Experiments show that cosmic ray muons reach Earth surface in greater numbers than they should, unless relativistic time dilation is taken into consideration. It also(adsbygoogle = window.adsbygoogle || []).push({}); seems to confirm the SR formula mathematically.

However, looking at a lot of different experiment records, I have some doubts about the validity of the experiments. I would like to get an opinion from those in this forum who are knowledgeable in this area.

My questions are:

1) Consensus looks as if the cosmic muons travel at about 98% of the speed of light, and therefore have a γ of about 5, and some experiments confirm this. This seems to confirm the SR time dilation formula with a very high precision.

- Now, there seem to be
some different experiments showing different γ'sranging from about 5 to 189 (based on what I can find on the internet). Why this variation of γ? Is it because different experiments focus on different energy levels of muons?- Which are the reliable/officially accepted experiments?

2) There also seems to be an assumption that the cosmic ray protons produce muons at an altitude ofabout 15 km (~ 9 miles)from the Earth surface.

- Is there any validation of this assumption? Where did this assumption come from?
- Should the protons not be creating muons at various altitudes (perhaps with some sort of Poisson distribution between altitude and muon numbers produced?)
- Is this assumption a necessary one for the purpose of validating the SR formula?

One overall question- how valid are the cosmic muon experiments as a proof of relativity theory (i.e. is it among the top proofs, or low down in the order)? I am not questioning the fact whether muon lifetime does get extended (which I accept), only how valid the "exact mathematical application" of SR formula is given what seems to be somewhat fuzzy assumptions?

Any insights will be greatly helpful.

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# Is cosmic muon lifetime extension a valid test of relativity?

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