Why we don't see a negative refractive index in rainbows and gravitational lenses?
I think that this effect can be, because nano- and microparticles of water and dast are similar to dielectric particles which use for building metamaterials
Look at this paper,
https://www.osapublishing.org/DirectPDFAccess/840E5D73-B8BA-9187-E59D04285F60E6DB_174396/oe-16-23-19152.pdf?da=1&id=174396&seq=0&mobile=no
My previous link seems broken, you can try this one.
Article Correct Definition of the Poynting Vector in Electrically an...
I don't see how water droplets in rainbow (or not) can have negative index ?
Impurities can change the index of water ... But how to make it negative ?
Same for gravitation : it can change indexby making the material penser, but not make it negative ...
Dear Michel H Grosmann , here uses an analogy with metamaterials. As metamaterial cells can be used not only metallic SRR or other elements, which was described in this paper Conference Paper Metamaterials on antenna solutions
, but also dielectric particles. The array of such multiple dielectric particles can have in some frequency range the negative refractive index. In my opinion, similar effects can be by using water droplets and Impurities as well.
Refractive index is a measure if how the photons interact with matter in a transparent or low dielectric material
If the index is high the photon is continually being considered as a candidate for hitting another particle
Each time this happens a unit of Planck time passes and the effect of this is that the photon appears to slow down. This is because 0 Planck time passes for the photon while traveling through free space. If it's a high energy photon such as UV light it is even more likely to be a candidate, so UV light slows down even more making the spectrum. Since the photon enjoys maximum speed of the speed of light and no time passing while traveling through a vacuum, it would require time to go backwards if true negative refractive index were possible. Does that completely answer your question or do i need to prove to you that time cannot go backwards. There are exotic man made materials which are called left-handed or metamaterials but they work by slowing down all the particles and then making the UV less slow making it look like on a macro level that the UV has speeded up,
Thank you, dear Edward Slevin ! But what about negative index refraction in metamaterials and optical metamateraials as well?
Refractive index is a measure if how the photons interact with matter in a transparent material
If the index is high the photon is continually being considered as a candidate for hitting another particle
Each time this happens a unit of Planck time passes and the effect of this is that the photon appears to slow down. This is because 0 planck time passes for the photon while traveling through free space. If it's a high energy photon such as UV light it is even more likely to be a candidate, so UV light slows down even more making the spectrum. Since the photon enjoys maximum speed of the speed of light and no time passing while traveling through a vacuum, it would require time to go backwards if negative refractive index were possible. Does that completely answer your question or do i need to prove to you that time cannot go backwards. There are exotic man made materials which are called left-handed or metamaterials but they work by slowing down all the particles and then making the UV less slow making it look like on a macro level that the UV has speeded up,
Dear Edward Slevin ,
I think that your point of you is in contra with the practical results of use metamaterials. You need to expand your situational awareness. As a start point I suggest to your attention this my publication:
Conference Paper Metamaterials on antenna solutions
Article Metamaterials in antenna technology: basic principles and re...
Metamaterials come in at least 2 types. I am not sure if this covers all metamaterials, but it may.
1. The negative property is caused by the properties of the particle - for instance when the particle has resonant properties (usually at wavelengths much larger than its size.
2. The negative property is caused by the periodic arrangement of the particles or parts of the metamaterial, with a period small compared to the wavelength.
The second requirement may be needed for the first to work.
Water droplets do not have resonant properties at wavelengths much larger than their size (and are large compared to the wavelength of visible light), and are not in a regular arrangement, so do not fulfil the requirements for the majority of metamaterials.
Similarly interstellar dust or other material interacting with gravity waves is not in a regular arrangement. I don't know if it is resonant to gravity waves at gravity wave frequencies, but I doubt it, in particular as I expect it's size and shape varies enormously.
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