They live among us (3) - The enabling force

Carrying on the occasional series. Part one here. Part two here. Or use the series label.

I was planning to keep the series relatively short and jump straight to the late 1970s and Alien, but then I realised what I'd be missing. Not least what I'd consider one of the mainstream alien lifeforms least considered in the mainstream. Which fiction?

Listen.

It's 2001: A Space Odyssey of course. I'll say now it will be the film only. For discussing influence, it seems best. Despite close collaboration between author and director, more minds ultimately shaped movie than book, and this series is about the mood of the time, mass experience. I will include spoilers, if the idea can be said to apply to this film.