The Symmetric Twin Paradox
in [Relativity]
|
Prev: Black Hole is Black Day for Earth
Next: n-stars.
From: colp on 18 Jun 2010 17:11 On Jun 19, 12:56 am, "papar...(a)gmail.com" <papar...(a)gmail.com> wrote: > On 17 jun, 22:33, colp <c...(a)solder.ath.cx> wrote: > > > > > On Jun 18, 2:13 pm, "Inertial" <relativ...(a)rest.com> wrote: > > > > Please reproduce your working, and I'll point out the errors. I don't have > > > access to the article, only your comments on it. > > > Here's the relevant text from the article. The previous version being > > discussed was the classic twin paradox (Taurai and Tauwi are the names > > of the twins). > > > B. Twin Paradox (Symmetric) > > We shall set forth a new version of the twin paradox which is > > truly symmetric and this will introduce a true paradox and we > > shall provide a solution. Suppose Taurai unlike in the previous > > version, decided to be adventurous too. He decides to rocket > > into space and travels not with his twin brother but all by himself > > and instead of Alpha-Centauri he travels at the same constant > > relativistic speed as Taurwi [this speed is measured by > > the Earth bound observers] to an imaginary constellation (call > > it Constellation Alpha-Christina) which is equidistant and directly > > opposite to Alpha Centauri along the line of sight joining > > the Earth and Alpha Centauri. > > > On their day of departure, their family and friends bid them > > farewell and wish thema safe travel. Withoutmuch say, on the > > day of reunion, the family and friends [who all have studied > > physics at university and understand very well the STR] have > > no doubt that they [the Twins] will all have aged the same. > > The big question is, will the twins agree with their family and > > friends that they have aged the same? The truth is that, each > > of the twins will see the other as having aged less than they so > > they would not agree with their family and friends that they > > must be the same age. Herein we have a paradox! Who is > > older than who here? > > First typical mistake of students. .... is believing that they have been told without proving it for themselves. > What is relevant is that each twin > has a clock which, according to his own readings and knowledge, is > ticking exactly like it was before the travel. No, what is relevant is the prediction that SR makes about each twin's observation of the other's clock.
From: colp on 18 Jun 2010 17:26 On Jun 18, 6:13 pm, "Inertial" <relativ...(a)rest.com> wrote: > "colp" <c...(a)solder.ath.cx> wrote in message > > news:e9264a25-c903-41a1-9995-2ab4a781a956(a)k17g2000pro.googlegroups.com... > > > > > On Jun 18, 11:24 am, "Inertial" <relativ...(a)rest.com> wrote: > >> "colp" <c...(a)solder.ath.cx> wrote in message > > >>news:bd7d4a85-d7b3-40e3-884c-720b9255f608(a)11g2000prv.googlegroups.com.... > > >> > On Jun 18, 8:14 am, PD <thedraperfam...(a)gmail.com> wrote: > >> >> On Jun 16, 1:25 am, colp <c...(a)solder.ath.cx> wrote: > > >> >> > The classic twin paradox is asymmetric in that one twin remains on > >> >> > Earth while the other leaves (i.e. only one of them accelerates and > >> >> > deaccelerates). In the symmetric twin paradox both twins leave > >> >> > Earth, > >> >> > setting out in opposite directions and returning to Earth at the > >> >> > same > >> >> > time. The conventional explanation for the classic twin paradox is > >> >> > since only one twin accelerates, the ages of the twins will be > >> >> > different. In the symmetric case this argument cannot be applied. > > >> >> > The paradox of the symmetric twins is that according to special > >> >> > relativity (SR) each twin observes the other twin to age more slowly > >> >> > both on the outgoing leg > >> >> > and the return leg, so SR paradoxically predicts that each twin will > >> >> > be younger than > >> >> > the other when they return to Earth. > > >> >> No. This is a basic misunderstanding due to oversimplification, and it > >> >> is exactly the kind of thing that the original puzzle was intended to > >> >> highlight for learners of relativity. > > >> > It is true that I haven't discussed what happens at turnaround, but > >> > only for the reason that turnaround cannot possibly compensate for the > >> > SR time dilation. > > >> So you just don't bother doing the math and just ASSUME that it isn't > >> important and then wonder why you get stupid results > > > Maths is consistent with logic. > > You have used neither Here are the relevant logical elements that I have used in this thread: truth: SR predicts that each twin observes the other twin to age more slowly both on the outgoing leg and the return leg. truth: In no case does SR predict that a twin observes the other to age more quickly. inference: SR predicts that each twin will younger than the other at the end of the experiment.
From: colp on 18 Jun 2010 17:37 On Jun 18, 4:18 pm, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > colp says... > > > > >B. Twin Paradox (Symmetric) > >We shall set forth a new version of the twin paradox which is > >truly symmetric and this will introduce a true paradox and we > >shall provide a solution. Suppose Taurai unlike in the previous > >version, decided to be adventurous too. He decides to rocket > >into space and travels not with his twin brother but all by himself > >and instead of Alpha-Centauri he travels at the same constant > >relativistic speed as Taurwi [this speed is measured by > >the Earth bound observers] to an imaginary constellation (call > >it Constellation Alpha-Christina) which is equidistant and directly > >opposite to Alpha Centauri along the line of sight joining > >the Earth and Alpha Centauri. > > >On their day of departure, their family and friends bid them > >farewell and wish thema safe travel. Withoutmuch say, on the > >day of reunion, the family and friends [who all have studied > >physics at university and understand very well the STR] have > >no doubt that they [the Twins] will all have aged the same. > >The big question is, will the twins agree with their family and > >friends that they have aged the same? The truth is that, each > >of the twins will see the other as having aged less than they so > >they would not agree with their family and friends that they > >must be the same age. Herein we have a paradox! Who is > >older than who here? > > There is no paradox here! The paradox is that SR predicts that each twin will be younger than the other at the completion of the experiment. > To say that SR leads to a paradox, > you need to show that there is some experiment that can be > performed such that SR gives two different ways to calculate > the results, which gives two different answers. Yes. > That's not > the case here. It is the case because the two different ways to calculate the age of the other twin are apparent from the experiment. One way is to determine if Taurai will be older than Taurwi by evaluating the predictions of SR from Taurai's frame of reference, and the other way is to determine if Taurai will be older than Taurwi by evaluating the predictions of SR from Taurwi's frame of reference.
From: colp on 18 Jun 2010 17:46 On Jun 18, 3:20 pm, rotchm <rot...(a)gmail.com> wrote: > > > Dont change the subject of *our* discussion. > > > All I am discussing is the paradox. See my OP if you are confused by > > this. > > Liar. I'm not lying. > Google kept a record. So show the record in context instead of snipping the context. > *YOU* asked about the errors in the > article. I asked the question In the context of the paradox. I'm not interested in irrelevant errors. The fact that you have got to take my question out of context in order to find a point of contention only goes to show weak your position is.
From: Androcles on 18 Jun 2010 17:54
"colp" <colp(a)solder.ath.cx> wrote in message news:5a49e5b9-8da2-4dea-9dc1-ac4211b1eeb6(a)v29g2000prb.googlegroups.com... On Jun 18, 3:20 pm, rotchm <rot...(a)gmail.com> wrote: > > > Dont change the subject of *our* discussion. > > > All I am discussing is the paradox. See my OP if you are confused by > > this. > > Liar. I'm not lying. > Google kept a record. So show the record in context instead of snipping the context. > *YOU* asked about the errors in the > article. I asked the question In the context of the paradox. I'm not interested in irrelevant errors. The fact that you have got to take my question out of context in order to find a point of contention only goes to show weak your position is. ============================================= WTG! Slap the stupid prat, colp. |