For those interested in optical properties

The site is an interface to a public domain database of refractive index data for many substances and materials. What makes it very useful is that the website calculates properties like reflectance at different angles and wavelengths interactively and displays the data as plots.

Manybe sometime in the far away future I will write an R interface. The web site as is, can be instructive for example to learn how the reflectance of glass or acrylic changes with the angle of incidence of radiation.