^^^^
That book sounds like a good antidote to the nonsensical
Chariots Of The Gods (which theorized ancient cultures had help from aliens).
http://en.wikipedia.org/wiki/Chariots_of_the_gods
Chariots of the Gods?: Unsolved Mysteries of the Past is a book written in 1968 by Erich von Däniken. It is centered on the hypothesis that many ancient civilizations' technologies and religion were given to them by space travelers who were welcomed as gods.
Most scientists and historians do not take the ideas seriously, claiming that the book's conclusions were based on faulty, pseudoscientific evidence, some of which was later demonstrated to be fraudulent and/or fabricated, and illogical premises.
Nutjobs:
http://www.legendarytimes.com/
de Camp is well known for his fantasy and science fiction books.