It’s one of many theories that he has, and people are unable to convince him otherwise.
UPDATE: B.o.B. has now released a track supporting his flat earth theory, which samples Neil DeGrasse Tyson.
It includes lines like "use your common sense / Why is NASA part of the department of defense?" and "Indoctrinated in a cult called science / And graduated to a club full of liars / Heliocentrism, you were the sixth victim."
Recently he has started to debate his ideas with a number of people across the internet, maintaining his belief that the world is flat.
To summarise his beliefs;
- It is impossible to ever see the curvature of the Earth.
- Just because in some photos it does appear to be curved, this is due to either editing of photos, or curved lenses.
- NASA has repeatedly changed the shape they think the Earth is - from sphere, to oblate spheroid, to pear-shaped.
- Any pictures of the Earth being spherical are actually CGI.
- While we can see spherical planets in the sky, we cannot actually see them for ourselves - only through telescopes.
- The UN and NASA are hiding the fact the earth is flat by banning anyone from exploring the poles.
- The UN's flag represents the actual shape of the world.