Anilkumar Posted December 18, 2011 Share Posted December 18, 2011 (edited) Respected ladies & gentlemen, I would hereby request you all to consider this case as; 'an Ordinary man's attempt to convince the Extraordinary people', Please forgive me if I am wrong, considering me as 'a fool who tried to correct Albert Einstein, & failed miserably'. All my life I have admired Albert Einstein and continue to do so. He is the highest example of intellectual prowess. I am writing this discourse because; despite innumerous attempts to comprehend 'warping of Space', I haven't been able to convince it to myself, as I feel it is not rational. Kindly be sympathetic with me for making this humble attempt. My Account: Quote "The states of accelerated motion and being at rest in a Gravitational field are physically identical". Unquote This is the supposition which did the magic, and the GR thus originated. If this had not been supposed, GR would not have taken birth. But; this is also the very supposition which is responsible for the irrational conclusion of GR that 'Space warps'. When Albert Einstein equated Gravitational field to accelerated motion, GR was revealed to him. He set forth to describe the Universe according to GR. But while doing so, the mistake he committed was – he dropped Gravity/Gravitational field, once for all, as he had accounted for it, instead, by taking into consideration its identical substitute, 'Accelerated motion'. But honorable ladies & gentlemen, Gravity/Gravitational field is not so, an unremarkable entity to be dropped and forgotten once for all. Why? Since; 'Accelerated motion' is not an adequate substitute for Gravity/Gravitational field. It is just one trait of its. Though Gravity displays the characteristics of 'Accelerated motion' it has one other quality, which has not been accounted for by the GR. And that is; 'Gravitational field acts like a medium also'. [Medium does not mean here an intermediating medium. It means something like an atmosphere around earth.] Every manifestation of matter & energy is affected in its motion by this medium, the Gravitational field, like the motion of a magnetic material is affected when it enters a Magnetic field. Magnetic field affects the motions of only magnetic materials, but Gravity affects the motion of everything in this Universe. The medium-like property of Gravitational field is not taken into consideration by GR. But its effects were visible on motion and had to be accounted for. So, in the absence of Gravitational field and as the Substituted 'Accelerated motion' could not be credited with those affects, the onus was laden on Space. Why Space? Because it does not have any properties of its own & any unaccounted property or unexplainable activity can be attributed to or can be laden on it, which it doesn't mind. It doesn't refuse. It doesn't oppose. It doesn't affect anything else. It doesn't change anything else. It does not have any side effects. But it certainly gives undue properties to Space. This is but absolutely irrational. I am not a Physicist or a Scientist. The experts on Gravitational field have to confirm how the Gravity as a medium, affects motion? Whether Gravitational field as a medium can explain the effects that are attributed to the warped Space? But as for now, attributing these effects to the Gravitational field than to the 'Warping of Space' is not irrational, like it is when they are attributed to Space. Thank you. Edited December 18, 2011 by Anilkumar Link to comment Share on other sites More sharing options...
Greg Boyles Posted December 18, 2011 Share Posted December 18, 2011 (edited) Respected ladies & gentlemen, I would hereby request you all to consider this case as; 'an Ordinary man's attempt to convince the Extraordinary people', Please forgive me if I am wrong, considering me as 'a fool who tried to correct Albert Einstein, & failed miserably'. All my life I have admired Albert Einstein and continue to do so. He is the highest example of intellectual prowess. I am writing this discourse because; despite innumerous attempts to comprehend 'warping of Space', I haven't been able to convince it to myself, as I feel it is not rational. Kindly be sympathetic with me for making this humble attempt. My Account: Quote "The states of accelerated motion and being at rest in a Gravitational field are physically identical". Unquote This is the supposition which did the magic, and the GR thus originated. If this had not been supposed, GR would not have taken birth. But; this is also the very supposition which is responsible for the irrational conclusion of GR that 'Space warps'. When Albert Einstein equated Gravitational field to accelerated motion, GR was revealed to him. He set forth to describe the Universe according to GR. But while doing so, the mistake he committed was he dropped Gravity/Gravitational field, once for all, as he had accounted for it, instead, by taking into consideration its identical substitute, 'Accelerated motion'. But honorable ladies & gentlemen, Gravity/Gravitational field is not so, an unremarkable entity to be dropped and forgotten once for all. Why? Since; 'Accelerated motion' is not an adequate substitute for Gravity/Gravitational field. It is just one trait of its. Though Gravity displays the characteristics of 'Accelerated motion' it has one other quality, which has not been accounted for by the GR. And that is; 'Gravitational field acts like a medium also'. [Medium does not mean here an intermediating medium. It means something like an atmosphere around earth.] Every manifestation of matter & energy is affected in its motion by this medium, the Gravitational field, like the motion of a magnetic material is affected when it enters a Magnetic field. Magnetic field affects the motions of only magnetic materials, but Gravity affects the motion of everything in this Universe. The medium-like property of Gravitational field is not taken into consideration by GR. But its effects were visible on motion and had to be accounted for. So, in the absence of Gravitational field and as the Substituted 'Accelerated motion' could not be credited with those affects, the onus was laden on Space. Why Space? Because it does not have any properties of its own & any unaccounted property or unexplainable activity can be attributed to or can be laden on it, which it doesn't mind. It doesn't refuse. It doesn't oppose. It doesn't affect anything else. It doesn't change anything else. It does not have any side effects. But it certainly gives undue properties to Space. This is but absolutely irrational. I am not a Physicist or a Scientist. The experts on Gravitational field have to confirm how the Gravity as a medium, affects motion? Whether Gravitational field as a medium can explain the effects that are attributed to the warped Space? But as for now, attributing these effects to the Gravitational field than to the 'Warping of Space' is not irrational, like it is when they are attributed to Space. Thank you. It seems to me you are attributing the similar properties to a gravitational field that you have said is irrational to attribute to spacetime, i.e. that it is akin to a 'fabric'. If you say that a gravitational field is like fabric then why do you say it is irrational to regard space-time as a fabric that can be warped? Edited December 18, 2011 by Greg Boyles Link to comment Share on other sites More sharing options...
Anilkumar Posted December 18, 2011 Author Share Posted December 18, 2011 (edited) It seems to me you are attributing the similar properties to a gravitational field that you have said is irrational to attribute to spacetime, i.e. that it is akin to a 'fabric'. If you say that a gravitational field is like fabric then why do you say it is irrational to regard space-time as a fabric that can be warped? Yes, my friend Greg Boyles. But I don't say Gravitatinal field is a fabric. I said it is like a medium, similar to atmosphere arround the earth, or the magnetic field arround a Magnet. A field affects. Like the magnetic field affects magnetic materials, Electric field affects a charged particle, similarly Gravitational field affects everything. But Space is incapable of acting on anything. And Nothing can affect it inturn, except occupying it. Thank you. Edited December 18, 2011 by Anilkumar Link to comment Share on other sites More sharing options...
Greg Boyles Posted December 18, 2011 Share Posted December 18, 2011 (edited) Yes, my friend Greg Boyles. But I don't say Gravitatinal field is a fabric. I said it is like a medium, similar to atmosphere arround the earth, or the magnetic field arround a Magnet. A field affects. Like the magnetic field affects magnetic materials, Electric field affects a charged particle, similarly Gravitational field affects everything. But Space is incapable of acting on anything. And Nothing can affect it inturn, except occupying it. Thank you. I also said that spacetime might be similar to the atmosphere where physical objects displacing the air might be similar to massive objects warping spacetime, and you dismissed it I believe. Again we are just going around and around in circles here. You are starting off your new theory with your preconceived position that space can only be occupied and nothing else. If you start off with a preconceived notion then I don't see how you can be open to where the mathematics and research might lead you. It is not the way that good science is done as far as I am aware. The phrenologists from the 19 century went badly wrong for similar reasons as I understand it. Anyone else? Edited December 19, 2011 by Greg Boyles Link to comment Share on other sites More sharing options...
Anilkumar Posted December 19, 2011 Author Share Posted December 19, 2011 (edited) I also said that spacetime might be similar to the atmosphere where physical objects displacing the air might be similar to massive objects warping spacetime, and you dismissed it I believe. Again we are just going around and around in circles here. You are starting off your new theory with your preconceived position that space can only be occupied and nothing else. If you start off with a preconceived notion then I don't see how you can be open to where the mathematics and research might lead you. It is not the way that good science is done as far as I am aware. The phrenologists from the 19 century went badly wrong for similar reasons as I understand it. Anyone else? Certainly, even now I would dismiss if you compare Space with Atmosphere. The reason is: The atmosphere, the Magnetic field, the Electric field and the Gravitational field – are all 'Physical'. They can and do exhibit – Physical properties. They can act on physical matter. The only property that Space has is; it allows itself to be occupied. It can not act on physical matter. It can not and does not exhibit any other property. . . . physical objects displacing the air might be similar to massive objects warping spacetime, and you dismissed it I believe. You can not displace anything in Space. There is nothing to displace there. The only thing that you could displace in the body of empty space is the conceptual 'fabric'; verbally. You are starting off your new theory with your preconceived position This is not a preconceived position. This is a rational position. The basis of my contention [God, how I hate contention] is not preconception. It is rationality. I don't see how you can be open to where the mathematics and research might lead you. When did rationality 'close' itself to where the mathematics and research might lead it? It [being closed to reasoning] is always the prized possession of Irrationality and pride. Rationality is the name of 'Openness' - to go where reasoning leads. It is not the way that good science is done as far as I am aware. Which one? Taking Irrational decisions or, following where rationality leads you? The phrenologists from the 19 century went badly wrong for similar reasons as I understand it. Only time will tell, who did like Phrenologists. Mistakes will not sit idle, they will be magnified. You can't build bridges on the foundation of mistakes. They will collapse. ---------------------------------********************* Keep that aside, can I call you Greg? You are a good person. Edits: I had to remove the extra spaces in between the lines, which were not intended. They appear whenever I type the matter in the my text editor and bring it here. Thank you. Edited December 19, 2011 by Anilkumar Link to comment Share on other sites More sharing options...
Greg Boyles Posted December 19, 2011 Share Posted December 19, 2011 (edited) Certainly, even now I would dismiss if you compare Space with Atmosphere. The reason is: The atmosphere, the Magnetic field, the Electric field and the Gravitational field – are all 'Physical'. They can and do exhibit – Physical properties. They can act on physical matter. The only property that Space has is; it allows itself to be occupied. It can not act on physical matter. It can not and does not exhibit any other property. You can not displace anything in Space. There is nothing to displace there. The only thing that you could displace in the body of empty space is the conceptual 'fabric'; verbally. This is not a preconceived position. This is a rational position. The basis of my contention [God, how I hate contention] is not preconception. It is rationality. When did rationality 'close' itself to where the mathematics and research might lead it? It [being closed to reasoning] is always the prized possession of Irrationality and pride. Rationality is the name of 'Openness' - to go where reasoning leads. Which one? Taking Irrational decisions or, following where rationality leads you? Only time will tell, who did like Phrenologists. Mistakes will not sit idle, they will be magnified. You can't build bridges on the foundation of mistakes. They will collapse. ---------------------------------********************* Keep that aside, can I call you Greg? You are a good person. How can you be so sure that the idea of spacetime being a 'medium' of some sort, similar to what you are saying about a gravitational field, is irrational? If something as intangible and beyond our human senses as a magentic field can be warped and distorted, why do you consider it so irrational to say that the same may be possible of spacetime? Surely your starting point can only be your highly biased experience of the universe based upon limited human senses. This is starting to head into the realms of philosophy. Take the Flatland analogy for a 4D finite but boundless universe. In a real 2D universe you would not have squares and circles sitting on the surface of a sheet of elastic material, representing 2D spacetime, and taking up area on that surface. Rather the squares and circles would be embedded in and interwoven with the elastic material wouldn't they? If so how could they have any perception that their spacetime is a medium in which they are embedded and that can be warped and distorted along with their bodies. They would undoutedly say the same thing as you, that their spacetime is empty and can only be occupied but not warped or distorted. Edited December 19, 2011 by Greg Boyles Link to comment Share on other sites More sharing options...
michel123456 Posted December 19, 2011 Share Posted December 19, 2011 (edited) Since Anilkumar seems to recognize the gravitational field as an entity, here is the next question: What is a gravitational field? Isn't it a property of spacetime around a massive object? -------------------- Because we will go around and around in circles (as Greg said) - how can something that is not an entity have properties?- and such questions, here is my answer: the gravitational field is the massive object. Edited December 19, 2011 by michel123456 Link to comment Share on other sites More sharing options...
Anilkumar Posted December 19, 2011 Author Share Posted December 19, 2011 (edited) How can you be so sure that the idea of spacetime being a 'medium' of some sort, similar to what you are saying about a gravitational field, is irrational? If something as intangible and beyond our human senses as a magentic field can be warped and distorted, why do you consider it so irrational to say that the same may be possible of spacetime? Surely your starting point can only be your highly biased experience of the universe based upon limited human senses. This is starting to head into the realms of philosophy. Take the Flatland analogy for a 4D finite but boundless universe. In a real 2D universe you would not have squares and circles sitting on the surface of a sheet of elastic material, representing 2D spacetime, and taking up area on that surface. Rather the squares and circles would be embedded in and interwoven with the elastic material wouldn't they? If so how could they have any perception that their spacetime is a medium in which they are embedded and that can be warped and distorted along with their bodies. They would undoutedly say the same thing as you, that their spacetime is empty and can only be occupied but not warped or distorted. Good day Greg Boyles. How can you be so sure that the idea of spacetime being a 'medium' of some sort, similar to what you are saying about a gravitational field, is irrational? The answer is, in your question, dear fellow. 'the idea of spacetime' The spacetime is an idea. Created by us human beings. Then you tried to burden it with a 'physique' – make it a 'fabric' of sorts. in order to explain some un-explainable observed facts. Those facts were un-explainable because, you had left out the originator of those observed facts. It is certainly irrational to attach a physique to an idea. But rationality reduced it back to an 'idea'. Space is not an 'idea'. It is an entity. Yet it cannot have a Physique or cannot be a Medium, because its definition prevents it from having/being one. If something as intangible and beyond our human senses as a magentic field can be warped and distorted, why do you consider it irrational to say that the same may be possible of spacetime? Surely your starting point can only be your highly biased experience of the universe based upon limited human senses. I am saying spacetime and Space, [if they are not one & the same] both, cannot have a physique, or be a medium, not for the reason that; they are intangible and beyond my senses; it is because it is irrational. This is starting to head into the realms of philosophy. Take the Flatland analogy for a 4D finite but boundless universe. In a real 2D universe you would not have squares and circles sitting on the surface of a sheet of elastic material, representing 2D spacetime, and taking up area on that surface. Rather the squares and circles would be embedded in and interwoven with the elastic material wouldn't they? If so how could they have any perception that their spacetime is a medium in which they are embedded and that can be warped and distorted along with their bodies. They would undoutedly say the same thing as you, that their spacetime is empty and can only be occupied but not warped or distorted. I don't understand this. That person, who thinks rationally, and also at the same time understands all that, only, can convince you. But if you want to toss this off into some other realm and continue with the oversight left unchecked, all I can do is, wish you luck, that's all. I am not obliged to make anybody, believe me. ------------------------------*********************** Since Anilkumar seems to recognize the gravitational field as an entity, here is the next question: What is a gravitational field? Isn't it a property of spacetime around a massive object? -------------------- Because we will go around and around in circles (as Greg said) - how can something that is not an entity have properties?- and such questions, here is my answer: the gravitational field is the massive object. There is contradiction here in; Gravitational field is the property of spacetime around a massive object. --------------------------and the gravitational field is the massive object. And what is the role of spacetime curvature? Edited December 19, 2011 by Anilkumar Link to comment Share on other sites More sharing options...
URAIN Posted December 19, 2011 Share Posted December 19, 2011 (edited) Good day Greg Boyles. The answer is, in your question, dear fellow. 'the idea of spacetime' The spacetime is an idea. Created by us human beings. Then you tried to burden it with a 'physique' – make it a 'fabric' of sorts. in order to explain some un-explainable observed facts. Those facts were un-explainable because, you had left out the originator of those observed facts. It is certainly irrational to attach a physique to an idea. But rationality reduced it back to an 'idea'. Space is not an 'idea'. It is an entity. Yet it cannot have a Physique or cannot be a Medium, because its definition prevents it from having/being one. I am saying spacetime and Space, [if they are not one & the same] both, cannot have a physique, or be a medium, not for the reason that; they are intangible and beyond my senses; it is because it is irrational. I don't understand this. That person, who thinks rationally, and also at the same time understands all that, only, can convince you. But if you want to toss this off into some other realm and continue with the oversight left unchecked, all I can do is, wish you luck, that's all. I am not obliged to make anybody, believe me. ------------------------------*********************** There is contradiction here in; Gravitational field is the property of spacetime around a massive object. --------------------------and the gravitational field is the massive object. And what is the role of spacetime curvature? You had said mathematics may shortcut but it will not wrong in any time. What about the mathematics related to GR? How it will be correct ? If space will not take curve? Edited December 19, 2011 by URAIN Link to comment Share on other sites More sharing options...
swansont Posted December 19, 2011 Share Posted December 19, 2011 Yes, my friend Greg Boyles. But I don't say Gravitatinal field is a fabric. I said it is like a medium, similar to atmosphere arround the earth, or the magnetic field arround a Magnet. A field affects. Like the magnetic field affects magnetic materials, Electric field affects a charged particle, similarly Gravitational field affects everything. But Space is incapable of acting on anything. And Nothing can affect it inturn, except occupying it. Thank you. Magnetic field is a medium? I don't think I've run across that before. The pre-relativity physics had electric magnetic fields in a medium: the ether. That was the medium that purportedly oscillated when you had EM waves. But basically you are arguing semantics here. GR replaces the gravitational field with a different abstraction based on geometry, which we call spacetime. Neither one is a medium, and you continue to conflate this with "space". You are making a straw man argument. Link to comment Share on other sites More sharing options...
Anilkumar Posted December 19, 2011 Author Share Posted December 19, 2011 (edited) Magnetic field is a medium? I don't think I've run across that before. The pre-relativity physics had electric magnetic fields in a medium: the ether. That was the medium that purportedly oscillated when you had EM waves. Most words have various meanings. We would be doing justice to the purpose of the usage of any word only when we consider, purely the intended meaning. I didn't say it is a medium. I said it is like a medium. I used the word 'Medium' for lack of a better word. And to filter out the unintended meanings from being taken, I particularly stated that 'Medium does not mean here an intermediating medium. It means something like an atmosphere around earth'. Which I suppose, rules out the word 'medium' meaning- the one required for propagation, like ether. But again don't say Atmosphere is a medium for propagation of sound. I don't mean that. What I am indicating here is the 'presence' around the body. I also gave analogies of the Magnetic & Electric fields, to facilitate the meaning of the ability of Gravitational field to act at a distance. I hope that my intended meaning is clear, and from this point on the word 'field' would be sufficient, instead of using the word 'medium' to avoid superfluous meanings. But basically you are arguing semantics here. GR replaces the gravitational field with a different abstraction based on geometry, which we call spacetime. . . . Is GR replacing a Physical entity with an abstraction? And the Geometry of the abstraction says that another entity is bent. Accordingly, that entity has to bend, irrespective of whether that entity has the ability to bend or not. Is this a question of semantics? . . . and you continue to conflate this with "space". How can I not conflate spacetime with Space, while spacetime has the ingredients of space. . . . You are making a straw man argument. The spacetime has four dimensions, out of which, three dimensions represent Empty space. And you say spacetime is not equal to Space. Who is making a straw man argument? --------------------------************************* You had said mathematics may shortcut but it will not wrong in any time. What about the mathematics related to GR? How it will be correct ? If space will not take curve? Mathematics is a tool with which a given data is processed. It will never make a mistake in the processing of a given data. Irrational abstractions & concepts can also be converted into data and given. Edited December 19, 2011 by Anilkumar Link to comment Share on other sites More sharing options...
DrRocket Posted December 20, 2011 Share Posted December 20, 2011 Hello dear Greg Boyles, I have never said 'Time does not warp'. Throughout the thread I have been saying 'Gravity affects Motion & Duration'. I have said Mass can not affect Space other than occupying/filling it. Space can't warp. As it does not have that capability. This is just flat wrong. What it demonstrates is fundamental lack of understanding of general relativity. Curvature of spacetime (not "space") is what we call "gravity". Both "space" and "time" are local, coordinate-dependent notions. Lack of spacetime curvture is evidence of total absence of gravity. Since gravity permeates the universe there is no lack of curvature. Now go read Gravitation by Misner, Thorne and Wheeler. 1 Link to comment Share on other sites More sharing options...
Anilkumar Posted December 20, 2011 Author Share Posted December 20, 2011 This is just flat wrong. What it demonstrates is fundamental lack of understanding of general relativity. Curvature of spacetime (not "space") is what we call "gravity". Both "space" and "time" are local, coordinate-dependent notions. Lack of spacetime curvture is evidence of total absence of gravity. Since gravity permeates the universe there is no lack of curvature. Now go read Gravitation by Misner, Thorne and Wheeler. The proposition that "space" and "time" are notions, is an upshot of the supposition, that Gravitational field is identical to accelerated motion. This is wrong. Because, accelerated motion is only a characteristics of Gravitational field. Gravitational field is an entity and is mass/matter related. Acceleration is not an entity, and is not mass/matter related. Acceleration is merely the manifestation of the, effect of the Gravitational field. Just for this, don’t read any books. Just close your eyes and think rationally. Books are not the last word on anything. But rationality is the last word, on everything. Books have told us enough of this. Link to comment Share on other sites More sharing options...
Mellinia Posted December 20, 2011 Share Posted December 20, 2011 Most words have various meanings. We would be doing justice to the purpose of the usage of any word only when we consider, purely the intended meaning. I didn't say it is a medium. I said it is like a medium. I used the word 'Medium' for lack of a better word. And to filter out the unintended meanings from being taken, I particularly stated that 'Medium does not mean here an intermediating medium. It means something like an atmosphere around earth'. Which I suppose, rules out the word 'medium' meaning- the one required for propagation, like ether. But again don't say Atmosphere is a medium for propagation of sound. I don't mean that. What I am indicating here is the 'presence' around the body. I also gave analogies of the Magnetic & Electric fields, to facilitate the meaning of the ability of Gravitational field to act at a distance. I hope that my intended meaning is clear, and from this point on the word 'field' would be sufficient, instead of using the word 'medium' to avoid superfluous meanings. Is GR replacing a Physical entity with an abstraction? And the Geometry of the abstraction says that another entity is bent. Accordingly, that entity has to bend, irrespective of whether that entity has the ability to bend or not. Is this a question of semantics? How can I not conflate spacetime with Space, while spacetime has the ingredients of space. The spacetime has four dimensions, out of which, three dimensions represent Empty space. And you say spacetime is not equal to Space. Who is making a straw man argument? --------------------------************************* Mathematics is a tool with which a given data is processed. It will never make a mistake in the processing of a given data. Irrational abstractions & concepts can also be converted into data and given. I do suggest reading up on general relativity. Spacetime may have the word space in it, and it does concern spatial dimensions but it isn't really just taking "three spatial dimensions and one temporal dimension" together. I'm not even sure it only has three spatial dimensions. Space and time are "integrated" together. Affecting space affects time and vice versa. I don't know why, but it does. Isn't spacetime the "medium" that you call "gravitational field"? Einstein described the gravitational field as spacetime curvature. Spacetime which is present around everything. "Acceleration" and "Gravitation" both curve spacetime the same way, affecting the temporal dimension thus is equated. It doesn't mean that gravitation is substituted with acceleration. Einstein done away with gravitation by explaining that actually, the curvature of spacetime is gravity and that curvature is caused by mass/energy. Link to comment Share on other sites More sharing options...
imatfaal Posted December 20, 2011 Share Posted December 20, 2011 Just for this, don't read any books. Just close your eyes and think rationally. Books are not the last word on anything. But rationality is the last word, on everything. Books have told us enough of this. "If I have seen a little further it is by standing on the shoulders of Giants." Isaac Newton. This is a common meme throughout human existence - ie we cannot start ab initio every single time. there is just too much out there to establish anything from real first principles - you cannot start from self awareness and build up to the existence of the cosmic microwave background. science is a collaborative effort - that is why it is so important that the foundations and axiomata are solid; if one starts building from false assumptions then the result will likely be flawed. without gaining a grounding in what has already been discovered and proved you are very unlikely to find anything new or true - this grounding is received through reading books. rationality is not the last word - there is no last word, but our highest arbiter is experimental agreement with theoretical prediction. it matters nothing how rational, logical, and common-sensical a theory is; if it is in disagreement with experimental results in the real world, then something is wrong and it is not reality that is incorrect. 1 Link to comment Share on other sites More sharing options...
swansont Posted December 20, 2011 Share Posted December 20, 2011 Most words have various meanings. We would be doing justice to the purpose of the usage of any word only when we consider, purely the intended meaning. I didn't say it is a medium. I said it is like a medium. I used the word 'Medium' for lack of a better word. And to filter out the unintended meanings from being taken, I particularly stated that 'Medium does not mean here an intermediating medium. It means something like an atmosphere around earth'. Which I suppose, rules out the word 'medium' meaning- the one required for propagation, like ether. But again don't say Atmosphere is a medium for propagation of sound. I don't mean that. What I am indicating here is the 'presence' around the body. I also gave analogies of the Magnetic & Electric fields, to facilitate the meaning of the ability of Gravitational field to act at a distance. I hope that my intended meaning is clear, and from this point on the word 'field' would be sufficient, instead of using the word 'medium' to avoid superfluous meanings. It looked to me that you were saying that a magnetic field is a medium. But you are correct that words tend to have various meanings. "Space" is one of those words. In the context of GR, it is not referring to the absence of material, or the region that can be filled. It is referring to the mathematical construct we use to describe events. Is GR replacing a Physical entity with an abstraction? And the Geometry of the abstraction says that another entity is bent. Accordingly, that entity has to bend, irrespective of whether that entity has the ability to bend or not. Is this a question of semantics? No, GR is replacing one abstraction with another. There is no entity. Saying that spacetime is warped is an analogy, a description, used to convey the concept. How can I not conflate spacetime with Space, while spacetime has the ingredients of space. Spacetime is the four-dimensional manifold we use to describe what happens. Near a mass this is curved. The spacetime has four dimensions, out of which, three dimensions represent Empty space. And you say spacetime is not equal to Space. Who is making a straw man argument? One of the lessons of relativity is that you cannot make this separation (Minkowski space and Euclidean space are different geometries; the use of "space" in this context is mathematical, representing all the coordinates), and it is still a mixing of concepts. Link to comment Share on other sites More sharing options...
Anilkumar Posted December 21, 2011 Author Share Posted December 21, 2011 (edited) "If I have seen a little further it is by standing on the shoulders of Giants." Isaac Newton. This is a common meme throughout human existence - ie we cannot start ab initio every single time. there is just too much out there to establish anything from real first principles - you cannot start from self awareness and build up to the existence of the cosmic microwave background. science is a collaborative effort - I haven't talked anything against this. I never said, science isn't a collaborative effort. I am merely objecting some aspects of an already proposed theory. I think such talk will not help resolve this matter. rationality is not the last word - there is no last word, but our highest arbiter is experimental agreement with theoretical prediction. it matters nothing how rational, logical, and common-sensical a theory is; if it is in disagreement with experimental results in the real world, then something is wrong and it is not reality that is incorrect. "rationality is not the last word" "our highest arbiter is experimental agreement" "it matters nothing how rational, logical, and common-sensical a theory is" I pity the person who 'says this and also at the same time claims to be scientific'. What is "empirical evidence" OR Why do we go for experimental evidence? When we propose something, we go and check for empirical evidence, because we want to verify whether it happens/occurs in the proposed way or not. Only that happens/occurs which is rational. Irrational things do not happen/occur. When we propose something, we check its rationality, by checking whether it happen/occurs in the proposed way or not. I.E. checking for experimental agreement is checking for rationality of the proposal. "Experimental agreement" is a name given by Science to 'Rationality'. They don't mean different. GR says Space is a notion. I claim or propose that Space is an entity. Do you want experimental evidence for the existence of 'Space'? I can give it. If there is evidence of Space, it is also a proof that 'spacetime curvature' proposed by GR is a notion. ----------------------------------*********************** I do suggest reading up on general relativity. I am reading. Spacetime may have the word space in it, and it does concern spatial dimensions but it isn't really just taking "three spatial dimensions and one temporal dimension" together. I'm not even sure it only has three spatial dimensions. Space and time are "integrated" together. Affecting space affects time and vice versa. I don't know why, but it does. Isn't spacetime the "medium" that you call "gravitational field"? Einstein described the gravitational field as spacetime curvature. Spacetime which is present around everything. "Acceleration" and "Gravitation" both curve spacetime the same way, affecting the temporal dimension thus is equated. It doesn't mean that gravitation is substituted with acceleration. Einstein done away with gravitation by explaining that actually, the curvature of spacetime is gravity and that curvature is caused by mass/energy. Let's first ascertain; Isn't 'spacetime curvature' regarding spatial and temporal things? ----------------------------------*********************** But you are correct that words tend to have various meanings. "Space" is one of those words. In the context of GR, it is not referring to the absence of material, or the region that can be filled. It is referring to the mathematical construct we use to describe events How can a bend in the mathematical construct, become a bend in the Physical? No, GR is replacing one abstraction with another. There is no entity. Which abstraction is replaced by which abstraction? Which entity is not there? Saying that spacetime is warped is an analogy, a description, used to convey the concept. Which concept? Spacetime is the four-dimensional manifold we use to describe what happens. Near a mass this is curved. As because, GR has been able to describe what happens; the Relativists want, the Description - a mathematical construct, to take the place of, the entity, which is making it happen? One of the lessons of relativity is that you cannot make this separation (Minkowski space and Euclidean space are different geometries; the use of "space" in this context is mathematical, representing all the coordinates), and it is still a mixing of concepts. I am aware that they cannot be separated. But I did it to show that spacetime cannot separate itself away from its originators, the Space & the Time; and say 'I am something altogether different, I don't belong to either Space or Time or I don't know who is Space and who is time'. Thank you everybody. Have a nice day. Imaatfaal I am sorry if I have hurt you. I know you love truth more than any thing else. Edited December 21, 2011 by Anilkumar Link to comment Share on other sites More sharing options...
Greg Boyles Posted December 21, 2011 Share Posted December 21, 2011 How can a bend in the mathematical construct, become a bend in the Physical? 1) This statement makes it obvious to me that you consider GR a mathemtaical construct that does not represent reality. 2) The word bend or warp are words of convenicene that help us to inderstand what is going on through an analogy. It is clear that a magnetic field cannot bend like a length of wire can, but what actually happens to a magnetic field is analogous to this. 3) A mathematical construct does not bend but merely describes what is happening in reality which you could label with any word if you wish - bend, warp, displace,.......what ever. Link to comment Share on other sites More sharing options...
Mellinia Posted December 21, 2011 Share Posted December 21, 2011 1. Einstein did not equate "gravitation" with "acceleration". He equated "acceleration due to gravity" with "acceleration due to external forces that gives the same acceleration as the former". (Sorry, but i need to be precise.) This meant that taking the acceleration due to Earth's gravity to be 9.87ms-2, your weight balance reading on Earth would be the same as your weight balance reading when you're on a rocket with 9.87ms-2 acceleration. 2. Spacetime is not just "three dimensions of space and one dimension of time". What you refer to as"gravitational field", a "medium", "like the atmosphere of the Earth" has a name, it's called spacetime. Space and time integrated together. Manipulating time affects space and vice versa. 3. "Warping" is not attributed to space. Sometimes you might see people discussing about "warping space" because space is much more easier to imagine than time. You can "imagine the 'warping' of space" but not time. Space is where everything's happening and time is the sequence in which everything's happening. 4. Mathematics allow us to "see" the "bend". "Bending of spacetime"caused us to be able to see a star directly behind the Sun because light travels on a "curved spacetime" caused by the Sun. Link to comment Share on other sites More sharing options...
Greg Boyles Posted December 21, 2011 Share Posted December 21, 2011 (edited) 1. Einstein did not equate "gravitation" with "acceleration". He equated "acceleration due to gravity" with "acceleration due to external forces that gives the same acceleration as the former". (Sorry, but i need to be precise.) This meant that taking the acceleration due to Earth's gravity to be 9.87ms-2, your weight balance reading on Earth would be the same as your weight balance reading when you're on a rocket with 9.87ms-2 acceleration. 2. Spacetime is not just "three dimensions of space and one dimension of time". What you refer to as"gravitational field", a "medium", "like the atmosphere of the Earth" has a name, it's called spacetime. Space and time integrated together. Manipulating time affects space and vice versa. 3. "Warping" is not attributed to space. Sometimes you might see people discussing about "warping space" because space is much more easier to imagine than time. You can "imagine the 'warping' of space" but not time. Space is where everything's happening and time is the sequence in which everything's happening. 4. Mathematics allow us to "see" the "bend". "Bending of spacetime"caused us to be able to see a star directly behind the Sun because light travels on a "curved spacetime" caused by the Sun. Sort of makes sense to me, as much as it can without my understanding the mathematics behind it. Although it is hard to get my head around the spacetime thing as to precisely what it means in terms of every day experience......no surprises there I guess. Edited December 21, 2011 by Greg Boyles Link to comment Share on other sites More sharing options...
swansont Posted December 21, 2011 Share Posted December 21, 2011 Which abstraction is replaced by which abstraction? Which entity is not there? The abstraction of a field with the abstraction of geometry. Which concept? The concept that motion can be described with geometry. As because, GR has been able to describe what happens; the Relativists want, the Description - a mathematical construct, to take the place of, the entity, which is making it happen? In either case, mass (or more generally, as it were, energy-momentum) "makes it happen". But the description of what happens is mathematical. I am aware that they cannot be separated. But I did it to show that spacetime cannot separate itself away from its originators, the Space & the Time; and say 'I am something altogether different, I don't belong to either Space or Time or I don't know who is Space and who is time'. But that's not what you seem to be doing. You seem to be interchanging "Euclidean space" (or Minkowski space) with "(empty) space" simply because they both have the word "space" in them. They do not represent the same thing. Link to comment Share on other sites More sharing options...
URAIN Posted December 22, 2011 Share Posted December 22, 2011 The abstraction of a field with the abstraction of geometry. The concept that motion can be described with geometry. In either case, mass (or more generally, as it were, energy-momentum) "makes it happen". But the description of what happens is mathematical. But that's not what you seem to be doing. You seem to be interchanging "Euclidean space" (or Minkowski space) with "(empty) space" simply because they both have the word "space" in them. They do not represent the same thing. Dear swansont I don't therefore I am asking that, Now how fourth dimension helping to us? What are the uses of it? Like, 3 dimensions helps to know area of the matter. Link to comment Share on other sites More sharing options...
swansont Posted December 22, 2011 Share Posted December 22, 2011 Dear swansont I don't therefore I am asking that, Now how fourth dimension helping to us? What are the uses of it? Like, 3 dimensions helps to know area of the matter. The fourth dimension allows ordering of events and addresses issues of simultaneity. Link to comment Share on other sites More sharing options...
Anilkumar Posted December 23, 2011 Author Share Posted December 23, 2011 (edited) In general relativity it is spacetime, not "space" that shows curvature. In fact in general relativity there is no such thing, on a global basis, as either time or space. Time and space are purely local notions, and are dependent on the arbitrary selection of a local coordinate system. Why/How Space is a notion? Why/How, Matter, is, not a notion? . . . Mass and more precisely mass/energy not only warps spacetime, but determines the curvature of spacetime via the stress-energy tensor and the Einstein field equations. Nothing can warp spacetime. The statement that "Gravity affects Motion & Duration" is meaningless babble. It is not even wronog, just nonsense words. If you want to understand what general relativity really says, ralther than make a ridiculous criticism of a theory that you manifestly don't begin to understand, then you need to read a real book on the subject. Gravitation by Misner, Thorne and Wheeler would be a good start. Gravity affects Motion/Matter. [Not sure about Time.] It is not right to stick to an idea, which you cannot bear. Only time can tell which one is ridiculous babble. Edited December 23, 2011 by Anilkumar Link to comment Share on other sites More sharing options...
Anilkumar Posted December 23, 2011 Author Share Posted December 23, 2011 (edited) 1. Einstein did not equate "gravitation" with "acceleration". He equated "acceleration due to gravity" with "acceleration due to external forces that gives the same acceleration as the former". I meant the same thing. The equivalence principle. 2. Spacetime is not just "three dimensions of space and one dimension of time". What you refer to as"gravitational field", a "medium", "like the atmosphere of the Earth" has a name, it's called spacetime. Space and time integrated together. Manipulating time affects space and vice versa. Gravitational field can be given any name. But, it is absolutely not, Space & Time integrated together. It cannot be. 4. Mathematics allow us to "see" the "bend". "Bending of spacetime"caused us to be able to see a star directly behind the Sun because light travels on a "curved spacetime" caused by the Sun. There is no bend. We are able to see a star directly behind the Sun because the motion of light is acted upon by Sun's Gravitational field. --------------------------************************* The abstraction of a field with the abstraction of geometry. Gravitational field cannot be an abstraction. It is an entity. Are other fields, the Magnetic field, & the Electric field mere abstractions? But that's not what you seem to be doing. You seem to be interchanging "Euclidean space" (or Minkowski space) with "(empty) space" simply because they both have the word "space" in them. They do not represent the same thing. No. I am not interchanging "Euclidean space" (or Minkowski space) with "(empty) space". They cannot be interchanged, as; Euclidean space is a mathematical model and, "(empty) space", is an entity; which GR does not come to terms with. Edited December 23, 2011 by Anilkumar Link to comment Share on other sites More sharing options...
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