Surface type and emission/absorption

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SUMMARY

Matt black surfaces are superior emitters and absorbers of infrared radiation compared to shiny surfaces due to their lack of free electrons, which allows them to absorb electromagnetic waves effectively. Shiny metal surfaces reflect incoming radiation, making them poor emitters. The discussion highlights the mechanism behind this phenomenon, emphasizing that the texture and color of a surface significantly influence its thermal emission properties.

PREREQUISITES
  • Understanding of electromagnetic radiation principles
  • Knowledge of thermal emission and absorption concepts
  • Familiarity with infrared radiation properties
  • Basic physics of surface interactions with light
NEXT STEPS
  • Research the principles of thermal radiation and Planck's Law
  • Explore the emissivity of different surface materials
  • Investigate the role of surface texture in thermal dynamics
  • Learn about the comparison of infrared absorption between various colors and finishes
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Physicists, materials scientists, engineers, and anyone interested in thermal dynamics and surface properties in relation to infrared radiation.

Jimmy87
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Hi,

I am trying to get some information about why Matt black surfaces are such good emitters and shiny surfaces are not. When you try and look this up there really isn't much so I have tried to string what I have found together.

Shiny metal surfaces have free electrons which cancel the incoming electromagnetic wave by reflecting it hence they are poor emitters. This much I have found. Are Matt black surfaces good absorbers simply because they have no free electrons so they just absorb the infrared?

The other question I have is do Matt black surfaces absorb more infrared than say a coloured surface such as red? I can't see why Matt black is such a good absorber/emitter unless you are dealing with the visible spectrum as it will absorb all colours if it is black?

Thanks for any help offered.
 
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Jimmy87 said:
I am trying to get some information about why Matt black surfaces are such good emitters and shiny surfaces are not.

emitters of what ?
define what you are referring to
 
davenn said:
emitters of what ?
define what you are referring to
Sorry - I suppose infrared mainly. What is the mechanism to explain why black surfaces emit heat so well?
 

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