Does the human eye have limitations on detecting black surfaces?

In summary, black surfaces apparently absorbs all light, that's why it appears black, but does it ever reflect light off its surface?
  • #1
alchemist
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black surfaces apparently absorbs all light, that's why it appears black, but does it ever reflect light off its surface?
what if its a polished black suface..we could actually see our own reflection on these surfaces.. so is there light being reflected at all? is there any difference from the usual reflection?
 
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  • #2
Something perfectly flat black will reflect no light at all and would essentially be invisible. Such a surface is simply unattainable.

The difference between glossy and flat is that glossy reflects light more or less at the macroscopic angle of incidence. So since no black surface will ever be perfect, they can be polished to reflect like a mirror.
 
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  • #3
How does a perfectly black surface become 'invisible'. Are you suggesting that it becomes transparent? I thought it would still be black.
 
  • #4
I think he means that your eyes will receive no light coming from there, which is true. However, as you say, your brain will clearly distinguish that pattern in your retina and label it as "black", which means that you will "see" it.
 
  • #5
i believe the closest attained [by a special paint] was something like 97 or 98%...pretty damn close, but not quite there yet
 
  • #6
In a broader sense, nothing is 'black', nor can anything be perfectly black (except for black holes). If an object absorbs light, it will get a little hotter, and so it will emit a little more in the infrared (this is a simplification). If our eyes could 'see' IR, we may find that 'black' objects were actually among the brightest objects!
 
  • #7
If I recall it properly, the reason why you see "Black" is really because your retinas cannot process (see) a certain color (wavelength) of Violet, at the bottom end of the visible light scale...

Then again, it is a bit like looking up at the night sky (away from cities where you could see those old fashioned things called "Stars") inasmuch as, you think, in your mind, that you see the "inky blackness of outer space", and you have fooled yourself completely! as what you are looking at is chock a block FULL of light, just that, you cannot see light, you only 'see' light when reflecting/interacting off/with a surface...light, when in motion, is completely invisible!

(If you doubt that, just look at/in the space between the lamp and the table...you do not see the light travelling!)
 
  • #8
Originally posted by Nereid
In a broader sense, nothing is 'black', nor can anything be perfectly black (except for black holes).

Even black holes have Hawking Radiation, but it's effectively black.

Things can look perfectly black to the human eye even if they are not truly black because there is a lower limit for photons hitting the retina for it to register.
 
  • #9
Welcome to Physics Forums Iron Sun X!

Did you take the solar eclipse photo in your avatar?
Iron Sun X wrote: Things can look perfectly black to the human eye even if they are not truly black because there is a lower limit for photons hitting the retina for it to register.
both an upper and lower frequency limit, and a photons per second limit in either retina (retinal signals are not additive).
 
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1. What is reflection on black surfaces?

Reflection on black surfaces is the phenomenon where light is bounced off a black surface, causing it to appear darker. This is because black surfaces absorb most of the light that hits them, rather than reflecting it back.

2. Why do black surfaces reflect less light?

Black surfaces reflect less light because they have a high absorption rate. This means that the material of the surface is able to absorb a higher percentage of light that hits it, rather than reflecting it. This results in a darker appearance.

3. How does the color of a surface affect its reflection?

The color of a surface directly affects its reflection. Light-colored surfaces, such as white, reflect more light and appear brighter. Dark-colored surfaces, such as black, reflect less light and appear darker. This is due to the absorption and reflection properties of different colors.

4. Are there any practical applications for reflection on black surfaces?

Yes, there are several practical applications for reflection on black surfaces. For example, black surfaces are often used in photography and cinematography as a background to help create contrast and highlight the subject. In solar panels, black surfaces are used to absorb more sunlight and convert it into energy. Black surfaces are also used in thermal insulation, as they absorb more heat and help keep a space warmer.

5. Can black surfaces also reflect light?

Yes, black surfaces can still reflect light, just at a lower rate compared to lighter surfaces. The amount of light reflected by a black surface depends on the material it is made of and the angle at which the light hits it. However, the reflection may not be visible to the naked eye due to the low amount of light being reflected.

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