Before revision: That the Earth is an approximately spherical object that is rotating and in rapid motion around the Sun, rather than the apparently obvious and common-sensical appearance of the Earth as a startionary approximately flat plane illuminated by a Sun that rises and falls throughout the day.
After revision: That the Earth is an approximately spherical object that is rotating and in rapid motion around the Sun, rather than the apparently obvious and common-sensical appearance of the Earth as a stationary approximately flat plane illuminated by a Sun that rises and falls throughout the day.