We introduce the macroscopic point of view for questions around scalar curvature.
Then we discuss the macroscopic cousins of three conjectures: 1) a
conjectural bound of the simplicial volume of a Riemannian manifold in
the presence of a lower scalar curvature bound, 2) the conjecture that
rationally essential manifolds do not admit metrics of positive scalar
curvature, 3) a conjectural bound of ?²-Betti numbers of aspherical
Riemannian manifolds in the presence of a lower scalar curvature
bound. Group actions on Cantor spaces surprisingly play an important role in the proof. The talk is based on joint work with Sabine Braun.