The real twin paradox.
in [Relativity]
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From: colp on 23 Nov 2007 13:43 On Nov 24, 1:14 am, bz <bz+...(a)ch100-5.chem.lsu.edu> wrote: > colp <c...(a)solder.ath.cx> wrote innews:9558199a-541d-4784-8c9a-5fc442a86509(a)e6g2000prf.googlegroups.com: > > > > > On Nov 23, 6:22 pm, bz <bz+...(a)ch100-5.chem.lsu.edu> wrote: > >> colp <c...(a)solder.ath.cx> wrote > >> innews:f92c81d1-fbb0-47e3-8303-d4ce14366ebe(a)i12g2000prf.googlegroups.com > >> : > > >> > On Nov 23, 3:50 pm, bz <bz+...(a)ch100-5.chem.lsu.edu> wrote: > >> >> colp <c...(a)solder.ath.cx> wrote > >> >> innews:eeaf80ee-faa5-489c-8a82-7f8224e631eb(a)b40g2000prf.googlegroups. > >> >> com > >> >> : > >> > <snip> > >> >> > SR says that they won't read the same from the frame of reference > >> >> > of one of the twins. > > >> >> SR says that they do not read the same until the twins are reunited. > > >> > SR cannot explain the discontinuity between the clocks showing > >> > progressively different times and the clocks showing the same time at > >> > the end of the experiment. > > >> You are making a false assumption. You assume that they see each others > >> clocks as ticking slow, even when they approach each other. > >> In order to do that, they would need some faster than light > >> communications method so they could see what the other clock actually > >> said. > > > That isn't a false assumption. To consider the effect of signal > > propagation times makes the argument more complicated, but it doesn't > > change the element of time dilation which is the essence of the > > paradox. > > >> But they have to depend on signals that travel at the speed of light. > >> Remember the Doppler shift I mentioned earlier? It effects the timing > >> of the time signals also. > > > Yes, but the cumulative effect is nil. > > >> As they head toward each other, they see the other persons clock > >> ticking FASTER than theirs is ticking. > >> As they get closer together, it takes less and less time for the clock > >> signals to travel the distance between ships > > >> If you work through the math, you find that as they come toward each > >> other, they see each others clocks running fast. > >> The clocks 'catch up', converging upon the same 'correct' reading as > >> they land. > > > The apparent clock speedup due to the decreasing relative distance on > > the return leg is equal to the apparent clock slowing due to > > increasing relative distance on the outbound leg. > > You 'see' your twins clock ticking faster than yours. > Once the signals from his ship, after his turn around, reach you, the > doppler shifts are doubled. Wrong. The cumulative effect is nil. f' = f + fv / c v is the velocity of the transmitter relative to the receiver in meters/second: positive when moving towards one another, negative when moving away http://en.wikipedia.org/wiki/Doppler_effect
From: Bryan Olson on 23 Nov 2007 14:08 Sue... wrote: > Relativty of simultaneity is a point particle concept. Have you considered trying to understand the references you cite? http://www.bartleby.com/173/9.html -- --Bryan
From: colp on 23 Nov 2007 15:25 On Nov 23, 10:44 pm, "harry" <harald.vanlintelButNotT...(a)epfl.ch> wrote: > "colp" <c...(a)solder.ath.cx> wrote in message > > news:9e729dd4-6300-40e3-8142-1cc5be37880e(a)e23g2000prf.googlegroups.com... > > > > > On Nov 23, 8:27 pm, "harry" <harald.vanlintelButNotT...(a)epfl.ch> > > wrote: > >> "colp" <c...(a)solder.ath.cx> wrote in message > > >>news:3b9b6646-038c-47ff-94e1-f804966c2e47(a)d4g2000prg.googlegroups.com... > > >> > On Nov 23, 3:18 am, "harry" <harald.vanlintelButNotT...(a)epfl.ch> > >> > wrote: > >> >> "colp" <c...(a)solder.ath.cx> wrote in message > > >> >>news:43e6b051-fef5-444c-a97c-2f5500b8ca1e(a)b40g2000prf.googlegroups.com... > > >> >> > On Nov 22, 5:48 am, "Josef Matz" <josefm...(a)arcor.de> wrote: > >> >> > <snip> > >> >> >> Hello Dirk > > >> >> >> If you could mathematically demonstrate that the time delays of the > >> >> >> symmetric clock A as viewed by B can be > >> >> >> compensated somehow you have solved the paradox ! > > >> >> >> Would you tell us idiots how this runs in SR ? > > >> >> > A solution could include an argument from general relativity as > >> >> > well, > >> >> > since the twins must spend time in non-inertial frames in order to > >> >> > accelearate/decelerate and turn around. I don't think it would solve > >> >> > the paradox though because the dilation effects can be increased > >> >> > arbitrarily by extending the amount of time spent in inertial > >> >> > frames. > > >> >>http://math.ucr.edu/home/baez/physics/Relativity/SR/TwinParadox/twin_... > > >> >>http://en.wikipedia.org/wiki/Twin_paradox > > >> > Those arguments depend on the asymmetry of the original thought > >> > experiment. Since asymmetry is absent in the thought experiment > >> > descriped in the OP, they do not solve the paradox described in this > >> > thread. > > >> The OP is you, right? > > > Dirk quoted me from sci.physics > > >> Anyway, it doesn't matter much: the same calculations > >> apply only in the symmetrical case the result is that both clocks > >> indicate > >> the same (of course). > > > This paradox involves a different argument than the original paradox. > > The symmetry argument demands a different outcome but it involves the same > calculaions. Only the numbers that you plug in differ - and the outcome > differs accordingly. > > > The paradox is that SR says that a twin must observe time dilation of > > the other twin, but logic says he can't because the clocks end up with > > the same time. SR predicts apparent time dilation, but never allows > > apparent time compression. > > When you finally open your mind and look into relativity of simultaneity, > you may finally "get it". Otherwise, you won't. Ever. The relativity of simultaneity is irrelevant at the end of the experiment, and that is where the paradoxical observation occurs.
From: colp on 23 Nov 2007 15:58 On Nov 23, 10:38 pm, "harry" <harald.vanlintelButNotT...(a)epfl.ch> wrote: > "colp" <c...(a)solder.ath.cx> wrote in message > > news:85218094-8bf1-438e-bb30-eba87ab8e226(a)s19g2000prg.googlegroups.com... > > > > > On Nov 23, 8:24 pm, "harry" <harald.vanlintelButNotT...(a)epfl.ch> > > wrote: > >> "colp" <c...(a)solder.ath.cx> wrote in message > > >>news:d44fb984-12e6-4a0d-8af1-3990ae9789e8(a)s8g2000prg.googlegroups.com... > > >> > On Nov 22, 11:16 pm, "harry" <harald.vanlintelButNotT...(a)epfl.ch> > >> > wrote: > >> >> "colp" <c...(a)solder.ath.cx> wrote in message > > >> >>news:45e50819-65f6-46a3-a821-5c3698dd146a(a)p69g2000hsa.googlegroups.com... > > >> >> > On Nov 21, 11:40 pm, "Dirk Van de moortel" > >> >> > <dirkvandemoor...(a)ThankS-NO- > >> >> > SperM.hotmail.com> wrote: > >> >> >> "colp" <c...(a)solder.ath.cx> wrote in > >> >> >> messagenews:06b84031-18aa-4644-bfb7-43f49f46ae6a(a)i37g2000hsd.googlegroups.com... > >> >> >> > This thought experiment is like the classic twin paradox, but in > >> >> >> > this > >> >> >> > expirement both twins leave earth and travel symmetric return > >> >> >> > trips > >> >> >> > in > >> >> >> > opposite directions. > > >> >> >> > Since the paths taken by the twins in this experiment are > >> >> >> > symmetric, > >> >> >> > they must be the same age when they meet on their return to > >> >> >> > earth. > > >> >> >> > In this experiment the twins maintain constant observation of > >> >> >> > each > >> >> >> > other's clocks, from when they depart until they return and find > >> >> >> > that > >> >> >> > their clocks tell the same time. > > >> >> >> > Special relativity says that each twin must observe that the > >> >> >> > other's > >> >> >> > clock is running slow, and at no time does special relativity > >> >> >> > allow > >> >> >> > for an observation which shows that the other clock is running > >> >> >> > fast. > > >> >> >> No, special relativity says much more precise than that > >> >> >> "moving clocks" are running slow. > > >> >> > The Lorentz-Fitzgerald transform is more precise that my > >> >> > description, > >> >> > but that doesn't mean that my description is wrong. > > >> >> >> It says something about intertial observers who measure > >> >> >> times between ticks on remote, moving clocks. > > >> >> >> When your two clocks fly apart, each clock will measure > >> >> >> this time to be longer and conclude that the other clock > >> >> >> is "running slower". > >> >> >> While clock A is coasting, according to clock A, each > >> >> >> tick on clock A is simultaneous with some tick on clock B > >> >> >> with a smaller time value. > >> >> >> While clock B is coasting, according to clock B, each > >> >> >> tick on clock B is simultaneous with some tick on clock A > >> >> >> with a smaller time value. > > >> >> > Yes, that is the standard theory. > > >> >> >> After clock A has made its turnaround, it has shifted to > >> >> >> another inertial frame, in which according to clock A, each > >> >> >> tick on clock A is simultaneous with some tick on clock B > >> >> >> with a larger time value. > >> >> >> After clock B has made its turnaround, it has shifted to > >> >> >> another inertial frame, in which according to clock B, each > >> >> >> tick on clock B is simultaneous with some tick on clock A > >> >> >> with a larger time value. > > >> >> > Wrong. The other clock tick is still observed to have a smaller time > >> >> > value. > >> >> > This is because in the Lorentz-Fitzgerald transform the relative > >> >> > velocity term is squared, making the the issue of the clocks > >> >> > separating vs the clocks approaching irrelevant to the amount of > >> >> > time > >> >> > dilation. > > >> >> >http://en.wikipedia.org/wiki/Time_dilation > > >> >> That is indeed irrelevant butyou are still mistaken because time>> >> dilation > >> >> is ALSO irrelevant at the instant of switching reference frames. > > >> > Straw man. Time dilation requires a finite amount of time to be > >> > observable, so time dilation is not observable at the instant of > >> > switching reference frames. > > >> You SNIPPED the explanation that TIME DILATION IS ALSO IRRELEVANT. > > > What are you talking about? > > > It is relevant because the according to SR it must be observed but > > according to logic it cannot be observed. > > >> Therefore, probably you're too stubborn too listen. Too bad. > > > More likely that you've run out of arguments are are playing gamez. > > Let's see who is playing "gamez": You claimed that I was mistaken based on a straw man: > > - "harry": > "you are still mistaken because time dilation > is ALSO irrelevant at the instant of switching reference frames. Try:http://en.wikipedia.org/wiki/Relativity_of_simultaneity" I then pointed out the straw man and snipped the wiki reference. > > - "colp" replied: > "Straw man. Time dilation requires a finite amount of time to be > observable, so time dilation is not observable at the instant of > switching reference frames." I did not snip your explanation as you claimed, because a wiki reference is not an explanation. > > In a nutshell, I pointed out that for the turnaround you used (unwittingly?) > a straw man - time dilation No you didn't. I was talking about the return leg, not the turnaround. You said that time dilation is irrelevant at the instant of switching reference frames in response to me saying that time dilation is observed (according to SR) on the return leg. > - and redirected your attention to the essential > point that you had overlooked. Your comments seem to be based on your misunderstanding of my criticism of Drik's post. My argument wasn't about the turnaround. > You replied by calling your own straw man a > straw man That is ludicrous. Why would I do that? > but you snipped the relevant point - in order to keep ignoring it? I snipped a wiki reference. You didn't make a point because your argument was based on an apparent mistake on your part.
From: colp on 23 Nov 2007 16:04
On Nov 24, 5:09 am, Dono <sa...(a)comcast.net> wrote: > On Nov 23, 1:03 am, colp <c...(a)solder.ath.cx> wrote: > <....> > > You are stillhttp://eldoradoclub.net/images/wacko-lg_1_.gif You believe a paradoxical theory that is based on an assumption and argue about the wrong experiment? I think that you are projecting. |