Comment by program_whiz
2 days ago
The good news about this navigation is that the best course for almost any journey is just "straight line", with a minor deviation here and there. Its funny, but due to the emptyiness of space, even in our solar system, if you just pick a random direction, you likely won't hit anything. Trace a line to pluto from earth, and its clear 99.99999...% of the time if its not behind the sun. So the mentats maybe don't have such a tough job :)
I can make up a plausible sci-fi explanation for the need easily: the folded space might not look like our almost euclidean geometry. Maybe in folded space masses take volume proportional to the mass.
Could even envision it in some future film. E.g. when NCC-1701-N goes to warp in addition to the blur effect all the stars swell up.
Interstellar travel is a bit more difficult than that, and doing it at FTL speeds is presumably more difficult still.
But that’s not really important. Science fiction is allowed to make things up that aren’t perfectly realistic. Campbell surmised that a good science fiction author would pick just one unrealistic thing, such as FTL space travel, for every story, and the reader would oblige by suspending their disbelief. Frank Herbert might have stretched that a bit but I still think he wrote a good story. I don’t hold it against him.
I agree with lostmsu's point here that "folding space" is not as literal as you're interpreting it. "Folding" and "Navigation" is a metaphor some sort of extra-dimensional or non-euclidian operation that enables space travel. What it entails exactly eludes our perception.