He walks through the relationship between gravitational force, mass, and geometric form in space. The larger the object, the stronger its internal gravity, and that gravity acts on every particle of mass within it. That force wants to pull everything toward the center, and the shape that requires the least energy to maintain under that pull is a sphere. It's why planets are round and smaller asteroids are not. If you take two objects of equal density but different size, the larger one experiences far greater internal gravitational pressure. That pressure reshapes the material over time, forcing it into spherical geometry. The smaller object lacks sufficient mass to generate that kind of internal force, so it remains irregular. This is basic gravitational mechanics, not speculation, though applying it to specific bodies like Ceres versus smaller asteroids requires assumptions about composition and density.