One of my all-time favorite movies is the 1951 science fiction thriller, The Day the Earth Stood Still. It tells the story of an alien (Klaatu) who comes to planet Earth to say that the galaxy is pretty upset with us and fears that, with our new nuclear weapons, we might not just blow ourselves to smithereens but inflict significant damage on others. It turns out that the rest of the universe has put itself under the power of robots who enforce peace and quiet and if we do not mend our ways these robots will un-mend us once and for all. To make the point, Klaatu has brought one of the robots (Gort) along with him, and when as inevitably happens we humans fail to take proper heed and end up killing Klaatu, Gort sets out intending death and destruction. The carnage is prevented only because a young war widow (Helen Benson), who has befriended Klaatu and who has been told what to do in an emergency, manages in time to turn off Gort with the crucial words “Klaatu Barada Nikto.” I am sure I was not the only eleven-year-old who spent the next year uttering those words whenever I got in a jam. Somehow they never seemed to quite work with my schoolmasters.
Now, my point is that – with an interesting exception that I will mention shortly – Klaatu appears as a normal human being. Played by Michael Rennie without any special makeup, he rents a room in a boarding house in Washington DC, and causes no special attention when he appears at the breakfast table with the other guests. He goes off around the city with Helen's son Bobby and again there is nothing strange, although despite speaking English perfectly he does show ignorance of our ways – at the Arlington Cemetery grave of Bobby's father he fails to understand the point of violence and later naively swaps some precious diamonds for a few dollars. Physically, Klaatu is like a member of Homo sapiens and intellectually too. It is true that he is very, very bright, but not in a weird way. When he meets the physicist Professor Barnhardt – modeled on Albert Einstein – the two are clearly in the same intellectual ballpark.