How the Tiniest Particles in the Cosmos Saved Us All from Annihilation

Matter and anti-matter completely annihilate when they meet, erupting into pure energy. If the Universe began with equal amounts of each, why does anything still exist? The answer may lie with the smallest particle of all.

Ripples in spacetime known as gravitational waves could reveal the answer to one of the greatest questions in the study of the Cosmos — why anti-matter in the early Universe did not completely annihilate every particle of matter and vice versa.