LESSON 5 · What Everything Is Made Of
Made in the Lab
Medicine isn't the only place antimatter shows up. Physicists make it on purpose.

Cosmic rays slamming into the upper atmosphere create antimatter constantly. Even thunderstorms produce brief bursts of it, and a thin band of antiprotons is trapped in Earth's magnetic field high above us. In every case the antimatter exists only in vanishingly small amounts, annihilating almost as fast as it forms.