B.o.B is making headlines for his controversial theory about the shape of Earth. Despite the scientific consensus otherwise, the Atlanta rapper insists that the Earth is flat and posted several photos of flat horizons to try and prove his point. His tweets caught the attention of noted astrophysicist Neil deGrasse Tyson, who shot down his conspiracy theory.

On Monday night, B.o.B released a “diss” track called “Flatline” aimed at Tyson after the two exchanged opposing views.

“Aye, Neil Tyson need to loosen up his vest / They’ll probably write that man one hell of a check,” he raps.

He also takes aim at NASA (“Why is NASA part Department of Defense?”), tells listeners to “do your research” on Holocaust denier David Irving, and claims “Stalin was way worse than Hitler.”