Here in our Universe, one great mystery is how, if matter and antimatter can only be created or destroyed in equal-and-opposite amounts, our Universe came to be dominated by normal (regular) matter, with barely a trace of antimatter present. Sure, dark energy (68%) and dark matter (27%) might make up the majority of the Universe, but the rest of it is made up of particles from the Standard Model: quarks, gluons, leptons, and photons. Of that 5%, nearly all of it (4.9%) is regular matter, made of protons, neutrons, and electrons, while the amount of antimatter — like antiprotons, antineutrons, or positrons — is negligible. And yet, in every particle physics reaction we’ve ever measured, matter and antimatter can only ever be created or destroyed in equal amounts: making one proton requires also making one antiproton; destroying one electron requires destroying one positron as well.…