Proton decay

Since the unification of electromagnetic and weak interactions, physicists had been working on integrating strong interactions as well into a Grand Unified Theory (GUT). As part of this research, it was proposed that protons may decay with a very large half life of 10^31 years, but no proof of this has been found yet.
 Abdus Salam 1973 Proton decay

Since the unification of electromagnetic and weak interactions, physicists had been working on integrating strong interactions as well into a Grand Unified Theory (GUT). As part of this research, it was proposed that protons may decay with a very large half life of 10^31 years, but no proof of this has been found yet.