evidence: B.o.B, whom you might know from his hits "Airplanes," "Nothin' On You" and "Strange Clouds," kicked things off Monday when he started tweeting about how he believes the Earth is flat. He also tweeted about why he believes NASA is hiding the truth about the edge of the world. And he shared several meaningless diagrams about the planet including one about flight routes. [...] @bobatl Flat Earth is a problem only when people in charge think that way. No law stops you from regressively basking in it. [...] Alarmingly, B.O.B isn't the first celebrity flat Earth truther. Earlier this month, Tila Tequila, of MTV fame, fired off a series of tweets demanding proof the Earth was round.