#cosmic-structure

Introduction Background explainer (for casual readers): In everyday terms, a baryon is a “building‑block” particle—made of three quarks—out of which nearly all familiar matter is built. The two lightest baryons are the proton (two “up” quarks + one “down”) and the neutron (one up + two downs); together they make up the nuclei of every atom and, by extension, people, planets, and pizza. Because…