On Tue, Mar 4, 2014 at 4:57 PM, Edgar L. Owen <edgaro...@att.net> wrote:
> Jesse, > > Good, we agree it's a valid method for determining 1:1 age correlations in > a common inertial frame in which they are both at rest. I claim that frame > is the correct one to determine the actual age correlation because it > expresses the actual relation in a manner both A and B agree > You are avoiding my question of whether identifying this frame with A and B's "view" or "perspective" is just a matter of convention as you previously seemed to agree, or whether it is tied to them in some more fundamental way. If it's just a matter of convention, then A and B could equally well "agree" to define any other frame as their own "view" of the situation. > is transitive among all observers, AND is the exact same method that gives > the correct answer WHEN A AND B MEET and everyone, even you, agrees on the > 1:1 age correlation. > > Our disagreement over choice of frames is spinning its wheels and not > getting anywhere. It's a matter of how to INTERPRET relativity, rather than > relativity itself. And I have given very convincing reasons why a > privileged frame that preserves the actual physical facts that affect age > changes is appropriate. You just don't agree with them. > But you refuse to answer my very simple questions about your "reasons", like my question about whether you ASSUME FROM THE START that a particular definition of simultaneity (the one you prefer) is the "actual reality", or whether you claim to have "convincing reasons" for this definition of simultaneity representing "reality" that don't simply assume it from the start. > > As to your example claiming to prove my method leads to a contradiction, > just give me the bottom line, a simple synopsis. I don't have the time to > wade through a detailed example only to find the only disagreement is over > choice of frames again. > I promise you the example has nothing to do with any frames other than the ones in which each pair is at rest. Again, the only assumptions about p-time that I make in deriving the contradiction are: ASSUMPTION 1. If two observers are at rest in the same inertial frame, then events on their worldlines that are simultaneous in their rest frame are also simultaneous in p-time ASSUMPTION 2. If two observers cross paths at a single point in spacetime P, and observer #1's proper time at P is T1 while observer #2's proper time at P is T2, then the event of observer #1's clock showing T1 is simultaneous in p-time with the event of observer #2's clock showing T2. ASSUMPTION 3. p-time simultaneity is transitive That's it! I make no other assumptions about p-time simultaneity. But if you want to actually see how the contradiction is derived, there's really no shortcut besides looking at the math. If you are willing to do that, can we just start with the last 2 questions I asked about the scenario? Here's what I asked again, with a few cosmetic modifications: Please have another look at the specific numbers I gave for x(t), coordinate position as a function of coordinate time, and T(t), proper time as a function of coordinate time, for each observer (expressed using the inertial frame where A and B are at rest, and C and D are moving at 0.8c), and then tell me if you agree or disagree with the following two statements: For A: x(t) = 25, T(t) = t For B: x(t) = 0, T(t) = t For C: x(t) = 0.8c * t, T(t) = 0.6*t For D: x(t) = [0.8c * t] + 9, T(t) = 0.6*t - 12 --given the x(t) functions for B and C, we can see that they both pass through the point in spacetime with coordinates x=0, t=0. Given their T(t) functions, we can see that B has a proper time T=0 at those coordinates, and C also has a proper time T=0 at those coordinates. Therefore, by ASSUMPTION 1 above, the event of B's proper time clock reading T=0 is simultaneous in p-time with the event of C's proper time clock reading T=0. Agree or disagree? --given the x(t) functions for A and D, we can see that they both pass through the point in spacetime with coordinates x=25, t=20. Given their T(t) functions, we can see that A has a proper time T=20 at those coordinates, and D has a proper time T=0 at those coordinates. Therefore, by ASSUMPTION 1 above, the event of A's proper time clock reading T=20 is simultaneous in p-time with the event of D's proper time clock reading T=0. Agree or disagree? (if you don't understand the math of how to use x(t) to determine whether someone passed through a given point in spacetime with known x and t coordinates, or how to determine their proper time T at this point, then just ask and I will elaborate) If you agree with both of these, then I will proceed to the next few "agree/disagree" statements that follow from the three assumptions, and if you agree with them all you'll have no way to avoid the contradiction. > > On the other hand if you ASSUME privileged frames the way I do and think > my method of using them leads to a contradiction that isn't just another > disagreement over choice of frames that were assumed, then give me a simple > example, the simplest you can come up with. > Yes, you can see that "ASSUMPTION 1" above assumes the rest frame of a given pair of observers is privileged as far as p-time simultaneity goes. And the above is really the simplest possible example I can come up with that demonstrates the contradiction, the contradiction requires a minimum of two pairs of inertial clocks. If it would help I can also draw a spacetime diagram, but this will only be useful if you are fairly familiar with spacetime diagrams in SR, and anyway the only way to verify that such a diagram is correct is to look at the equations for x(t) and T(t), so there's ultimately no way to understand the example without looking at the basic algebraic equations I've written above. 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-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.
