title: A prognosis for the proton.
abstract: Two different hypotheses in modern physics according to which protons might disappear are discussed: Gravitational collapse of matter into black holes, and proton decay according to Unified Gauge Theories. The latter might soon be observed in experiments in which sensitive detectors are placed in a mass of 1000 tons of matter (10(33) protons) in a deep tunnel or mine. One hundred observed decays per year would correspond to an "expected lifetime" of 10(31) years for an individual proton, as predicted by these theories.
mesh_terms: D004601:Elementary Particles; D008433:Mathematics; D011522:Protons; D011789:Quantum Theory
chemical_list: D011522:Protons