what you say is true, but in this case there is no voyaging the territory going on at all. what the engineer proposes is like looking at a map and correcting th

what you say is true, but in this case there is no voyaging the territory going on at all. what the engineer proposes is like looking at a map and correcting the map without exploring the real world. it is possible to guess corrections to the map without actually exploring the world, but it means detecting inconsistencies. Correcting the map without travelling or referencing neglected observations would entail a realization. For example suppose our map of the world looked like 3 copies of the world, and we somehow believed there are 3 New Yorks, 3 Paris'es etc, that seem to develop in parallel, ... then the person proposing that the first repetition is actually a return to the same point would be making a point to the rest of the world using the triple copy earth. Here there is no pointing out a misconception of the laws of physics, and there is no referencing of anomalous observations, so you can not fix the map using nothing but the old map unless you also point out what is wrong with the map.