🌐🧱 Passive Pressurization via Self-Gravity of Walls
Kardashev range: 1.3–2.4
If habitat walls become massive enough, their own gravity starts helping hold onto atmosphere. That shifts pressure retention from being only a materials problem into a geometry-and-mass problem as well.
Notes
This points toward giant enclosed environments where atmospheric support comes partly from the structure itself, including the broader family of gravitational balloon concepts.