Jesse, To answer your final question. If I understand your 3 points correctly then I agree with all 3. Though I suspect we understand them differently. When you spring your 'proof' we will find that out.

And to your first points. I agree completely that there is no objective or actual truth about VIEWS of simultaneity from different frames. That is standard relativity which I accept completely. But you still find it impossible to understand we can DEDUCE or calculate an ACTUAL physical simultaneity irrespective of VIEWS of it. And just as proper time invariance is NOT ANY VIEW but a deduction or calculation, we CAN use deductions and calculations that DO NOT correspond to any particular view to determine relativistic truth.... That such a methodology is permissible? Do you agree that the symmetric relationship defined by the twins executing the exact same proper accelerations at their exact same proper times is a meaningful physical concept? That we can speak meaningfully about a symmetric relationship? You've been referring to it as if you do. Note that the twins certainly consider it a meaningful physical scenario because they can exchange and execute specific flight plans on that basis. If so you agree that some frames preserve that real physical relationship and some don't? If so please tell me why if we want to analyze that ACTUAL real physical relationship we should not choose a frame that preserves it? And second, do you agree my method is consistently calculating something, and that something is transitive, even if you don't agree it's a physically meaningful concept? If not then please try to prove it's not unambiguous and transitive, using MY definitions of MY theory rather than your 3 points. In other words assume it and then try to disprove it works. Edgar On Saturday, March 1, 2014 5:51:37 PM UTC-5, jessem wrote: > > > > On Sat, Mar 1, 2014 at 5:35 PM, Edgar L. Owen <edga...@att.net<javascript:> > > wrote: > > Jesse, > > Let me ask you one simple question. > > In the symmetric case where the twins part and then meet up again with the > exact same real actual ages isn't it completely logical to conclude they > must also have been the exact same real actual ages all during the trip? > > If, as you claim, the same exact proper accelerations do NOT result in the > exact same actual ages all during the trip then how in hell can the twins > actually have the exact same actual ages when they meet up? > > > > It's not that I'm claiming that there's an objective truth that they DON'T > have the same ages during the trip. I'm just saying that as far as physics > is concerned, there simply IS NO OBJECTIVE OR "ACTUAL" TRUTH ABOUT > SIMULTANEITY, and thus there is neither an "actual" truth that they are the > same age or an "actual" truth that they are different ages. These things > are purely a matter of human coordinate conventions, like the question of > which pairs of points on different measuring-tapes have the "same y > coordinates" in any given Cartesian coordinate system. Similarly, questions > of simultaneity reduce to questions about which pairs of points on > different worldlines have the "same t coordinate" in any given inertial > coordinate system, nothing more. > > > > > What is the mysterious mechanism you propose that causes twins that do not > have the same actual ages during the trip to just happen to end up with the > exact same actual ages when they meet? > > > Again, I do not say there is any objective truth that they "do not have > the same actual ages", I simply say there is no objective truth about which > ages are "actually" simultaneous in some sense that is more than just an > arbitrary coordinate convention. But if you're just asking about how things > work in FRAMES where they don't have the same actual ages during the trip, > the answer is that in such a frame you always find that the answer to which > twin's clock is ticking faster changes at some point during the trip, so > the twin whose clock was formerly ticking faster is now ticking slower > after a certain time coordinate t, and it always balances out exactly > ... -- 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. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.