At 08:52 am 10-03-05 -0800, Harry Tuttle wrote: <snip>
> *Negative refraction* is brand new (age ~4) > to physics and astronomy, but has been causing > a stir in fields of applied-materials science. > When light crosses a boundary, it is bent in a > characteristic way. Keepers of the faith, like > Horgan, would love to see it stay that way, so > that they can have the smug satisfaction of > saying "told ya so". But in 2001, researchers > showed that certain artificial materials bend > light in the opposite direction. Over a year > later S-A, having tried to ignore this exciting > R&D for as long as it could, finally did a > modest and slightly negative assessment - > hoping, one supposes, that this nonsense would > just go away, since it doesn't fit into their > end-of-science mega-theme. It hasn't gone away. <snip> Stimulated by Tuttle's incisive post I googled *Negative refraction* to find out about this interesting discovery. http://www.physicstoday.org/vol-57/iss-6/p37.html >From the opening sentence..... ------------------------------------------------------- "Materials engineered to have negative permittivity and permeability demonstrate exotic behavior, from a negative refractive index to subwavelength focusing." ------------------------------------------------------- .....I could recognise the mistake that was being made. For years I made a similar mistake myself. Permittivity and Permeability are simply Iterative Hierarchical Strains of EM space. One is a measure of tensile strain, the other a measure of balancing compressive strain. If epsilon is positive then mu must be negative and vice-versa. So let us say that permeability represents positive space strain, then permittivity must represent negative space strain and must be accompanied by a minus sign. So the statement should really read, --------------------------------------- "Materials engineered to have positive permittivity and negative permeability demonstrate exotic behavior, from a negative refractive index to subwavelength focusing." -------------------------------------- In other words the signs of permittivity and permeability are reversed. For most materials the quasi Solid Phase is in compression and the quasi Fluid Phase is in tension, using the terms Solid and Fluid in the sense they are used in Di-phase Theory. But for some materials, such as jelly and children's balloons, it is the other way around. The Fluid Phases (water and air respectively) are in compression and the Solid Phases (organic networks) are in tension. In effect, these new materials are the equivalent of jelly and balloons on the EM scale of things. The trouble with physicists is that they are so lost among the trees they very rarely get a good look at the wood. ;-) Cheers Frank Grimer ===================================== vox Domini confringentis cedros et confringet Dominus cedros Libani et disperget eas quasi vitulus Libani et Sarion quasi filius rinocerotis =====================================
