Slate Plus members get ad-free podcasts and bonus episodes of shows like Dear Prudence and Slow Burn. Sign up now to listen and support our work.Ong's Hat, or The Incunabula Papers, is a conspiracy theory that arose on the early internet. Combining cutting edge science, mysticism, and obvious hokum, it intrigued thousands of people who tried to find out what it all meant. Today we uncover the secrets of Ong's Hat, the man behind it, and the new art form it inadvertently birthed. Check out our showpage at slate.com/culture/decoder-ringThis episode is brought to you by the following advertisers:Aleph Mattresses, a handmade mattress experience: TrustAleph.com②Learn more about your ad choices. Visit megaphone.fm/adchoices