Today is Earth Day. To celebrate, B.o.B—who previously claimed the Earth was flat—has dropped his latest mixtape, appropriately titled E.A.R.T.H (which stands for Educational Avatar Reality Training Habitat). It's available as a free download over at DatPiff; stream it below. The nine-track collection samples scientists, pundits, and President Barack Obama, and spans controversial topics like astral projection and cloning. One song, "Fkn' Science Bro," includes references to fossil fuel, climate change, and even dinosaurs. The Atlanta rapper also alludes to his notorious argument with astrophysicist Neil Degrasse Tyson, who put B.o.B on blast earlier this year for claiming that the Earth is flat. He previously addressed the subject on "Flatline," a Tyson-dissing song that espouses multiple conspiracy theories, including the work of Holocaust denier David Irving. As a rebuttal, Tyson's nephew dropped his own Drake-inspired diss track, "Flat to Fact."