It is a diss track aimed at physicist Neil DeGrasse Tyson, whom he had gotten into an argument with on Twitter, over B.o.B's stated belief that the Earth is flat.

[1][2][3][4] The song was panned by critics and music industry commentators for its support of conspiracy theories and its anti-Semitism.

Vulture music critic Nate Jones commented, "It’s called 'Flatline,' which is both a reference to the horizon of the Earth and also a fitting description of B.o.B’s career.

"[5] Jonathan Greenblatt, the CEO of the Anti-Defamation League, issued a statement saying that B.o.B's "lyrics are irresponsible and could potentially promote anti-Semitic beliefs, especially in those people who might already be infected by such notions.

[8][9] In response to B.o.B's Twitter arguments with Neil deGrasse Tyson, the latter's nephew, an amateur rapper using the stage name Ellect, released a diss track of his own titled "Flat to Fact" which echoes several of his uncle's talking points and features Tyson himself providing spoken word interjections.