Concerning the Muon Experiment: The muon doesn't see time dilation in it's own frame nor does the Earth. So both their clocks are ticking along at the same rate in their respective frames but they see the other's clock tick slower. The muon is explained by saying the Earth sees the muon's clock slower and the muon, with a normal tick rate in it's own frame, sees the Earth move over a smaller distance. This argument seems inadequate to me because isn't the reverse true if neither frame is preffered. That is, the muon sees the Earth's clock slower while the Earth sees the muon move a smaller distance. Can anyone point out where this thinking is flawed? I have not been able to resolve this issue and would like to! Consider time for the muon, in order for no light to reach it beyond the edge of the known universe as defined in the earth frame (156b ly) and the muon frame (9.6b ly), then the time accumulated on the muons clock (if it could exist forever, consider the time accumulated by an observer in the muons frame) would have to be less than that accumulated on the Earth clock. That statement does not agree with the statement that each clock ticks normally in their own frame and each sees the other clock as running slower.