About: http://webisa.webdatacommons.org/290177529

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	True, maybe, for the transmitter, however the wave front???s motion is a vector quantity, depending upon your position, the spot size of the light from the source, i.e. light bulb or laser.
http://www.w3.org/ns/prov#wasQuotedFrom	pbs.org