Surface type and emission/absorption

  • Thread starter Jimmy87
  • Start date
  • #1
647
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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.
 

Answers and Replies

  • #2
davenn
Science Advisor
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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
 
  • #3
647
11
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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