Wiktionary
n. 1 railroad track 2 (context topology English) A set of curves lying in a surface, meeting one another at their respective endpoints in a specific way that resembles railroad tracks
Wikipedia
In the mathematical area of topology, a train track is a family of curves embedded on a surface, meeting the following conditions:
- The curves meet at a finite set of vertices called switches.
- Away from the switches, the curves are smooth and do not touch each other.
- At each switch, three curves meet with the same tangent line, with two curves entering from one direction and one from the other.
The main application of train tracks in mathematics is to study laminations of surfaces, that is, partitions of closed subsets of surfaces into unions of smooth curves. Train tracks have also been used in graph drawing.
Usage examples of "train track".
I stood up and lifted the black locomotive and carriage cars off of the train track.
I'll lie low until the storm's at its fiercest, then I'll make my way down to the train track and come back up behind the hotel.
As team members above him lined themselves up with the luminescent strip on the helmet of the Striker beneath them, Squires searched the ground for landmarks: the train track, the bridge, the mountain peaks.
I could feel the tremors coming from her, like a train track vibrating.
There were roads, a train track, and what was still West Berlin, deep in the eastern heart of a divided Germany, that wouldn't be reunited for decades.
Now the houses and their old-fashioned yards lay beneath the sundial stripe of the elevated train track, a band of shadow that darkened a full quarter of the block.
Convex curves, concave curves, horseshoe curves, straightaways, descending grades, and ascending grades featured more train track than there were coconuts in Tuvalu.