-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Tom York wrote:
> Christoph Hormann <chr### [at] gmxde> wrote:
> 
> 
>>Note that according to the most common definitions of the index of
>>refraction a negative one is not possible (this has nothing to do with
>>physics but mere mathematics).  So if you want to know if POV-Ray
>>correctly handles what you call negative ior you first have to decide
>>what a negative ior actually is.
> 
> 
> The sign of the index of refraction is arbitrary, going strictly by the
> mathematics. The physical principle that fixes the sign is conservation of
> energy. To conserve energy across a material boundary, normal materials
> have to have a positive IOR and these metamaterials have to have a negative
> IOR.
> 
> 
[Semiologic mode on: (I need more explanation)]

The refraction is the propagation of the EM wave inside the material.
The positive IOR (IOR>0) might be used to keep the information that the
EM wave is moving from zone A made of material to zone B made of air (or
whatever). Same for the opposite, moving from B to A.
That's refraction. So far so good.
Now, if I try to imagine your negatif IOR (really, IOR < 0 ? not just
IOR < 1 ?) as an interface which when encountered by the EM wave send
the EM wave back in the zone it is coming from, it is not what I would
call refraction (usually it's called reflection).
There is of course the classical "total reflection angle" due to
refraction, but that's only a side effect.

Please note also that even an IOR < 1 would be quite puzzling: it would
means that light would travel faster than in the void when inside this
material (faster than c). it would be an interesting universe.
(especially if the information can be made to travel with the
corresponding EM wave)... Nahhh, just dreaming.

There is also a possible usage for the sign of the IOR, which could be
an oversimplification of the phase change/polarisation of a signal.
Assuming a clockwise rotation of E toward M, going thru one "negatif
ior" material could end up with an opposite rotation (anticlockwise).

Now, maybe your "metamaterial" is just a mirror with subsurface
scattering/refraction ? A kind of variable angle of reflection ?

[end of questionning]

- --
Eifersucht ist die Leidenschaft, die mit Eifer sucht, was Leiden schafft.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.0 (MingW32)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQFDDZM/s/YJ43cSjHIRAs/sAKCm8aDA0utdzv5/1t3efFvW6U2+LQCdFjUp
3xxOLC6vEiAuI9emL+KOvIE=
=45bZ
-----END PGP SIGNATURE-----

Post a reply to this message