Date (happened)
  • 1955 (probable)
    derived from the event's own title: "Two public lectures at Caltech in 1955"
  • c. February 1967 (probable)
    Passage 548717 says the prior day's Los Angeles Times reported Professor Dicke was present to give two lectures at Caltech.
Told / reported
21 February 1967 (possible)
Standing preferred delivery claim on lecture nid 1912.
Robert Dicke's two Caltech lectures were current around 21 February 1967; the source does not state their exact dates.