Eckard

So do I. And that is an obvious challenge based on the translation of the first postulate you are quoting. Because as I said earlier, the standard 1923 work does not phrase it this way, it writes of "in all frames of reference". Which is physically correct, ie any law which corresponds with reality must be applicable in all circumstances, would be the most generalised way of putting it.

The caveat of uniform motion is an irrelevance (which is not the same as rigid bodies, but indicates how he is thinking. So even in this 'version' the first postulate is not wrong, just over conditioned. It is the second postulate which matters.

"My argument is simple: If the second rigid body was very long it could transfer information with a velocity in excess of c"

This is incorrect. Light only ever starts at c and can only decrease. The size of a body is irrelevant. Light is created at one spatial position, other light is created at another spatial position.

The whole issue here is how does reality occur, not how photons interact with it.

Paul

In order to test my understanding of the velocity of light and of simultaneity, Daryl Janzen introduced two gunslingers (this word is not in my dictionary, I just assume receivers of the same signal) who are located on a train with equal distance from the common a source of that signal located in the middle of the train.

Yes, according to the endnotes of my essay, they will see the signal at the same moment. It is reasonable and possible to choose only one co-ordinate system that refers to the train.

An observer on the ground may sees the train moving to the right. This motion does not matter.

Eckard

    Sorry Paul,

    I disagree with you. Einstein himself identified a co-ordinate with a rigid body. Such rigid body would have infinite length. In order to transfer a signal faster than with light, It would be sufficient to vary the position of this second co-ordinate relative to the co-ordinate of reference.

    And yes, I question the first postulate when it is understood claiming that the laws of nature are SIMULTANEOUSLY valid "in all frames of reference". Once we have chosen a co-ordinate, the other dependencies are affected by Doppler illusions.

    Eckard

    Dear Edwin,

    You might continue calling me Eckhard. I will still respect you as someone much more knowledgeable than me. Maybe we are both intending to reach more than we can achieve. You and others confirmed that my essay was easy to read. I could hope for a much lower scoring if everyone did read it and did understand my arguments as a serious attack against established tenets.

    I highly appreciate those few like you who may begin to realize that there seems to be a babble of arrogance in physics. Well, complex calculus is a very valuable tool but its mandatory use under all circumstances relates to the belief-related decision of those like Newton to put the god-related abstract so-called absolute time on the first place and ignore the just positive elapsed time.

    J. v. Neumann enchanted his disciples by creating the numbers out of nothing. I am less impressed by such brilliant maneuvers.

    Thank you again for pointing me to Daryl Janzen. I hope he will take issue.

    Best regards,

    Eckard

    Eckard,

    Thanks for your answer. I'm sorry you felt that I mean to 'test' you with this question. I just thought it would be a nice concrete place to start a discussion about relativity and check on what we can agree, as you previously suggested.

    And sorry for the confusion over the definition of a 'gunslinger'. From Wikipedia: Gunfighter and gunslinger /ˈɡʌnslɪŋər/, are 20th-century words, used in cinema or literature, referring to men in the American Old West who had gained a reputation as being dangerous with a gun.

    In the scenario I posted, which I adapted from Greene's 'Fabric of the Cosmos', the two men are dueling with laser pistols, so their 'bullets' travel at c. And someone observes it all from outside the train. I asked: "Do the gunslingers see the signal at the same time, or not? According to which perspective? If no, is it still a fair fight (assuming each stands his ground)? How do you reconcile this with there being one common time?"

    We don't agree on the answer to the first question, so let's consider your suggestion 3: "The velocity of light c equals to the distance d between the position of emitter at the moment of emission and the position of receiver at the moment of detection divided by the time of flight t: c=d/t."

    In the frame of the observer outside the train, the signal propagates at c towards both gunslingers, from the place of emission. While the signal is propagating, the guy on the left is approaching that point of emission and the guy to the right is moving away from it. The distance that the light eventually travels in order to reach the guy on the left should therefore be less, in the outside observer's frame of reference, than the distance that the light eventually travels in order to reach the guy at the right. With c constant, this means, by your suggestion 3, that the signal reaches the guy at the left in less time than it takes to reach the guy to the right.

    On the other hand, in the gunslingers' proper frame of reference on the train, they never move relative to the place where the signal is emitted, so the distance that the light travels is the same in either direction, takes the same amount of time to get to both gunslingers, and is therefore observed by each of them at the same time.

    Do you disagree that the signal will be observed synchronously in the gunslingers' frame, but the gunslinger on the left will see the signal before the one on the right in the frame of the observer standing outside the train? If we can agree on this basic picture, which doesn't say anything about what's *really* going on, but only demonstrates the issue that Einstein and others realised, then we can move on to discuss how we would interpret it. The key, in my opinion, has to do with what Paul brought up in his first post above, on Jun. 12, 2013 @ 18:47 GMT. As I keep saying, synchronicity and simultaneity are different things.

    Regards,

    Daryl

    Oh I can't help myself. Can I say already what I think is the problem with Einstein's proposal that synchronous events are simultaneous? It's perfectly exemplified in the following quotation from Greene (next three paragraphs):

    "So: *if you buy the notion that reality consists of the things in your freeze-frame mental image of right now, and if you agree that your* now *is no more valid than the* now *of someone located far away in space who can move freely, then reality encompasses all of the events of spacetime*. The total loaf exists [he's been chopping up space-time like a loaf of bread]. Just as we envision all of space as *really* being out there, as *really* existing, we should also envision all of time as *really* being out there, as *really* existing, too. Past, present, and future certainly appear to be distinct entities. But, as Einstein once said, "For we convinced physicists, the distinction between past, present, and future is only an illusion, however persistent." The only thing that's real is the whole of spacetime.

    "In this way of thinking, events, regardless of when they happen from any particular perspective, just *are*. They all exist. They eternally occupy their particular point in spacetime. There is no flow. If you were having a great time at the stroke of midnight on New Year's Eve, 1999, you still are, since that is just one immutable location in spacetime. It is tough to accept this description, since our worldview so forcefully distinguishes between past, present, and future. But if we stare intently at this familiar temporal scheme and confront it with the cold hard facts of modern physics, its only place of refuge seems to lie within the human mind.

    "Undeniably, our conscious experience seems to sweep through the slices. It is as though our minds provide the projector light referred to earlier, so that moments of time come to life when they are illuminated by the power of consciousness. The flowing sensation from one moment to the next arises from our conscious recognition of change in our thoughts, feelings, and perceptions. And the sequence of change seems to have a continuous motion; it seems to unfold into a coherent story... The intuitive image of a projector light that brings each new *now* to life just doesn't hold up to careful examination. Instead, every moment is illuminated, and every moment remains illuminated. Every moment *is*. Under close scrutiny, the flowing river of time more closely resembles a giant block of ice with every moment forever frozen into place."

    People do think of space-time as existing, but not always just as such a frozen block. In the general relativistic picture, objects are more often thought to move around, warping space-time as they go. How often have you heard that when something falls into a black hole, it has to keep falling towards the singularity at r=0 because r is the timelike direction within the event horizon, so even light can't escape it? It can move in any spatial direction it likes, but even light has to keep going towards r=0. Let me ask you: if one of these gunslingers we're talking about jumped into a black hole, could he shoot a laser bullet towards r=2m and one towards r=0 (say he's got two guns and fires them simultaneously in either 'direction') so that, although they'd both fall towards the singularity out of necessity, the latter bullet would actually get there 'first'? Should that be any more possible to do than for you to take a gun and point it towards the past and another and point it towards the future and have the latter make it to 2014 before the former? The whole concept is so completely inconsistent and blatantly wrong!--and it's truly remarkable that it's persisted as long as it has.

    So, the first point I addressed in my essay--which I couldn't avoid having to address because nothing else I could say would make any sense from the point of view of the current incorrect paradigm in physics--is the blatant inconsistency in this common way of thinking of space-time as something that exists: due to the "relativity of simultaneity", people *do* think of space-time as existing, as the Greene quotation illustrates, *but the idea smuggles in an extra dimension that's not formally part of the theory*! They think of a block universe--all of space-time--as existing, which sneaks in the same sense of temporality as we think of when we think of a block of wood as existing. Just as a 3D block of wood sitting somewhere as time passes is a 4D concept, described by 4D physics with three spatial and one temporal dimensions, a 4D block universe existing as Greene has described it is a *5D* concept, described by four space-time dimensions and one temporal dimension. There's more unobservable (and completely unjustifiable) structure in this view than there is when we just assume absolute simultaneity and a true rest frame, which is what Einstein rejected from the point of view of parsimony; i.e., he was so parsimonious that his theory led to a conception of reality with *more* added junk than if he'd just accepted what's *obvious* from the beginning.

    But the 5D idea that Greene describes really is a misrepresentation of what Einstein's SR is actually supposed to imply. So: what does Einstein's proposal that simultaneity is relative *really* mean? The block universe that's a logical consequence of the proposal is *just* a 4D slice of that 5D reality. The block universe doesn't exist; it's just a temporally singular thing that pops in and out of that 'existence' in an instant.

    My point is that when one finally understands, and makes this clear distinction, and denies the temporality that our thoughts always want to sneak into the idea, then it should be very clear that the Einsteinian view, that synchronous events should be simultaneous, *must* be wrong. The reason is obvious: *something* exists; there is *some* sense in which time passes, because right now is earlier than right now is earlier than right now, etc.--or at least it's not all on par as we perceive it. That much is true, even if it's because all of eternity *exists* in the 5D sense described by Greene, and our consciousnesses simply flow through our worldtubes like a river that flows everywhere and never runs dry. For that consciousness to flow, and the block to exist, that fifth dimension is required. The pure 4D block universe, unadulterated by our thoughts, is impossible to reconcile with any realistic sense of the world, and those who argue for it always do fall back on the 5D concept at one time or other, if not always so overtly as Greene does.

    So, what I propose is that only the three-dimensional world around us exists, and there is only one true sense of simultaneity. In the gunslingers example, the signal either reaches them simultaneously or it doesn't, regardless of whether that is described as synchronous in the chosen frame of reference or not. This bit of structure that's necessary to form a coherent theory of existence that's consistent with the apparent flow of time, etc., precludes any informational bits that might come to be. Above all else, without *existence*, bits can't exist--for bits that exist can't be the cause of their own existence.

    So how do we reconcile the results of the gunslingers example with the notion of absolute simultaneity? Take the outside observer to be perfectly at rest in the cosmic rest-frame. Now consider the perspective of the two gunslingers. Is it so difficult to see that from their perspective, if they'd just lift the blinds so they can see the world around them, then they too would realise that the guy to the left is going to see the signal first, because he meets it part-way between his position at the time of emission and the signal's position at the time of emission?

    Of course it's not difficult to see that that's going to be their perception. Just because everything can also be described as if the train were at rest and the Universe were zipping past--just because he can bounce a ball on the floor, or toss it in the air, and have it come right back to his hand--doesn't mean the gunslingers are unable to come to grips with the fact that they're actually moving, and the sense that the guy to the left is going to see the signal first.

    But this is the rock that the whole relativity church was built upon: Mach's failed argument that even if there is a cosmic rest frame we could never observe it; Einstein's wrong argument that it's just superfluous structure and the theory's just as good without it. WE HAVE A VERY PRECISE OBSERVATION OF A COSMIC REST-FRAME, and all the relative motion between galaxies, which is very small compared to the speed of light, is full well understood to be motion through the Universe.

    So let's go back to Greene's statement: *if you buy the notion that reality consists of the things in your freeze-frame mental image of right now, and if you agree that your* now *is no more valid than the* now *of someone located far away in space who can move freely*. This statement has been fed to us for a hundred years, and it's just plain wrong. For which freeze-frame mental image of right now are we supposed to say is the valid one for the gunslingers to hold: the one with the blinds shut or the one with them open? If the former is no more valid a mental image to them than the latter, and acceptance of the latter in light of all the cosmological evidence we've found over the past century is also consistent with the apparent fact that time does flow, then why the **** should we hold the former up as the crown jewel of objective thought, which proves to us without a doubt that there's no such thing as the passage of time, and all eternity 'exists'? If the freeze-frame mental image of right now that's held by the gunslingers when they've blocked out the evidence from the world around them leads to an unrealistic description of physical reality when we assume that it's a true representation of "right now", then we should instead assume that the true representation of "right now" is the freeze-frame mental image of right now that's held by the gunslingers when they've opened the blinds!

    Cheers,

    Daryl

    Eckard

    I might just say first, my original comment which sparked this thread of exchange is that SR is not what Basudeba and you think it is, which was evidenced by the exchange you two were having. Your literal translation of the first postulate was very interesting. I find it the culmination of a farce, that although the man was clearly wrong in his concept of relativity, in 2013 there is not even a definitive statement of his postulate. As I said, this technically does not matter, just gives easier insight into the flawed thinking. It is the second postulate that matters.

    Now, in response to the above. Einstein, et al, were fixated with avoiding anything but 'simple' movement because they thought relative movement was caused by a differential in a force (later identified as gravity)which ALSO caused length alteration. So having as a reference for calibration something that is, of itself, altering is a problem. In other words, the connection between what can constitute a reference (co-ordinate)and rigidity is in their heads, not necessarily reality. It may or may not be so that a differential in gravitational force incurred not only causes alteration in momentum, but also causes a dimension alteration.

    The point is that this caused a predisposition in their mind-set to think that their is some form of relativity in existence. [Which there is, but it is in the timing of the receipt of light]. By virtue of two fundamental, and counterbalancing mistakes, Einstein identified that relativity. In effect he asserted a differential in existence. He did not mean to do this, he thought he was accounting for the way timing works and observation. But what people intend to do, or think they are doing, is irrelevant. It is what they actually did which matters.

    Specifically, my point was that, while I do not know how light works, the length of anything will be identified by different physical lights. Rigidity or otherwise is irrelevant, and light does not travel faster than its original start speed which is a constant being the result of an atomic interaction. It can be calibrated to be, in effect, travelling faster, if one chooses an appropriate reference, ie one travelling towards it.

    Re your second para. Certainly the caveat of 'steady motion' is superfluous. The whole intent of the first postulate seems to be that existence is independent of the perspective from which it is calibrated. Which is correct. The follow on being that therefore any law which explains existence must be operable in all circumstances. But Einstein was viewing things differently, so to say 'all frames' is wrong, but is an interpretational fault, ie not apparently what Einstein was saying. And as you say, the apparent alteration in rate of change, when there is relative movement, is an optical illusion akin to the Doppler effect (an explanation of that was the first post I ever put up on NPA).

    Paul

    Daryl, my dear,

    Having learned the word gunslinger, I would appreciate you having understood my arguments. You might consider me bold if I do not deal with your worries concerning spacetime.

    Since I were a teacher of EE, I understand light as waves. My previous essay made aware of an experiment by Norbert Feist who seemed to confirm that acoustic waves behave as light in Michelson's experiment. Therefore I dealt with the expectations for the outcome of Michelson's experiment. I realized that all literature on relativity did adopt the correction by Potier/Lorentz of Michelson's first guess, and this correction is not quite correct. This flaw can however not account for Michelson's null result. While Feist's experiment was also flawless, his conclusion is wrong. Michelson was already correct in 1881 when he concluded that there is no medium that carries the light.

    Unfortunately, Michelson was unable to explain his null result. At least he rejected Einstein's relativity as a monster. When I looked for my own solution to the enigma, I decoupled my ongoing trust in the validity of Maxwell's equations from Maxwell's guess that there is a material medium which carries electromagnetic waves. In principle this corresponds to what was already done by those like Hertz, Heaviside, and Gibbs who formulated Maxwell's equation without convective term.

    You wrote: "In the frame of the observer outside the train, the signal propagates at c towards both gunslingers, from the place of emission. While the signal is propagating, the guy on the left is approaching that point of emission and the guy to the right is moving away from it. The distance that the light eventually travels in order to reach the guy on the left should therefore be less, in the outside observer's frame of reference,..."

    I clearly pointed out that the outside observer does not matter, see also my suggestion 2. There is no reason to believe that an ideal observation acts upon the propagation of light.

    Did I understand you correctly that you believe the two wild West men don't receive the signal simultaneously? I consider this option disproved by Michelson's null result.

    Regards,

    Eckard

    Eckhard,

    Yes, "there seems to be a babble of arrogance in physics", quite a bit of babble.

    And I too am glad that I pointed Daryl out to you.

    With respect to some statements below: I believe that both you and Daryl have spent more time on Special Relativity than have I, but I would offer the following. I am tending toward the opinion that it is the ever-present gravitational field that is the 'medium' through which light propagates. I won't bother quoting them again, but some textbook authors of General Relativity texts state clearly that the gravitational field has energy and hence is a 'material substance', which is compatible with my theory. If this is the case, then I would expect the relevant gravity for the MM experiment would be the local gravity on the Earth, and this should not be different for any time of season or orbital location about the sun, or orientation of the beams, thereby producing a null result.

    In this case, although I have not studied Daryl's long replies, I would expect the 'gunslinger' on the left to receive the signal before the one on the right.

    Although I believe you are more interested in Special Relativity than General Relativity, I find Professor Vishwakarma's essay to be both very interesting and, I believe, supportive of my theory.

    I am personally frustrated by both your score and Daryl's score and Mark Feeley's score in this contest, but it is not worth expounding upon the reasons I perceive for this.

    Best,

    Edwin Eugene Klingman

    Hi Eckard,

    I think we're making progress on this misunderstanding. You wrote "I clearly pointed out that the outside observer does not matter, see also my suggestion 2", but remember that stating a point is very different from defending it, and although you had stated it above I saw no justification. I'll argue that your suggestion 2 is incorrect, but in order to do that I think there's another misunderstanding to clear up. Your next sentence, "There is no reason to believe that an ideal observation acts upon the propagation of light", indicates that you think the outside observer would be thought of as somehow acting upon the light propagation, which couldn't be further from the truth. The outside observer is simply using a coordinate system appropriate to describe things from his point of view. He uses his proper time as the time, and spatial coordinates are defined so that light moves at c and the train moves in the x-direction with velocity v. If the length of the train is 2*x0, then x0 is the distance from either gunslinger to the signal. After the signal flashes a distance x0 from the gunslinger on the left, it moves to the left at speed c while the gunslinger moves to the right at speed v, so the distance that the signal has to travel, in the coordinate system that's used by the outside observer, is less than x0. Similarly, because the gunslinger on the right moves away from the location of the flash in this frame of reference, the signal has to travel a greater distance than x0.

    If you disagree that it's reasonable for the guy outside to describe things in a coordinate system that's stationary with respect to himself, such as milestones along the track, so that the train is described to have nonzero velocity from his point of view, then you need to explain this better. Everyone should be allowed to use coordinates that make sense to use from their perspective.

    Daryl

    Eckard/Daryl

    There is only one reality at a time, ie a physically existent state of whatever comprises it. Simultaneity of occurrence is two or more of the individual states which comprise the entirety occurring at that time. We see, or sense in any form, with the receipt of physically existent representations of that occurrence. Since there is travel involved, and in different physical circumstances, then the timing of that receipt will vary according to spatial relationship. This is where the 'relativity' is, there is no relativity of existence.

    Now, the other major point is that Einstein, despite what he intended, has no observation, there is no light to observe with. So the attempt to reconcile rate of change and speed of light in his theory is a waste of time, because it is an issue that does not exist.

    Paul

    • [deleted]

    Dear Daryl,

    I share and appreciate your criticism of block universes, Minkowski's spacetime, etc. I even understand your intention to cheat yourself and nonetheless operate with notions like proper time of the outside observer. Doesn't the notion local time in contrast to common time go back to Lorentz's attempt to explain the null result of Michelson's experiment by means of a hypothetical length contraction and time dilution?

    Well, "everyone should be allowed to use coordinates that make sense to use from their perspective." Everyone, Christian, Muslim, or whatever should be allowed to use his own time scale including his own reference of time.

    Nonetheless, Paul's belief seems to be reasonable:"There is only one reality at a time". My most fundamental conjecture is causality, and I do not see a causal link between two arbitrarily chosen frames of reference.

    Doesn't Michelson's experiment indicate that we must not consider a relationship between a cause (the emission of the signal) and its effects (arrival at the gunslingers) depending on any independent perspective?

    Of course, if the observer belongs to the same reality, then he may be causally related to light signals from each gunslinger and from the source in the middle between them. However, you did not yet specify its spatial position. Let's assume the simplest case and imagine the observer moving re source and gunslingers along the line given by these three subjects. Then there are three possibilities with different Doppler effects but not Einstein's average effect.

    Regards,

    Eckard

    Paul,

    You repeatedly argued: "Einstein, despite what he intended, has no observation, there is no light to observe with."

    What do you mean? You seem to refer to Einstein's 1905 paper "On the Electrodynamics of Moving Bodies". There a source A emits light, and B reflects it back to A. If I understood Einstein correctly, he considered A the observer.

    Maybe, you meant with your expression "light to observe with" a pulse of light that illuminates A and B simultaneously? This could possibly make sense because such pulse defines spatial co-ordinates and precludes a different local synchronization.

    Eckard

    Dear Eckard,

    Thanks for posting. Lorentz did describe a "true" time, but he also thought of length contraction as a physical effect rather than just a difference due to the use of different coordinate systems.

    I think we are making headway here, and I might see a crucial point of misunderstanding. When you say that everyone should be able to use their own time scale including their own reference of time, do you mean that you think I'm saying the gunslingers should use the outside observer's proper time as their own? Is this what you mean when you write "...your intention to cheat yourself and nonetheless operate with notions like proper time of the outside observer"?

    If so, this is an important point, and I'll refer to the figure in my essay below to make sense of it, but I need to explain something else first, before even worrying about proper time. I assure you that I think everyone should measure time locally as their own proper time.

    But the key to understanding what I've said so far isn't simply time, but motion, and whether anyone conceives of anything at all as moving. Let's call the two endpoints of the train where the gunslingers are A (left) and B (right), and the centre of the train where the signal is lit C. Let's not refer to proper time explicitly yet, but really just think of these three letters as marking points in three-dimensional space that I can refer to as local time's thought to pass.

    From the outside observer's perspective, A, B, and C are all moving to the right. When the signal flashes, that occurs at a point C' that remains fixed in space as A, B, and C all move relative to it. C moves to the right of C', but not as quickly as the signal heading towards B. And the signal moves away from C' (not C; but don't worry, this works out relativistically) at the same rate in both directions. At the same time, A is actually moving towards C' and B is moving away from C'. Therefore, there's no doubt that the signal reaches A before it reaches B, as described in this frame of reference.

    You expressed a concern that it's difficult to reconcile Paul's view that there is only one reality at a time: "...I do not see a causal link between two arbitrarily chosen frames of reference."

    I'm attempting to explain to you how this could be, but before I can I need to make sure you really get Einstein's point: we can restrict our attention to the point of view on the train, closing the blinds to the outside world; then, it's very easy to reconceive of the points A, B, and C as all remaining at rest. When the signal flashes, C remains at the point C'' where it flashed. Clearly, then, the signal is described in this frame of reference as reaching A and B at the same time.

    There should be no confusion about this. In the gunslingers' frame of reference, the signal is described as reaching each of them at the same time, and in the outside observer's frame of reference it's described as reaching the gunslinger on the left before the one on the right. But I assure you that there is a way of connecting these two descriptions in which there is one consistent real "now". In the end, all observers retain their intuitive sense of time's passage, but still it has to do more with how motion is conceived.

    So, is the train really moving or is it sitting still and the outside observer is running past it? It doesn't really matter, as long as we pick one. Einstein's whole argument hinges on the Machian premiss that we can't pick one, because how could we ever hope to determine whether an inertial frame of reference is ultimately at rest. What if this is all happening on the Earth, which is orbiting the Sun, which orbits the Galaxy, etc.? And Einstein argued that the imposition of such an absolute rest frame adds superfluous structure to the theory, so he rejected that from the point of view of parsimony. BUT twentieth century cosmology has taught us that there is an ultimate cosmic rest-frame, so Einstein and Mach were just plain wrong in this regard.

    So, how do we reconcile the relativistic description with the associated common now, so that there's only ever one three-dimensional reality that exists? I've previously said that the train is actually moving; so let's stay consistent with that picture and head back to the train. The gunslingers open the blinds and see that the train they're on is rolling along the tracks. Let's take the perspective of the gunslinger at A. According to him, the distance to C still remains constant; but because he now sees that he's in motion, it's also obvious to him that the point C' where it occurred must move towards him after the signal flashes, so that, while he describes the observation of the signal by himself and his opponent as synchronous in his proper frame of reference, he also understands that it will have travelled a slightly shorter distance to get to him, so that he should really see it before his opponent does, in an absolute sense.

    Now, I said above that the passage of time can still be described, in his proper frame of reference, as his proper time. This is sometimes called the clock hypothesis, and in terms of a space-time diagram, which is just a map of the events that occur in the three-dimensional universe, this axis is his worldline, as it's traced out. This whole concept--the graduation of his worldline is the proper time axis; space is moving past him; the light reaches him and his opponent synchronously, but, in the sense of his existence in the absolute space he's moving through, it isn't really simultaneous--is all encapsulated in the graph on the right hand side of Figure 2 in my essay, if you think of A as the outside observer and the two gunslingers as C and H, or something like that (maybe C is the centre of the train and H is the gunslinger to the right). Absolute space (x) isn't orthogonal to the proper time (t') axis of the gunslingers, because they're moving through it.

    But here's the most important bit: when reading the graph, think of x, the absolute space that traces upwards as time updates, as being "attached" at the point A_A--i.e., the outside observer who remains at rest absolutely. Then, as this "tilted" space evolves in time (or updates sequentially from one time to the next, as I think Paul would say), it actually slides past relative to C and H, just as I was saying they'd think of it when they open the blinds. And last but not least, the synchronous events, which occur along x', at t'=constant, are not truly simultaneous, because they don't occur in absolute space at the same time. It's all represented as a continuous progression on the space-time graph, but all that ever exists is just space.

    Whew. That's really a mouthful. Please say if anything is still unclear.

    All the best,

    Daryl

    Eckard

    "Nonetheless, Paul's belief seems to be reasonable:"There is only one reality at a time""

    This is noted, however I just want to stress that what constitutes a reality is the physically existent state of whatever comprises it. Do not think in terms of 'things', but the physical state.

    Now, it is not a matter of "if the observer belongs to the same reality". It is a matter of when did what is being observed occur. There is only one physical occurrence (forget the detail of physical state for now). As that existential sequence of occurrence progresses, there is an interaction which results in lights. The essential nature of light being that it exists over time in the same (or nearly so form). So without going into all the intricacies of how light is created, transmits, etc, at the general level the issue is the timing of receipt of lights which are representations of that occurrence (and subsequent ones indicating alteration), which is fundamentally a function of spatial position. And if recipients are moving relative to the source of the lights, then the rate of receipt will vary from the actual rate .

    BUT, moving on to your next post. Whilst an understanding of light is critical, so that we can discern, by extrapolation, what occurred, this is irrelevant in understanding Einstein. 1905 and SR, GR is different. Read his stuff, and indeed anyone such as Cox & Forshaw trying to explain it. He makes allusions to observers, etc, and there is always light. But it is not light that anyone is, or can, observe with. It is just a ray, or lightening, or whatever. In Cox and Forshaw it is a light beam clock, and you certainly do not observe with that. In other words, his light is just there as a constant for the calibration of distance and duration. What this means is that his second postulate is irrelevant, because it is not deployed as defined. Indeed, SR is the only physical circumstance in which the two postulates could co-exist. A state of effectively, nothing. But there wasn't any light.

    Paul

    Daryl (Eckard)

    Length alteration was considered a physical effect, and it is what sparked off the line of thinking, but it became a consequence of a more, supposed relativity.

    "Einstein's whole argument hinges..." It is Einstein's intention which...Because what he was trying to say is different from what he actually, ie effectively said. The difference is all about the light representation of the occurrence, not the occurrence itself. But because of his mistakes, he reified that difference as a characteristic of existence. The nearest he gets to saying so is:

    Einstein para 4 section 9 1916

    "Events which are simultaneous with reference to the embankment are not simultaneous with respect to the train, and vice versa (relativity of simultaneity). Every reference-body (co-ordinate system) has its own particular time; unless we are told the reference-body to which the statement of time refers, there is no meaning in a statement of the time of an event. Now before the advent of the theory of relativity it had always tacitly been assumed in physics that the statement of time had an absolute significance, ie that it is independent of the state of motion of the body of reference. But we have just seen that this assumption is incompatible with the most natural definition of simultaneity; if we discard this assumption, then the conflict between the law of the propagation of light in vacuo and the principle of relativity (developed in section 7) disappears".

    This is rubbish. Events occur. And they either occur at the same time or they do not. What differs is the receipt of a light based representation thereof.

    Paul

    Hello,

    Nice essay, and hanks for your comment n mine.

    When I originally esponde to your comment I missed where you included absolute reality. Yes, I agree with what you said.

    Have a nice day !

    "This is rubbish. Events occur. And they either occur at the same time or they do not. What differs is the receipt of a light based representation thereof."

    Paul, I completely agree!

    Daryl

    I thought you might, but there is a difference between us somewhere, but I have forgotten what it is. Am getting very tired, left the theatre last night at the interval as I was falling asleep.

    Paul

    Dear Edwin,

    You dropped "Dear" but persistently wrote "Eckhard" instead of Eckard. I am sure, you didn't so intentionally. However some others might see this a sign that we are unable to disagree with each other on some details but nonetheless strongly support each other.

    What about the 120 orders of magnitude, I found a convincing comment by Israel Perez.

    By the way, I did not much deal with Einstein's relativities. Wouldn't this be a waste of time? My intention has been to reveal what might be wrong with the usual notion of time. Only this caused me to deal with Einstein and those he relied on.

    If I understood you correctly, you are ascribing some properties of Maxwell's aether to gravity. Israel Perez, Daryl Jantzen and Paul Reed seem to also partially disagree with Einstein's theories.

    For a while I questioned the Michelson's indeed not quite correct corrected by Potier expectation. Now, I infer from the null result that we may be urged to accept a different solution. Isn't my suggestion a new one? There were many who questioned c but who questioned the usual understanding of the first postulate?

    Best Regards,

    Eckard