Lorentz Jr Posted March 11, 2023 Share Posted March 11, 2023 (edited) 1 hour ago, Phi for All said: There is no "space time fabric", for instance. Spacetime is a description of the geometry involved in the continuum of spatial and temporal dimensions. And what kind of magic wand are you waving with the "quantization beyond the standard model" part? The same kind of magic wand you physicists wave with the word "geometry". So spacetime has a geometry. So what? Lots of things have geometry. Geometry is just a mathematical description. It doesn't mean fields and gravity waves happen by magic or unicorns or leprechauns. It doesn't mean spacetime isn't implemented by something that an amateur might call a "fabric" or "ether". From Einstein's 1920 address in Leiden: Quote Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this ether may not be thought of as endowed with the quality characteristic of ponderable media, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it. This is only the summary in the last paragraph. There's a fuller discussion earlier in the talk. Edited March 11, 2023 by Lorentz Jr Link to comment Share on other sites More sharing options...
MigL Posted March 11, 2023 Share Posted March 11, 2023 10 minutes ago, Lorentz Jr said: From Einstein's 1920 address in Leiden: A lot of Physics has happened in the last 103 years. A Einstein was smart but even he could not predict the future. 13 minutes ago, Lorentz Jr said: Geometry is just a mathematical description. It doesn't mean fields and gravity waves happen by magic or unicorns or leprechauns. A field is defined by numerical values, and directions, at each point in space. That is exactly what geometry does at every point in space-time. Why do you think 'geometry' does not define a field ? Link to comment Share on other sites More sharing options...
Lorentz Jr Posted March 11, 2023 Author Share Posted March 11, 2023 (edited) 9 minutes ago, MigL said: A lot of Physics has happened in the last 103 years. A lot of politics has happened in that time. Today's physicists use the word "geometry" as a rhetorical bludgeon to shut people up when they complain about the unscientific nature of relativity as a metaphysical principle. "It's just a matter of geometry". Baloney! Geometry is mathematics, and math is description. It doesn't explain anything or rule out things having some kind of substantive implementation. 9 minutes ago, MigL said: A field is defined by numerical values, and directions, at each point in space. That is exactly what geometry does at every point in space-time. Why do you think 'geometry' does not define a field ? The word "define" is confusing here. Anything can be defined. Definitions are just relationships between ideas and words. The point is that geometry can only describe, and it's scientifically absurd to say that things happen with no implementation. Saying that something can't be a "fabric" because it's a "geometry" is a rhetorical BS tactic, and referring to "magic wands" in the same post is hypocritical. Edited March 11, 2023 by Lorentz Jr -4 Link to comment Share on other sites More sharing options...
Markus Hanke Posted March 12, 2023 Share Posted March 12, 2023 8 hours ago, Lorentz Jr said: Today's physicists use the word "geometry" as a rhetorical bludgeon to shut people up when they complain about the unscientific nature of relativity as a metaphysical principle. The problem I see with this statement is that relativity itself wasn’t ever meant to be a “metaphysical principle” - right from the outset it served a very practical purpose, namely being a descriptive model that doesn’t suffer from the internal contradictions and conflicts with observational data that Newtonian physics did. In that it has been pretty successful, and crucially it allowed us to reduce our reliance on some rather dubious concepts - such as for example Newtonian forces. I mean, think about it - a Newtonian “force” is a supposed thing that cannot be directly observed or detected (we only ever see its effects), that is entirely non-local, somehow acts instantaneously across arbitrary distances, and there is no underlying mechanism that might explain how it could possibly do all these things. Metaphysically speaking this is entirely ridiculous by anyone’s standards. Yet it works to some degree, and thus to this day we teach it in our schools. If you are looking for an underlying metaphysical principle in relativity, then it would be that of symmetries - turns out that the fundamental objects which SR deals with (Lorentz transformations, tensors, spinors etc) are representations of the Lorentz group, whereas GR is a gauge field theory with GL(4) as its fundamental symmetry group. Of course Einstein himself didn’t know that at the time. Symmetries are also the metaphysical principle underlying many other areas of physics, most notably HEPP. Seems to me these things are all pretty useful! Link to comment Share on other sites More sharing options...
Lorentz Jr Posted March 12, 2023 Author Share Posted March 12, 2023 (edited) 9 hours ago, Lorentz Jr said: Today's physicists use the word "geometry" as a rhetorical bludgeon to shut people up when they complain about the unscientific nature of relativity as a metaphysical principle. 1 hour ago, Markus Hanke said: The problem I see with this statement is that relativity itself wasn’t ever meant to be a “metaphysical principle” You're changing the subject, Markus. I made a complaint about current practices, and you're criticizing it based on past intentions. 1 hour ago, Markus Hanke said: - right from the outset it served a very practical purpose, namely being a descriptive model that doesn’t suffer from the internal contradictions and conflicts with observational data that Newtonian physics did. Still off-topic. 1 hour ago, Markus Hanke said: I mean, think about it No, you think about it, Markus. I've been thinking about it for two or three years now. The laws of physics are exactly the same for all observers, and yet somehow astronauts who fly through space magically age less than people who stay on Earth. All kinds of things happen in the vacuum, with field disturbances and time-varying metrics, and yet somehow this all happens with no "fabric", i.e. implementation, to make it happen. That contradicts and conflicts with the most fundamental principles of science. 1 hour ago, Markus Hanke said: If you are looking for an underlying metaphysical principle in relativity, then it would be that of symmetries And yet somehow the outcomes aren't always symmetric. Edited March 12, 2023 by Lorentz Jr Link to comment Share on other sites More sharing options...
Genady Posted March 12, 2023 Share Posted March 12, 2023 (edited) 3 hours ago, Markus Hanke said: relativity ... allowed us to reduce our reliance on some rather dubious concepts - such as for example Newtonian forces. It's worth noting that Newtonian forces were 'eliminated' by Hamiltonian and Lagrangian formulations of mechanics. Edited March 12, 2023 by Genady 1 Link to comment Share on other sites More sharing options...
swansont Posted March 12, 2023 Share Posted March 12, 2023 12 hours ago, Lorentz Jr said: So spacetime has a geometry. So what? Lots of things have geometry. Geometry is just a mathematical description. It doesn't mean fields and gravity waves happen by magic or unicorns or leprechauns. It doesn't mean spacetime isn't implemented by something that an amateur might call a "fabric" or "ether". I believe that was Phi’s point: “fabric” is an amateur or pop-sci description, and if you’re going to have a serious discussion of science, you can’t be invoking amateur descriptions. 2 hours ago, Lorentz Jr said: No, you think about it, Markus. I've been thinking about it for two or three years now. The laws of physics are exactly the same for all observers, and yet somehow astronauts who fly through space magically age less than people who stay on Earth. All kinds of things happen in the vacuum, with field disturbances and time-varying metrics, and yet somehow this all happens with no "fabric", i.e. implementation, to make it happen. That contradicts and conflicts with the most fundamental principles of science. What “fundamental” principle is that? Special relativity is a fairly straightforward consequence of the invariance of c. No magic involved. Link to comment Share on other sites More sharing options...
Markus Hanke Posted March 12, 2023 Share Posted March 12, 2023 (edited) 3 hours ago, Lorentz Jr said: You're changing the subject, Markus. I made a complaint about current practices, and you're criticizing it based on past intentions. Ok, let me explain. My understanding of what you are trying to say is that we are missing a deeper mechanism of how gravity works, and why it is the way it is. We have an equation that allows us to describe any given scenario of classical gravity, but we don’t know why the equation works, or why it looks the specific way it does. We can’t even be 100% sure yet that the equation we are using is indeed the best possible description of classical gravity - I think it is at least conceivable that one of the very many possible modifications of GR might eventually turn out to be better. I’m not prepared to categorically rule this out, though for various reasons I think it is unlikely. But regardless, I agree with you on the basic premise - we do not know yet what the underlying mechanism might be, so our understanding of gravity is still lacking in that regard. It’s an epistemic description, but not an ontological one. As you put it, there’s time varying metrics etc, but no underlying mechanism to “make that happen”. What I question though is why you seem to hold GR accountable for not providing such a mechanism. It was never designed to do this, since it is simply a generalisation of SR, which in itself proposes no mechanisms either - it simply arose from the empirical observation that Minkowski spacetime provides a model that fits very well to available observational data. Newton also never provided any “implementation” of how his forces work - he simply posited them as a convenient computational tool, not as an ontological description of reality. So I feel that pointing out that what you are looking for is outside the remit of GR is a valid criticism. I also don’t agree that current practices make no attempt at find such underlying mechanisms, because that is what the whole quest for quantum gravity is ultimately all about - and it is an area of research that is ongoing and very active. Naturally in such a quest there’s going to be very many dead ends, especially since the domain in question is beyond our technological capabilities to probe it directly, essentially making is fumble in the dark here. Within current constraints (technology, funding, politics etc etc) I actually think we are doing pretty much the best we can in that regard. Our efforts aren’t perfect, but they are all we can muster right now. I think you are demanding way too much from contemporary physics - you seem to basically say that “if it isn’t a fully fledged ontological explanation, then it’s not science”. I cannot agree with this. I think any epistemic description of an aspect of the world that allows us to make predictions by way of computation is valuable, at least as an intermediary step, even if it is not explicitly ontological in nature. Of course we want such models to approach the status of an ontological explanation over time, but that is not going to happen all at once. You start with something purely descriptive, and then keep refining it; occasionally you might need to change your paradigms; and in the end we might get to something that approaches ontology. I understand physics as being a process that will take time. My guess is that the day will come when GR will be understood as merely the semi-classical description of something much more fundamental, but we are not at that stage yet. Mind you, there is also no guarantee that there actually is a fundamental ontological explanation - perhaps spacetime just is what it is and can’t be further reduced, in the same way that the specific and irrational numerical value of pi can’t be reduced to any more fundamental “mechanism”. I sincerely hope for this not to be the case, but I think we are also not in a position to categorically rule that out yet. 3 hours ago, Lorentz Jr said: The laws of physics are exactly the same for all observers, and yet somehow astronauts who fly through space magically age less than people who stay on Earth. Obviously, because they are using the same laws, but different boundary conditions. Sharing the same laws does not mean that everyone measures the same thing irrespective of the situation they find themselves in - it means only that they agree on what each of them measures. To be specific, the law in question is the total amount of proper time physically accumulated on a clock that propagates from one event to another. This is not just some nebulous theoretical concept, but it is what you physically see accumulated on a clock that you are holding in your hand while travelling. That total time is calculated as \[\tau =\int _{C} ds=\int _{C}\sqrt{g_{\mu \nu } dx^{\mu } dx^{\nu }}\] as you probably know already. This law is the same for everyone, since it is written in covariant form. What is not the same for everyone is the path C that you need to put in as a boundary/initial condition in order to evaluate that integral - it naturally depends on the pair of events that are being connected, and it also depends on the spatial trajectory that is being travelled. So once you evaluate that line integral, you are (in general) going to obtain different numerical results depending on your choice of C, even though the same law was used by everyone involved. That is just how line integrals work. Once again you can ask why this is so - why does this law look the way it is, ie why is it a line integral and thus dependant on a choice of path? But SR/GR cannot answer this question, because it is outside their remit. Hopefully we can eventually come up with a more fundamental model that can explain why this law looks the way it does, but at present we don’t have that yet. 3 hours ago, Lorentz Jr said: And yet somehow the outcomes aren't always symmetric. Of course not. These are gauge symmetries we are talking about. If they were always global, then the entire rich phenomenology of the universe around us would disappear - there wouldn’t be the kind of particle zoo we find, and there wouldn’t be any gravity. PS. When I speak about a “deeper mechanism” in the context of context of gravity, what I mean specifically is why, in the classical limit, curvature and gravitational sources are locally related via an equation of the general form G=T, as opposed to some other relationship. Part of the reason is clearly mathematical consistency, since the properties of G and T themselves already rule out most alternative forms of the equation. Another already known constraint comes from topological considerations, to do with the conservation of certain topological quantities. So we are not completely clueless as to the “why”, it’s just that the bigger picture is incomplete. Note also that once the local relationship between sources and curvature is established, and boundary conditions are set, then what happens in all the rest of spacetime is a foregone conclusion on account of the basic requirements of continuity and differentiability. So once you know what the deeper link between sources and curvature is, you don’t actually need any other “mechanisms” - it’s then simply a matter of logical consistency, because you can’t randomly glue any old geometry onto any old source distribution. The only true mechanism here is that initial (purely local!) link from sources to geometry. Edited March 12, 2023 by Markus Hanke Added a PS Link to comment Share on other sites More sharing options...
Markus Hanke Posted March 12, 2023 Share Posted March 12, 2023 5 minutes ago, Genady said: It's worth noting that Newtonian forces were 'eliminated' by Hamiltonian and Lagrangian formulations of mechanics. Indeed! Link to comment Share on other sites More sharing options...
martillo Posted March 12, 2023 Share Posted March 12, 2023 5 hours ago, Markus Hanke said: I mean, think about it - a Newtonian “force” is a supposed thing that cannot be directly observed or detected (we only ever see its effects), that is entirely non-local, somehow acts instantaneously across arbitrary distances, and there is no underlying mechanism that might explain how it could possibly do all these things. Metaphysically speaking this is entirely ridiculous by anyone’s standards. Yet it works to some degree, and thus to this day we teach it in our schools. Not ridiculous for me. I can think in an entire Universe running in some kind of "Universal Supra-Computer" running all physics laws (even the force law) over a (huge I know) set of elementary particles. That "machine" as powerful as needed of course. Link to comment Share on other sites More sharing options...
Lorentz Jr Posted March 12, 2023 Author Share Posted March 12, 2023 (edited) 5 hours ago, Lorentz Jr said: The laws of physics are exactly the same for all observers, and yet somehow astronauts who fly through space magically age less than people who stay on Earth. All kinds of things happen in the vacuum, with field disturbances and time-varying metrics, and yet somehow this all happens with no "fabric", i.e. implementation, to make it happen. That contradicts and conflicts with the most fundamental principles of science. 2 hours ago, swansont said: What “fundamental” principle is that? Causality. All these things happen with no mechanism to make them happen. GR isn't so bad, because curvature is at least a shallow explanation, I'm not complaining about that. But then people say it's only "geometry", not "fabric". Any serious discussion with amateurs should explain any subtleties they need to understand, instead of playing "Gotcha!" with them by simply denying what they said with only the meaningless "explanation" that "it's just geometry". We've discussed SR before (a mechanism for time dilation in the twin paradox requires a preferred frame, and many physicists subscribe to a "hard" or "strong" interpretation of SR that denies such a frame exists). Edited March 12, 2023 by Lorentz Jr Link to comment Share on other sites More sharing options...
Genady Posted March 12, 2023 Share Posted March 12, 2023 51 minutes ago, martillo said: Not ridiculous for me. I can think in an entire Universe running in some kind of "Universal Supra-Computer" running all physics laws (even the force law) over a (huge I know) set of elementary particles. That "machine" as powerful as needed of course. This Universal Supra-Computer is run according to some laws, perhaps. What runs those laws? Another Ultra-Universal-Supra-Dupra-Computer, perhaps. And that Computer? And then there are turtles all the way down. Link to comment Share on other sites More sharing options...
swansont Posted March 12, 2023 Share Posted March 12, 2023 34 minutes ago, Lorentz Jr said: Causality. All these things happen with no mechanism to make them happen. GR isn't so bad, because curvature is at least a shallow explanation, I'm not complaining about that. But then people say it's only "geometry", not "fabric". Any serious discussion with amateurs should explain any subtleties they need to understand, instead of playing "Gotcha!" with them by simply denying what they said with only the meaningless "explanation" that "it's just geometry". My attitude is that if you show up intending to discuss physics - in a context that you are challenging mainstream physics - you should have sufficient knowledge to do so. I shouldn’t have to explain the basics to someone who is not asking that the basics be explained. 34 minutes ago, Lorentz Jr said: We've discussed SR before (a mechanism for time dilation in the twin paradox requires a preferred frame, and many physicists subscribe to a "hard" or "strong" interpretation of SR that denies such a frame exists). It’s interesting that you object to not having a mechanism for time dilation but not to having none for time. You are misusing what is meant by a preferred frame, and apparently, causality. 1 Link to comment Share on other sites More sharing options...
Lorentz Jr Posted March 12, 2023 Author Share Posted March 12, 2023 (edited) 3 hours ago, Markus Hanke said: My understanding of what you are trying to say is that we are missing a deeper mechanism of how gravity works, and why it is the way it is. No, that's not it. There's nothing wrong with shallow theories if there's no clear evidence for specific mechanisms. The problem is when people deny that any mechanism ("fabric") exists or formulate principles (no preferred frame) that are incompatible with the existence of any mechanism. 3 hours ago, Markus Hanke said: What I question though is why you seem to hold GR accountable for not providing such a mechanism. I don't, and what I question is why you keep knocking down these straw men. I hold people like Phi (and almost everyone else in the mainstream physics community 🙄) accountable for using the idea of "geometry" as a way to suggest that no mechanism is required. They use it as a "magic wand" to create confusion between physical mechanisms and mathematical descriptions. 3 hours ago, Markus Hanke said: you seem to basically say that “if it isn’t a fully fledged ontological explanation, then it’s not science”. No, that's another straw man. I'm not criticizing the theories, I'm criticizing people who interpret the theories in confusing or unscientific ways. 3 hours ago, Markus Hanke said: perhaps spacetime just is what it is and can’t be further reduced, ... but I think we are also not in a position to categorically rule that out yet. That sounds reasonable. 🙂 3 hours ago, Markus Hanke said: Obviously, because they are using the same laws, but different boundary conditions. Boundary conditions are a mathematical concept, not a physical one. If two systems have different outcomes between the same two points in spacetime, there must have been some physical difference between their environments. 3 hours ago, Markus Hanke said: What is not the same for everyone is the path C that you need to put in as a boundary/initial condition Boundary conditions are a mathematical concept, not a physical one. They don't say anything about physical mechanisms. 3 hours ago, Markus Hanke said: Hopefully we can eventually come up with a more fundamental model that can explain why this law looks the way it does, but at present we don’t have that yet. Sure we do. Lorentz's ether interpretation says there's an ether with its own reference frame, and time dilation is caused by motion through that mediuim. Not that there aren't problems with that idea, like why is there no experimental evidence for what the preferred frame is? But at least it's scientifically valid. Trying to "explain" the frame-independent time dilation in the twin paradox through paths and boundary conditions is not. 1 hour ago, martillo said: I can think in an entire Universe running in some kind of "Universal Supra-Computer" running all physics laws (even the force law) over a (huge I know) set of elementary particles. That "machine" as powerful as needed of course. Speaking of "living in a simulation" theories, they do provide another (barely) conceivable explanation for the lack of evidence for a preferred frame, because a simulation can do whatever the simulator is capable of making it do. For instance, c as a universal speed limit smells suspiciously like a CPU processing rate. I don't like to emphasize them, because they seem so nutty, but they're still technically more scientific as physical mechanisms than appeals to boundary conditions and "paths through spacetime". 48 minutes ago, Genady said: And then there are turtles all the way down. That's not unique to simulation theories. It's a fundamental question about reductionism. What are quarks and leptons made of? What are their constituents made of? Does the tower go down infinitely far, in which case even the smallest actions entail infinite amounts of information processing? Or is there a swamp of nondeterminism underneath it, in which case the universe is ultimately founded on magic? It's one of the questions I've given up on trying to answer, because I'm not sure it's possible to answer it. 45 minutes ago, swansont said: It’s interesting that you object to not having a mechanism for time dilation but not to having none for time. I take time to be another one of the great unanswerable questions. Chalk it up to God and leave it at that, because the only other alternative is being wrapped up in a straightjacket and living the rest of your life in a rubber room. It's too hard a problem. Time dilation is different though. That's just the behavior of clocks, and why should the behavior of clocks never be affected by anything? There's a certain narcissism in defining something as important as time in terms of whatever gadgets our current technology happens to be capable of producing. If two synchronized clocks disagree after one of them has flown through space for a while, then obviously something happened to alter the ticking rate of at least one of them. 45 minutes ago, swansont said: You are misusing what is meant by a preferred frame, and apparently, causality. You are making vague assertions with no supporting logic or evidence. Edited March 12, 2023 by Lorentz Jr Link to comment Share on other sites More sharing options...
Genady Posted March 12, 2023 Share Posted March 12, 2023 30 minutes ago, Lorentz Jr said: It's a fundamental question about reductionism. What are quarks and leptons made of? What are their constituents made of? Does the tower go down infinitely far, in which case even the smallest actions entail infinite amounts of information processing? Or is there a swamp of nondeterminism underneath it, in which case the universe is ultimately founded on magic? It's one of the questions I've given up on trying to answer, because I'm not sure it's possible to answer it. I gave up on answering that question as well, but for a different reason. I see this problem not as a problem of how the universe works or of logic, but a limitation of our, i.e., human, way of understanding things. This is what the biological evolution gave us for living in the world around us, our modus operandi. It did not evolve to explain the universe. Link to comment Share on other sites More sharing options...
apprentus Posted March 12, 2023 Share Posted March 12, 2023 The event horizon is the boundary around a black hole beyond which nothing, not even light, can escape its gravitational pull. It marks the point of no return, where any object or information that crosses it is trapped within the black hole's singularity. From the perspective of an outside observer, an object that crosses the event horizon appears to slow down and become increasingly red-shifted as it approaches the horizon, until it appears to freeze at the horizon and become invisible. This is because the gravitational pull of the black hole is so strong that time and space become severely distorted, and the object's movement slows down to the point of appearing motionless. From the perspective of an object crossing the event horizon, however, there is no visible or physical barrier, and it can pass through the horizon without noticing any change. Once inside the horizon, however, the object will inevitably be pulled towards the black hole's singularity. In this sense, the event horizon marks a dramatic transition from "somewhere" outside the black hole to "everywhere" inside the black hole, where all objects and information are inexorably drawn towards the singularity at the center. Link to comment Share on other sites More sharing options...
MigL Posted March 12, 2023 Share Posted March 12, 2023 When people, or Physicists, speak of 'geometry' or 'fabric', are they referring to the model or the actual space-time ? All we know is that a model, incorporating 'geometry', or curvature if you will, manages to very accurately predict what happens with test masses in actual space-time. We have no idea whether the 'reality' of actual space-time, or its 'fabric', incorporates such curvature. But the mathematical model, which is GR, does utilize geometry, also mathematical, to make its extremely accurate predictions. Are you maybe mistaking the model for any undelying rality, Lorentz Jr. ( which we may possibly never know ) ? Link to comment Share on other sites More sharing options...
martillo Posted March 12, 2023 Share Posted March 12, 2023 1 hour ago, Genady said: This Universal Supra-Computer is run according to some laws, perhaps. What runs those laws? Another Ultra-Universal-Supra-Dupra-Computer, perhaps. And that Computer? And then there are turtles all the way down. At least it gives answers for our current level understanding of the Universe. It opens another level for similar questions, I agree. But you know, the Greeks started with atoms, after came protons, electrons and neutrons and then now quarks, leptons and bosons. Who knows if yet another deeper level appears. So may be to pass to another level could be needed to be done. Link to comment Share on other sites More sharing options...
Genady Posted March 12, 2023 Share Posted March 12, 2023 1 minute ago, martillo said: At least it gives answers for our current level understanding of the Universe. It opens another level for similar questions, I agree. But you know, the Greeks started with atoms, after came protons, electrons and neutrons and then now quarks, leptons and bosons. Who knows if yet another deeper level appears. So may be to pass to another level could be needed to be done. Yes, Lorentz Jr. has already said it here: 2 hours ago, Lorentz Jr said: That's not unique to simulation theories. It's a fundamental question about reductionism. What are quarks and leptons made of? What are their constituents made of? Does the tower go down infinitely far, in which case even the smallest actions entail infinite amounts of information processing? Or is there a swamp of nondeterminism underneath it, in which case the universe is ultimately founded on magic? It's one of the questions I've given up on trying to answer, because I'm not sure it's possible to answer it. And I have already replied to it here: 1 hour ago, Genady said: I gave up on answering that question as well, but for a different reason. I see this problem not as a problem of how the universe works or of logic, but a limitation of our, i.e., human, way of understanding things. This is what the biological evolution gave us for living in the world around us, our modus operandi. It did not evolve to explain the universe. Link to comment Share on other sites More sharing options...
swansont Posted March 12, 2023 Share Posted March 12, 2023 2 hours ago, Lorentz Jr said: I take time to be another one of the great unanswerable questions. Chalk it up to God and leave it at that, because the only other alternative is being wrapped up in a straightjacket and living the rest of your life in a rubber room. It's too hard a problem. Time dilation is different though. That's just the behavior of clocks No, it’s the behavior of time. There’s nothing in the derivation of time dilation that involves a clock. 2 hours ago, Lorentz Jr said: , and why should the behavior of clocks never be affected by anything? There's a certain narcissism in defining something as important as time in terms of whatever gadgets our current technology happens to be capable of producing. If two synchronized clocks disagree after one of them has flown through space for a while, then obviously something happened to alter the ticking rate of at least one of them. Yes, something happened to the ticking rate, because e.g. time moved at a slower pace, and clocks measure time. If you are inferring that there is some mechanical effect on the clock, it’s incumbent upon you to provide the details, and the evidence. Quote You are making vague assertions with no supporting logic or evidence. They are your assertions, not mine. You have not said what you think either of the terms actually means, but the notion of not having a preferred frame is limited to inertial frames, i.e. the conditions under which time dilation is derived and where the symmetry of different frames holds. Causality refers to ordering of events. It does not mean that everything has a mechanistic cause. Time dilation is not a mechanical effect on clocks, so it does not require a mechanistic cause. It’s an effect on time, owing to the invariance of c. Link to comment Share on other sites More sharing options...
Lorentz Jr Posted March 12, 2023 Author Share Posted March 12, 2023 (edited) 1 hour ago, MigL said: Are you maybe mistaking the model for any undelying rality, Lorentz Jr. ( which we may possibly never know ) ? Phi (and many others before him) made the positive assertion, "There is no space time fabric". That claim isn't part of GR, and I agree with Einstein's view that some kind of underlying reality is necessary to explain why GR works. 34 minutes ago, swansont said: No, it’s the behavior of time. There’s nothing in the derivation of time dilation that involves a clock. Yes, something happened to the ticking rate, because e.g. time moved at a slower pace, and clocks measure time. If you are inferring that there is some mechanical effect on the clock, it’s incumbent upon you to provide the details, and the evidence. "Clocks don't tick more slowly, time moves more slowly." You're just moving the goalposts with semantic gibberish, swanson. If the astronaut is younger than his twin when he returns to Earth, then why did "time move more slowly" on the spaceship? The laws of physics on the ship are exactly the same as on Earth, and yet somehow less "time" elapsed on the ship. 34 minutes ago, swansont said: Causality ... does not mean that everything has a mechanistic cause. You're very creative, swanson. Very persistent and very creative. 😄 Edited March 12, 2023 by Lorentz Jr Link to comment Share on other sites More sharing options...
martillo Posted March 12, 2023 Share Posted March 12, 2023 1 hour ago, Genady said: 3 hours ago, Genady said: I gave up on answering that question as well, but for a different reason. I see this problem not as a problem of how the universe works or of logic, but a limitation of our, i.e., human, way of understanding things. This is what the biological evolution gave us for living in the world around us, our modus operandi. It did not evolve to explain the universe. You gave up but may be others don't. You don't need to prevent them going on. Link to comment Share on other sites More sharing options...
Genady Posted March 12, 2023 Share Posted March 12, 2023 14 minutes ago, martillo said: You don't need to prevent them going on. Of course not, I don't need to, I don't want to, I can't. Let them keep marching. Even if they don't go anywhere. Link to comment Share on other sites More sharing options...
MJ kihara Posted March 12, 2023 Share Posted March 12, 2023 Back to the hijack,a little bit,from the diagram there is the issue of graviton,the discussion about general relativity it's predictions have been tested and proved beyond doubt.Dark matter and dark energy influence is said to be there from it's gravitational influence of normal matter.given that from the definition of graviton as indicated( in the diagram) does that diagram not reconcile general relativity and quantum gravity? Then the issue of time dilation becomes easier to understand... because entanglement comes into the picture...I struggled to understand the tough 'words/terms' then I had to come up with this diagram and a few others for people like me, take me as an invited guest using plain language. Link to comment Share on other sites More sharing options...
swansont Posted March 12, 2023 Share Posted March 12, 2023 2 hours ago, Lorentz Jr said: "Clocks don't tick more slowly, time moves more slowly." You're just moving the goalposts with semantic gibberish, swanson. If the astronaut is younger than his twin when he returns to Earth, then why did "time move more slowly" on the spaceship? The laws of physics on the ship are exactly the same as on Earth, and yet somehow less "time" elapsed on the ship. I urge you to look at the derivation of time dilation. Without that as a common base, there is no discussion. And it just leaves you criticizing a theory you aren’t familiar with. I also note that you haven’t defended your claims at all, but expect me to defend a strawman of your fabrication. Which law of physics requires time to be the same in all frames? 2 hours ago, Lorentz Jr said: You're very creative, swanson. Very persistent and very creative. 😄 I stand on the shoulders of giants, who developed the ideas. Unfortunately they can’t understand them for you. 59 minutes ago, MJ kihara said: Back to the hijack,a little bit,from the diagram there is the issue of graviton,the discussion about general relativity it's predictions have been tested and proved beyond doubt.Dark matter and dark energy influence is said to be there from it's gravitational influence of normal matter.given that from the definition of graviton as indicated( in the diagram) does that diagram not reconcile general relativity and quantum gravity? Then the issue of time dilation becomes easier to understand... because entanglement comes into the picture...I struggled to understand the tough 'words/terms' then I had to come up with this diagram and a few others for people like me, take me as an invited guest using plain language. ! Moderator Note We aren’t discussing your diagram here. That discussion is taking place in your thread 2 Link to comment Share on other sites More sharing options...
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