Many years ago, I read a great book by an engineer on these sorts of things — written in the 1970s!

He noted that no one ever speculates that, say, Notre Dame cathedral was built by aliens, but only buildings created by people of color. “I wonder why that is?” he said, sarcastically.

(It was a very entertaining book in general — I wish I could remember the name. He recreated the famous Baghdad Batteries and used them to electroplate a thin gold surface onto a lead bracelet. He then pointed out that the Pyramids have been a tourist attraction for 4000 years, and had an amusing little dialog — “Honey, that gold bracelet we bought on vacation last year turned my wrist green!”)