How does the surface property affect blackbody radiation?

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
1 reply · 2K views
henry wang
Messages
30
Reaction score
0
In an attempt to explain why a matt surface of aluminium is a better emitter/absorber of blackbody radiation than shiny surface of aluminium, my university lecturer suggested to me that:
  • By brushing a metal surface to create a matt finish, the surface of the metal becomes rougher.
  • Rougher means there is a lot more curvature of the material, thus creating essentially lots of lightning rods with strong electric field around them.
  • Photons somehow interact with the "lightning rods", and become more likely to be absorbed by the material.
  • Photons can go through multiple scattering on the rough surface, which also contribute to absorption.
Does photons interact with the electric field? If so, how does it interact with it such that it increases chances of absorption? What are some other surface properties that can affect the efficiency absorption?
Also, would a insulator have higher emissivity than a conductor?
 
Physics news on Phys.org
Not an answer,but perhaps relevant. It at least illustrates the complexity of the question.
Image from https://en.m.wikipedia.org/wiki/Light_scattering

Diffuse_refl.gif