The concept of tractor and pressor beams was popularized in the ''Lensman'' novels written by E.E. "Doc" Smith. <ref>http://www.daviddarling.info/encyclopedia/T/tractor_beam.html</ref> | The concept of tractor and pressor beams was popularized in the ''Lensman'' novels written by E.E. "Doc" Smith. <ref>http://www.daviddarling.info/encyclopedia/T/tractor_beam.html</ref> |