Little green aliens and the term "little green men" have fallen out of general use in serious science fiction circles and are most commonly used to ridicule the notion that aliens may exist, with a few exceptions, such as Yoda in the "Star Wars" movie saga. A derisive usage can be seen in the episode "Tomorrow Is Yesterday", set in 1969, as Captain Kirk, captured by the US Air Force while attempting to steal film showing the "Enterprise" in Earth's atmosphere, calls himself a "little green man from Alpha Centauri" when interrogated by the base security officer. Earlier in the same episode, a rescued Air Force captain brought aboard the "Enterprise" tells Kirk he's never believed in little green men, immediately before meeting the obviously alien Mr. Spock (who replies, "Neither have I"). In the 1988 "Doctor Who" serial "Remembrance of the Daleks", the line is parodied when the Doctor states that the Daleks are aliens. Group Captain Gilmore asks if he's fighting little green men, to which the Doctor says "no, little green blobs in bonded polycarbide armour".