Optical Ceramics in Nature

We will use many of the concepts introduced in this chapter when we discuss gemstones in Chapter 36. Nature does make use of these 

This is a group of animals that includes sea urchins and sea stars, one of which is the brittlestar Ophiocoma wendtii). 

The cross section through one of these lenses demonstrates how the light is focused onto the nerve and even how the spherical aberration is corrected. 

(Bob) (1928-1992) developed Lucalox , a transparent polycrystalline alumina (AI2O3) ceramic, at the GE laboratory in Schenectady in 1961 GE is still a major supplier of lamp envelopes but Silvania, Osram and others also manufacture the envelopes now. 

Maxwell, James Clerk (1831-1879) developed the electromagnetic wave theory of light. 

---