About: http://webisa.webdatacommons.org/53850892

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	However, light sources, other than the sun, emit light at less than four pi steradian, due to the geometry of creating or delivering the optical energy.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com