The Board is Warped

Spacetime is bent by bodies of mass as shown in the lower half of the mural. The attraction between 2 bodies of masses M and m, r distance apat is F=GMm/r^2, where G is the universal gravitational constant 6.67*10^-11 Nm^2/kg^2. Mr. Curtis the physics teacher often draws problems on the board, and when his lines are not straight, he complains that his lines ARE straight, except the board is warped, making them appear curved. The top half of the mural even includes the circular magnets that are always on Mr. Curtis's whiteboard.