# What exactly "triggers" a matter/antimatter detonation? Tags: antimatter - Score: 13 - Views: 1660 - Answers: 3 - Answered: yes - Asked by: Somatic (257 rep) - Asked: 2016-01-27 - Edited: 2016-01-28 - Site: physics ## Question I know that when matter touches antimatter, they both explode and turn into energy. However, by my understanding, atoms don't really touch; their nuclei don't physically contact each other, since electromagnetic repulsion keeps them away. If this is true, then what is the inciting moment that sets off the explosion? At what point do the two substances go from being separate pockets of matter and antimatter to being energy? Is it when the electron clouds get close enough? How does antimatter know to explode? ## Answers ### Answer by mpv (score: 9 [ACCEPTED]) Annihilation is a quantum process and as such it is probabilistic. You are correct that particles do not touch in a classical sense, but each interaction has a cross section. Particle and antiparticle are attracted to each other because of opposite charge and when they get sufficiently close, they interact. In case of electrically charged particles (like electron and positron) the interaction h