Let $S$ be the surface of a convex body embedded in $\mathbb{R}^3$. For me $S$ is a convex polyhedron, but I am happy to view $S$ as a smooth body with positive Gaussian curvature at each point, or with non-negative Gaussian curvature at each point. Likely these various versions do not affect the question I am posing. Maybe even convexity is not required.

Let $x \in S$ be an arbitrary point on $S$, and $u$ an arbitrary direction
vector tangent to $S$ at $x$.
Shoot off a geodesic $\gamma$ from $x$ in direction $u$, and let it proceed
until it intersects its own path at some point $y$.
Rather than let the geodesic cross itself at $y$, have it instead
reflect from $\gamma$ like a mirror: angle of incidence $=$ angle of reflection.
And continue: every time $\gamma$ would cross itself, instead it reflects.
Call this $\gamma$ a *reflecting geodesic*.
("Self-avoiding" is eye-catching but inaccurate.)

. For generic $x$ and $u$, is it true that for "most" surfaces $S$, a reflecting geodesic $\gamma$, emanating from $x$ in direction $u$, converges to a point?Q

I would prefer not to attempt to define precisely what "most surfaces" means, but in the polyhedral world, it would suffice for $S$ to be the convex hull of random points in space. (Vertices would be hit with probability zero.) I know that, without the "generic" qualifier, a reflecting geodesic might get caught in an infinite loop. For example, on a cube, $\gamma$ intersects itself at $90^\circ$ (essentially: because of the Gauss-Bonnet theorem):

^{ A geodesic starting at the center of the left-front face eventually intersects itself at $90^\circ$ on the bottom face. }

These reflecting geodesics may seem contrived, but something close to these came up in my research, and I am hoping that an answer to

**might help.**

*Q*