About: http://webisa.webdatacommons.org/441483575

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	As a result of Maxwell???s work in the 1860s it was known that all electromagnetic waves, including visible light, travel at a speed of in a vacuum.
http://www.w3.org/ns/prov#wasQuotedFrom	ck12.org