threads

  • · Replies 40 ·
2
Replies
40
Views
5K
  • · Replies 207 ·
7
Replies
207
Views
14K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
9
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 19 ·
Replies
19
Views
3K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 35 ·
2
Replies
35
Views
5K
  • · Replies 3 ·
Replies
3
Views
2K