A Twitter feud between Neil deGrasse Tyson and hip-hop artist B.o.B. over the "Flat Earth" theory turned into an all-out rap battle, NPR reported. The famed astrophysicist enlisted his nephew's help and responded to B.o.B.'s diss track supporting "Flat Earth" theory, titled "Flatline," with his very own diss track, titled "Flat to Fact."

The feud started when B.o.B. (real name Bobby Ray Simmons, Jr.) went on a Twitter rant about the "Flat Earth" conspiracy theory and argued that the Earth is actually flat instead of round.

"The cities in the background are approx. 16miles apart... where is the curve? please explain this," the "Airplanes" rapper tweeted, along with a photo of himself with the horizon in the background.

After a series of tweets, deGrasse Tyson responded to B.o.B. from his official Twitter account on Monday with his own explanation of why the buildings in Manhattan appear to be standing in a straight line instead of a curve and finished his lecture with a friendly note.

"Duude - to be clear: Being five centuries regressed in your reasoning doesn't mean we all can't still like your music," deGrasse Tyson tweeted.

B.o.B. then released then later deleted a diss track via SoundCloud on Tuesday, titled "Flatline," which further elaborated on "Flat Earth" theory and he called the astrophysicist in the lines "Aye, Neil Tyson need to loosen up his vest / They'll probably write that man one hell of a check," according to Genius.

Not to be outdone, deGrasse Tyson fired back with his own diss track with his nephew Steve Tyson on vocals, titled "Flat to Fact," USA Today reported, which is a play on the title of Drake's diss track to rapper Meek Mill, "Back to Back."

"Very important that I clear this up / You say that Neil's vest is what he needs to loosen up? / And he's amazing cause the brother's getting paid / When the ignorance you're spinning helps to keep people enslaved, I mean mentally," Steve raps in a parody of Drake's flow.

Listen to deGrasse Tyson's diss track "Flat to Fact" below.