About: http://webisa.webdatacommons.org/75903007

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	The time information is optically transmitted as sequential light pulses by controlling a light source, such as a light emitting diode (LED) in the wall clock or table clock.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com