1965 - James Gunn[?] and Bruce Peterson[?] use observations of the relatively low absorption of the blue component of the Lyman-alpha line[?] from 3C9[?] to strongly constrain the density and ionization state of the intergalactic medium
... - Sally Rand[?], dancer (+ 1979)
April 7 - Ralph Bunche[?], diplomat, winner of the Nobel Peace Prize
April 16 - Fifi D'Orsay, actress (+ 1983)
April 22 - Robert ...