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
... applied force will cause one end of the axis to push against the upper rim of the groove, while the other end of the axis pushes against the lower rim of th ...