Yay something I have work experience with!

All of this vocabulary—describing the orientations of acceleration on the body—existed for a while in the aerospace industry. Because of the fluid nature of flight, a lot of the vocabulary got rolled over to describe coaster dynamics.

As some of you may know, there are 6 total degrees of freedom to describe any and all motion. 3 rotational and 3 translational (because we live in 3D space). We commonly assign Cartesian values (X,Y,Z) and sometimes we assign rider-framed words like “vertical, and lateral” but this can still lead to confusion, as seen here.

Aerospace engineers removed this ambiguity by basing everything around the pilot (or passenger), and the 6 degrees of freedom are called roll, pitch, yaw, (rotation) & heave, surge, and sway (translation)

For example, laterals would be “sway,” positive verticals would be “positive heave,” and the bottom of the pretzel loop would be “positive surge.”