Jesse, To address your points in order:
1. Yes, you said that proper ages are invariant. But note the important point that the proper age of A to himself is a direct observation (he looks at his age clock), but to anyone else is a computation and NOT an observation. In fact from their native comoving frames they will observe A at some other age than their calculation. So the calculations trump the views. Thus it is valid in relativity to CALCULATE things we CANNOT OBSERVE from our frame. That's what I do to establish 1:1 correlations of actual ages. I use calculations that trump Views, that trump observations. We don't always have to use frame views to establish relativistic truth. Do you agree with that? You must if you accept proper age invariance. Also note that the ticks of the symmetric twins' own comoving clocks serve as event markers. So if the proper ages of the twins are invariant to all observers, then all observers can simply observe their clock tick markers reading exactly the same for the same proper ages of both twins. That PROVES the 1:1 correlation that the real actual ages of the symmetric twins always occur at the same clock tick markers and thus they are the same proper ages at the same times. Thus all observers agree that the proper ages of both twins occur at the same clock tick marker readings of the twins own proper clocks. This is one more proof the actual ages of the symmetric twins are equal during the trip, and EVERY OBSERVER AGREES ON THIS. Thus it is a real physical fact. 2. What all these quotes mean in saying that all frames are equally valid is that all observer VIEWS are real actual VIEWS of reality. That they are what the observer actually observes. I certainly agree with that. However as I've pointed out they don't all preserve the actual physical reality of SPECIFIC facts. I just pointed out how they don't with respect to the invariance of proper times which are not observable views but calculations. Proper age invariance is a physical fact at odds with the notion that all frames are equally valid as anything else than VIEWS. 3. No. By "the different ages of twins in relative motion are not agreed and thus are views rather than actual physical facts" I mean just that, and just what I've always said. The 1:1 correlation is NOT the VIEW of one twin of the other's clock. It is a logical calculation and not a view that establishes that 1:1. 4. ******You now say you "DON'T CLAIM YOU PROVE P-TIME SIMULTANEITY IS NOT TRANSITIVE!". OK, great. Wonderful! That's progress, and a complete change from what you said previously. You then are apparently trying to prove something else. But please, respectfully, you are trying to disprove MY theory, so please let ME state MY theory and then try to disprove that rather than trying to disprove something that isn't my actual theory. I just gave a concise statement of my theory earlier today. Can you disprove it or can't you? Edgar On Saturday, March 1, 2014 11:42:18 AM UTC-5, jessem wrote: > > > > On Sat, Mar 1, 2014 at 9:55 AM, Edgar L. Owen <edga...@att.net<javascript:> > > wrote: > > Jesse, > > Of course there is a rational justification for selecting one frame over > another in many cases. All frames are NOT equal when it comes to > representing ACTUAL physical facts. > > E.g. we can choose various frames to make someone's age pretty much any > number we like but nevertheless they are still actually the age they think > they are. If Alice is really 30 we can choose a frame in which she is all > sorts of different ages > > > I've already told you that proper time at an event on Alice's worldline is > frame-independent, did you forget already? If one frame says Alice is 30 at > a particular event in her worldline, like the event of her passing a > particular object or observer (or her age when she reunites with her twin), > then ALL frames say this, there is no need to use her comoving frame to get > the correct answer. Different frames may disagree about simultaneity--what > Alice's age is at the "same moment" that Bob turns 40, at a distant spatial > location--but this is precisely why physicists don't believe there is any > "actual physical fact" about simultaneity in relativity (this doesn't rule > out presentism since there could still be a "metaphysical fact" about > simultaneity, but no physical experiment would be able to determine it if > there was, unless relativity turns out to be incorrect in its physical > predictions). > > > > > but she is still actually 30. Different VIEWS of her age don't change her > actual age. Isn't that obvious, and don't you agree with this? > > > "Don't change her actual age" WHEN? Doesn't change her age at some > specific event on her worldline, or doesn't change what her age is "now" at > the same moment that some distant observer like Bob reaches a particular > age, say 40? If the first I agree that she has an actual age at any given > event on her wrodline, but there ARE no different "views" of this since all > frames agree on her proper age at any specific event on her worldline. If > the latter I don't agree there is any physical basis for saying she has a > unique "actual age" when Bob is 40, since relativity doesn't give any > physical basis for a preferred definition of simultaneity. > > > > Your expertise in relativity is clear but you don't seem to understand > that all frames are NOT equal when it comes to representing actual physical > fact. You don't understand the fundamental notion in relativity that some > frames represent actual physical fact, but others represent only HOW OTHER > OBSERVERS VIEW those physical facts. > > > Not a physicist in the world would agree with you that there is a > "fundamental notion in relativity that some frames represent actual > physical facts", you appear to be completely confused about the difference > between your own p-time views and mainstream relativity. In special > relativity there can NEVER be a basis for considering one inertial frame > more "correct" than any other. There are only two kinds of facts in > relativity: > > 1. Facts about frame-independent matters like the proper time of an > observer at a particular event on their worldline; all frames agree in > their predictions about these, so they don't give any reason to prefer one > frame over another. > > 2. Facts about frame-dependent matters like the coordinate velocity of an > object at a particular event on its worldline, or the question of which > point on worldline B is simultaneous with a particular point on worldline > A; different frames disagree on these matters, and in relativity NO FRAME'S > STATEMENTS ABOUT FRAME-DEPENDENT MATTERS ARE CONSIDERED MORE VALID THAN ANY > OTHER FRAME'S. > > If you don't believe me that it's a basic principle of relativity that all > frames are considered equally valid and none are preferred over others, > here are some quotes from books written by physicists that I found on > google books: > > "If one reference frame moves uniformly relative to another, then the two > are equally good frames for observing nature, and two identical experiments > performed in the two frames will give identical results." > > --From "Relativity for the Questioning Mind" by Daniel Styer, at > http://books.google.com/books?id=Ebr7YhJcUd0C&lpg=PP1&pg=PA13 > > "The descriptions of the two sets of observers are equally real and > equally valid, each within their own frame of reference. Since no preferred > frame exists, there is no objective basis for ascribing any more reality to > one description than the other." > > --From "Understanding Relativity: A Simplified Approach to Einstein's > Theories" by Leo Sartori, at > http://books.google.com/books?id=gV6kgxrZjL8C&lpg=PP1&pg=PA173 > > "If Albert and Betty clap nearly simultaneously, one observer may report > that Albert clapped first, whereas a second observer, in motion with > respect to the first, may report that Betty clapped first. It makes no > sense to ask, 'Who really clapped first?' The question assumes that one > viewpoint, one reference frame, is valid or 'real' and the other is not. > But time is not absolute; it is a property of a particular frame of > reference. Both observers' viewpoints are equally valid." > > --From "The Theory of Almost Everything: The Standard Model, the Unsung > Triumph of Modern Physics" by Robert Oerter, at > http://books.google.com/books?id=KAMlsa8jjt4C&lpg=PP1&pg=PT35 > > General relativity goes even further and says that the laws of GR hold > equally well in *all* smooth coordinate systems, here is Einstein himself > on the subject, from "Fundamental Considerations of the Postulate of > Relativity": > > "there is nothing for it but to regard all imaginable systems of > co-ordinates, on principle, as equally suitable for the description of > nature" > > You can see this quote at > htt<http://books.google.com/books?id=QE-fMnpR8hAC&lpg=PR1&pg=PA39> > ... -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. 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