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And who/what defines the speed?Does the universe have a gold standard for 'motion' or not?
Illusion is not science.If we see your length contraction,then you see our lengthening.
Does this make it easier to understand though? I have to agree with Sim there, it doesn't. Myself I think and expect that it should be no difference between a uniform motion and a acceleration, I've made arguments for that elsewhere here on TNS. But for arguments sake, let's assume that it actually matter if it's a acceleration or not. What would it make time? A 'field' that when 'compressed' slows the 'compressed' travelers time? And a Lorentz contraction would then include? A whole universe? But only mine??Mine universe?What about 'yours' then? As I 'compressed' mine, actually compressing my whole universe, but yours never noticed? And what would it make of three 'travelers' 'compressing' their universe's relative each other?What kind of existence does that make?==Add to that, that in this case it will only be an acceleration that can do it. If I use the arguments presented above. That really would make 'speed' a very weird thing, wouldn't it? And an 'acceleration' even weirder as we would have two kinds, the constant and the non-constant. Speed as such can't have a meaning except 'locally' inside the same ''inertial' frame of reference' if so? Earth I was thinking of there ==And to that you can add that I'm not sure where/if cut offs for 'frames of reference' are? Where do I draw the line? And how? We say that Earth is a inertial frame of reference, don't we? What about the molecules, atoms? They may all 'speed away' at the approximate same 'speed' as our Earth, and solar system, and galaxy etc. but they do have 'speeds' of their own too, don't they? Shouldn't that make them into 'frames of reference' too? it becomes a very 'flowing' concept to me, all depending on where I define my 'system'.
On the other hand, shouldn't we all be 'time dilated' constantly, relative all other 'frames of reference'? If we should, where is the Lorentz contractions? Against that one might argue, as I did before, that it's only a acceleration that creates it? possibly also that in the twin experiment neither twin notice any time dilation, and only the moving twin noticing the Lorentz contraction. but then we come to the question of how 'time' differ between uniformly moving frames, knowing who should age slower?
If you look at it from that point of view there is no need for the universe to differ between uniformly moving frames as each frame defines itself, in its relation to gravity and motion. The problem still being motion or 'speed'? But with each frame defining it there will be needed a constant. And we have it already, the speed of light in a vacuum. I like this one better and better.
1. where is the 'smallest' defined 'frame of reference' you can imagine?
2. Your definition seems to put all 'time dilation' on acceleration? Or am I reading you wrong? If we assume that, then it seems to me that all Lorentz contraction should disappear in a uniform motion. So then your 'speed' won't contract your SpaceTime, as long as you don't assume Doppler to be a contraction too? If you do, are there any experiments testing that idea?
Against that you can point out that all 'frames', when 'joined', seems to become the exact same, which to me seems to hang on two definitions. And here's a funny part, it's not 'acceleration', but 'motion' that seems to define it? And invariant mass (stress/tension of space).
And it's the fact that we have two contra dictionary statements that made me think of it as defined by relations inside those unique frames. It makes it easier for me to define ...
All frames, when joined in one rest frame together, are only exactly the same if the space and time coordinates were defined in the following way:All the frames were together at rest and the space and time coordinates were chosen to be the same.Then, you could take those frames, accelerate them in some directions move them around at constant velocity, decelerate them, bring them back and line their origins up at rest. At this point, all the measurements are synced once again. However, while those frames were moving (accelerating or not) the measurements were not synced up properly. This syncing of moving frames can only be accomplished if previously moving frames sync up their measurements at some point in time and space. Then, while they continue to move as they were, they continue to have comparable spacetime coordinates.
Quote from: yor_on on 16/02/2011 20:46:30On the other hand, shouldn't we all be 'time dilated' constantly, relative all other 'frames of reference'? If we should, where is the Lorentz contractions? Against that one might argue, as I did before, that it's only a acceleration that creates it? possibly also that in the twin experiment neither twin notice any time dilation, and only the moving twin noticing the Lorentz contraction. but then we come to the question of how 'time' differ between uniformly moving frames, knowing who should age slower?If we have two relatively moving frames (constant and one being 0 or not), then as I understand it, the time is always being dilated for both and both are being length contracted. Here is what I understand of the twin paradox.If you end up with two equally aged people moving relative to each other, accelerating to the relative motion is a problem but suppose we ended up with equally aged people with motion relative each other, and they both die at the same age (their life is the same amount of time in their respective frames of reference after the position and time coordinates are synced) Each will have appeared to died after the other in the frame they are in. To a person who also synced up the time and position of the twins and had them moving at equal speed in opposite directions relative to that person, they appeared to die simultaneously, but after the time they did in their frames.The problem with saying who actually aged more is that relative to each other, they both aged more and the only way to compare clocks is at the proper time, which means you read the clocks at the same point in space. This is impossible unless they turn (or one person turns) around and come back. Then acceleration takes effect. This destroys the formulas for constant motion. When the clocks are brought back to the same point in space, the times read the same and so the twins must have died at the same time.
But as for arguing that no positional SpaceTime system, or 'frame of reference' are more 'true' than any other? Conceptually I agree, but looked at from my reality I find it very easy to define what 'system' that 'ticks' for me. That I also can compare it to a Black hole, or a speeding rocket, and see a sliding correlation between them does not invalidate that. A easy argument is how we define a experiment to be true. We need to be in the same frame of reference for finding it true, as for example Einstein did with a constantly uniformly accelerating rocket at one G. Proving all experiments to deliver the same results, ignoring tidal forces, as for a planet of the same gravity.I believe that definition to hold for all uniformly moving frames too, that you will get the same results from a experiment in that black box, their speed relative each other making no difference.Somehow reality seems to come down to 'relations'.
Would the second paragraph be the one about 1G at Earth being identical to a uniform (constant) acceleration at the same G?
As I understand it Lorentz used them first to explain the Michelson-Morley experiment "In order to explain this absence of any effect of the Earth's translation, I have ventured the hypothesis, that the dimensions of a solid body undergo slight change, of the order of v2/c2, when it moves through the ether.From this point of view it is natural to suppose that, just like the electromagnetic forces, the molecular attractions and repulsions are somewhat modified by a translation imparted to the body, and this may very well result in a change of dimensions. The electrons themselves become flattened ellipsoids.This would enable us to predict that no experiment made with a terrestrial source of light will ever show us an influence of the Earth's motion."
But to apply them you will need to have a defined 'position' relative something else, or a 'origin' common to both as a reference point, and that's not what I was referring too. I discussed it from a 'black box scenario' when i called them 'equal'.
And no, it's not really true, although in fact it is one of the major headaches you lift up when you write "But I hold that the reality is the same no matter what frame you are in. Our clocks might tick differently, but they tick differently in the same way for both of us. The rate at which my clock ticks faster than yours is the same rate faster your clock ticks than mine. "That you know that the 'time dilation' will belong to one twin, not both, is why there have been a recent proposition where they offer valid proofs for how you can solve that problem relative very far so called 'fixed stars'. It is in fact so that you in two moving frames of reference, like Earth versus a uniformly moving rocket near light speed, are free to define either Earth or the rocket as being a 'inertial frame' having a 'zero motion' relative the other, although some might want to differ here. But as it turns out, in the twin experiment only one of our twins can be said to be 'time dilated' relative the other, if we accept that they otherwise originally should show the same biological age (Earth). And it's to get around that fact this proposal has been lifted up as a answer (Fixed stars) as I understands it.