Isaac Asimov. Published in 1989, 14246 characters, or 7 standard pages, long.
An essay regarding the view that wrong is wrong, that saying "the Earth is flat" would be as wrong as saying "the Earth is a sphere", given that it's actually something like an oblate spheroid. I read it some time ago I think but came across it again on 1st March 2010 (while browsing the Julia Sweeney forum having listened to Letting Go of God the night before).
Links and referencesEdit
http://chem.tufts.edu/AnswersInScience/RelativityofWrong.htm (the essay in question)