Re: what is metamaterial?
Meta comes froom Geek, well said, but I dont like this definition you gave "not exactly a material"
Meta means something about that something. For example, metalanguage means language about language, like html tags and so
In this case, the best definition I can think about is a material done with materials, this means, a material with its own characteristics made using other materials with different characteristics.
The are no negative permitivitty or permeability materials in nature. Thus, this metamaterials with negative indexes are done using other that have positive indexes.
Then, materials done with materials