matter-antimatter asymmetry

Matter-antimatter asymmetry refers to the observed imbalance in the universe: there is much more matter than antimatter. When matter and antimatter particles meet, they annihilate each other, releasing energy. Theories suggest that shortly after the Big Bang, matter and antimatter were created in nearly equal amounts, but subtle differences—called CP violation—caused a slight excess of matter. Over time, this tiny imbalance led to the universe we see today, filled predominantly with matter, allowing galaxies, stars, and planets to exist. Understanding this asymmetry is key to explaining why the universe is composed mostly of matter.