It's to do with the routes they follow through space-time. Don't forget that these effects are all relative to a particular reference frame -- from the muon's perspective, it's the Earth's time which is slowed down, plus the distance it has to travel through the atmosphere is shortened by the length contraction (I think you'll find this is explained on that web page I linked to, with the relevant space-time diagrams - http://en.wikipedia.org/wiki/Time_dilation_of_moving_particles).
So time passes more slowly for the muons *as measured by someone on Earth*, but if the muon could measure time on Earth, it would find that it has also slowed down, from the muon's point of view - the effect is symmetrical. Discrepancies (like the "twin paradox") only show up when one of the reference frames is accelerated to match the velocity of the other one (e.g. when the muon is slowed down by encountering a ground-based detector). (The fact that the effect is relative to a reference frame is, I imagine, why it's called the theory of relativity :-) On 24 May 2014 04:39, John Ross <jr...@trexenterprises.com> wrote: > If time does not pass more slowly when the muons go fast why is their > life span longer? > > > > *From:* everything-list@googlegroups.com [mailto: > everything-list@googlegroups.com] *On Behalf Of *LizR > *Sent:* Thursday, May 22, 2014 5:43 PM > > *To:* everything-list@googlegroups.com > *Subject:* Re: TRONNIES > > > > On 23 May 2014 12:24, John Ross <jr...@trexenterprises.com> wrote: > > Yes, I have thought about the muon experiments. I will have to work on > this issue some more. I just do not believe time passes more slowly when > you go fast. I think there must be another explanation of why so many > muons make it to the earth surface. > > > > There are lots of other examples of time dilation. Any particles in an > accelerator with a half life decay more slowly when moving near c. The GPS > system has to allow for relativistic time dilation due to both the relative > speed of the satellites and their position in the Earth's gravitational > field (i.e. there are corrections for both special and general relativity). > This effect can also be seen in atomic clocks flown around the world, and > in sundry other places. It is very well attested by any number of > experiments. > > (It isn't *quite* correct to say that time passes more slowly when you go > fast, however. But that is a detail at this point in the discussion.) > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com. > To post to this group, send email to everything-list@googlegroups.com. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com. > To post to this group, send email to everything-list@googlegroups.com. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
