As you might recall, B.o.B has been recently tweeting how the Earth is flat. Astrophysicist Neil DeGrasse Tyson got involved, but wasn't able to shy the rapper from his path. Now, B.o.B has released "Flatline," a diss track of sorts that calls out Tyson and samples one of his lectures. (He raps "Neil Tyson need to loosen up his vest / They'll probably write that man one hell of a check.") It also tells listeners to read Holocaust denier David Irving ("Stalin was way worse than Hitler," B.o.B. raps) and references several other conspiracy theories.

Update (5:11 p.m.): Tyson has issued a response to B.o.B's track—sort of. His nephew, who performs under the name TYSON, furthers the flat earth beef with a new diss track. It’s a reinterpretation of Drake's Meek Mill diss "Back to Back,” reworked as "Flat to Fact," which the astrophysicist has endorsed on Twitter: "As an astrophysicist I don’t rap, but i know people who do," he wrote, linking to the song. Listen to it above.