The real twin paradox.
in [Relativity]
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From: Sue... on 20 Dec 2007 03:27 On Dec 20, 1:04 am, Bryan Olson <fakeaddr...(a)nowhere.org> wrote: > Sue... wrote: > > <<From the scientific point of view, the important > > thing is to understand the clearly defined meaning > > of "proper time", based on the concept of an > > "ideal clock" corrected for all local sensible > > conditions, justified by the empirical fact that > > all physical phenomena are affected identically - > > including their rates of temporal progression - > > by their state of inertial motion (which is not a > > locally sensible condition). >> > >http://www.mathpages.com/rr/s4-07/4-07.htm > > I believe that by "not a locally sensible condition" > he means it is not what we would expect. I do not think > he is saying the theory is logically inconsistent, or > even absurd. I'm not clear on what Sue was trying to > show with this quote. That is your *belief*. If you read the whole webpage, you *belief* may change. > > > What is the factual material you were introduced to > > where two experiments did not have identical results > > (temporal aspects as well) and the difference could be > > traced to inertial motion between the experiments? > > The same theory that implies the twins paradox rules > out two experiments differing in the way you ask. Sue, > by now you should have noticed that I am on side of > Einstein's theory of relativity, which I would not be > had I such "factual material" as you request. If you > want to ask a relativity denier, you are a distance of > zero from one, regardless of the frame from which we > measure it. I have never heard of those experiments. You did not answer my question. You are not taking Einstein's position if you have to slice and dice the clear meaning of PoR. Inertial means no external force applied. Inertia is the force what slams a crash test dummy into a steering wheel > > Or maybe I misunderstood the question. Certainly two > observations may differ on how Jupiter's moons move, > due to being observed from different states of > inertial motion. The catch is that Jupiter's moons > are part of the two experiments, so the two differed > in thiere motion relative to their subject, and not > merely in "inertial motion between the experiments". > Sue has messed up on that distinction many times. That again is parsing for a semaantic loophole. It is not science. The purpose is to give both experiments a common process as a crosscheck to see if causality is violated. PoR is about inertia, not time. Einstein never advanced a theory of inertia but GR shows what is wrong with Newton's theory. Here is a theory of inertia consistant with GR when you tire of parlor tricks with the flaws in SR that Einsten himself pointed out. http://arxiv.org/abs/physics/0107015 ....and a recent comparison of a few relevant experiments. http://arxiv.org/abs/0707.3806 Sue... > > -- > --Bryan
From: Daryl McCullough on 20 Dec 2007 09:04 Bryan Olson says... >Sue... wrote: >> <<From the scientific point of view, the important >> thing is to understand the clearly defined meaning >> of "proper time", based on the concept of an >> "ideal clock" corrected for all local sensible >> conditions, justified by the empirical fact that >> all physical phenomena are affected identically - >> including their rates of temporal progression - >> by their state of inertial motion (which is not a >> locally sensible condition). >> >> http://www.mathpages.com/rr/s4-07/4-07.htm > >I believe that by "not a locally sensible condition" >he means it is not what we would expect. I think it is an awkward translation. What I believe he means is that it is not locally *observable*. The word "sensible" is being used in the following sense: (from http://dictionary.reference.com/browse/sensible) 4. capable of being perceived by the senses; material: the sensible universe. >I do not think >he is saying the theory is logically inconsistent, or >even absurd. I'm not clear on what Sue was trying to >show with this quote. It's never clear. Sue uses references not to clarify things, but to muddy them. -- Daryl McCullough Ithaca, NY
From: Sue... on 20 Dec 2007 09:16 On Dec 20, 9:04 am, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: [...] > > It's never clear. Sue uses references not to clarify > things, but to muddy them. Try Sue's thought experiment. GPS and PR demonstrates that clocks slow near a mass. Einstein and Mach say gravity there causes inertia here. http://nobelprize.org/nobel_prizes/physics/laureates/1921/einstein-lecture.html If you are traveling far from any mass, half the masses that could slow your clock are moving toward you; half the masses that could slow your clock are moving away from you; Net change in the inertial field is 0. << As Einstein said: The weakness of the principle of inertia lies in this, that it involves an argument in a circle: a mass moves without acceleration if it is sufficiently far from other bodies; we know that it is sufficiently far from other bodies only by t he fact that it moves without acceleration. >> http://www.mathpages.com/rr/s4-07/4-07.htm Sue... > > -- > Daryl McCullough > Ithaca, NY
From: Daryl McCullough on 20 Dec 2007 11:32 Sue... says... > >On Dec 20, 9:04 am, stevendaryl3...(a)yahoo.com (Daryl McCullough) >wrote: >[...] >> >> It's never clear. Sue uses references not to clarify >> things, but to muddy them. > >Try Sue's thought experiment. > >GPS and PR demonstrates that clocks slow near a mass. Technically, that's not correct. The more precise statement is that if R1 < R2 near a large mass, for a clock at constant r, dTau/dt at R1 < dTau/dt at R2 where Tau is the time shown on a clock, and t and r are measured using Schwarzschild coordinates. >Einstein and Mach say gravity there causes inertia here. Actually, although General Relativity was *inspired* by Mach's principle, it doesn't actually satisfy Mach's principle, in general. Mach's principle says that inertia is caused by distant matter. In General Relativity, the spacetime metric is an independent field; it is affected by the distribution of matter, but it isn't uniquely determined by it. -- Daryl McCullough Ithaca, NY
From: Sue... on 20 Dec 2007 12:16
On Dec 20, 11:32 am, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > Sue... says... > > > > >On Dec 20, 9:04 am, stevendaryl3...(a)yahoo.com (Daryl McCullough) > >wrote: > >[...] > > >> It's never clear. Sue uses references not to clarify > >> things, but to muddy them. > > >Try Sue's thought experiment. > > >GPS and PR demonstrates that clocks slow near a mass. > > Technically, that's not correct. I have seen no evidence that they speed up or stay the same. Are you claiming that they do? > The more precise statement > is that if R1 < R2 near a large mass, for a clock at constant > r, > > dTau/dt at R1 < dTau/dt at R2 > > where Tau is the time shown on a clock, and t and r are > measured using Schwarzschild coordinates. > > >Einstein and Mach say gravity there causes inertia here. > > Actually, although General Relativity was *inspired* by > Mach's principle, it doesn't actually satisfy Mach's > principle, in general. Mach's principle says that inertia > is caused by distant matter. In General Relativity, the > spacetime metric is an independent field; That is consistant with induction couplings. > it is affected > by the distribution of matter, but it isn't uniquely > determined by it. *Affected* and *Completely determined by* don't hold the same meaning for me. << I shall turn to those problems which are related to the development which I have traced. Already Newton recognized that the law of inertia is unsatisfactory in a context so far unmentioned in this exposition, namely that it gives no real cause for the special physical position of the states of motion of the inertial frames relative to all other states of motion. It makes the observable material bodies responsible for the gravitational behaviour of a material point, yet indicates no material cause for the inertial behaviour of the material point but devises the cause for it (absolute space or inertial ether). This is not logically inadmissible although it is unsatisfactory. For this reason E. Mach demanded a modification of the law of inertia in the sense that the inertia should be interpreted as an acceleration resistance of the bodies against one another and not against "space". This interpretation governs the expectation that accelerated bodies have concordant accelerating action in the same sense on other bodies (acceleration induction). This interpretation is even more plausible according to general relativity which eliminates the distinction between inertial and gravitational effects. It amounts to stipulating that, apart from the arbitrariness governed by the free choice of coordinates, the gm v -field shall be completely determined by the matter. Mach's stipulation is favoured in general relativity by the circumstance that acceleration induction in accordance with the gravitational field equations really exists, although of such slight intensity that direct detection by mechanical experiments is out of the question. >> http://nobelprize.org/nobel_prizes/physics/laureates/1921/einstein-lecture.html You are presenting one after another argument on behalf of Newton's ether and his corpuscular light bullets. If you and Jeckyl are persistant enough, you may actually convince me that Einstein was wrong. Sue... > > -- > Daryl McCullough > Ithaca, NY |