|Is an O'Neill Cylinder like a model railroad loop?|
“O'Neill Cylinders Explained -- Deep Space Colony of the Future” (14 minutes) by “Epsilon Is Greater Than” (Feb. 2020).
Two scientists do the math on a whiteboard and talk about how to build sustainable deep space environments, to have sustainable life in space, without “gravity wells”.
There is no actual scenery in this video, and the comment about HIV was a bit offputting.
They mention the O'Neill cylinders in “Babylon 5” and the Cooper Station in “Interstellar”.
Update: April 8: Also look at Interstellar Research Group's "Construction Scenarios for O'Neill Cylinder Space Settlement Habitats, 30 min, 2019, all mathematics, here.