About: http://webisa.webdatacommons.org/447130489

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Consequently, by varying this angle such as by tilting the crystal while keeping the direction of incident light fixed, a variation of refractive index is produced with respect to the extraordinary ray in the crystal.
http://www.w3.org/ns/prov#wasQuotedFrom	google.fr