Curvature describes the geometry of the Universe. We know that there is curvature on a small scale due to gravitational effects, but this curvature is thought to average out on a large scale so that space can be approximated as Euclidean when describing the geometry of the Universe as a whole.

Current measurements of the curvature of the observable Universe are consistent with it being flat (0 curvature). However, it is possible that the Universe is curved and has a very small curvature (cosmic inflation would provide an explanation for why the curvature is so small).

Resolves YES if there is consensus in 2040 that the Universe has an overall curvature on a large scale, and that this curvature has been experimentally measured. Resolves NO if this has not happened. I may resolve to PROB if there is a measurement that is generally believed to be correct and show that the Universe has curvature, but has some doubt around it.