Simultaneity of Relativity
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From: mpc755 on 10 Oct 2009 11:56 On Oct 10, 11:53 am, PD <thedraperfam...(a)gmail.com> wrote: > On Oct 10, 10:52 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Oct 10, 10:51 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Oct 10, 11:46 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > On Oct 10, 10:38 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > If pebbles are dropped simultaneously at A and A' and pebbles are > > > > > > > dropped simultaneously at B and B', if the waves from A and B reach M > > > > > > > simultaneously do the waves from A' and B' reach M' simultaneously? > > > > > > > Answer in what way? > > > > > > It doesn't pertain to the Einstein gedanken, which is done out in the > > > > > > open so that at best there is ONE medium. > > > > > > If Einstein's Train Thought Experiment was done 'out in the open' then > > > > > you are tying the stationary aether to one of the frames of reference, > > > > > No, *I'm* not, you are. Einstein made no presumption that an aether > > > > was present at all. > > > > And in fact, I asked you how you can tell with the information given > > > > that there is an aether tied to *either* frame of reference. I > > > > explicitly asked you how you know that the aether isn't moving > > > > relative to *both* the embankment and the train. > > > > > > which is a different thought experiment than the one Einstein > > > > > proposes. > > > > > > Asking, 'Answer in what way?' is hiding from answering the following > > > > > question: > > > > > > If pebbles are dropped into the water simultaneously at A and A' and > > > > > pebbles are dropped into the water simultaneously at B and B', if the > > > > > waves from A and B reach M simultaneously do the waves from A' and B' > > > > > reach M' simultaneously? > > > > > Sorry, but now you're asking questions about the MPC train thought > > > > experiment, not the Einstein gedanken. > > > > I was interested when you were claiming this has something to do with > > > > Einstein's gedanken, but I'm not interested in a wholly different > > > > example involving two tanks of water and pebbles. > > > > If pebbles are dropped into the water simultaneously at A and A' and > > > pebbles are dropped into the water simultaneously at B and B', if the > > > waves from A and B reach M simultaneously do the waves from A' and B' > > > reach M' simultaneously? > > > Ah, ok, now we're back to your passive-aggressive mode of > > communication, where you simply repeat the same statement over and > > over and over again, without addressing any of the remarks that have > > been made about your original claims. > > You do realize, don't you, that this is why you don't date much. This does have to do with the original claims. You're inability to answer the simple question just shows you do not care to understand the original claims. The pebble is the flash of light and the water is the aether. If pebbles are dropped into the water simultaneously at A and A' and pebbles are dropped into the water simultaneously at B and B', if the waves from A and B reach M simultaneously do the waves from A' and B' reach M' simultaneously?
From: mpc755 on 10 Oct 2009 11:58 On Oct 10, 10:48 am, glird <gl...(a)aol.com> wrote: > On Oct 10, 9:52 am, PD wrote: > > > mpc755 wrote: > > > I understand exactly what is > > > occurring in Einstein's Train > > > Thought experiment. > > > Not as Einstein explained it, no you > don't. > > > You understand the MPC Train Thought > > Experiment, which is something > > completely different than the > > Einstein Train Thought Experiment. > > Yes. > > > << Lightning strikes at A/A' and B/B' behave exactly like the waves of > > pebbles dropped into stationary pools of water on the train and > stationary pools of water on the embankment. > If there are stationary pools on the train and on the embankment, the > waves the pebbles create from A and B reaches M and the light from A' > and B' reaches M' simultaneously. > If there are stationary pools on the train and on the embankment, the > light waves from A and B reach M and the light wave from A' and B' > reach M' simultaneously. >> > > > > > See? That's the MPC Train Thought > > Experiment, not the Einstein one. > > PD is right. In Einstein's, A and A' coincide when a given ray hits > point AA', and B and B' coincide when ray 2 hits BB'. In MPC's, A and > A' are different points than each other in 3-d space and so are b and > B'. > In Einstein, the space between AA' and BB' is empty and light moves > at c wrt to it while the train - thus points A', B' and midpoint M' - > moves to the right at v. in mpc, a luminiferous aether is trapped > within the moving train and is therefore moving wrt to the outside > aether taken as at rest wrt the embankment. > Therefore, as PD said, mpc's conclusions are unrelated to > Einstein's. > > BTW, this gedanken experiment by Einstein is to the layman, and > doesn't explain why simultaneity is relative to the states of motion > of different observers' clocks. > > glird > > them ir point It makes no difference if the points A and A' coincide side-by-side or not in Einstein's Train Thought Experiment. The only thing that matters in Einstein's Train Thought Experiment is the flash at A/A' occurring in a single instant and the flash of light at B/B' occurring in a single instant and for A and B to be equi- distant from M and for A' and B' to be equi-distant from M' and for the distance from A to M and B to M to be the same as the distance from A' to M' and B' to M'. Let me ask you about Einstein's Train Thought Experiment with the following variation. As described in the above sentence, if there is are simultaneous lightning strikes at A and A' and there are simultaneous lightning strikes at B and B', if the light from A and B reaches M simultaneously does the light from A' and B' reach M' simultaneously? And in terms of simultaneous, I am referring to any frame of reference. In other words, from the perspective of an observer on the embankment, if the light from A and B reaches the observer at M simultaneously, does the light from the lightning strikes at A' and B' reach M' simultaneously?
From: Bruce Richmond on 10 Oct 2009 15:04 On Oct 10, 11:28 am, mpc755 <mpc...(a)gmail.com> wrote: > On Oct 10, 2:49 am, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > > > > On Oct 9, 11:31 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Oct 9, 7:50 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > > On Oct 9, 1:26 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > On Oct 9, 1:17 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Oct 9, 12:08 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > On Oct 9, 12:30 pm, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > > On Oct 9, 10:06 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > > > On Oct 9, 10:52 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > > > > On Oct 9, 8:53 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > > > > > On Oct 9, 8:57 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > > > > > > On Oct 8, 8:34 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > > > > > > > > > > > > > > > > Sorry, I've fouled this up. > > > > > > > > > > Yes, the light from A and B reaches M' at different times, but the > > > > > > > > > light from A' and B' reaches M' simultaneously. > > > > > > > > > A and A' are a single strike. B and B' are a single strike. > > > > > > > > Yes, A and A' are a single strike but A and A' are two different > > > > > > > locations in three dimensional space. A in on the embankment and A' is > > > > > > > on the train. > > > > > > > No, they are not. You have not read the gedanken carefully. A lighting > > > > > > strike hits in ONE place, not two. A and A' are two labels for the > > > > > > same point. In the original gedanken, A and A' label the point where > > > > > > the train meets the track at one end of the train. That is ONE POINT. > > > > > > > Please reread it and pay more attention than what you have been doing > > > > > > so far. > > > > > > The lightning strike leaves marks at A, A', B, and B'. This is four > > > > > different locations in three dimensional space. A and A' and B and B' > > > > > were co-located at the time of the strikes, but they are four > > > > > different locations. > > > > > > If A and A' are two labels for the same point, why does the Observer > > > > > at M measure to A and B and the Observer at M' measure to A' and B'? > > > > > The measure to the appropriate marks because there are four marks.. > > > > > > Please try and understand if you have four marks at four locations > > > > > that is four points. > > > > > The mark at A on the tracks and the mark at A' on the train were made > > > > when the two points were together. > > > > > M considers the strike to have happen at A. There are scorch marks on > > > > the tracks marking the spot. There are also scorch marks on the > > > > train, but the train is moving relative to the tracks, so the marks on > > > > the train are not where the strike took place in the track frame. > > > > > M' considers the strike to have happen at A'. There are scorch marks > > > > on the train marking the spot. There are also scorch marks on the > > > > tracks, but the tracks are moving relative to the train, so the marks > > > > on the tracks are not where the strike took place in the train frame. > > > > > > > > > The light from A/A' travels through the *same medium* that the > > > > > > > > embankment and the open flatbed train cars are immersed in. The light > > > > > > > > from B/B' does the same thing. > > > > > > > > So how does the light, coming from a single lightning strike (A/A'), > > > > > > > > traveling through a common medium, arrive at the same observer M' both > > > > > > > > simultaneously and not simultaneously as the light from B/B'? > > > > > > > > It doesn't. If the train contains open flatbed cars, then you are > > > > > > > implying the medium is stationary relative to the embankment. > > > > > > > No, I'm not. There's no such implication at all. What you know is true > > > > > > is that there is ONE medium, not two. > > > > > > If there is one medium that is stationary relative to one of the > > > > > frames of reference in Einstein's train thought experiment then that > > > > > means it is moving relative to the other frame of reference which > > > > > means there is a preferred frame of reference. > > > > > There is only one medium and it is not stationary relative to either > > > > frame, so neither one is preferred. > > > > What if there is water that is stationary on the train and water that > > > is stationary on the embankment and a lightning strike occur > > > simultaneously at A' on the train and A on the embankment and another > > > lightning strike occurs simultaneously at B' on the train and B on the > > > embankment. If the light from the lightning strikes at A and B travels > > > through the stationary water on the embankment and reaches M > > > simultaneously, does the light from the lightning strikes at A' and B' > > > travel through the stationary water in the train and reach M' > > > simultaneously?- Hide quoted text - > > > > - Show quoted text - > > > Because Relativity refers to "empty space". If you look out at the > > stars there is empty space between us and them. If there is an aether > > out there, there is only one aether between the stars and anything > > moving relative to them. So you need to make your theory work with > > just one aether. > > That is where Relativity is incorrect. The aether is more like water > than you give it credit for. > > We could say there is one water, Then do so. > but the water on the embankment is > stationary relative to the embankment and the water on the train is > stationary relative to the train. > > The same is correct for aether. > > For everything to be truly relative in Einstein's Train Thought > Experiment the aether needs to be relative in the embankment frame of > reference and the train frame of reference which means the aether is > stationary relative to both frames of reference.- Hide quoted text - > > - Show quoted text - Relativity doesn't care about the aether, it cares only that all rays of light travel at the measured speed of c. It is physically imposible for one aether to be at rest WRT two frames that are moving WRT each other. But it is possible for both frames to be moving WRT the aether, so neither one is favored.
From: Bruce Richmond on 10 Oct 2009 15:19 On Oct 10, 11:38 am, mpc755 <mpc...(a)gmail.com> wrote: > On Oct 10, 9:50 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Oct 9, 10:27 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > On Oct 9, 7:04 pm, Bruce Richmond <bsr3...(a)my-deja.com> wrote: > > > > > On Oct 9, 11:06 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > On Oct 9, 10:52 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > On Oct 9, 8:53 am, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > On Oct 9, 8:57 am, PD <thedraperfam...(a)gmail.com> wrote: > > > > > > > > > On Oct 8, 8:34 pm, mpc755 <mpc...(a)gmail.com> wrote: > > > > > > > > > > > > > > > > > > > Sorry, I've fouled this up. > > > > > > > > > > > > > > > > > > > What Einstein's gedanken says is that the light from A/A' and the > > > > > > > > > > > > > > > > > > light from B/B' arrive simultaneously at M and NOT simultaneously at > > > > > > > > > > > > > > > > > > M'. > > > > > > > > > > > > > > > > > > > And if this were viewed from M', because the propagation toward M' is > > > > > > > > > > > > > > > > > > c from either A/A' or B/B', then it would be clear that events at A > > > > > > > > > > > > > > > > > > and B were not simultaneous. > > > > > > > > > > > > > > > > > > > PD > > > > > > > > > > > > > > > > > > OK, at least you now understand Relativity of Simultaneity. > > > > > > > > > > > > > > > > > > In Simultaneity of Relativity, both frames are equal. > > > > > > > > > > > > > > > > > That's all well and good, but experiment agrees with Einstein, not > > > > > > > > > > > > > > > > with your picture. > > > > > > > > > > > > > > > > How would you know? You just figured out what Relativity of > > > > > > > > > > > > > > > Simultaneity is two minutes ago. > > > > > > > > > > > > > > > :>) > > > > > > > > > > > > > > Well, I certainly did have difficulty explaining it right at first. > > > > > > > > > > > > > > > But the experimental stuff has been figured out a long time ago. > > > > > > > > > > > > > > > > > > Consider the > > > > > > > > > > > > > > > > > aether to be 'entrained' by the embankment in the embankment frame of > > > > > > > > > > > > > > > > > reference and for the aether to be 'entrained' by the train in the > > > > > > > > > > > > > > > > > train frame of reference. > > > > > > > > > > > > > > > > > OK, but the train observer could well be sitting on top of the train > > > > > > > > > > > > > > > > out in the open air, right along with the air that is surrounding the > > > > > > > > > > > > > > > > embankment. > > > > > > > > > > > > > > > > So unless you've got overlapping aethers, one passing through the > > > > > > > > > > > > > > > > other, then there would have to be a boundary between the two moving > > > > > > > > > > > > > > > > masses of aether, where they are rubbing up against each other. And in > > > > > > > > > > > > > > > > that case, there would be a region of aether in between where it is > > > > > > > > > > > > > > > > moving somewhat in between what the two entrained aethers are moving. > > > > > > > > > > > > > > > > And then just by moving, say, the embankment observer a little closer > > > > > > > > > > > > > > > > to the train, or the train observer a little to one side, then you'd > > > > > > > > > > > > > > > > start seeing the effect of the aether moving at a speed somewhat in > > > > > > > > > > > > > > > > between. However, this is not observed in equivalent experiments. > > > > > > > > > > > > > > > > Post a link to the experiments you are referring to. > > > > > > > > > > > > > > > Google "experimental basis for relativity" > > > > > > > > > > > > > > If you say this is not observed in equivalent experiments, you should > > > > > > > > > > > > > be willing and able to backup up such a statement with specifics. > > > > > > > > > > > > > > But, since you just figured out what Relativity of Simultaneity is > > > > > > > > > > > > > five minutes ago, its understandable you can't backup the claims you > > > > > > > > > > > > > make. > > > > > > > > > > > > > Such cheesy baiting. > > > > > > > > > > > > If you actually do the search I recommended, and you click on the > > > > > > > > > > > > FIRST link it returns, you'll have a lovely list of experiments. > > > > > > > > > > > > If you cannot do even this without whining, is it an indicator that > > > > > > > > > > > > you are hopelessly lazy or hopelessly incompetent? > > > > > > > > > > > > > > > > > This is what I mean by following the implications of an idea all the > > > > > > > > > > > > > > > > way through to look for *uniquely distinguishing* predictions. I've > > > > > > > > > > > > > > > > just given an example of a clear implication of AD, one that would be > > > > > > > > > > > > > > > > testable. And unfortunately, it doesn't match experiment. So it's > > > > > > > > > > > > > > > > gotta be wrong. > > > > > > > > > > > > > > > > Experiments like de Sitter and the double star? > > > > > > > > > > > > > > > No. That has to do with something else entirely.. > > > > > > > > > > > > > > That has to do with a test that distinguishes ballistic emission > > > > > > > > > > > > > > theory and relativity. > > > > > > > > > > > > > > Nothing to do with simultaneity. > > > > > > > > > > > > > > Simultaneity of Relativity is emission theory in an entrained aether. > > > > > > > > > > > > > No, it's not. In your theory the speed of light is relative to the > > > > > > > > > > > > aether. In ballistic theory it is relative to the source. > > > > > > > > > > > > If the train is half full of water and the water is stationary in the > > > > > > > > > > > train and you drop pebbles at A' and B', the waves from A' and B' will > > > > > > > > > > > reach M' simultaneously. > > > > > > > > > > > > If the embankment is half full of water and the water is stationary > > > > > > > > > > > relative to the embankment and you drop pebbles into the water at A > > > > > > > > > > > and B, the waves from A and B will reach M simultaneously. > > > > > > > > > > > > If you drop pebbles into the water at A and A' simultaneously and drop > > > > > > > > > > > pebbles into B and B' simultaneously, if the waves from A and B reach > > > > > > > > > > > M simultaneously, the waves from A' and B' will reach M' > > > > > > > > > > > simultaneously. > > > > > > > > > > > If it helps, MPC, Einstein's train gedanken can just as well take > > > > > > > > > > place on open, flat-bed cars. > > > > > > > > > > The water is stationary relative to the embankment and the train is > > > > > > > > > moving along under the water and not affecting the water. Pebbles are > > > > > > > > > dropped at A/A' and B/B'. The wave from B/B' travels from B to M'. The > > > > > > > > > waves from A and B and reach M simultaneously. The wave from A reaches > > > > > > > > > M'. > > > > > > > > > And notice that the waves from A and B do not arrive at M' at the same > > > > > > > > time. > > > > > > > > Yes, because the water is stationary relative to the embankment. In > > > > > > > this scenario, the embankment is the preferred frame. > > > > > > > > For Einstein's train thought experiment to be truly relative, there > > > > > > > can be no preferred frame. > > > > > > > > Therefore, the water must be stationary relative to the embankment in > > > > > > > the embankment frame of reference and stationary relative to the train > > > > > > > in the train reference frame. > > > > > > > Yes! And notice that, because the train cars are open, flatbed cars, > > > > > > you have to satisfy both criteria at the same time! > > > > > > > Here's where the fun starts. So if there is an aether (or water as you > > > > > > want to analogize), it has to be stationary with respect to the > > > > > > embankment AND to the train, at the same time. Not different > > > > > > scenarios. At the same time. > > > > > > > > In this scenario, my animation holds in the light from A and B reaches > > > > > > > M and the light from A' and B' reaches M' simultaneously. > > > > > > > No, certainly not. Because it's the same medium. > > > > > > The embankment observer notes that the light from A and B reaches M' > > > > > > at different times. > > > > > > Yes, the light from A and B reaches M' at different times, but the > > > > > light from A' and B' reaches M' simultaneously. > > > > > There is only one wave front emitted at A/A' and one at B/B'. Your > > > > inimation is wrong.> > The train observer has to agree with that. > > > > Why is everyone afraid to answer my thought experiment with pebbles > > > and the waves they create and stationary water on the train and > > > stationary water on the embankment? > > > > If pebbles are dropped simultaneously at A and A' and pebbles are > > > dropped simultaneously at B and B', if the waves from A and B reach M > > > simultaneously do the waves from A' and B' reach M' simultaneously? > > > Answer in what way? > > It doesn't pertain to the Einstein gedanken, which is done out in the > > open so that at best there is ONE medium. > > If Einstein's Train Thought Experiment was done 'out in the open' then > you are tying the stationary aether to one of the frames of reference, > which is a different thought experiment than the one Einstein > proposes. Einstein did not have an aether in his experiment. The observer at M declared that the speed of light was c, relative to him, in both directions to provide him with a definition of simultanity. The observer M' on the train is allowed to do the same. But since they are moving relative to each other they come up with conflicting calculations of when the strike at A/A' happen. The LT allows them to resolve the differences.
From: Bruce Richmond on 10 Oct 2009 15:39
On Oct 10, 11:58 am, mpc755 <mpc...(a)gmail.com> wrote: > On Oct 10, 10:48 am, glird <gl...(a)aol.com> wrote: > > > > > > > On Oct 10, 9:52 am, PD wrote: > > > > mpc755 wrote: > > > > I understand exactly what is > > > > occurring in Einstein's Train > > > > Thought experiment. > > > > Not as Einstein explained it, no you > don't. > > > > You understand the MPC Train Thought > > > Experiment, which is something > > > completely different than the > > > Einstein Train Thought Experiment. > > > Yes. > > > > << Lightning strikes at A/A' and B/B' behave exactly like the waves of > > > pebbles dropped into stationary pools of water on the train and > > stationary pools of water on the embankment. > > If there are stationary pools on the train and on the embankment, the > > waves the pebbles create from A and B reaches M and the light from A' > > and B' reaches M' simultaneously. > > If there are stationary pools on the train and on the embankment, the > > light waves from A and B reach M and the light wave from A' and B' > > reach M' simultaneously. >> > > > > See? That's the MPC Train Thought > > > Experiment, not the Einstein one. > > > PD is right. In Einstein's, A and A' coincide when a given ray hits > > point AA', and B and B' coincide when ray 2 hits BB'. In MPC's, A and > > A' are different points than each other in 3-d space and so are b and > > B'. > > In Einstein, the space between AA' and BB' is empty and light moves > > at c wrt to it while the train - thus points A', B' and midpoint M' - > > moves to the right at v. in mpc, a luminiferous aether is trapped > > within the moving train and is therefore moving wrt to the outside > > aether taken as at rest wrt the embankment. > > Therefore, as PD said, mpc's conclusions are unrelated to > > Einstein's. > > > BTW, this gedanken experiment by Einstein is to the layman, and > > doesn't explain why simultaneity is relative to the states of motion > > of different observers' clocks. > > > glird > > > them ir point > > It makes no difference if the points A and A' coincide side-by-side or > not in Einstein's Train Thought Experiment. > > The only thing that matters in Einstein's Train Thought Experiment is > the flash at A/A' occurring in a single instant and the flash of light > at B/B' occurring in a single instant and for A and B to be equi- > distant from M and for A' and B' to be equi-distant from M' and for > the distance from A to M and B to M to be the same as the distance > from A' to M' and B' to M'. You were ok up to the last part. The flashes met at M'. They can only meet at one point on a line between the two strikes, and that one point is where M is. M' was not with M when the flashes arrived, so he did not see the flashes at the same instant. IOW he saw the flashes at different times. Since the strikes at A' and B' were equal distances from M' the strikes must have happen at different times. In the frame of M' the strike at the front of the train happen first, M' passed by M, and then the strike at the back of the train happen. By the time the strike at the back of the train happen the front had moved beyond where its strike happen. So the distance between A' and B' is greater than the distance between A and B. You only think they are the same distance because M says the two strikes happen at the same time. |