TIME DILATION: an experiment with mu-mesons
This classic film documents an experiment done in 1963 the results of which can only be explained...
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TIME DILATION: an experiment with mu-mesons
This classic film documents an experiment done in 1963 the results of which can only be explained when one accepts the consequence that moving clocks run slow. This phenomenon is known as time dilation. The timekeeping device is the mu-meson, a subatomic particle with origins away from the Earth moving at relativistic speed. What follows here is an explanation of the experiment described in that film.
Many mu-mesons rain down every hour on the Earth from sources outside of the Earth. The mu-mesons are radioactive and they decay into other particles. The mu-mesons are detected by a scintillation chamber which emits a flash of light whenever a particle enters the chamber or decays in it. Experimenters used photomultiplier tubes to detect light flashes and an oscilloscope measure the time between an entering flash and a decay flash.
Using a 4.5 feet thick pile of iron bars, experimenters are able to stop the mu-mesons in the detection chamber. Mu-mesons travel at .99c which translates to 1000 feet per microsecond. Mt Washington where this experiment takes place, is 6300 feet above sea level. The crux of the experiment is: how many mu-mesons will survive a trip from an altitude of 6300 feet to sea level. Of a sample of 568 mu-mesons arriving at the top of Mt Washington only 27 live longer than 6.3
