Pluto's demotion was an early harbinger of the denial of science - a lot of people honestly refused to accept it and felt it was "false".

Trivia note: many years after I first learned about the Kuiper Belt, probably from Asimov, I learned Dutch.

Now know I know that "Kuiper" (meaning literally "cooper", barrel maker) is pronounced something like "Cope-r", whereas I always pronounced it like "Cowper".

(Actually, the "ui" sound doesn't appear in English, but it's close to the "o" in "cope", if you said it with a posh UK accent.)