Mordred Posted April 21 Posted April 21 (edited) 17 minutes ago, externo said: I will show you another mathematical formulation which agrees with Lorentz's point of view that would be useful perhaps you should start showing the related math to go with which Lorentz Eather variation your using as there are numerous changes and revisions over the course of its development. One of those variations violated conservation of energy/momentum due to symmetry loss with regards to the preferred frame Edited April 21 by Mordred
Markus Hanke Posted April 22 Posted April 22 (edited) 17 hours ago, externo said: Inertia comes from the ether. When we accelerate the ether manifests itself as inertia. You didn’t answer my question, you’re just making another unsubstantiated claim. 17 hours ago, externo said: Instead of the speed of light changing, it is simultaneity changing and the speed of light remaining constant. It’s invariant, not constant. There’s a difference here. But yes, since the speed of light is finite and the frames are separated, there’s of course relativity of simultaneity; and since acceleration is a change of velocity, the relationship between the frames is time-dependent. 17 hours ago, externo said: The article clearly establishes that there are physical discontinuities in Minkowski space I’ve already pointed out that the metric of a relativistically rotating disk is not the Minkowski metric. 17 hours ago, externo said: You talk about paths in Minkowski spacetime as if it had a physical reality. SR is of course “just” a mathematical model, same as any other model in physics. However, the lengths of paths through spacetime correspond to what clocks physically display, so that’s pretty “real” to me. Like I said, if you connect the same two points in any territory along different paths, it’s hardly a surprise that, in general, these come out at different lengths. What deeper mechanism do you need for that? 17 hours ago, externo said: You see that the twin ages less over the duration of the entiere journey, which is Lorentz's interpretation. That’s no one’s ‘interpretation’, it’s what the standard SR maths say, as I have shown you earlier. There are no interpretations involved in this. 17 hours ago, externo said: As soon as it leaves the Earth's frame of reference it begins to age less, so its perception of symmetry during the inertial journey is false. He believes that the Earth is aging less than him when in reality it is the opposite. Only one of the frames experiences proper acceleration, which is not a relative measure - both frames agree on who’s accelerated and who isn’t. So there’s not any symmetry in this situation, except during those times when both frames are inertial. But that symmetry concerns the instantaneous rate at which the clocks tick, not their readings - if one of the clocks has first undergone non-inertial motion, and then becomes inertial, their tick rates are symmetrical, but nonetheless one clock displays a different total proper time. The effect of non-inertial motion is accumulative, which is what I pointed out above with line integrals - you have to account for the entire journey. 17 hours ago, externo said: This is not consistent with Einstein's interpretation that the traveler ages less during interial travels. I don’t know what you mean by this. 9 hours ago, externo said: Redshift is the manifestation of a change in speed between light and the accelerating one. No it isn’t - frequency shift is due to the fact that energy is a frame-dependent quantity, it has nothing to do with changes in c. Light propagates at the same speed in both frames, but they don’t agree on its energy. Edited April 22 by Markus Hanke
externo Posted April 22 Author Posted April 22 3 hours ago, Markus Hanke said: It’s invariant, not constant. There’s a difference here. But yes, since the speed of light is finite and the frames are separated, there’s of course relativity of simultaneity; and since acceleration is a change of velocity, the relationship between the frames is time-dependent. So you consider that the change in simultaneity is physical, that's not what the others say. If it is physical it implies that the Earth suddenly ages for real during the U-turn 3 hours ago, Markus Hanke said: I’ve already pointed out that the metric of a relativistically rotating disk is not the Minkowski metric. Sorry, but the SR spacetime metric is the Minkowski metric, there are no others. We can write it in another form but it remains the Minkowski metric. If you read the article you will see that it is explicitly written that there is a physical problem of discontinuity in space-time. Quote The time discontinuity is physical, not merely coordinate. https://arxiv.org/pdf/gr-qc/0604118.pdf 3 hours ago, Markus Hanke said: SR is of course “just” a mathematical model, same as any other model in physics. However, the lengths of paths through spacetime correspond to what clocks physically display, so that’s pretty “real” to me. Like I said, if you connect the same two points in any territory along different paths, it’s hardly a surprise that, in general, these come out at different lengths. What deeper mechanism do you need for that? That’s no one’s ‘interpretation’, it’s what the standard SR maths say, as I have shown you earlier. There are no interpretations involved in this. I will propose in my next message another model which gives the same result and which is Euclidean, non-symmetrical, and which works within the framework of Lorentz theory. 3 hours ago, Markus Hanke said: That’s no one’s ‘interpretation’, it’s what the standard SR maths say, as I have shown you earlier. There are no interpretations involved in this. So math agrees with Lorentz but not with Einstein. Einstein claims that the traveling twin ages less than Earth during the inertial journey, unless he claims nothing at all, in which case he doesn't even have a theory but a simple paraphrase of the equations. 3 hours ago, Markus Hanke said: Only one of the frames experiences proper acceleration, which is not a relative measure - both frames agree on who’s accelerated and who isn’t. So there’s not any symmetry in this situation, except during those times when both frames are inertial. But that symmetry concerns the instantaneous rate at which the clocks tick, not their readings - if one of the clocks has first undergone non-inertial motion, and then becomes inertial, their tick rates are symmetrical, but nonetheless one clock displays a different total proper time. The effect of non-inertial motion is accumulative, which is what I pointed out above with line integrals - you have to account for the entire journey. I really don't understand this, especially since the acceleration period can be reduced to an infinitely short time. The journey of the traveling twin is then reduced to two inertial journeys. 3 hours ago, Markus Hanke said: No it isn’t - frequency shift is due to the fact that energy is a frame-dependent quantity, it has nothing to do with changes in c. Light propagates at the same speed in both frames, but they don’t agree on its energy. Energy is a frame-dependent quantity due to difference in speed between frames of reference. If the the frequency of the electromagnetic signal increases, it is because the one accelerating has changed its velocity in relation to the signal or because the one who emitted the signal has changed is velocity in relation to the signal.
externo Posted April 22 Author Posted April 22 (edited) EUCLIDEAN LORENTZ TRANSFORMATIONS The factor γ has the value 1/γ = sqrt (1-v²/c²) We can write this relation (1/γ)² + (v/c)² = 1/γ² + β² = 1 We can put 1/γ = cos θ and β = sin θ Contracted length =1/γ * proper length = cos θ * proper length Simultaneity shift = β * proper length = sin θ * proper length therefore the proper length is the hypothenuse of a triangle whose sides are cos θ * proper length and sin θ * proper length Hence the Pythagorean relation: Proper length² = Contracted length² + Simultaneity shift² Likewise Coordinate time ² = Proper time ² + Distance traveled² We recognize here the Minkowski metric: Proper time² = Coordinated time² – Distance traveled² These two relationships make it possible to highlight a Euclidean rotation of the space-time axes: Proper distance = dx' = cos θ * dx + sin θ * dx = 1/γ dx + β dt Proper time = dt' = cos θ * dt - sin θ * dt = 1/γ dt - β dx These are the Euclidean Lorentz transformations. They are not symmetrical and are reciprocal. This formula was first established by Gabriel LaFrenière: https://web.archive.org/web/20120228112717im_/http://glafreniere.com/images/lorentz03c.gif In this new version the proper time is therefore the time coordinate of the moving object in the same way as the proper length is its space coordinate, and not the space-time distance as in Minkowski spacetime. Additionally, the mathematics being Euclidean, what is drawn on the paper corresponds to the actual lengths. Here is a graphical comparison of the two methods: TR is one dimentional aether. T is Earth and R is another planet. They are assumed to be almost immobile in the ether. F is a rocket, to which we have attached its rotated space-time axes. We see that the distance dL² is measured by the rocket as a distance dx² + dt², this is the observational space contraction. We also see that from the point of view of F, T is located in the past and R in the future, but it is only the coordinates that change and not the objects. By contrast Minkowski space-time represent T and T' as well as R and R', which is the block universe: instead of simply changing the coordinates of the objects Minkowski space-time change the objects themselves. So there is confusion, hyperbolic mathematics is misleading. Where does symmetry come from? When you are in the moving system and you use the rotated time axes, you measure the lengths of space and time shorter than they are. This is a perspective effect due to rotation. The moving object projects the real lengths of space and time onto its fictitious axes. One thing to note: the new space-time axes aren't really fictional. Matter in motion is transformed, and with this transformation these new space-time axes are associated. Einstein's error was to believed that all of space-time was changing simultaneously when it was in fact only the moving object. Thus the symmetric Lorentz equations only indicate the coordinates measured in the frames of reference, they are symmetrical because the measurements are symmetrical, but this symmetry is simply the symmetry associated with the measurements between two coordinate systems rotated relative to each other. To achieve such a result it is necessary to consider that there is an immutable privileged frame of reference and that the time of moving objects is only a local time. So there is no block universe. Time is not a vector either, it is a dimension of space, the scalar dimension of Hamilton's quaternions which represents the density of the ether. Accelerating amounts to performing a Euclidean rotation in space-time which is also a contraction of the ether. This representation is more than a mathematical model, it is a physical model of space-time and I think it conforms to the algebra of physical space. https://en.wikipedia.org/wiki/Algebra_of_physical_space Edited April 22 by externo
Eise Posted April 22 Posted April 22 (edited) I am following the discussion a bit, but not precisely. In the end, I am not the expert. Still, I have a question for @externo: Assuming that you agree that the Lorentz transformations are correct, how could they have different results when interpreting them with a Lorentzian aether on one side, and no aether at the other side? Minkowski derived his spacetime metric from the Lorentz transformations, not from Einstein's interpretation. You can try it. Take the Minkowskian metric for spacetime distances: (ct')2 - x'2 = (ct)2 - x2 And then plugin the Lorentz transformations. Do it! It is not too difficult. And? Did you need an aether for that? Edited April 22 by Eise
joigus Posted April 22 Posted April 22 1 hour ago, externo said: So you consider that the change in simultaneity is physical, that's not what the others say. If it is physical it implies that the Earth suddenly ages for real during the U-turn The 'change' in simultaneity is 'real'? Simultaneity is a frame-dependent concept, rather. The Earth 'suddenly ages' for real? The accelerating twin finds a path in ST for which proper time is less, rather. Time dilation/length contraction are real. As much as anything else that you see. They're very much like foreshortening. Is foreshortening just a matter of 'perspective', and therefore 'not real'? If you think that's the case, try to get a 4m-long pole inside a garage through a 3m-wide door with the pole's length parallel to the door. A clever person --who knows the laws of foreshortening-- manages to get the pole inside the garage by rotating it, and then rotating it back once inside (the close equivalent of the twin's U-turn). Don't get me wrong. You seem to be trying to make sense in an honest way, but you're trapped in an early-20th-century illusion. That's why you express yourself in such an obscure --and incorrect-- way. Some of the things you've said, though, sound like you're groping towards Mach's principle. But with the wrong toolkit taken from the junkyard of discarded ideas. And with the wrong outlook. Your 'ether' or 'absolute space' is (if anything) the distribution of energy in the universe.* That's why most of us look at you in disbelief, like the proverbial Earth-bound twin, wondering, "where have you been all these years? Your ideas haven't changed at all since the early 20th Century!" ----------------------------------- * Unfortunately (or not) Mach's principle is not a very useful constructive starting point in order to reach the right theory of gravitation. Although GR is definitely Machian in spirit: The distribution of stuff tells you how much you must deviate from locally inertiall in order to be aware that you're moving. 1
externo Posted April 22 Author Posted April 22 (edited) 1 hour ago, Eise said: I am following the discussion a bit, but not precisely. In the end, I am not the expert. Still, I have a question for @externo: Assuming that you agree that the Lorentz transformations are correct, how could they have different results when interpreting them with a Lorentzian aether on one side, and no aether at the other side? Minkowski derived his spacetime metric from the Lorentz transformations, not from Einstein's interpretation. You can try it. Take the Minkowskian metric for spacetime distances: (ct')2 - x'2 = (ct)2 - x2 And then plugin the Lorentz transformations. Do it! It is not too difficult. And? Did you need an aether for that? Lorentz transformations were derived with the idea that there was an aether and that the speed of light was constant relative to this aether. In order to remove the idea of the ether or at least remove its state of motion, we must add the condition that the speed of light is constant in both directions of motion in moving frames, unlike classical kinematics. This condition allows us to get rid of the idea of a fixed frame of reference for the universe. Einstein's interpretation is therefore eroneous if there is a preferred rest reference frame for the universe. ---------------------------------- 57 minutes ago, joigus said: The 'change' in simultaneity is 'real'? Simultaneity is a frame-dependent concept, rather. The Earth 'suddenly ages' for real? The accelerating twin finds a path in ST for which proper time is less, rather. Time dilation/length contraction are real. As much as anything else that you see. They're very much like foreshortening. Is foreshortening just a matter of 'perspective', and therefore 'not real'? If you think that's the case, try to get a 4m-long pole inside a garage through a 3m-wide door with the pole's length parallel to the door. A clever person --who knows the laws of foreshortening-- manages to get the pole inside the garage by rotating it, and then rotating it back once inside (the close equivalent of the twin's U-turn). Don't get me wrong. You seem to be trying to make sense in an honest way, but you're trapped in an early-20th-century illusion. That's why you express yourself in such an obscure --and incorrect-- way. Some of the things you've said, though, sound like you're groping towards Mach's principle. But with the wrong toolkit taken from the junkyard of discarded ideas. And with the wrong outlook. Your 'ether' or 'absolute space' is (if anything) the distribution of energy in the universe.* That's why most of us look at you in disbelief, like the proverbial Earth-bound twin, wondering, "where have you been all these years? Your ideas haven't changed at all since the early 20th Century!" ----------------------------------- * Unfortunately (or not) Mach's principle is not a very useful constructive starting point in order to reach the right theory of gravitation. Although GR is definitely Machian in spirit: The distribution of stuff tells you how much you must deviate from locally inertiall in order to be aware that you're moving. You can take a look at the Euclidean version of Lorentz transformations, it imposes that there is an ether reference frame relative to which moving objects change their simultaneity. I don't think Lorentz's idea is obsolete; there are more and more studies on it these days. Energy needs a support to exist, it does not exist in a vacuum. I agree that length contraction may be an effect of perspective, but time dilation cannot be only that, because it would cancel out when the twin returns, just as his length returns to normal. Edited April 22 by externo
Eise Posted April 22 Posted April 22 (edited) 26 minutes ago, externo said: 1 hour ago, Eise said: Assuming that you agree that the Lorentz transformations are correct, how could they have different results when interpreting them with a Lorentzian aether on one side, and no aether at the other side? Minkowski derived his spacetime metric from the Lorentz transformations, not from Einstein's interpretation. You can try it. Take the Minkowskian metric for spacetime distances: (ct')2 - x'2 = (ct)2 - x2 And then plugin the Lorentz transformations. Do it! It is not too difficult. And? Did you need an aether for that? Lorentz transformations were derived with the idea that there was an aether and that the speed of light was constant relative to this aether. In order to remove the idea of the ether or at least remove its state of motion, we must add the condition that the speed of light is constant in both directions of motion, unlike classical kinematics. This condition allows us to get rid of the idea of a fixed frame of reference for the universe. Einstein's interpretation is therefore eroneous if there is a preferred rest reference frame for the universe. You did not answer the questions. Looking at all your other postings here, I can only conclude you are discussing here in bad faith. Either answer my questions (and all others that were posed to you...), or I am 100% sure of that. Edited April 22 by Eise
externo Posted April 22 Author Posted April 22 (edited) 16 minutes ago, Eise said: You did not answer the questions. Looking at all your other postings here, I can only conclude you are discussing here in bad faith. Either answer my questions (and all others that were posed to you...), or I am 100% sure of that. Yes, you need an ether for Minkowski space to work in the real world. If an object accelerates and changes simultaneity the signals it receives from space always come from the same source than before, which does not change time, there is no change in physical simultaneity of space-time, therefore there is no time vector, it's just a scalar. Edited April 22 by externo
Eise Posted April 22 Posted April 22 Just now, externo said: Yes, you need an ether for Minkowski space to work in the real world. If an object accelerates and changes simultaneity the signals it receives from space always come from the same source which does not change time, there is no change in physical simultaneity of space-time, therefore there is no time vector, it's just a scalar. Again no answer. Bye.
externo Posted April 22 Author Posted April 22 (edited) 5 minutes ago, Eise said: Again no answer. Bye. You are very smart for reading, understanding and responding to my message in one minute. YOU are in bad faith. Edited April 22 by externo -3
externo Posted April 22 Author Posted April 22 53 minutes ago, Eise said: I had no derivation to check, so I could answer very quickly. Lorentz transformations were derived with the assumption of an ether. Without this assumption they are not derivable in classical kinematics. Einstein derived them by assuming the speed of light to be constant in all inertial frames, which is not classical kinematics. I claim in this thread that if you deprive yourself of classic cinematics you are not consistent with the physical world.
Eise Posted April 22 Posted April 22 (edited) Again, no answer. Plugin the LTs in the Minkowski metric, and see what you get. Edited April 22 by Eise
joigus Posted April 22 Posted April 22 2 hours ago, Eise said: Did you need an aether for that? This is a point I've been meaning to bring up too. If you insist on saving the aether, you can, by introducing cumbersome hypotheses that clocks in motion slow down somehow and certain 'tensions' shorten the moving lengths somehow. Hendrik Lorentz did try something like that for a while from what I know. 1 hour ago, externo said: Lorentz transformations were derived with the idea that there was an aether and that the speed of light was constant relative to this aether. Old quantum theory was derived with the idea that particle positions were well defined. Later developments showed they aren't. Early relativistic ideas (Lorentz, Poincaré, etc) were developed with the idea of aether/absolute space. Later developments showed you can drop it and nobody would be any the wiser. 1 hour ago, externo said: we must add the condition that the speed of light is constant in both directions of motion, unlike classical kinematics. You should read what other members are telling you: 8 hours ago, Markus Hanke said: It’s invariant, not constant. It's invariant, not constant. It produces the same reading in all inertial frames. You should also do the exercise that @Eise suggests. Just a pure mathematical exercise, with no appeal to any ether. It produces what's observed. 2 hours ago, externo said: I agree that length contraction may be an effect of perspective, You missed the point, I'm afraid. I didn't say that. Unless you're willing to admit that moving is a matter of perspective. Then I did say that. But then, staying where you are (not moving at all) is but a particular way of moving. And moving in general, is tilting an angle along a hyperbola.
KJW Posted April 22 Posted April 22 (edited) On 4/21/2024 at 8:39 PM, externo said: During an acceleration there is a change in simultaneity. Do you think this change is physical or just mathematical? At the time of the U-turn, the Earth suddenly ages for the traveler. Do you think this aging is physical or mathematical? "Physical or mathematical" is a false dichotomy. In the case of the notion of simultaneity, at a given instant of a given trajectory in spacetime, there is a set of physical points in spacetime that form a physical three-dimensional space that is simultaneous to the given instant of the given trajectory. But if you examine the points themselves, you'll find nothing that physically indicates that they are simultaneous to the given instant of the given trajectory. Different instants give rise to different three-dimensional spaces, and different spacetime trajectories have their own sets of three-dimensional spaces. But you are incorrect in what you consider to be the space of simultaneity for the travelling twin of the twin paradox. You assume that the simultaneity of the travelling twin is the same as that of an outbound inertial trajectory during the outbound part of the journey and the same as that of an inbound inertial trajectory during the inbound part of the journey. But the space of simultaneity for the travelling twin is distinct from that of any inertial trajectory, taking into account the change that occurred during the journey. It should be noted that the space of simultaneity of individual points of any trajectory depends on the entire trajectory, not just a part of it. On 4/21/2024 at 8:39 PM, externo said: Do you think Minkowski spacetime is physical or only mathematical? I think spacetime is physical. If I look at myself in the mirror, I am seeing what I looked like in the past. And the further away the mirror is, the further back into my past I am looking. On 4/21/2024 at 8:39 PM, externo said: Do you think the metric of an accelerated frame of reference is physical or only mathematical? The principle of general relativity is that all coordinate systems are equally valid. But each observer has their own natural frame of reference. This is physical in the sense that it is based on the relationship of the physical observer to the spacetime. It is not however a physical property of the spacetime itself. However, the metric of a given coordinate system of a given physical spacetime is in principle the result of physical measurements of length and time using physical rulers and physical clocks. Edited April 22 by KJW
externo Posted April 22 Author Posted April 22 (edited) 3 hours ago, joigus said: Old quantum theory was derived with the idea that particle positions were well defined. Later developments showed they aren't. Early relativistic ideas (Lorentz, Poincaré, etc) were developed with the idea of aether/absolute space. Later developments showed you can drop it and nobody would be any the wiser. Well, we can't drop it, that's my point. I gave in my first message the reason why I think the aether (or rather a preferred frame) is necessary for the physical coherence of the theory. ------------------------------- 50 minutes ago, KJW said: "Physical or mathematical" is a false dichotomy. In the case of the notion of simultaneity, at a given instant of a given trajectory in spacetime, there is a set of physical points in spacetime that form a physical three-dimensional space that is simultaneous to the given instant of the given trajectory. But if you examine the points themselves, you'll find nothing that physically indicates that they are simultaneous to the given instant of the given trajectory. Different instants give rise to different three-dimensional spaces, and different spacetime trajectories have their own sets of three-dimensional spaces. But you are incorrect in what you consider to be the space of simultaneity for the travelling twin of the twin paradox. You assume that the simultaneity of the travelling twin is the same as that of an outbound inertial trajectory during the outbound part of the journey and the same as that of an inbound inertial trajectory during the inbound part of the journey. But the space of simultaneity for the travelling twin is distinct from that of any inertial trajectory, taking into account the change during the journey. It should be noted that the space of simultaneity of individual points of any trajectory depends on the entire trajectory, not just a part of it. When I say that the journey of the traveling twin is inertial it is because I assume that the change of direction occurs in a very short time. Once the change of direction is completed the journey is inertial there is no doubt about it. But you don't really answer, Lorentz's theory allows you to explain step by step what happens during the entire trip. Einsetin postulates that the speed of light is invariant in all frames of reference, this is a postulate of serious consequence, because it implies that there is a PHYSICAL change in simultaneity. You have to replace the PHYSICAL variation in the speed of light with something PHYSICAL, so in his version, when the twin turns around, the Earth suddenly PHYSICALLY ages, and this is not observed experimentally. Please understand that the only difference between Lorentz and Einstein is that Einstein gets rid of the privileged frame of reference by postulating the constancy of the one-way speed of light. 50 minutes ago, KJW said: I think spacetime is physical. If I look at myself in the mirror, I am seeing what I looked like in the past. And the further away the mirror is, the further back into my past I am looking. That's not Minkowski spacetime. Now see: if Minkowski spacetime is physical, the moment the twin turns around, the Earth suddenly ages relative to it, but this does not appear experimentally, the signal emanating from the Earth does not suddenly age. The experiment contradicts that space-time is physical. If, on the other hand, you think that Minkowski spacetime is not physical, then only space is physical and therefore the speed of light can only be constant with respect to space. Edited April 22 by externo
Mordred Posted April 22 Posted April 22 (edited) Why do you keep declaring Einstein theory does this or does that even after everyone has told you most your misconceptions are wrong. The Earth does not suddenly age different simply because one observer looks at it. There is literally billions of observers on Earth they all do not have any effect on the rate the Earth ages. That is pure nonsense. The Minkowskii metric doesn't even state that. By the way thanks for providing the math I asked for. Unfortunately so far as pointed out all the evidence with regards to c being invariant is something you shouldn't ignore. Edited April 22 by Mordred
KJW Posted April 22 Posted April 22 53 minutes ago, externo said: When I say that the journey of the traveling twin is inertial it is because I assume that the change of direction occurs in a very short time. Once the change of direction is completed the journey is inertial there is no doubt about it. The usual presentation of the twin paradox is that the travelling twin's journey is two inertial journeys, and I have not considered anything different. But although the journey is locally inertial at almost all times during the journey, the change in direction prevents the journey from being globally inertial. So, you have to take into account whether or not what you are considering is a local or a global notion. 53 minutes ago, externo said: it implies that there is a PHYSICAL change in simultaneity. What does this actually mean? 53 minutes ago, externo said: when the twin turns around, the Earth suddenly PHYSICALLY ages I'll repeat: Quote But you are incorrect in what you consider to be the space of simultaneity for the travelling twin of the twin paradox. You assume that the simultaneity of the travelling twin is the same as that of an outbound inertial trajectory during the outbound part of the journey and the same as that of an inbound inertial trajectory during the inbound part of the journey. But the space of simultaneity for the travelling twin is distinct from that of any inertial trajectory, taking into account the change during the journey. It should be noted that the space of simultaneity of individual points of any trajectory depends on the entire trajectory, not just a part of it. There is no discontinuity in the time of the earth in the frame of reference of the travelling twin. You have made an error in your assessment of the frame of reference of the travelling twin. 53 minutes ago, externo said: That's not Minkowski spacetime. Minkowski spacetime doesn't exist, except locally or perhaps as part of a multiverse. Otherwise, it is a mathematical idealisation. That's why I dropped the "Minkowski" when I said, "I think spacetime is physical". But even in general relativity with curved spacetime, local physics is the physics of Minkowskian spacetime, so Minkowskian spacetime is more than just a mathematical idealisation or approximation. I should also state that one can calculate the result of the twin paradox without reference to the notion of simultaneity of the travelling twin by considering the Doppler effect that is observed by both twins of each other during the entire journey of the travelling twin. Each twin is literally observing the clock of the other twin.
externo Posted April 22 Author Posted April 22 (edited) 1 hour ago, Mordred said: Why do you keep declaring Einstein theory does this or does that even after everyone has told you most your misconceptions are wrong. The Earth does not suddenly age different simply because one observer looks at it. There is literally billions of observers on Earth they all do not have any effect on the rate the Earth ages. That is pure nonsense. The Minkowskii metric doesn't even state that. By the way thanks for providing the math I asked for. Unfortunately so far as pointed out all the evidence with regards to c being invariant is something you shouldn't ignore. It's simple reasoning. The theory imposes an ether naturally. The speed of light is constant relative to the ether. Now to remove this ether, we must postulate that the speed is invariant with respect to all frames of reference, but this requires that this invariance be physical, otherwise it is only a mathematical construction, the speed of light still changes and there still exists an ether. It turns out that this hypothesis of physical invariance requires that the Earth ages suddenly, that's how it is. It's pure nonsence but it's not my theory. The invariance of the one-way speed of light is not measurable, what is measurable is the invariance of the speed over a round trip, and Lorentz and Einstein both predict this invariance. ------------------------------- 1 hour ago, KJW said: What does this actually mean? It's simple reasoning. The theory imposes an ether naturally. The speed of light is constant relative to the ether. Now to remove this ether, we must postulate that the speed is invariant with respect to all frames of reference, but this requires that this invariance be physical, otherwise it is only a mathematical construction, the speed of light still changes and there still exists an ether. It turns out that this hypothesis of physical invariance requires that the Earth ages suddenly, that's how it is. It's pure nonsence but it's not my theory. 1 hour ago, KJW said: Minkowski spacetime doesn't exist, except locally or perhaps as part of a multiverse. Otherwise, it is a mathematical idealisation. That's why I dropped the "Minkowski" when I said, "I think spacetime is physical". But even in general relativity with curved spacetime, local physics is the physics of Minkowskian spacetime, so Minkowskian spacetime is more than just a mathematical idealisation or approximation. But do you think general relativity spacetime is physical? That's the real question. Because I claim it's just a non-physical mathematical model. The physical model is here: 1 hour ago, KJW said: I should also state that one can calculate the result of the twin paradox without reference to the notion of simultaneity of the travelling twin by considering the Doppler effect that is observed by both twins of each other during the entire journey of the travelling twin. Each twin is literally observing the clock of the other twin. But this is precisely the example I gave in the first message to show that Einstein's interpretation was false: Edited April 22 by externo
swansont Posted April 22 Posted April 22 14 minutes ago, externo said: It's simple reasoning. The theory imposes an ether naturally. The speed of light is constant relative to the ether. Now to remove this ether, we must postulate that the speed is invariant with respect to all frames of reference, but this requires that this invariance be physical, I’m not sure what this even means. c being invariant has certain consequences, two of which are time dilation and length contraction 14 minutes ago, externo said: otherwise it is only a mathematical construction, Physics is chock full of mathematical constructs, so it’s not like this is a strike against physics. 14 minutes ago, externo said: the speed of light still changes and there still exists an ether. It turns out that this hypothesis of physical invariance requires that the Earth ages suddenly, that's how it is. It's pure nonsence but it's not my theory. It’s not relativity, either. It’s a straw man of relativity. You’re the only one here saying the earth ages suddenly, and you’re not a credible source on the topic.
externo Posted April 22 Author Posted April 22 (edited) 14 minutes ago, swansont said: c being invariant has certain consequences, two of which are time dilation and length contraction Physics is chock full of mathematical constructs, so it’s not like this is a strike against physics. It’s not relativity, either. It’s a straw man of relativity. You’re the only one here saying the earth ages suddenly, and you’re not a credible source on the topic. The invariance on a round trip involves length contraction and time dilation, not the invariance in a one-way trip, which is a postulate of Einstein which has no other use than to eliminate the privileged frame of reference . 14 minutes ago, swansont said: Physics is chock full of mathematical constructs, so it’s not like this is a strike against physics. Epicycles are a mathematical construction that does not correspond to physical reality, "the sun revolves around the Earth" is another. 14 minutes ago, swansont said: It’s not relativity, either. It’s a straw man of relativity. You’re the only one here saying the earth ages suddenly, and you’re not a credible source on the topic. If the speed of light is physically invariant by change of frame of reference then instead simultaneity must vary physically. If you play to modify the laws of kinematics you must assume the consequences. Edited April 22 by externo
swansont Posted April 22 Posted April 22 1 hour ago, externo said: If the speed of light is physically invariant by change of frame of reference then instead simultaneity must vary physically. If you play to modify the laws of kinematics you must assume the consequences. I don’t know what you mean by “simultaneity must vary physically” Things are simultaneous or not, and it’s a temporal effect. Events that are simultaneous in one frame are not simultaneous in other frames. On 4/18/2024 at 4:39 AM, externo said: When the traveling twin turns around to reach Earth, it observes a blueshift of the light emitted by Earth instantaneously, not after some time. This seems to suggest that the blueshift arises from the twin's own acceleration and therefore its own motion through ether, not from the apparent movement of Earth relative to it. The earth twin sends out a continuous signal at some frequency, with some wavelength. The space twin travels at some speed, and sees this signal as red-shifted - they get the crest of one wave, but have moved away before the next crest can reach them, so they measure the signal with a longer wavelength and lower frequency. Then they turn around, and are now moving toward the source. They get the crest of one wave, but have moved closer before the next crest reaches them. Since the signal was sent continuously, this happens immediately - the light is already there to be detected. They measure the crests as being closer together and with a higher frequency. Blue-shifted. I can’t fathom why you think this would not happen as soon as they started moving toward earth. 1
Markus Hanke Posted April 23 Posted April 23 (edited) 21 hours ago, externo said: If it is physical it implies that the Earth suddenly ages for real during the U-turn I never mentioned any U-turn - I made it explicitly clear that I made no assumptions about what the path actually looks like, other than it being light-like (thus differentiable everywhere). Why? Because that’s irrelevant, since the difference in clock readings only depends on the total lengths of the two paths. It’s a global measure along the entire journey. Others here have repeatedly pointed this out too. And since both path length and proper acceleration are invariant measures, both twins agree on the outcome. 21 hours ago, externo said: So math agrees with Lorentz but not with Einstein. That’s a meaningless statement. I used Einsteinian SR to show how the twin scenario requires no “resolution”. 21 hours ago, externo said: the acceleration period can be reduced to an infinitely short time Really? How do you physically realise an instantaneous U-turn with infinite acceleration? Once again, the clock times are integral measures along the entire journey. 21 hours ago, externo said: If the the frequency of the electromagnetic signal increases, it is because the one accelerating has changed its velocity in relation to the signal In relation to the emitter, not the signal. There’s no rest frame for light. Edited April 23 by Markus Hanke
Eise Posted April 23 Posted April 23 I think I found an even better challenge for you, @externo because it seems you have problems with even simple math. This is the formula for the Doppler effect in a medium: vr = is the speed of the receiver relative to the medium, added to ± (above the division) = if the receiver is moving towards the source, subtracted if the receiver is moving away from the source vs = is the speed of the source relative to the medium, added to ± (below the division) if the source is moving away from the receiver, subtracted if the source is moving towards the receiver And last, but not least: c = is the propagation speed of waves in the medium Now this is the Doppler formula for light, assuming the source and the receiver are moving in a straight line from/to each other: where ß is the usual v/c. Now tell me, where do you see the speed of light in a medium? How do you explain that it does not appear in the formula? The above formula, AFAIK, can be derived from the Lorentz transformations, in which, you probably noticed, the speed of light in a medium does not occur either. Another problem I seem to see, is that you are thinking that relativity has something to do with signal delay. It hasn't. So the blueshift that the observer on earth sees after the traveler has turned around, of course takes time to reach earth. That is just signal time delay, nothing special.
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