I want to start by saying that I have really enjoyed this series, and what fallows is not an attempt to "debunk" any of the Science Brandon Sanderson has built. I just want some help rationalizing his Magic system for the sake of my immersion. So on to the crux of my issue
The system of lashing does not work within the logical confines constructed by Brandon Sanderson.
BS describes lashing as temporarily re-aligning whatever spren is responsible for making you fall towards the direction of your choosing. Furthermore, 2 lashings would make the force act as if you were twice your weight, 3 lashings three times your weight, and so on. Basically the surge binder can position their gravitational force vector in any orientation( and to some extent magnitude) they choose. Where this falls apart is when Kaladin is testing out his new abilities in the Chasm. He is hurtling towards a wall and lashes himself "back" and "left" to turn left . kaladin describes it as having a jumped off a cliff with a rope around his belly, however there would be no jerking motion. In fact, once he lashes himself backwards it would take as long as he had been lashed towards the wall for backwards lashing to bring him to a stop. He would have splattered straight into the wall! If he had been falling for even just 3 or 4 seconds, it would take at least that many backwards lashings to bring him to a stop within a second.
We constantly see him using these bindings to make quick jerking motions, but this is not at all how moving about solely by manipulating roughly equivalent forces ( as in a physical force F = ma) would work.
Moving about with these lashings should be much more similar to walking on Ice ( although for different physical reasons). Once he has picked up speed in any direction, a lashing in the other direction would bring about a smooth gradual directional change.
The concepts really break down when he is flying to the sky and then slowly comes to a stop once he has put lashings both up and down. In this case you would have no net force and you would just continue drifting up. Sure, air resistance will slow you down at first, but it would become almost negligible at slower speed and he would just lazily continue to drift up for a LONG time.
That being said, the system works perfectly in enclosed spaces like hallways and such. Without having enough space to accelerate to high speeds, the constant changes in acceleration vectors would lead to an almost instantaneous change in direction.
I really respect Brandon's use of logic in most of his magic systems. HE gives them a reason to work, but its use here just seems broken. His system is based off of classical mechanics ( which is really cool), but his disregard for a lot of the ramifications sort of wreck the experience.
TL;DR I like Brandon Sanderson's believable magic systems, unfortunately he undermines the very structure he uses to make the awesomeness of surge binding believable. Has anyone found some useful justifications to patch the system?
Edit: I was thinking something along the lines of orthogonal lashings immediately redirecting all of their force in the new direction... that could help make more sense, maybe?
