Figure 2.

The physical connection between gravity and the optical variables of elevation angle (γ) and its temporal rate of change $(\dot{\gamma })$. (A) Parabolic trajectories with different horizontal velocities (from 3 m/s to 10 m/s in steps of 1 m/s) and different gravity values (from 0.7g to 1.3g in steps of 0.1g, color coded from blue to red). (B) The elevation angle (γ) as a function of time for different gravities (color coded) and two different horizontal velocities (6 m/s, left, and 10 m/s, right), plotted for the first 200 ms of the trajectory. (C) The temporal rate of change of the elevation angle $(\dot{\gamma })$ as a function of time for different gravities (color coded) and two different horizontal velocities (6 m/s, left, and 10 m/s, right), plotted for the first 200 ms of the trajectory.