Iaians:

Funny you should bring up Velikovsky. My father was an honest-to-God real scientist and he was on the side of the scientific community on that one. Because "Worlds in Collision" was not science. It was no different than 'revealed truth' i.e. a new chapter of the bible or an astrological tract. It was attacked because it was being represented as a valid scientific theory which it was not. It was the equivalent of representing Creationism as Creation 'Science' which it is not, or putting it on a debating par with Darwinian evolution.

To quote Richard Feynman (who was in high school with my mother) "I know how hard it is to know something." [Cripes I'm beginning to sound like Donuel!]

Now, on the off chance that you confused Velikovsky's book with my reference to "The Day The Earth Stood Still", they are entirely different. "The Day The Earth Stood Still" is a science fiction movie based on an earlier short story called "Return of the Master." In the movie an alien of very human appearance lands a space ship in Washington D.C. and demands to talk to all of Earth's leaders. He is greeted with fear and hostility but he has a robot companion, "Gort" by name, who has the potential to be a Galactic enforcer. How the human appearing "Klaatu" can convince humans of his identity and importance, and what happens is a piece of good story-telling, yet a very simple tale as well.