About: http://webisa.webdatacommons.org/417481794

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	Unfortunately, there are a great number of problems with beam propulsion that need to be solved, some of which look like very hard nuts to crack.
http://www.w3.org/ns/prov#wasQuotedFrom	centauri-dreams.org