The discussion centers on the phenomenon of time dilation as it relates to muon decay, specifically addressing the half-life of muons, which is 2.2 microseconds. At light speed, only about 70 out of a billion muons reach Earth due to exponential decay, while time dilation suggests that the entire billion could arrive. Experimental tests conducted at various altitudes challenge the assumption of a 2.2 microsecond half-life in our frame, indicating discrepancies in decay rates. The conversation emphasizes the need for precise predictions and experimental validation regarding muon production rates in the upper atmosphere.
PREREQUISITESPhysicists, students of particle physics, and anyone interested in the practical applications of time dilation and muon decay in experimental settings.
Many thanks. Your reference to test at altitude would be of great interest. I have found predictions based on time dilation but so far have not found actual tests. If you had a more specific reference for me that would be appreciated.Ibix said:You are correct that the simple arrival of muons at the Earth's surface doesn't tell you anything. However, if you assume that their half life is 2.2μs in our frame then you are making predictions about the numbers you would expect to see at different altitudes (and their production rate in the upper atmosphere, which would need a very good explanation), which can be tested. We have done tests at different altitudes (see the experimental basis for SR sticky thread at the top of this forum) and the decay rates don't support a 2.2μs half life when measured in our frame.