NOTES
There is an obvious SF connection here - a fairly recent SF novelette was part of the inspiration of this talk - could inertial navigation systems designed on Earth work on a flat earth? How would you design an inertial navigation system that could work there, or on the Moon, or these other environments? I'll get to all that, after some detailed discussion of how it works on Earth.
The novelette was Charles Stross's Missile Gap (my original plan was to give this talk last year, when Charles Stross was guest of honor).