colp, why did AE use the word "relativity"?
in [Relativity]
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From: artful on 24 Jun 2010 21:58 On Jun 25, 7:56 am, colp <c...(a)solder.ath.cx> wrote: > On Jun 24, 10:42 pm, stevendaryl3...(a)yahoo.com (Daryl McCullough) > wrote: > > > colp says... > > > >Coordinate systems are arbitrary conventions which are not required by > > >the premises of SR. > > > Right. But simultaneity (deciding when two different events > > take place at the same time) is coordinate-dependent. > > > >The paradox isn't about events that are simultaneous because it > > >occurs when the twins return to the point that they started from. > > > It's *not* a paradox. > > It is a paradox because: > > 1. The SR premise of observed time dilation applies to one twin as > much as to the other. Yes .. both will see and calculate the same things happening to the other .. no paradox there > 2. Each twin observes the time dilation of the other on both the > outgoing and return legs. What they will SEE is the other twin aging more slowly on outward leg, and then aging faster on the return leg. The sum of the slow and faster aging gives you the same age when they reunite What they will CALCULATE is the other twin aging more slowing on the outward leg, then the other twin jumping ahead in time to where it is partway back and aging more slowly there. The total of the slower aging and the jump gives you the same age when they reunite. > 3. In no case does SR predict that a twin will observe the other's > time to be compressed. Wrong What they will SEE is the other twin aging more slowly on outward leg, and then aging faster on the return leg. The sum of the slow and faster aging gives you the same age when they reunite > 4. A twin must observe time compression of the other twin in order > that his observations agree with the fact that the twins are the same > age when they return to the starting point. What they will SEE is the other twin aging more slowly on outward leg, and then aging faster on the return leg. The sum of the slow and faster aging gives you the same age when they reunite >> Every inertial coordinate system predicts >> exactly the same results for the answer to the question: how >> old is each question when they reunite? > > That is true, but observations do not have to be restricted to a > single inertial coordinate system. Doesn't matter .. you still get the same results >> Different coordinate systems only predict different answers to >> questions of the form: Is event E1 simultaneous with event E2. >> >> >> Disagreement between coordinate systems is *not* a paradox. >> >> >In the symmetric twin paradox, SR predicts that each twin will see the >> >other's clock run slow, >> >> No, it does not. > > Yes it does. That is correct .. for the outward let when they are moving away from each other. > <quote> > 2. An ideal clock traveling at speed v for time period t will show an > elapsed time of T = t square-root(1-(v/c)^2). > </quote> > >> It predicts that each twin's clock runs slow >> as measured in the coordinate system in which the other twin >> is at rest. > > Yes, and that applies for both legs of the experiment. What they will SEE is the other twin aging more slowly on outward leg, and then aging faster on the return leg. The sum of the slow and faster aging gives you the same age when they reunite What they will CALCULATE is the other twin aging more slowing on the outward leg, then the other twin jumping ahead in time to where it is partway back and aging more slowly there. The total of the slower aging and the jump gives you the same age when they reunite. >> What it predicts for what each twin sees is the >> pattern of delayed and rushed signals that I've been over. > > That pattern included signal transit times which made it look like a > twin saw time compression on the return leg because of the diminishing > signal path length. Yes it does > It is important to differentiate between observation of non-local time > and patterns of delayed and rushed signals. What they will SEE is the other twin aging more slowly on outward leg, and then aging faster on the return leg. The sum of the slow and faster aging gives you the same age when they reunite What they will CALCULATE is the other twin aging more slowing on the outward leg, then the other twin jumping ahead in time to where it is partway back and aging more slowly there. The total of the slower aging and the jump gives you the same age when they reunite. >> >but it must be seen to run fast in order to that the twin's >> >clocks read the same time at the end of the experiment and >> >avoid the paradox. >> >> I went through that. In the symmetric case, if each twin >> is sending out signals to the other twin at the rate of >> once per second (as measured by the sender's clock), then >> those signals will be received delayed (less than one per >> second) during part of the journey, they will be received >> rushed (more than one per second) during the other part. > > Right. > >> If you add them up in the symmetric case, then the *average* >> rate of pulses received from the other twin is exactly one >> per second. >> >> There is no paradox. > > Repeating a denial adds nothing to your argument. But that's all you are doing .. repeating your denial that SR gives correct results. It DOES give correct results .. you just aren't using SR .. you are using a hacked partial version that only has time dilation. THAT 'theory' has contradictions. SR does not. Please don't attributes the failing of your 'theory' to SR. >> There are two different ways of looking at it: (1) In terms >> of coordinates, and (2) in terms of what is literally seen >> by each twin. Pick one or the other, but there is no contradiction >> in either case. > > By what is literally seen, you mean the received pulse rate, right? > > There is a contradiction between what is _observed_ by each twin, > where the observation can be derived from the received pulse rate by > taking the signal transit time into account. That's right. So there is no paradox. > Signal transit times are an unnecessary complication which obscures > the paradox. There IS no paradox What they will SEE is the other twin aging more slowly on outward leg, and then aging faster on the return leg. The sum of the slow and faster aging gives you the same age when they reunite What they will CALCULATE is the other twin aging more slowing on the outward leg, then the other twin jumping ahead in time to where it is partway back and aging more slowly there. The total of the slower aging and the jump gives you the same age when they reunite. >> But in the case of what each twin literally sees, it is not >> true that each twin sees the other twin's clocks slowed down. > > Ignoring signal transit times, the following points are true: > > 1. A twin sees the other's clock to be slowed on the outgoing leg. > 2. A twin sees the other's clock to be slowed on the return leg. > > Which of these points do you disagree with? The missing point you ignore every time .. that happens at the turnaround What they will CALCULATE is the other twin aging more slowing on the outward leg, then the other twin jumping ahead in time to where it is partway back and aging more slowly there. The total of the slower aging and the jump gives you the same age when they reunite. >> >The premises of SR specify observed time dilation, never time >> >compression, so the paradox cannot be avoided. >> >> The premises talk about time dilation as measured in an *INERTIAL* >> coordinate system. > > Yes. > >> The twins are *NOT* at rest in an inertial >> coordinate system. > > In the inertial coordinate system in which one twin is stationary, the > other is moving, and vice versa. But not throughout the experiment. >> If you stick to any specific inertial coordinate system, >> the time dilation formula correctly predicts the ages of >> the two twins when they get back together. > > Right. > >> The only way >> to get a contradiction out of it is if you erroneously >> pretend that each twin is at rest in an inertial coordinate >> system throughout the journey. > > No, you get the contradiction from an inference which is based on > valid observations which are made in two different inertial coordinate > systems. In these two systems one twin is at rest and one is moving. No .. you don't. >> That is not the case, and >> applying the rules for an inertial coordinate system is >> just making a mathematical mistake. >> >> Blaming that mistake on SR is just wrong. >> >> ><quote> >> >2. An ideal clock traveling at speed v for time period t will show an >> >elapsed time of T = t square-root(1-(v/c)^2). >> ></quote> >> >> You left out the premise: AS MEASURED in any inertial coordinate >> system. This rule is not talking about what a twin sees, it's >> talking about what is computed to be true, as expressed in an >> inertial coordinate system. > > What is the difference between what the twin sees and what is computed > to be true? What they will SEE is the other twin aging more slowly on outward leg, and then aging faster on the return leg. The sum of the slow and faster aging gives you the same age when they reunite What they will CALCULATE is the other twin aging more slowing on the outward leg, then the other twin jumping ahead in time to where it is partway back and aging more slowly there. The total of the slower aging and the jump gives you the same age when they reunite. >> >> >Since paradoxes do not exist in reality the only remaining conclusion >> >> >is that there is a preferred frame reference. >> >> >> Arbitrarily calling one frame the preferred frame makes no difference, >> >> whatsoever, to the issue of whether there is a paradox or not. >> >> >The preferred frame of reference is not determined arbitrarily. >> >> Then how are you proposing to determine it? > > Experimentally, or by logical induction. Experiment shows SR is correct (as much as experiments in science can do so). 'Logical induction' (ie mathematical logic and theory) shows SR is self-consistent and non-contradictory. >> What experiment >> determines which twin is *REALLY* at rest at what times? > > An experiment like the symmetric twin experiment. > In the experiment the older twin is closer to the the preferred frame > of reference than the younger twin. It makes no difference. And there IS no preferred frame >> Because the experimental results are the same for *EVERY* >> coordinate system. > > Actual physical experiments have not been conducted in *EVERY* > coordinate system. Irrelevant >> >> In the twin paradox, you have the paradoxical situation where >> >> (1) In the coordinate system of the stationary twin, the traveling >> >> twin is younger. >> >> (2) In the coordinate system of the traveling twin, the stationary >> >> twin is older. >> >> >> You could introduce a preferred frame, and *arbitrarily* say that >> >> the stationary twin's coordinate system is the preferred one, and >> >> that the traveling twin's coordinate system is bogus. How does >> >> that change anything? You want to call one twin's perspective >> >> correct, and the other twin's perspective deluded? Fine. So >> >> you change the words, to: >> >> >> (1) The traveling twin is *actually* younger than the stationary >> >> twin. >> >> >> (2) The stationary twin *appears* to be younger then the traveling >> >> twin, when viewed from a bogus coordinate system. >> >> >> That change is just words. It has made *no* difference to the >> >> physics. >> >> >The issue can be resolved by eliminating the paradoxical cases >> >> What paradoxical case are you talking about? > > (copied from above) >> >> In the twin paradox, you have the paradoxical situation where >> >> (1) In the coordinate system of the stationary twin, the traveling >> >> twin is younger. >> >> (2) In the coordinate system of the traveling twin, the stationary >> >> twin is older. > >> The paradox is that >> according to two different coordinate systems: each coordinate >> system measures clocks at rest in the other coordinate system >> to be running slow. That's just a fact. Calling one coordinate >> system "preferred" doesn't change that fact. > > Right. > >> >> >and deducing that the preferred frame of reference in the case of the >> >symmetric twins is the frame of reference in which the twins journey's >> >are symmetric. >> >> You can choose *ANY* frame whatsoever, and run a symmetric >> twin paradox for that frame. > > No, you don't get a paradox from the frame in which the twin's paths > are symmetric. You don't get a paradox in ANY frame of reference. >> So your notion of "preferred" >> frame would lead to the conclusion that *every* frame is a >> preferred frame. > > non sequitur No .. if you claim that the preferred frame is the one without paradox, then every frame is preferred.
From: artful on 24 Jun 2010 22:08 On Jun 25, 11:55 am, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > colp says... [snip] > >If I haven't proved that SR is wrong by showing that it can produce > >paradoxes, > > You *HAVEN'T*. You haven't produced a SINGLE derivation that > uses actual numbers. You haven't produced a single argument > that anything predicted by SR leads to a contradiction. > > This is not a matter of opinion. You have not performed > a SINGLE calculation. You KNOW that. You have not derived > anything at all. So you certainly haven't derived a contradiction > from the rules of SR. In fairness he has shown SOME calculations .. for the dilated time measurement for a clock in motion an inertial frame of reference compared to that of one at rest in that frame. But, as you point out, there is more to SR than just that. There's effectively (and informally) three main aspects to SR's treatment of time and space measurements. 1) length contraction, 2) time dilation, 3) relativity of simultaneity. If you look at any one or two of those in isolation (as many do) without considering the third, then you're not doing SR. Just like if you take away one side of a triangle, its not a triangle any more. Colp has actually taken away two sides of the triangle and still pretending that he is talking about the whole triangle. Its as though he is saying that if you look at just one side of a triangle, that side has no area, so the whole triangle has no area. If you look at only time dilation and ignore the rest of SR, the there are contradictions, so if you look at SR as a whole there must be contradictions. [snip]
From: Daryl McCullough on 24 Jun 2010 22:27 artful says... >There's effectively (and informally) three main aspects to SR's >treatment of time and space measurements. 1) length contraction, 2) >time dilation, 3) relativity of simultaneity. If you look at any one >or two of those in isolation (as many do) without considering the >third, then you're not doing SR. Just like if you take away one side >of a triangle, its not a triangle any more. Except that those are not three *independent* aspects. If you accept the first two, but deny the third, then you really will have a contradiction. >Colp has actually taken away two sides of the triangle and still >pretending that he is talking about the whole triangle. Its as though >he is saying that if you look at just one side of a triangle, that >side has no area, so the whole triangle has no area. If you look at >only time dilation and ignore the rest of SR, the there are >contradictions, so if you look at SR as a whole there must be >contradictions. Right. Relativity of simultaneity is a logically *necessary* component of SR. It's inconsistent without it. -- Daryl McCullough Ithaca, NY
From: spudnik on 2 Jul 2010 15:34
why is relativity, since the galilean form, such a big deal to comprehend?... all three of these relativisms are plainly equivalent, as stated, if one considers that the internal (angular) momenta of atoms are also limited to the speed of the transmission of energy, elctromagnetically (or, however that is suppposed to go with the four forces of QM, plus or minus gravity .-) nationalize BP's USA operations in Alaska, the Gulf, and at busy intersections! > Right. Relativity of simultaneity is a logically *necessary* component > of SR. It's inconsistent without it. thus&so: so, acid rain is the germain topic, since it was the First Cap and Trade (Waxman's '91 bill). so, what I haven't seen dyscussed in the WSUrinal e.g., is just how wonderfully this'd worked -- who made the money in the God-am "free market?" [NB, Waxman's cmte. also ran the healthcare bill.] thus quoth: Miskolczi saith in <http://www.met.hu/doc/idojaras/vol111001_01.pdf> > You are so full of it. thus&so: what if the same guy who was the source d'Eaugate for Bernward at the Post [*], was also the Vice President, who purposely set his mattress on fire in the first tower (second was hit by a 757 filled with fuel for most of a transcontinental flight, minus the steering loop); and, so, how many mattresses'd he have'd to set, to make for a controlled demolition? well, some of us believe that he was not just the acting president -- especially since the impeachment of Bill C.. also, what in Heck is a one-ball centrifuge -- doesn't one need two, at the least, for balance? * in the famed parlance of editor Bradley, or ms. Graham, Woodstein ne'er followed the Penzoil money to <a-hem>; see http://tarpley.net/online-books/george-bush-the-unauthorized-biography/ --BP's cap&trade plus free beer/miles on your CO2 creds at ARCO! http://wlym. |