Pions

Fundamental to all matter, protons and neutrons constitute the central nucleus of atoms. Different numbers and combinations of these protons and neutrons are what distinguish each element from another. Six of each give us carbon. Eight of each - oxygen. Seventy-nine protons make gold. All the different elements that make up all the matter in our world depend on protons and neutrons remaining bound together in atoms. Should these nucleons cease to hold together, every living organism, every mineral compound, every molecule of water or strand of DNA would instantly and violently break apart without any hope of reconstruction.

Fortunately for us, there are pions. These tiny particles constantly pop in and out of existence between the protons and neutrons in atomic nuclei. A proton ejects a pion, which is a fraction of a second later absorbed by a neighboring neutron. This neutron then emits a different pion that is collected by a different proton. This constant ‘pion exchange’ forces the protons and neutrons to not wander too far apart from each other, and thus staying in the nucleus.

Without pions, there would be no atomic nuclei. Without atomic nuclei, there would be no elements. Without elements, there would be no life. Without life, there would be no trees.