Halc wrote:I haven't been really following the example. I am trying to make sense of experiment 4, where speeds are sort of defined, but starting points are not. There are a lot more than 2 clocks. I have A E L S D at least.
Yes, David defines A, E, L, S and D as the "tick rates" of 5 clocks. The terminology we've now adopted is to prefix with 'C' when referring to the clock. So, for example, CA is a clock. A is its proposed tick rate. David makes claims about relative tick rates and suggests that to deny those claims is to logically contradict oneself. This is the issue at hand.
Yes, starting points are not defined here. Only relative speeds are. But starting points are not relevant to establishing relative tick rates. Two clocks that have zero velocity relative to each other (are stationary WRT the same inertial reference frame) can be agreed to have the same tick rate WRT each other. Therefore, for the purposes of making statements about relative tick rates (as David does), two clocks that are co-moving in this way can be regarded as the same clock. Hence, in the first leg of the experiment there are, for the purposes of considering tick rates, just 2 clock receding from each other at speed v. It is for leg 1 that David makes his statements about relative tick rates, for now.
L and S accelerate between legs, so those are the 'travelers' so to speak, out and back from A/D and from E respectively perhaps.
Yes. But since David's claims about tick rates apply specifically to leg 1, this is not relevant for now. It is only relevant when clocks meet again and the conversation moves on to the "twin paradox", the explanation for which we've both discussed. For now, it's David's claims for tick rates during leg 1, and his claims about people who deny those claims, that are being assessed.
All this is true only if all 5 clocks are in the same location to begin with. Maybe they are, but that isn't yet stated here.
As I say, it's true for the purposes of analyzing David's claims about relative tick rates.
Yes, that statement lacks a frame reference. The beginning has references, but they're dropped here. I notice L is not declared to be stationary relative to E at first.
CL is declared to be stationary relative to CE during leg 1 by stating that they both move at speed v relative to CA during that leg. Hence CL and CE can be regarded as effectively the same clock during leg 1, for the purposes of assessing tick rates.
This is different than the experiment 4 above. Maybe it should have got a new number. A and D were stationary relative to each other before. It seems to be pretty much the same situation, except CA2 is different, which explains the '2' I guess.
The relative movements of CL, CE, CD and CS are the same as they were before. The difference is that CA has been removed and CA2 has been added. None of David's claims about relative tick rates refer to CA or CA2. Therefore those clocks are irrelevant.
All relations seem described from A's perspective, so I'm betting that A is Ether, allowing David to appear to be talking in relative terms when he isn't.
What David appears to be claiming is that replacing CA with a clock that is moving differently from CA, relative to the other 4 clocks, (CA2) changes the things that he can say about those other 4 clocks' relative tick rates. He further claims that not saying those things constitutes us stating mathematical contradictions. This is the root of his "you SR people claim that 1=2" claim. This is why, in my opinion, he cannot simply be said to be saying the same thing but in different language. If either speaker accuses the other of a logical contradiction, then this is not a function of their respective languages. Either they are or they aren't.
When we've distilled experiment 4, leg 1, down to a consideration of 2 clocks separating at speed v (with, or without, another clock, CA/CA2, flying around) David's claim is that there is some objective sense in which one of those clocks ticks faster than the other, or vice versa, and which depends on the movements of that other (A) clock relative to the clocks being considered. And his further claim is that those who deny this are effectively saying that 1=2. Perhaps there's some way that he can get away with the first claim by (as you suggest) somehow associating the A clocks with the ether. But there is no way that the second claim can stand, regardless of any language disagreements.
Changing the languages in which we each speak does not alter the fact that 1 is not 2. Unless we're changing the meanings of the symbols '1' and '2'. Whatever other words we may disagree as to the definition of, we're not doing that!
Again, no frame reference, so the last two are meaningless outside of David's definitions
As I said, for reasons given above, I propose that David's claims are not merely meaningless outside of David's use of language. They are wrong in any language. He, of course, makes the same claim about us if we dispute what he says. And therein lies the dispute.