text: A meter has the same length no matter where you are.  The GPS system might use the curvature of the earth to modify the length of what the system describes as a meter, because a curved meter spans a shorter distance along one axis.  The length of a meter is immutable and is defined as: the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second where the speed of light, c, is 299,792,458 m/s.