Just a quick note
"the paths are straight lines because a straight line is the shortest distance between two points."
Actually a vortex is the shortest distance between two points. If the universe were static a straight line would be, but since all points are moving vortically and exist in curving time-space, the straight line isn't really straight at all. It's for that same reason that spacecraft take very well planned elliptical journeys to get to their destinations.
Follow that laser's path long enough, and just like a simple ray of light, one will note the curve. Much as light can be bent by gravity the laser is influenced by time-space as well.