Jesse, It's not clear to me what you mean by, "in every coordinate system the time-coordinate of A = the time-coordinate of B. Are you actually disagreeing with that (please answer clearly yes or no)".
The way I understand that the answer is clearly NO. The whole idea of relativity is that the time coordinates (clock times) of A and B are NOT in general the same in either A nor B's coordinate systems, or any other coordinate system. And I did answer your crossing tapes example in detail showing how it is not relevant for p-time. I'm beginning to wonder if you actual read my posts... Edgar On Sunday, February 9, 2014 12:13:53 PM UTC-5, jessem wrote: > > > > On Sat, Feb 8, 2014 at 6:55 PM, Edgar L. Owen <edga...@att.net<javascript:> > > wrote: > > Jesse, > > The ages are the only 'real' clocks here because they are not arbitrary > but real and actual and cannot be reset. They show different clock times in > the same present moment. All other clocks are arbitrary. > > I don't know what else I can add to this. I did address all of your > questions whether or not you like my answers... > > > No you did not, because my question had nothing to do with what clock you > consider "real", it was just about how things are defined in relativity > theory. There is no clear answer above to the question I actually asked in > the post you were responding to, namely: > > "in every coordinate system the time-coordinate of A = the > time-coordinate of B. Are you actually disagreeing with that (please > answer clearly yes or no)" > > And note that I specifically added the qualification "Keep in mind that > we were talking about what's true according to the definitions of > coordinate time in relativity, this question has nothing to do with > anything not part of relativity theory like p-time, nor is it asking > whether you *approve* of the definitions used in relativity." So, can you > please give me a yes-or-no answer to the question above, under the > understanding that we're just talking about coordinate time as it's defined > in relativity and not any other notion of time which you may feel is more > "real"? > > Then I also discussed the perfect point-by-point analogy between the twin > paradox scenario and the measuring-tapes-which-cross-at-two-points > scenario, and asked another yes-or-no question: > > "I know that in some conceptual way you don't think a spatial scenario can > be analogous to one involving time, but can you point out any specific > measurable, quantitative facts about the twin scenario that don't have a > direct analogue in measurable, quantitative facts in the measuring-tape > scenario? As usual this is not meant to be a merely rhetorical question, > please answer yes or no (and if "yes" point to a specific measurable > quantitative fact in the twin paradox that you think lacks an analogue in > the measuring tape scenario)." > > Can you please answer this as well? > > Jesse > > > > > > Edgar > > > > On Saturday, February 8, 2014 6:23:37 PM UTC-5, jessem wrote: > > > > On Sat, Feb 8, 2014 at 10:41 AM, Edgar L. Owen <edga...@att.net> wrote: > > Jesse, > > No, they do NOT have the same time coordinates in their respective frames > because their clocks read different t-values. > > > In the post you're responding to here I had another request for > clarification which you didn't answer: > > "in every coordinate system the time-coordinate of A = the time-coordinate > of B. Are you actually disagreeing with that (please answer clearly yes > or no), or are you just pointing out that the shared time-coordinate is > different in different systems, or that the shared time-coordinate will not > match the clock time for both of them?" > > Keep in mind that we were talking about what's true according to the > definitions of coordinate time in relativity, this question has nothing to > do with anything not part of relativity theory like p-time, nor is it > asking whether you *approve* of the definitions used in relativity. > > > > You simply cannot invent any frame that makes the actual difference in > their ages go away. > > > I didn't say anything about making the difference in ages go away. If when > they meet twin #1 is turning 30 and twin #2 is turning 40, then if event A > = (twin #1 turns 30) and event B = (twin #2 turns 40), in every coordinate > system A has the same time-coordinate as B, but they are really different > ages at that point. > > > > > All you are doing is trying to ignore the effect by assigning a new > arbitrary time to the meeting. That's fine but they are still really > different ages so in that sense they can never actually be at the same > clock time except by an arbitrary definition which ignores the fact of the > trip and thus refuses to address the whole point of the trip. > > > I have no idea what you think I am "refusing to address". Yes, they really > are different ages, I have never suggested otherwise--and they really are > those different ages at the same coordinate time as coordinate time is > defined in relativity (using local measurements on physical coordinate > clocks). You may not *like* that definition of "same time", but if you are > actually denying that what I am saying is true ACCORDING TO THE STANDARD > DEFINITIONS OF RELATIVITY, then you are misunderstanding something about > how relativity works. > > Speaking of refusing to address things, yet again you just drop the > subject of spatial analogues when I explain how every quantitative fact > about the twin paradox scenario has a directly analogous quantitative fact > in the measuring tape scenario. For example, as I mentioned, the fact that > the twins are the same age when they depart is analogous to the fact that > at the first crossing-point that the measuring tapes diverge from, they > both show the same marking (say, 0 centimeters) at that first crossing > point. We can also lay out these tapes on a piece of graph paper with > Cartesian coordinate axes drawn on, so that any point on any given tape has > a spatial coordinate as well as a measuring-tape marking, analogous to the > fact that any event on the twins' worldline has a coordinate time as well > as a clock time according to their own clock. > > I know that in some conceptual way you don't think a spatial scenario can > be analogous to one involving time, but can you point out any specific > measurable, quantitative facts about the twin scenario that don't have a > direct analogue in measurable, quantitative facts in the measuring-tape > scenario? As usual this is not meant to be a merely rhetorical question, > please answer yes or no (and if "yes" point to a specific measurable > quantitative fact in the twin paradox that you think lacks an analogue in > the measuring tape scenario). > > Jesse > > -- > 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-li...@googlegroups.com <javascript:>. > To post to this group, send email to everyth...@googlegroups.com<javascript:> > . > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/groups/opt_out. > > ... -- 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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