Aparently, I’ve conflated Level with Plumb, the walls cannot be parallel and plumb. Due to the curve, the center of gravity for the walls would require them to angle in slightly together or not be plumb.
You know how they say that gravity curves space-time?
And you remember from geometry class they told you all the rules you were learning were for “Euclidean” geometry, which had to do with flat space, and then they never mentioned it ever again?
Well basically this is a great example of where non-Euclidean geometry exists in the real world. Gravity bends space-time.
The original post has nothing to do with the curvature of space time, or non-Euclidean geometry.
This only has to do with the fact that on a plane (e.g floor of a building, of literally any size), above a gravity source (here, we can treat the earth as a point source), the gravitational vector will only be perpendicular to the surface at a single point. All other points will experience gravity at an angle.
Yeah I realized that before I submitted it but it still sounded cool.
Also I’m not entirely convinced that the fact we can model and real-world gravitational mass as a point is entirely independent of the fact that gravity curves spacetime.
Like, we don’t have infinite sheets of gravitational material out in space. Gravity tends to clump material together into spheres and, for quickly-rotating masses, discs. What are those shapes other than equipotent shells drawn around that curved space?
As a pediatric pedantic but fun point, in surveying, level lines are defined to follow the Earth’s curvature. This means they are technically not straight. Horizonal lines, which are perpendicular to plumb lines, are often used as approximations for level lines.
Generally it’s safe to use them interchangeably, but sometimes the distinction is important.
https://theconstructor.org/surveying/terms-in-leveling-uses/20077?amp=1
@eating3645 @sin_free_for_00_days The inventor should have a special place reserved in hell.
I can do it. Two walls: one on the north pole and one at the south pole would be parallel and plumb.
I guess you could put it on ever higher stilts to satisfy the parallel and level thing.
When your walls are level, you have a problem. Usually you want your walls to be plumb.
