 Some Christians ridicule the thinking that the Earth is a sphere by arguing that people far from the top would fall off the Earth.When they ask Davus what his opinion is, he avoids conflict by saying that only God knows these things.Hypatia also investigates the heliocentric model of the solar system proposed by Aristarchus of Samos by having an object dropped from the mast of a moving ship which demonstrates that a possible motion of the Earth would not affect the motion, relative to Earth, of a falling object on Earth.