⚛️ Cosmic-Ray Muon Survival Lab: Time Dilation in the Earth Frame, Length Contraction in the Muon Frame

Watch cosmic-ray muons fall through the atmosphere in two synchronised views: in the Earth frame their clocks run slow, in the muon frame the atmosphere is squashed. Both views give the same survival fraction, which a Monte Carlo of decay times confirms against the exact exponential law and the no-relativity prediction.