The real twin paradox.
in [Relativity]
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From: Bryan Olson on 22 Nov 2007 22:00 colp wrote: > Bryan Olson wrote: >> colp wrote: >>> Why are you unable to explain the paradox? >> The Colp Symmetric Twin Paradox Explained: >> >> SR predicts the twins will be the same age when they return to >> Earth, as does Newtonian mechanics. All experimental evidence >> agrees. > > O.K. > >> 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. Lacking any reference citing the claims to another source, I stand by my description of the error as colp's own theory. >> His theory >> adopted one effect of SR, but omitted others, leading to a >> ludicrous conclusion. > > What effect of SR do you think that I omitted? Several of us have explained and cited what colp is missing. For some reason, he thinks changing frames has no significant effect, contrary to what SR holds. -- --Bryan
From: bz on 22 Nov 2007 21:12 "Sue..." <suzysewnshow(a)yahoo.com.au> wrote in news: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. [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. I think that you must either change your stance or cease to cite this paper as support for your stance. -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+spr(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: bz on 22 Nov 2007 21:41 colp <colp(a)solder.ath.cx> wrote in news:6563b0dc-a429-4788-9be7- 1b7afcdf9533(a)e10g2000prf.googlegroups.com: > On Nov 23, 1:20 pm, Bryan Olson <fakeaddr...(a)nowhere.org> wrote: >> colp wrote: >> > Special relativity says that both >> > clocks are observed to run slower than each other, and this is >> > impossible when the clocks are in the same frame of reference. Thus >> > the only logical conclusion is that special relativity is wrong. >> >> You've gotten several good explanations of where your >> reasoning on what relativity predicts went wrong: it's >> all about the turn-around when the twins are far apart. > > Wrong. The turnaround does not have to occur at relativistic speeds. A turn around NEVER** occurs 'at relativistic speeds' because it involves reducing the 'velocity of separation' to zero before developing a 'closing velocity'. [**it is possible to remain at relativistic speeds by making a large arc, but this would be wasteful of time and fuel] > >> >> More generally, thought experiment alone cannot refute >> relativity. > > Wrong again. A thought experiment which results in a paradox is a form > of a reductio ad absurdum argument. > > http://en.wikipedia.org/wiki/Reductio_ad_absurdum but what is being reduced? The thing that is being reduced in the normal twins paradox is the idea that 'what is seen is important'. Each observer 'sees the other travel away and then return'. So it would seem natural that each would experience the same time effects. But what is unseen [but felt] is important. One accelerates. The other doesn't. One moves differently with respect to the universe than the other. Those differences are important. The 'paradox' you set down is also resolved by studying both travelers from the viewpoint of their younger sister. She stays at home on earth and tracks her brothers as they travel away and return. She sees their clocks running at the same rates but at a different rate from hers. The only thing absurd would be to assume that what each 'sees' happening to the clocks on earth or on the other ship actually has an effect on those clocks. The only thing that changes a clock is the fact that each takes a different path through time-space and ends up together again at a common time and space. Different distances have been traversed in the journey between the starting and ending points. Different distance in 'x,y,z' AND in 't'. So, it should be no surprise that the odometers that each carried with them have changed and the clocks have also changed. Since each traveler went the same distance, their odometers read the same. Their clocks also accumulated the same time. The stay at home sisters odometer has only added a few miles (she went out to dinner occasionally), but her clock has accumulated more time than her brothers. This is because the total distance that each traveled through space-time is equal. It is equal because they started together and ended up back together. It is like we start at 1,1 on the graph paper and both end up at 2,2 You travel directly, in a straight line from 1,1 to 2,2 I go from 1,1 to 2,1 and then from 2,1 to 2,2 I traveled a distance of 2 units, you only traveled the square root of 2 units. We started at the same point and ended at the same point but traveled different distances. Should this surprise anyone? -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+spr(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: bz on 22 Nov 2007 21:50 colp <colp(a)solder.ath.cx> wrote in news:eeaf80ee-faa5-489c-8a82-7f8224e631eb(a)b40g2000prf.googlegroups.com: > On Nov 23, 3:06 pm, Cosmik de Bris > <cosmik.deb...(a)elec.canterbury.ac.nz> wrote: >> colp wrote: >> > On Nov 23, 2:30 pm, Cosmik de Bris >> > <cosmik.deb...(a)elec.canterbury.ac.nz> wrote: >> >> colp wrote: >> >>> On Nov 23, 1:52 pm, Cosmik de Bris >> >>> <cosmik.deb...(a)elec.canterbury.ac.nz> wrote: >> >>>> colp wrote: >> >>>>> On Nov 23, 11:44 am, Cosmik de Bris >> >>>>> <cosmik.deb...(a)elec.canterbury.ac.nz> wrote: >> >>>>>> colp wrote: >> >>>>>>> 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.googlegrou >> >>>>>>>>ps.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. >> >>>>>> Nothing is ever perfectly symmetrical, >> >>>>> A circle is perfectly symmetrical. >> >>>>>> how far out of symmetrical does >> >>>>>> something have to be before it becomes asymmetrical? >> >>>>> A finite distance. >> >>>>>> Nothing magical >> >>>>>> happens when the thought experiment becomes symmetrical, how can >> >>>>>> it? >> >>>>> The paradox of the symmetric twins does not depend on magic. >> >>>>> The paradox depends of the fact that (according to SR) a twin >> >>>>> will observe the other clock slowing down and never observe it >> >>>>> speeding up, and yet it must tell the same time as his own clock >> >>>>> at the end of the experiment. >> >>>> As Dirk has told you, and I have told you in the other newsgroup, >> >>>> you need to learn some basics. >> >>> What you and Dirk think I need is irrelevant. >> >> We, Dirk, Bryan, me, are only trying to help you understand, but you >> >> just don't want to know. Your poor understanding is the problem. >> >> What you think are marvelous arguments are naiive. You think we >> >> can't answer your questions and therefore we don't know anything, >> >> but your questions are bordering on silly. >> >> >>> Why are you unable to explain the paradox? >> >> Because there isn't one. >> >> > By paradox I mean a proposition which contains an internal >> > contradiction. >> >> > The proposition is described in the opening post. The contradiction >> > is that SR says that a twin sees the other clock showing an earlier >> > time than his clock at the end of the experiment, while symmetry says >> > that the twin sees both clocks showing the same time. >> >> For the symmetrical case which you seem to think is miraculous in some >> way, SR says that the clocks will read the same at the end of the >> experiment. > > Like I said, the paradox of the symmetric twins does not depend on > magic (or miracles). > >> You say they won't. > > Wrong. I say that the results are contradictory. > 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. At that point in space-time, SR says that they WILL read the same. You are mistaken in what you think SR says. -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+spr(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: bz on 22 Nov 2007 22:01
colp <colp(a)solder.ath.cx> wrote in news:837a2c0c-8bfc-4aa8-8f45- 1267e6c0a1f6(a)e10g2000prf.googlegroups.com: > On Nov 23, 1:53 pm, "Sue..." <suzysewns...(a)yahoo.com.au> wrote: >> On Nov 22, 7:20 pm, Bryan Olson <fakeaddr...(a)nowhere.org> wrote: > <snip> >> >> > When my own trials of thought experiments yield >> > conflicting outcomes, as they often do, I have to ask >> > myself: Did I just refute the work of all those >> > scientists and mathematicians, or did I think I knew >> > more than I did? Turns out one of those possibilities >> > is quite a bit more likely than the other. >> >> Perhaps you should compare the 1905 paper used >> by proponents of the twins myth with the 1920 >> paper which only couples to inertia by mass >> energy equivalence. > > If there is one thing that science doesn't like, it is having to say > that it can't explain the phenomena. Science does NOT seek to explain phenomena. Science seeks to study phenomena that are observable, verifiable, identifiable and formulate theories that allow the prediction of further phenomena. A theory MUST be falsifiable. In other words, it must be possible to formulate an experiment that MIGHT show the theory to be wrong. A theory that can not be tested is not a scientific theory, it is philosophy. Take 'ghosts', demons, gods; science is perfectly content to say that it can't explain these things. It can't even study them because it cant observe them. It can, of course, study the behavior of people that claim to have seen these things. It can, of course, record what is present when someone claims to be seeing a ghost. Those are the realm of science and can be studied. But non observables can not and are not part of science. Your statement indicates a lack of understanding of how science works. Perhaps your [lack of]understanding of the aim of science is the basis of your confusion about the twins paradox. -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+spr(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap |