The real twin paradox.
in [Relativity]
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From: colp on 23 Nov 2007 02:58 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 but you 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.
From: colp on 23 Nov 2007 03:07 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 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.
From: Sue... on 23 Nov 2007 03:11 On Nov 22, 9:12 pm, bz <bz+...(a)ch100-5.chem.lsu.edu> wrote: > "Sue..." <suzysewns...(a)yahoo.com.au> wrote innews:97365a78-f48d-478b-a7cb-3f409b1ae08f(a)w34g2000hsg.googlegroups.com: > > > C. S. Unnikrishnan > > Gravitation Group, > > Tata Institute of Fundamental Research, > > Homi Bhabha Road, Mumbai 400 005, India > > http://www.iisc.ernet.in/currsci/dec252005/2009.pdf > > [quote] > It is well known from experiments that the rate of a clock, > while being affected by motion, does not change due to > acceleration. In particular, the rate of a clock in uniform > circular motion is the same as the rate of a clock that is in > rectilinear motion at the same speed. This means that the > rate of the clock B does not change in a manner different > from what is expected from the usual Lorentz factor > modification while decelerating from velocity v to zero. > [unquote] > > Notice, he says that the rate of a clock IS affected by motion. The author is not an authority on clocks. > > [quote] > I may also note here that a logically consistent possibility is to > acknowledge that the rate of a clock is modified according > to the standard Lorentz factor with the velocity always > relative to the average rest frame of the universe or > the frame in which the cosmic microwave background radiation > (CMBR) is isotropic, and then there is never a > paradox of the clocks. Indeed, the entire voluminous and > elaborate writings on the twin clock problem can all be > replaced by the single-sentence resolution that the clocks > age with Lorentz factors corresponding to their velocity > relative to the preferred frame of the matter-filled universe. > The answer is always unique, unambiguous and it > matches with all known experimental results. Further, it > does not discriminate between inertial and noninertial motion > and this simplifies and unifies all calculations on clock > comparisons, including those required in sophisticated > GPS timing. The universe as a preferred frame provides > the unambiguous solution to the twin clock problem, and > this point is discussed in detail elsewhere9. > [unquote] > > He does NOT claim that clocks are unaffected by motion. He says that there > is no paradox if you study the motion from a single framework. He picks > one based on the CMBR. It appears to me that the use of ANY single > inertial frame of reference would resolve the problem. The author is not an authority on moving clocks. > > I think that you must either change your stance or cease to cite this > paper as support for your stance. I have no problem using Einstein's 1920 paper and classical electromagnetism to support my position. I offer the C. S. Unnikrishnan paper as a fair response to Mike Weiss's self diminished and Baez discredited page whose logical falicy is summed up on the last page: "Your Honor, I will show first, that my client never borrowed the Ming vase from the plaintiff; second, that he returned the vase in perfect condition; and third, that the crack was already present when he borrowed it." http://math.ucr.edu/home/baez/physics/Relativity/SR/TwinParadox/twin_vase.html Sue... > > -- > bz > > please pardon my infinite ignorance, the set-of-things-I-do-not-know is an > infinite set. > > bz+...(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: harry on 23 Nov 2007 03:11 "colp" <colp(a)solder.ath.cx> wrote in message news: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: [...] I agree with you that the Doppler effect isn't particularly helpful. One can put clocks everywhere along the way so that no signal delay effects need to be accounted for. >> Of course it will NOT be the same as their stay-at-home sisters clock. >> Her >> clock will have accumulated more time than either of theirs. > > The paradox that I am talking about is desribed in the opening post. > It does not have a stay-at-home clock. One more clock was obviously ADDED to your example in order TO HELP YOU to understand that both clocks slow equally. However, it becomes increasingly clear that you are not here to be helped... Harald
From: Dono on 23 Nov 2007 03:12
On Nov 22, 11:48 pm, colp <c...(a)solder.ath.cx> wrote: > On Nov 23, 5:22 pm, Dono <sa...(a)comcast.net> wrote: > > > On Nov 21, 8:37 am, colp <c...(a)solder.ath.cx> wrote: > > > > 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 > > > Bzzzt, wrong. Try reading this: > > >http://en.wikipedia.org/wiki/Twin_paradox#Accelerated_rocket_calculation > > The opening post describes the scenario that I an arguing about. http://eldoradoclub.net/images/wacko-lg_1_.gif |