Severe thunderstorms are natural particle accelerators that create positrons, and orbiting satellites have detected the gamma-ray flashes of their annihilation. This episode strips away science-fiction tropes to explain what antimatter really is: mirror-image particles with identical mass and opposite charge. The hosts cover the 2023 CERN ALPHA-g experiment showing antihydrogen falls down like normal matter, the E=mc2 physics of annihilation, and the baryogenesis puzzle of why any matter survived the Big Bang, resolved by CP violation and a one-in-a-billion surplus.

From there the episode tours natural antimatter sources, from potassium-40 in bananas to the Van Allen belts and a positron cloud near the galactic center, then traces the lab story from Paul Dirac's 1928 equation and Carl Anderson's 1932 positron discovery to Penning traps, eva ...