Einsteinians test time dilation, the glorious consequence of Einstein's 1905 false constant-speed-of-light postulate:
http://web.mit.edu/8.13/www/JLExperiments/JLExp14.pdf "The idea of this experiment is, in effect, to compare the mean time from the creation event to the decay event (i.e. the mean life) of muons at rest with the mean time for muons in motion. Suppose that a given muon at rest lasts for a time tb. Equation 5 predicts that its life in a reference frame with respect to which it is moving with velocity v, is (gamma)tb, i.e. greater than its rest life by the Lorentz factor gamma. This is the effect called relativistic time dilation. (...) In this experiment you will observe the radioactive decay of muons and measure their decay curve (distribution in lifetime) after they have come to rest in a large block of plastic scintillator, and determine their mean life. From your previous measurement of the mean velocity of cosmic-ray muons at sea level and the known variation with altitude of their flux, you can infer a lower limit on the mean life of the muons in motion. A comparison of the inferred lower limit with the measured mean life at rest provides a vivid demonstration of relativistic time dilation."
Note that when Einsteinians refer to muons "at rest", they mean that those muons "come to rest in a large block of plastic scintillator". That is, any time a muon bumps into an obstacle so that its speed instantly changes from about 300000km/s to zero, the forced and quick disintegration of the muon makes Einsteinians sing "Divine Einstein" and go into convulsions. Why? Simply because rationality in today's science is so devastated that, as the muon undergoes such a terrible crash, Einsteinians can safely say 'Lo, a muon at rest' (nobody cares to contradict them) and infer that non-crashing (moving) muons undergo time dilation, as predicted by Divine Albert's Divine Theory, and so live longer than crashing ("at rest") muons. Sane scientists (if there are any) would compare the short lifetime of muons "at rest" with the short lifetime of a driver whose car has come to a sudden stop into a wall:
http://cosmic.lbl.gov/more/SeanFottrell.pdf Experiment 1: The lifetime of muons at rest (...) Some of these muons are stopped within the plastic of the detector and the electronics are designed to measure the time between their arrival and their subsequent decay."