 The theory posits that as the use of the term flying saucer in popular culture decreased, so too did sightings.Long before the Kenneth Arnold sighting of 1947 and the adoption of the term "flying saucer" by the public, depictions of streamlined saucer-shaped aircraft or spacecraft had appeared in the popular press, dating back to at least 1911.In particular, commentators like Milton Rothman have noted the appearance of the "flying saucers" concept in the fantasy artwork of the 1930s pulp science fiction magazines, by artists like Frank R. Paul.