Path: csiph.com!aioe.org!.POSTED!not-for-mail From: The Starmaker Newsgroups: sci.physics.relativity Subject: Re: Why is there more than one explanation for the Twin Paradox Date: Thu, 24 Aug 2017 10:12:53 -0700 Organization: Aioe.org NNTP Server Lines: 74 Message-ID: <599F0915.4871@ix.netcom.com> References: <1cb6775d-d2c1-498b-9576-088e3e7ed2be@googlegroups.com> <4790542.Sb9uPGUboI@PointedEars.de> <587d73ca-c675-4557-99a1-0d85d758a1ff@googlegroups.com> <0a540f5f-3cbc-4851-b3e6-f5e0554d4466@googlegroups.com> <8cbdd349-4c74-43cf-ab92-22834a42e8fb@googlegroups.com> <692ef002-ca41-4360-a474-a8f9834050e6@googlegroups.com> Reply-To: starmaker@ix.netcom.com NNTP-Posting-Host: X9ItFNC7Zcz4l6MobL/YRA.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org X-Antivirus: Avast (VPS 170824-0, 08/24/2017), Outbound message X-Antivirus-Status: Clean X-Mailer: Mozilla 3.04Gold (WinNT; U) X-Notice: Filtered by postfilter v. 0.8.2 Xref: csiph.com sci.physics.relativity:429920 Prokaryotic Caspase Homolog wrote: > > On Thursday, August 24, 2017 at 10:14:04 AM UTC-5, tjrob137 wrote: > > On 8/19/17 5:30 AM, Prokaryotic Caspase Homolog wrote: > > > On Friday, August 18, 2017 at 5:08:29 PM UTC-5, tjrob137 wrote: > > >> Note that muons experiencing 10^18 g as they go around a ring have the > > >> same lifetime measured in the lab as muons that travel at the same speed along a > > >> straight line with essentially no acceleration. So acceleration does not affect > > >> the timekeeping mechanism of muon decay. > > > > > > Acceleration should not have _no_effect_at_all_ on muon decay, merely > > > _unmeasurable_ effects. > > > > Hmmmm. From the structure of the standard model, specifically its Lorentz > > invariance, then insofar as the SM is valid, acceleration itself can have no > > effect on muon decay. > > > > There certainly are interactions with the vacuum that affect muon decay. But the > > vacuum is itself Lorentz invariant, so they are already included when comparing > > muon decay at rest to muon decay in flight, or muon decay over different paths > > (e.g. ring or straight). > > > > > Are there any sorts of heuristic arguments that one > > > might apply to estimate what level of acceleration might significantly affect > > > muon decay? > > > > Yes. More solid than merely "heuristic", see above. The result is zero, insofar > > as the SM is valid. > > > > > By analogy, I was considering singly-ionized helium traveling around a ring. > > > Given Coulomb's law and the dimensions of the helium ion, I imagine that the > > > second electron should be stripped from the helium ion, leaving an alpha > > > particle, at accelerations above, say, 5e21 g or so. > > > > Hmmm. Certainly magnets can strip electrons from atoms and ions [#]. But we > > model this as due to the magnet, not the acceleration. I don't know what it > > would take to strip He+ to alpha. > > > > [#] Large, high-energy accelerators at Fermilab, CERN, KEK, > > etc. all start by accelerating H- ions, because stripping > > H- to H+ (proton) is the best way to inject the beam into > > a ring; this means that before the injection one must design > > the beam transport with magnets weak enough to not strip the > > H- beam prematurely. BTW injection stripping is done with a > > foil, not a magnet (to preserve the beam emittance). > > > > > Looking at a table of muon properties, I see nothing obvious that would allow > > > me to perform any sort of "Fermi-estimate" on what accelerations might begin to > > > have a significant effect on muon lifespan. > > > > In the standard model there is no such effect. > > > > One can speculate on how "physics beyond the standard model" might affect muon > > decay, but that is a wide-open speculation, and there are more fruitful avenues > > to explore (i.e. reactions that are more amenable to experimental tests). Some > > searches that are actively being pursued: > > mu- A => e- A (neutrinoless) > > mu+ -> e+ gamma (neutrinoless) > > neutrinoless double beta decay (numerous nuclei) > > endpoint of tritium beta decay > > neutrino oscillations > > > > This last is so solidly established experimentally that many physicists consider > > the SM to be enhanced with nonzero neutrino masses and flavor mixing. But there > > are several different ways to do that.... > > Thanks! Lots of interesting detail in your response! another Tom Roberts responding to himself with a different handle of Prokaryotic Caspase Homolog??? wats that all about? it's lonely at the top, isn't it...