Re: [Phys-l] permittivity vs dielectric

[Bernard Cleyet <bernardcleyet@redshift.com>]

On 2011, Dec 22, , at 08:39, Paul Lulai wrote:

> Richard, 
> So it seems that the two values (dieletric constant and permittivity of that material) are, in essence, the same thing. 
> One could teach capacitance with permittivity values in place of dielectric constants (although it would be less practical)


Considerably, as the Index of refraction is the square root of the dielectric constant for non absorbing materials.  (not permittivity)  For absorbing materials it's complex.   i.e. metals have a complex dielectric constant.

"The frequency dependent dielectric constant is simply the square of the (complex) refractive index in a non-magnetic medium (one with a relative permeability of unity)."


I think "they" just don't want to get in that can of worms and especially in regard to negative permittivities and permeabilities! ***


http://en.wikipedia.org/wiki/Refractive_index#Dielectric_constant




***
http://wave-scattering.com/negative.html



bc still hasn't found the time to make such meta-materials for X-Band radiation.