Transversals to Line Segments in R3
Résumé
We completely describe the structure of the connected components of transversals to a collection of $n$ line segments in $\mathbb{R}^3$. We show that $n\geq 3$ arbitrary line segments in $\mathbb{R}^3$ admit $0, 1, \ldots, n$ or infinitely many line transversals. In the latter case, the transversals form up to $n$ connected components.