Jesse, My answer to your last paragraph is yes, as I understand it...
For transitivity ignore my first post on that, and just read the second that concludes there IS transitivity.. Edgar On Sunday, February 9, 2014 3:22:28 PM UTC-5, jessem wrote: > > > > On Sun, Feb 9, 2014 at 3:02 PM, Edgar L. Owen <[email protected]<javascript:> > > wrote: > > Jesse, > > 1. is correct. There is an objective truth that past events are > simultaneous in p-time. Recall I also gave the exact same answer yesterday > or the day before. > > > Thanks. So how about the issue of transitivity? If event A and event B > were objectively simultaneous in p-time, and event B and event C were > simultaneous in p-time, does this necessarily imply A and C were > simultaneous in p-time, or not? > > > > > It will always be able to determine what clock time t in one frame > occurred at the same p-time of any t' in another frame, but the actual > values of those t's and t''s will depend on the conditions in the preceding > paragraph, on the choice of frames. Which is what I said at least several > separate times in the preceding days. > > > By "clock time" you mean the actual physical reading on a clock, not any > other notion of coordinate time, right? Say one event is clock 1 reading > t=50 seconds, and another event is clock 2 reading t=30 seconds. These > events either ARE or AREN'T objectively simultaneous, correct? There can't > actually be different, equally valid answers to that question that depend > on one's "choice of frames", so when you say it will "depend on the > conditions in the preceding paragraph, on the choice of frames", do you > just mean that there are rules that tell us the objective truth about > p-time simultaneity should match some PARTICULAR frame's definition of > simultaneity, but that the particular frame that must be used depends on > the physical details of the objects involved, like whether the two clocks > are at rest relative to one another (in which case the rules say you *must* > use their rest frame's definition of simultaneity to determine p-time > simultaneity, you don't have any "choice" in the matter). Is this right or > am I still misunderstanding your wording? > > Jesse > > > > > > > > Edgar > > On Sunday, February 9, 2014 2:42:43 PM UTC-5, jessem wrote: > > > > On Sun, Feb 9, 2014 at 1:44 PM, Edgar L. Owen <[email protected]> wrote: > > Jesse, > > No, "the definition of p-time simultaneity itself depends on the > arbitrary "choice of coordinate system" is NOT true. I clearly stated > otherwise and explained why. Please reread if it isn't clear. > > > > Rereading doesn't help, I just don't understand what you mean since I > can't think of another way to interpret "Yes, the PARTICULAR 1:1 > relationship only exists with respect to some arbitrary coordinate system > (which I stated as just some other clock). The choice of that coordinate > system is of course arbitrary." > > Perhaps another question would help. Say it's true in some sense that a > meteor impact on Mars happens at the "same p-time" as a lightning strike on > Earth. Does either of these capture your view on how p-time works? > > 1. The fact that these events are "simultaneous in p-time" is an objective > truth by itself, it requires no context of a particular reference frame > (though there may still be a rule for determining this objective truth that > refers to reference frames, like "two events happening to objects that > share the same rest frame are objectively simultaneous in p-time if and > only if they are simultaneous in the time coordinate of their mutual rest > frame). > > 2. It is an objective truth that these events are "simultaneous in p-time" > in the context of one frame, and "not simultaneous in p-time" in the > context of another frame, but there is no frame-independent objective truth > about which events are simultaneous in p-time. > > If either of these does capture your view, please point out which one...if > neither does, then perhaps in trying to explain your view to me you could > keep in mind that these are the only two options *I* can imagine at the > moment, so perhaps you could explain how your third alternative would > differ from each of these two in turn. > > > > > > As for your last example, establishing past p-time simultaneity across > multiple frames is NOT transitive > > > So does "p-time simultaneity across multiple frames" mean that p-time > simultaneity is frame-dependent, as suggested in option 2 above? If not I > don't know how to interpret that phrase. > > > > > (in your sense of using the same intermediate frame t value). You can only > establish it between any two frames (at a time) in general because the > relativistic differences between multiple frame relationships as in your > example are not transitive. > > However take clocks A, B and C. You can always determine same past p-times > between A and B, and between B and C IN TERMS OF their clock time > relationships as calculated by standard relativity theory. However you > cannot in general say that because B's t' = A's t, and B's t' = C's t'' > that t and t'' were at the same p-time. Relativity doesn't work like that > as I'm sure you know. > > > > Relativity doesn't talk about p-time at all, so not sure what you mean. > Perhaps you would take my option 1 above, but you would just say that > although there are objective truths about p-time simultaneity, these truths > aren't transitive? In other words you could be saying that there is a > frame-independent objective truth that events A and B are simultaneous in > p-time, and a frame-independent objective truth that events B and C are > simultaneous in p-time, but this does not imply that A and C are > simultaneous in p-time. Is that right or am I still misunderstanding your > view? > > Jesse > > > > On Sunday, February 9, 2014 12:47:49 PM UTC-5, jessem wrote: > > > > > On Sun, Feb 9, 2014 at 11:19 AM, Edgar L. Owen <[email protected]> wrote: > > Jesse, > > Same thing as I'm saying. My other clock time is just a clock centered in > your coordinate system. It's the same idea. If you look at the equations of > relativistic clock time they are always of the general form dt'/dt = f( ). > I just note that the dt with respect to which dt' is calculated is another > clock. You simply note that other clock is some coordinate system. Exactly > the same. MY clock is the clock at the origin of YOUR coordinate system. > The equations are exactly the same. The concept is exactly the same. You > are talking about the exact same thing as I am. > > Yes, the PARTICULAR 1:1 relationship only exists with respect to some > arbitrary coordinate system (which I stated as just some other clock). The > choice of that coordinate system is of course arbitrary. That's irrelevant > because with EVERY choice of a coordinate system there will be some such > 1:1 relationship on the basis of which clock times can be used to determine > the same points in p-time. Depending on the choice of coordinate system > those clock times will of course be different but there will be such a > relationship that defines the clock times in ANY two relativistic systems > such that a same point in p-time can be defined in terms of a 1:1 relation > between those clock times. > > > Are you saying that the definition of p-time simultaneity itself depends > on the arbitrary "choice of coordinate system"? I thought p-time > simultaneity was supposed to be an objective matter, so the question of > whether any two past events were simultaneous in p-time could have only one > TRUE answer. I > > ... -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. 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