1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How shape of pattern affects the behaviour of light

  1. Apr 10, 2015 #1
    chameleon can change the colour of its skin by changing the structural arrangement of cell layers. I found someone said that the shape of patterns of particles can determine how the light behaves when striking the object. I wonder how it works?
  2. jcsd
  3. Apr 10, 2015 #2
    I think the simple explanation is that the space between special lattice atoms is more likely to reflect a photon of light, more so with lower frequency waves. An excited chameleon has a lattice which not only reflects to change color but also to reflect near-infrared light for thermoregulation. When they relax the absorbing atoms are closer together which reflect blue higher frequency photons but absorb most others. They have a yellow pigment to begin with mixed with the relaxed blue makes the typical green.
  4. Apr 14, 2015 #3
    I've also heard that it is possibly due to the formation of photonic crystals and photonic crystals have band gap which can control the propagation of certain wavelength. I want to know how it can control the wavelength that can propagate through the crystals. Is it something related to bragg's law?
  5. Apr 14, 2015 #4
    I'm not sure if interference or just simply absorption is the primary mechanism. It seems to me absorption is necessary for them to use near-infrared for heat, but I really don't know enough specifics to have a reliable answer.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook