The real twin paradox.
in [Relativity]
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From: Sue... on 24 Nov 2007 07:46 On Nov 24, 6:53 am, bz <bz+...(a)ch100-5.chem.lsu.edu> wrote: > "Sue..." <suzysewns...(a)yahoo.com.au> wrote innews:b2e46734-0b8a-4637-99d5-7f3d2b9d822e(a)w28g2000hsf.googlegroups.com: > > > > > > > On Nov 24, 4:59 am, bz <bz+...(a)ch100-5.chem.lsu.edu> wrote: > >> colp <c...(a)solder.ath.cx> wrote > >> innews:2145a8d3-287f-4ac0-a232-46a77fb32680(a)s19g2000prg.googlegroups.com > >> : > > >> > On Nov 24, 5:01 pm, bz <bz+...(a)ch100-5.chem.lsu.edu> wrote: > >> >> colp <c...(a)solder.ath.cx> wrote > >> >> innews:93dca4c9-c5c5-4708-9d0c-258e521aeb9b(a)s36g2000prg.googlegroups. > >> >> com > >> >> : > > >> >> > O.K. I see what you are saying now. But saying that they see a 1 > >> >> > GHz signal for "a while" is a bit misleading because they only see > >> >> > that signal for one instant in the entire journey. They start out > >> >> > seeing a redshifted signal and end up seeing a blue shifted signal > >> >> > so of course they've got to see the signal at it's natural > >> >> > frequency at some point. > > >> >> No! It is much longer than a single instant. > > >> > The reason that it is only an instant is that redshift/blueshift > >> > would be expected to occur for the receiver as well as the sender, > >> > based on symmetry. Typically earth-bound receivers don't have to deal > >> > with this issue, so it's no suprise that it didn't occur to you. > > >> > Your example said that the maximum signal transit time was longer > >> > than the "a while" that it took for turnaround to occur. So by the > >> > time the signal sent during turnaround got to the other twin, that > >> > twin would be accelerating or cruising, so the 1GHz signal would be > >> > blueshifted during observation and thus observed to be more than > >> > 1GHz. > > >> There is NO doppler shift when both ships are moving in the same > >> direction at the same velocity. > > >> Ship A can not know that B has turned around for a period of time. > >> Let us see how long that will take. > > >> At .5 c it will take our ship 1 year to return to earth. > >> By our clock on the ship, that will be 316 days. > >> 365 days if relativity had no effect on our clock. > > >> Signals we transmitted at turn around took 182.5 days to reach earth. > >> That was 158 days by our clock. > > >> We will be receiving signals from ship B at 1 GHz until we 'see' his > >> ship turn around. > > >> During our mutual, 1 year trips away from earth, before turn around at > >> exactly 1 ly from earth, we will both have transmitted 2.731x10^7 one > >> second ticks. > > >> we will both have only received 9.104x10^6 'one second ticks' from the > >> other ship up to the time we turn around. > > >> We assume instant turn around so no ticks at that instant. > > >> We need to pick up 1.821x10^7 more ticks at 1 tick per second before we > >> see B turn around. > > >> That is 210.733 days by our clock. So we will see 1 GHz signals from B > >> for 210.733 days. > > >> But it will take us 316 days to reach earth, so we will be left with > >> 105.366 days during which we will see signals transmitted by B after > >> turn around. > > >> That means we will receive 2.731x10^7 1 second ticks (take the number > >> of seconds in 105.366 days multiplied by 3[remember the doppler shift]) > > >> And guess what? > > >> That turns out to be the exact number of ticks that each of us > >> transmitted during our trip out and that will be the same number of > >> ticks transmitted during our trip back. > >> No ticks are missing at all. > > >> Amazing, isn't it. No paradox. Not even a single doc. > > > Now strap a light clock on the traveler and see if you > > get the same result. > > I used the relativistic formula for my calculations, Einstein et al. > > Everything works just fine. No paradox at all. > > In your terms, I used a light clock. In my terms I used a clock. Not many clocks have hydrogen gas blowing through them so that bit of semantics isn't going to fly. > > > <<We consider the two cases where the clock is > > stationary, Fig 10.1(a), and when it travels at > > velocity v relative to the aether, [dielectric] > > Fig 10.1(b), at right angles to the clock axis. > > Given that light will always travel at speed c > > relative to the aether we have the following > > clock times (1 tick) for stationary > > and moving cases: >> > >http://www.esotericscience.com/Relativity.aspx > > the web site should be called kookscience. [Irrelvant website details snipped] If a monkey with a typewriter writes the equations I trust you can recognise if they are correct. I could be wrong if you are resorting to data from a phone directory to support your arguments. > > You seem to like fringe science sources. Yes. Einstein's 1920 papaer is a bit on the wild side but much tamer than the 1905. Remmainder snipped. Einstein says we need a dielectric and it exist in real space but you refuse to include or acknowlege its effects. http://www.quackwatch.org/01QuackeryRelatedTopics/pseudo.html I am happy to discuss non-dielectric behavior at a subatomic level where the free_space definition may not apply in another thread. But that is not the case for this thread. It is clearly a macroatomic path and you can't replace real atoms with the subatomic particle of your choice just because it completes your fairy tale. Sue... > -- > bz > > > - Show quoted text -
From: Daryl McCullough on 24 Nov 2007 09:57 In article <4191946b-0701-4b77-986c-77373f0b4ee3(a)s36g2000prg.googlegroups.com>, colp says... >> >> The contradictory outcome was colp's own theory. >> >> > Wrong. The contradictory outcome is a result of the theory of >> > relativity predicting that an observation will disagree with a >> > logically expected observation. >> >> That's just more of the same wrong theory. > >Yes, the theory of relativity is wrong. If the theory of relativity is wrong, then there are two simple ways to demonstrate that it is wrong: (1) Show that it makes predictions that are contradictory, or (2) Show that it makes predictions that are proved false by experiment. But in both cases, you have to actually use the *actual* theory, and use the *actual* predictions it makes. You can't just make things up and call it relativity, and prove that that's contradictory. What are the *actual* predictions of Einstein's Special Relativity? For most of the thought experiments discussed here, the predictions consist of the following: 1. There is a special collection of coordinate systems, the inertial coordinate systems. If x,y,z,t are coordinates for an inertial coordinate system, then so are x', y', z', and t' obtained from (x,y,z,t) through the following transformations: A. Translations: x' = A + x y' = B + y z' = C + z t' = D + t B. Rotations: x' = x cos(A) + y sin(A) y' = y cos(A) - x sin(A) z' = z t' = t (and similiarly for rotations about yz and xz planes) C. Lorentz transformations: x' = gamma (x - vt), t' = gamma(t - vx/c^2) y' = y, z' = z. (And similarly for boosts in the y and z directions) 2. As measured in any inertial coordinate system, light has speed c in all directions, independant of the motion of the source. 3. If an ideal clock is at rest in an inertial coordinate system, then the time tau shown on the clock will advance at the rate (change in tau)/(change in t) = 1, where t is the time as measured in that coordinate system. 4. If a measuring stick has length L initially in one inertial coordinate system, and then is accelerated until it is at rest in another inertial coordinate system, then after it reaches its equilibrium length, it will have length L as measured in the new inertial coordinate system. Notice that *all* these predictions about relativity are about how things behave as measured in an inertial coordinate system. If a rocket is accelerating, then it doesn't have an inertial coordinate system. So anything you want to derive about an accelerating rocket cannot be simply the application of the Lorentz transformations---they don't apply to accelerated coordinate systems. -- Daryl McCullough Ithaca, NY
From: Dirk Van de moortel on 24 Nov 2007 10:01 "Cosmik de Bris" <cosmik.debris(a)elec.canterbury.ac.nz> wrote in message news:474761e2$0$25982$88260bb3(a)free.teranews.com... > Dirk Van de moortel wrote: >> >> "colp" <colp(a)solder.ath.cx> wrote in message >> news:efba2671-a734-4801-a8ec-64c62f428ff5(a)d4g2000prg.googlegroups.com... >>> On Nov 23, 9:53 am, "Dirk Van de moortel" <dirkvandemoor...(a)ThankS-NO- >>> SperM.hotmail.com> wrote: >> >> [snip] >> >>>> Have you tried drawing that diagram? >>> >>> There's not much point unless we can both see the diagram and talk >>> about what it represents. That would involve getting the diagram onto >>> the internet, which is more work that I am willing to contemplate >>> right now. >> >> Well, it has become clear from this (and from your other responses) >> that, for some unknown reason, you act like a person who is too stupid >> to understand the basics, or to even *try* to understand them, so I will >> stop wasting your time. If - and only if - you are ready to reply directly >> to my explanation with the spacetime diagram, feel free to do so. >> >> Dirk Vdm > > Thanks for trying Dirk, I have been trying to explain it to him in a > different newsgroup but everybody but him is wrong. He just doesn't want > to learn anything. Indeed - the archetype of the -very-very- stupid troll. A nice sort of sparring partner for practicing and honing your formulations to razor sharpness (-thanks JSH!-). But once you find where exactly they have their short-circuit annex intellectual (huh?) limits, it tends to get a bit boring. Also, keep in mind that educating this particular kind of life form is not a good idea. They are much more interesting in their bare, natural state, with a vastly larger entertainment value. The trick is to avoid allowing them to manage *your* time. Don't drop the crystal ball, Dirk Vdm
From: colp on 24 Nov 2007 10:13 On Nov 24, 10:59 pm, bz <bz+...(a)ch100-5.chem.lsu.edu> wrote: > colp <c...(a)solder.ath.cx> wrote innews:2145a8d3-287f-4ac0-a232-46a77fb32680(a)s19g2000prg.googlegroups.com: > > > > > On Nov 24, 5:01 pm, bz <bz+...(a)ch100-5.chem.lsu.edu> wrote: > >> colp <c...(a)solder.ath.cx> wrote > >> innews:93dca4c9-c5c5-4708-9d0c-258e521aeb9b(a)s36g2000prg.googlegroups.com > >> : > > >> > O.K. I see what you are saying now. But saying that they see a 1 GHz > >> > signal for "a while" is a bit misleading because they only see that > >> > signal for one instant in the entire journey. They start out seeing a > >> > redshifted signal and end up seeing a blue shifted signal so of > >> > course they've got to see the signal at it's natural frequency at > >> > some point. > > >> No! It is much longer than a single instant. > > > The reason that it is only an instant is that redshift/blueshift would > > be expected to occur for the receiver as well as the sender, based on > > symmetry. Typically earth-bound receivers don't have to deal with this > > issue, so it's no suprise that it didn't occur to you. > > > Your example said that the maximum signal transit time was longer than > > the "a while" that it took for turnaround to occur. So by the time the > > signal sent during turnaround got to the other twin, that twin would > > be accelerating or cruising, so the 1GHz signal would be blueshifted > > during observation and thus observed to be more than 1GHz. > > There is NO doppler shift when both ships are moving in the same direction > at the same velocity. That condition never occurs in the experiment. The point is that a paradox exists due to the time dilation expected by SR. The length of time that a 1 GHz signal will be observed in your example is incidental.
From: colp on 24 Nov 2007 10:22
On Nov 25, 4:01 am, "Dirk Van de moortel" <dirkvandemoor...(a)ThankS-NO- SperM.hotmail.com> wrote: > "Cosmik de Bris" <cosmik.deb...(a)elec.canterbury.ac.nz> wrote in messagenews:474761e2$0$25982$88260bb3(a)free.teranews.com... > > > > > > > > > Dirk Van de moortel wrote: > > >> "colp" <c...(a)solder.ath.cx> wrote in message > >>news:efba2671-a734-4801-a8ec-64c62f428ff5(a)d4g2000prg.googlegroups.com... > >>> On Nov 23, 9:53 am, "Dirk Van de moortel" <dirkvandemoor...(a)ThankS-NO- > >>> SperM.hotmail.com> wrote: > > >> [snip] > > >>>> Have you tried drawing that diagram? > > >>> There's not much point unless we can both see the diagram and talk > >>> about what it represents. That would involve getting the diagram onto > >>> the internet, which is more work that I am willing to contemplate > >>> right now. > > >> Well, it has become clear from this (and from your other responses) > >> that, for some unknown reason, you act like a person who is too stupid > >> to understand the basics, or to even *try* to understand them, so I will > >> stop wasting your time. If - and only if - you are ready to reply directly > >> to my explanation with the spacetime diagram, feel free to do so. > > >> Dirk Vdm > > > Thanks for trying Dirk, I have been trying to explain it to him in a > > different newsgroup but everybody but him is wrong. He just doesn't want > > to learn anything. > > Indeed - the archetype of the -very-very- stupid troll. Considering that you have not denied that you made an error in the opening post when you implied that observed time compression occurred on the return leg, I will take your comment as a compliment. |