disappear suddenly or unexpectedly, leaving no indication of where one has gone. Used figuratively in this lecture.
a coined variation of the
phrase into the blue meaning into the far distance; also, into the unknown. The
word blue here refers to the sky or atmosphere and horizon is the
line or circle seen at a distance that forms the apparent boundary between the earth and sky. Thus, to
sail off into the wide blue horizon is to go off to distant regions or places unknown.