Why is black colour good absorber and radiator of heat ?

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Discussion Overview

The discussion revolves around the properties of black color as a good absorber and radiator of heat, exploring the relationship between color, light reflection, and heat absorption. It includes definitions and explanations related to the physics of color and energy absorption.

Discussion Character

  • Conceptual clarification
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants note that black absorbs almost all light and therefore increases energy and heat, while white reflects most light and absorbs little.
  • There are repeated references to the definition of black as a color that reflects no light, leading to higher heat absorption.
  • One participant expresses curiosity about why black absorbs more light compared to white, indicating a desire for deeper understanding.
  • Another participant confirms the relationship between black color and heat absorption, suggesting that black objects produce more heat due to their absorption characteristics.

Areas of Agreement / Disagreement

Participants generally agree on the definition of black as a good absorber of light and heat, but there is some uncertainty regarding the underlying reasons for this property, particularly in relation to the comparison with white.

Contextual Notes

The discussion does not resolve the deeper inquiry into why black absorbs more light than white, leaving this aspect open for further exploration.

sankalpmittal
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I have read in my class 10th book and other books that black(usually dark) colour is avoided in summers and this is the reason why impure ice melts quickly .

I am wondering why ?
 
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The color of any object is the light it reflects. An object is white if it reflects all or almost all of the light falling on it (and so absorbs little light). An object is black if it reflects no or very little light (and so absorbs almost all light). And, of course, light is energy. Absorbing little light only a slight increase in energy, absorbing a lot of light means a larger increase in energy and so a larger increase in heat.
 
russ_watters said:
By definition of the word "black".

Why is black colour good absorber and radiator of heat ? (usually dark colours)

How ? By definition ??
 
HallsofIvy said:
The color of any object is the light it reflects. An object is white if it reflects all or almost all of the light falling on it (and so absorbs little light). An object is black if it reflects no or very little light (and so absorbs almost all light). And, of course, light is energy. Absorbing little light only a slight increase in energy, absorbing a lot of light means a larger increase in energy and so a larger increase in heat.

Yes you are absolutely correct but why black colour absorbs large amount of light as compared to white .
 
russ_watters said:
By definition of the word "black".

HallsofIvy said:
The color of any object is the light it reflects. An object is white if it reflects all or almost all of the light falling on it (and so absorbs little light). An object is black if it reflects no or very little light (and so absorbs almost all light). And, of course, light is energy. Absorbing little light only a slight increase in energy, absorbing a lot of light means a larger increase in energy and so a larger increase in heat.

Got you ! Thanks russ_watters . The answer to this question was by definition of word black .

Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light. Although black is sometimes described as an "achromatic", or hueless, color, in practice it can be considered a color, as in expressions like "black cat" or "black paint".
http://en.wikipedia.org/wiki/Black


So black absorbs all the frequencies of light and doesn't reflect so more heat is produced in that , right .


Thanks to you all who replied .:smile:
 
sankalpmittal said:
So black absorbs all the frequencies of light and doesn't reflect so more heat is produced in that , right .
Yes.
 
Redbelly98 said:
Yes.

OK Thanks .
 

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