Cherenkov light front
PMT hit
PMT (idle)
sampled proton
predicted N/τ × t
observed decays
Decay detected
Grand Unified Theories predict that the proton is not perfectly stable: heavy X/Y gauge bosons let it decay, dominantly into a positron and a neutral pion, with a lifetime that scales as the fourth power of the unification energy scale. This 2D cross-section renders a real water-Cherenkov detector — a circular tank wall lined with photomultiplier tubes around a lattice of sampled protons — and drives it with an actual Poisson decay process computed from your chosen GUT scale and fiducial detector mass, using the same proton-density numbers real experiments like Super-Kamiokande use. Each simulated decay sends two back-to-back particles outward that radiate light at the fixed Cherenkov angle in water, sweeping an expanding front that lights up the PMTs sitting at the correct angle exactly as a real detector would record it, while live readouts and a running chart track the predicted lifetime, decay rate, elapsed simulated time and the observed decay count against the N/τ expectation line.