<Li> John Cleese as Professor Karl Barnhardt, a Nobel Prize - winning physicist who specializes in the evolutionary basis of altruism . Helen takes Klaatu to him to further change his mind . </Li> <P> The role was the most difficult to cast, and eventually the filmmakers decided to approach Cleese, noting "Who would you rather make the argument (to Klaatu) for mankind than John Cleese?" Stoff, a producer, had met Cleese a few times beforehand and had noted his intellect . The actor was surprised the filmmakers were interested in him, and decided playing a dramatic role would be easier than to play a comedic one at his age . He was often reminded to speed up his dialogue so that Reeves would not appear in synchronity with normal human speech patterns . Cleese said he is not interested in extraterrestrial life because he often philosophizes about the purpose of life and why humans are distracted by trivial matters . Cleese spoke about portraying abilities outside his own experience in the scene in which Klaatu corrects a formula Barnhardt has written on a blackboard: "The trouble is, I had to be able to write the equation, because Barnhardt has been working on it for 60 years . I learned to carefully copy things down that mean nothing to me at all . In A Fish Called Wanda, I spoke a lot of Russian without having any idea what it means ." </P> <Ul> <Li> Jon Hamm as Dr. Michael Granier, a NASA official who recruits Helen into his scientific team investigating Klaatu . Granier is fascinated by Klaatu, but is torn between his official obligation to detain the alien and protect his country . </Li> </Ul> <Li> Jon Hamm as Dr. Michael Granier, a NASA official who recruits Helen into his scientific team investigating Klaatu . Granier is fascinated by Klaatu, but is torn between his official obligation to detain the alien and protect his country . </Li>

The day the earth stood still 2008 spoiler