"... most of [Hollywood] 2050's productions would have seemed incomprehensibly highbrow to 1950."Oh dear. I can't see this vision of the future becoming reality any time soon.
Childhood's End begins in the aftermath of WW2, when the development of nuclear weapons threatened to annihilate life on earth. Spaceships arrive and hover over the world, and alien Overlords establish order to ensure humans do not destroy themselves.