The standard model of particle physics says that protons are stable and live forever, yet it has some flaws, especially in uniting quantum mechanics with Albert Einstein’s theory of relativity, which describes gravity.
The proton decay hypothesis was first described by Andrei Sakharov in 1967, yet despite experimental efforts, all the ways to find evidence on Earth have failed. Therefore, Patrick Stengel from the National Institute of Nuclear Physics in Ferrara, Italy, and his colleagues are proposing digging a 5-kilometer-deep hole into the Moon to search for signs of ancient protons decaying into kaons.
