About: http://webisa.webdatacommons.org/419035345

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	It is because light is a wave, and the speed of a wave depends on its medium, not on the emitter.
http://www.w3.org/ns/prov#wasQuotedFrom	letstalkphysics.com