Others feel that since it has never been observed that it cannot take place. In order to understand how this event may occur, one must be familiar with the constituents of atoms. Electrons, neutrons, and protons compose atoms. The three marbles represent quarks, and in the universe there exists but six types. The three particles that compose protons and neutrons are up quarks and down quarks.
Protons have two ups and a down.
The activities of those quarks found in protons determine the ability of nature to rid the universe of every life and celestial character. The process by which this ability is exercised is called proton decay. In this sense, decay simply means to change into different particles. Decay is an accurate description of the process because the particle discharges energy in order to become a smaller particle, or a group of particles whose combined mass is less. Electrons and positrons are identical except they have opposite electric charge.