Difference between black and transparent object

  • Context: High School 
  • Thread starter Thread starter gracy
  • Start date Start date
  • Tags Tags
    Difference Transparent
Click For Summary

Discussion Overview

The discussion explores the differences between black and transparent objects, focusing on light absorption, reflection, and transmission. Participants examine the reasons behind the color perception of these objects and the implications of light behavior in various materials.

Discussion Character

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

Main Points Raised

  • Some participants propose that black objects are black because they absorb all wavelengths of light, while others suggest it could be due to a lack of reflection of light.
  • It is noted that black objects do not transmit light, which is why they cannot be seen through.
  • Participants discuss how the color of transparent objects is influenced more by the transmitted light than the reflected light, depending on the viewing angle.
  • Questions arise regarding whether the color of an object is determined solely by the wavelengths it reflects or if transmitted wavelengths also play a role.
  • Examples are provided, such as a thin gold leaf appearing golden in reflected light but green when viewed against bright light due to transmission effects.
  • Some participants mention that certain materials can be transparent to specific wavelengths while being opaque to others, as illustrated by the example of a red filter allowing only red light to pass through.
  • Discussion includes the phenomenon of thin layers of transparent materials producing intense colors through selective reflection and transmission, with examples like bird feathers and oil films on water.

Areas of Agreement / Disagreement

Participants express differing views on the reasons behind the color of black objects and the role of transmitted light in color perception, indicating that multiple competing views remain without consensus.

Contextual Notes

Some claims about color perception depend on specific conditions, such as viewing angles and the nature of the light source. The discussion also touches on the complexities of light absorption in materials, which may not be fully resolved.

gracy
Messages
2,486
Reaction score
83
Difference between transparent and black object?I mean black object is black because 1-it absorbs all the wavelengths of light OR 2-because it doesn't reflect any wavelength of light
If first one is the reason then alright but if second one then transparent object should also be black as it does not reflect(reflects only 5%)it all transmit (about 95%)
 
Last edited:
Science news on Phys.org
Black objects don't transmit light either, they absorb light. That's why you can't see through them. :)
 
Matterwave said:
Black objects don't transmit light either, they absorb light. That's why you can't see through them. :)
Why black objects are black?Because of reason 1 in my original post?Not because of reason 2?
 
If you look at a transparent object, you see not only the light reflected from it, but also the light coming from behind and transmitted by the object.
 
ehild said:
If you look at a transparent object, you see not only the light reflected from it, but also the light coming from behind and transmitted by the object.
Till now i have been told that we only see color of objects depending upon what wavelength they reflect ,do the color of the object also depends on the wavelength which is transmitted?
 
Yes. The colour of transparent objects is more the colour of the transmitted light than the reflected one. But it depends also, how you look at them. What colours you see if you look through your sunglasses? And how do they look like in reflected light?
 
Water is colorless ,why?Is it transparent?
 
gracy said:
Water is colorless ,why?Is it transparent?

It can be described as transparent but, in reality, even a thin layer of water does absorb some of the of light (some wavelengths more than others) , which you can detect if you go diving in ('clear') water of more than 10m or so. The Red end of the (visible) spectrum is absorbed more than the Blue end and objects will look generally 'bluer'. your brain does its best to compensate for this but, in the end, you just seem to see things in 'monochrome'.
As it happens, UV is absorbed too. The absorption / frequency characteristic is complicated with various peaks and troughs (See this wiki link) because of the way the water molecules interact with various frequencies of WM waves.
 
gracy said:
Till now i have been told that we only see color of objects depending upon what wavelength they reflect ,do the color of the object also depends on the wavelength which is transmitted?
A very thin gold leaf, viewed in reflected light, appears golden because it reflects the yellows and reds especially well. But if you hold it up against a bright light, it appears green. Being very thin it allows some light to pass through, and this transmitted light is white minus the colours it reflects on the other side.
 
  • #10
gracy said:
Till now i have been told that we only see color of objects depending upon what wavelength they reflect ,do the color of the object also depends on the wavelength which is transmitted?

Yes. Objects can be transparent to some wavelengths and not others. A red filter (eg for stage lighting) allows red light through and absorbs other colours. The result is that only red light illuminates the stage. If you look at the filter with a white light behind it only red light arrives at the eye so it looks red.

The plastic on a TV remote control is opaque to visible light but it is transparent to invisible infra red light so it can control the TV. The plastic is usually back but could be any colour. So it can be transparent to Infra Red, opaque to visible light but reflect any or all visible light.
 
  • #11
Very thin lays of very transparent materials can produce very intense colours by reflecting some wavelengths and transmitting others. There is (virtually) no absorption of energy within the layers all the light is either reflected or transmitted. (Interference Filters)
Examples: Bird Feathers, Butterfly wings, Dichroic halogen lamps, which do not use pigments or dyes. Most familiar example is the bright colours from oil films on puddles of rainwater. Notice the colours are not 'rainbow-like' but very striking and unusual.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
10K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
11
Views
3K
  • · Replies 7 ·
Replies
7
Views
6K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
4
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 19 ·
Replies
19
Views
2K