Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Andy Stephenson on 28/02/2011 20:30:04

Title: Can insulators truely reflect light?
Post by: Andy Stephenson on 28/02/2011 20:30:04

Andy Stephenson asked the Naked Scientists:
   
I heard it said that the only truely specular reflection come from an electrically conductive surface can this be true?

What do you think?

Title: Can insulators truely reflect light?
Post by: Bored chemist on 28/02/2011 20:57:30

No, some dielectric mirrors are much better reflectors than polished metals.
http://en.wikipedia.org/wiki/Dielectric_mirror

Title: Can insulators truely reflect light?
Post by: williampcochran on 28/02/2011 20:57:30

well as a child i was using a magnifying glass to burn different materials, wood, matches, and god help me, insects!!! but one thing that would not burn at all no matter how long i held the beam on it was an ordinary white paper plate. i don't know if that helps to answer but there it is. not enough heat was being absorbed into the material to ignite, and the reflection was too intense to look at for long.

Title: Can insulators truely reflect light?
Post by: Soul Surfer on 01/03/2011 22:58:21

Non conductive materials reflect light because if the impedance mismatch at their surfaces caused by the change in velocity of light in the material.  This a simple standard property of the propagation of electromagnetic radiation in materials at frequencies where the size and separation of the atoms is small compared with the wavelength.