Jesse, You continue to quibble over terminology to avoid engaging the real issues. Of course by 'view' I DO mean the actual equations in terms of a coordinate system with origin at a particular observer. There is OF COURSE a single set of equations that describes that view. You can describe that observer from any number of other coordinate systems but that would not be THAT observer's own view.
Answers to your next question: Yes, of course the OBSERVABLES are based on some coordinate system, but you can't seem to get it through your head that any observer A who observes another observer B can also know the equations governing how that observer B observes A himself. Do you deny that? I'll skip now to the point you make in your last paragraph responding to my symmetric trip case: Your comments here are true (more standard relativity) but irrelevant. Why, because the point of the symmetric trip argument is TO ESTABLISH a 1:1 correlation ONLY BETWEEN THE PROPER TIMES OF A and B, not any of the "any other coordinate systems" you attempt to drag into the discussion to obfuscate things. Do you agree in the symmetric trip case we can establish a 1:1 correlation between the proper times of just A and B MEANING IN ONLY THE VIEWS FROM THEIR TWO COORDINATE SYSTEMS? The answer is of course we can because both A and B know the exact conditions of their symmetric trips, therefore they know the exact equations each other use to describe their trips. And we do know in this case that the PROPER TIMES OF A and B WILL BE IN A 1:1 CORRESPONDENCE OVER THE WHOLE TRIP FROM BEGINNING TO END. A's t = B's t' over the whole duration of the trip. I know you will find some reason to refuse to agree to this no matter how true and obvious it is, but it is logically inescapable. And this 1:1 relationship is transitive between all observers, and it does establish a p-time plane of simultaneity between all observers in terms of their proper times, and since the current proper time of any observer is the present moment of his p-time, this does demonstrate a current universe present moment. So when A's proper clock read age 30, B's proper clock would also have read age 30, and both A and B would have been in the same current p-time at that point, in the same current present moment. I've demonstrated this over and over with all sorts of examples. If you can't understand it, or can't bring yourself to accept it, so be it, but it is a demonstrable truth. Edgar On Tuesday, February 25, 2014 5:16:52 PM UTC-5, jessem wrote: > > > On Tue, Feb 25, 2014 at 4:02 PM, Edgar L. Owen <edga...@att.net<javascript:> > > wrote: > > Jesse, > > So we agree on my first two points. And yes, I agree you can have as many > arbitrary coordinate systems as you like but that adds nothing to the > discussion. > > I accept your criticism of my third point which was not worded tightly > enough. I'll reword it... > > What I mean here is that all observers can know how relativity works both > for them, and for all other observers. In other words they can know exactly > what equations any observer A uses to calculate the observables of any > other observer B, in particular the equation A uses to calculate the clock > time of B relative to A's own proper time clock. This is standard > relativity theory assumed in all relativity examples. it follows for any > observer who knows relativity theory. > > With that revision do you now agree? > > > > No, you still seem to be laboring under the misconception that there is > some single set of equations that define the "view" of a given observer, > which they use to calculate observables for distant clocks. But all > relativistic calculations depend on the use of a COORDINATE SYSTEM, and > only with inertial observers in flat SR spacetime is there a standard > linguistic convention which treats the "view" of a given observer as > shorthand for a specific coordinate system, his inertial rest frame. > > Please answer these questions: > > --Do you disagree that equations that observer A uses to "calculate the > observables of any other observer B" are always based on A using some > particular coordinate system? (if so, can you give an example of an > equation that could be used to make such a calculation which would not > depend on any specific coordinate system, but which would still be > observer-dependent in some sense, so it would still be meaningful to > identify this equation specifically with observer A?) > > --If you don't disagree with the statement above, do you disagree with my > statement that there's no specific coordinate system that is understood by > physicists to represent a particular observer's "view" or "perspective" in > general relativity, so that if you just talk about equations "used by" > observer A without specifying a coordinate system, physicists wouldn't know > what you were talking about? > > > > > > You inconveniently snipped the examples where I made clear what I meant by > this and did not respond. Here they are again: > > > I did respond, I said it was wrong, because that there is no basis in > relativity for an agreement between observers about "rates". > > > > Thus it is possible for all observers to know the RATES of all proper > clocks in this system, and all observers will agree on all those proper > clock RATES. Note I'm talking here only of RATES, not of proper TIME clock > readings. We will get to that. > > E.g. IF THEY UNDERSTAND RELATIVITY, then all observers would agree that > the PROPER clock in a certain gravity would be running at 1/2 the rate as > PROPER clocks in no gravity. > > > Nope, this is just a misconception that is obviously based on an incorrect > intuitive understanding, not any detailed understanding of particular > equations used in relativity (if it was, you would write out the equations > rather than making vague statements like "if they understand relativity"). > My point was that there are only two ways to compare "rates" of clocks at > different points in space in general relativity: > > 1. Pick a coordinate system, and look at the rate each clock is ticking > relative to coordinate time at a pair of points on each clock's worldline > (or an interval on each clock's worldline, if you want to talk about > average rates over an extended period rather than instantaneous rates) > > 2. Restrict yourself to talking about visual rates a given observer sees > using light signals > > And as I said, in NEITHER case will you get universal agreement--for 1), > if two different observers use two different coordinate systems they can > disagree about the rates, and for 2), two different observers each looking > at one another can disagree about the ratio of the other clock and their > won clock in terms of visual speeds. > > If you disagree, please actually address this ARGUMENT rather than just > accusing me of not having read you closely enough and repeating something > I've already told you I don't agree is true. Specifically, please answer > these questions: > > --Do you disagree that 1) and 2) are the only methods *in relativity* of > comparing rates of clocks that are separated in space? Yes or no? (if you > do disagree, please be specific and give the equations and/or technical > term for a third > ... -- 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.
