Marius Posted December 4, 2021 Posted December 4, 2021 (edited) Quote In our solar system, the Earth orbits the Sun, as do the other eight planets. They all travel on or near the orbital plane, an imaginary disk-shaped surface in space. All of the orbits are circular or elliptical in their shape. If the space in our solar system is curved by the sun's mass, and planets orbit on said curvature of space-time, then how is it possible that the planets orbit in the same plane ? Which is flat. If Einsteins theory is correct, then no such flat plane should exist in our solar system. And the planets orbits should be on a curved space instead of a flat space, with their orbits stacked one on top the other as they fall deeper and deeper in the 'curvature of space-time'. Like in the illustration below where I added two more orbits to see how they stack up (the original only had one, and I cannot for the life of me find an illustration of GR with more than one planet/orbit) Edited December 4, 2021 by Marius -1
TheVat Posted December 4, 2021 Posted December 4, 2021 Not a 2D curvature. The rubber sheet analogy removes two dimensions of 4D spacetime. And spacetime is not embedded in a higher dimensional extended 5D space, whereas the 2D sheet is in 3D space. It is a very limited and shallow analogy which just gives one conceptual piece of the puzzle. We cannot visualize a 4D curvature so easily.
swansont Posted December 4, 2021 Posted December 4, 2021 35 minutes ago, Marius said: If Einsteins theory is correct, then no such flat plane should exist in our solar system The plane is a description from Newtonian physics, which is adequate to explain the vast majority of the behavior of the orbits. Much in the same way as we use classical physics to explain things and not invoke negligible quantum effects.
beecee Posted December 4, 2021 Posted December 4, 2021 3 hours ago, Marius said: If Einsteins theory is correct, Einstein's theory certainly is correct within its known bounds of applicability, but the non existent problem you present is actually explained by good old Newtonian mechanics. The Sun and planets formed from a rotating accretion disk 5 billion years ago, the angular momentum of that disk, saw it flattened so enabling the Sun/planets to form in nearly all the same plane. Much the same reason applies to why the Earth is an oblate spheroid.
Janus Posted December 4, 2021 Posted December 4, 2021 The second image is an analogy which visualizes space as being 2 dimensional and bent through a third dimension. It is not representative of reality. In it all of space is the surface shown as a grid. And while the diagram shows the Sun and planets as solid objects sitting on that grid, they would better be represented as circles on the surface. Like already stated in order to make it simpler to present, 2 of the spatial dimensions are removed. Here's am animation that gives an idea of what this same analogy would look is you included the other two dimensions The other thing to keep in mind is that the "Curvature" of space-time is not an actual bending of anything. It is a term used to convey the idea that space-time deviates from the rules that govern Euclidean geometry in the presence of mass. It is called curvature because it gives results like those you would get if you try to do plane geometry on a surface that is not flat. 1
studiot Posted December 4, 2021 Posted December 4, 2021 It amazes me how you keep coming up with such clear and simple correct statements and presentations, @Janus, +1
Marius Posted January 2, 2022 Author Posted January 2, 2022 (edited) On 12/4/2021 at 6:48 PM, swansont said: The plane is a description from Newtonian physics, which is adequate to explain the vast majority of the behavior of the orbits. Much in the same way as we use classical physics to explain things and not invoke negligible quantum effects. Its not, they are actually observed to be in the same plane. This contradicts the aberration that gravity is caused by a curvature of space-time and planets orbit on the curved space. As does the flat geometry of the universe in general. There is nothing curved or bent. On 12/4/2021 at 9:26 PM, beecee said: Einstein's theory certainly is correct within its known bounds of applicability, but the non existent problem you present is actually explained by good old Newtonian mechanics. The Sun and planets formed from a rotating accretion disk 5 billion years ago, the angular momentum of that disk, saw it flattened so enabling the Sun/planets to form in nearly all the same plane. Much the same reason applies to why the Earth is an oblate spheroid. You are not getting the point, Einstein. This is exactly where Einsteins theory is applicable in our solar system, and it is exactly where it fails to explain the orbits off all the planets, which are all in the same flat plane- which makes no sense if SPACE IS CURVED. So now you explain Einstein's gravity with Newton's law, are you fucking joking ? Einstein contradicts Newton, he says gravity is not a force but a curvature of space-time, while Newton says gravity is a force in a flat space ! There is no problem between Newtons theory and the planets orbiting in a flat plane, like you mention it is perfectly explainable using Newton's law, but there is a huge problem in the case of Einsteins theory, which cannot explain why the planets orbit in the same flat plane if the space in which they orbit is curved. On 12/4/2021 at 11:08 PM, Janus said: The second image is an analogy which visualizes space as being 2 dimensional and bent through a third dimension. It is not representative of reality. In it all of space is the surface shown as a grid. And while the diagram shows the Sun and planets as solid objects sitting on that grid, they would better be represented as circles on the surface. Like already stated in order to make it simpler to present, 2 of the spatial dimensions are removed. Here's am animation that gives an idea of what this same analogy would look is you included the other two dimensions The other thing to keep in mind is that the "Curvature" of space-time is not an actual bending of anything. It is a term used to convey the idea that space-time deviates from the rules that govern Euclidean geometry in the presence of mass. It is called curvature because it gives results like those you would get if you try to do plane geometry on a surface that is not flat. If its not an actual bending of anything then why do mainstream scientists keep pretending that it is ('matter tells space how to curve, and space tells matter how to move'), and keep giving the same fabric sheet example over and over ? And how is the aberration in the video an accurate description of reality ? Do you seriously think that it has anything to do with reality ? Where do you think you are, the Matrix ? Edited January 2, 2022 by Marius -3
MigL Posted January 2, 2022 Posted January 2, 2022 The above members have explained things to you in the clearest possible manner, yet you are either unable, or unwilling, to comprehend. The model we have of gravity tells us that gravity's behaviour is exactly the same as if space-time, the co-ordinate system, was curved. It is not a 'description' of reality, but rather, a predictive model. And your incredulity ( or incomprehension ) notwithstanding, it does an excellent job at those predictions.
Marius Posted January 2, 2022 Author Posted January 2, 2022 (edited) 1 hour ago, MigL said: The above members have explained things to you in the clearest possible manner, yet you are either unable, or unwilling, to comprehend. The model we have of gravity tells us that gravity's behaviour is exactly the same as if space-time, the co-ordinate system, was curved. It is not a 'description' of reality, but rather, a predictive model. And your incredulity ( or incomprehension ) notwithstanding, it does an excellent job at those predictions. The first two explained Einsteins theory of gravity using Newton's law of universal attraction. Why didnt they use Einsteins theory ? Because they comprehend it, or because they dont comprehend it ? And only comprehend Newton instead ? And you comprehend it ? If so, then can you make a calculation of the orbit of planets Jupiter and Saturn around the sun using Einsteins General Relativity gravity equations, and prove that they orbit in the same plane ? Not Newton, Einstein !!! And for the Matrix guy: Einsteins theory literally says that space is curved by mass and that this curvature of space is causing matter to move in an circular/eliptical path and light to bend as it passes through that space. This actual curvature of space is what in his and the mainstream opinion causes the light of stars to be bend near the sun (gravitational lensing), and the planets to orbit around the sun. Edited January 2, 2022 by Marius -1
Genady Posted January 2, 2022 Posted January 2, 2022 45 minutes ago, MigL said: The above members have explained things to you in the clearest possible manner, yet you are either unable, or unwilling, to comprehend. The model we have of gravity tells us that gravity's behaviour is exactly the same as if space-time, the co-ordinate system, was curved. It is not a 'description' of reality, but rather, a predictive model. And your incredulity ( or incomprehension ) notwithstanding, it does an excellent job at those predictions. Not assuming that you, @MigL, don't know this and apologizing if I repeat something since I didn't follow this thread, just want to clarify, that space is factually, measurably curved. Even here on Earth, if we measure its diameter and the length of the equator very precisely, we find that the latter is not equal pi times the former, as Euclid prescribes, but in fact is shorter. I don't remember how much shorter, but think I can look it up, if needed.
zapatos Posted January 2, 2022 Posted January 2, 2022 3 minutes ago, Genady said: space is factually, measurably curved That's the first time I heard that. How do you measure space? You mentioned measuring the earth, and I know you can measure how things behave in space, but how do you actually measure space itself?
Genady Posted January 2, 2022 Posted January 2, 2022 1 minute ago, zapatos said: That's the first time I heard that. How do you measure space? You mentioned measuring the earth, and I know you can measure how things behave in space, but how do you actually measure space itself? Directly. Ideally, you make a hole through the center of the Earth and measure the length of straight line from surface to surface -- diameter. You walk around the equator with a meter stick. Then you see if the second number is equal the first times pi. It is not.
MigL Posted January 2, 2022 Posted January 2, 2022 And is your measuring apparatus, rulers, clocks, etc. not also curved ? We use light to determine what is 'straight', yet light curves around massive objects. All we can do is measure the effects; we can't measure the underlying 'reality'. As members are fond of saying around here ... "The model is just the map, while 'reality' is the actual terrain"
Genady Posted January 2, 2022 Posted January 2, 2022 (edited) If we send light through the hole through the center of the Earth, there are no massive objects to bend it. If we use the same clocks on the surface of the Earth for the measurements, they curved the same throughout. We can measure geometrical features of the space. The point is, we will find that they do not fit Euclidean theorems. In case of Earth, they will fit the theorems of spherical geometry, of the 3-sphere! Edited January 2, 2022 by Genady
MigL Posted January 2, 2022 Posted January 2, 2022 1 hour ago, Marius said: And you comprehend it ? If so, then can you make a calculation of the orbit of planets Jupiter and Saturn around the sun using Einsteins General Relativity gravity equations, and prove that they orbit in the same plane ? Not Newton, Einstein !!! For the orbits of Jupiter and Saturn, Newtonian gravity gives essentially the same results as GR. The only anomaly is the procession of the orbit of Mercury, which is much deeper in the Sun's gravitational well, and subject to much greater 'curvature' on the time axis. Since GR essentially reduces to Newtonian gravity at the lo mass/lo energy limit, only a fool would attemt to solve the set of EFEs for outer planetary orbits when Newtonian gravity will suffice. Even NASA uses Newtonian gravity models to land rovers on Mars and 'sling-shot' Voyager around outer planets. What does that have to do with comprehending GR ?
zapatos Posted January 2, 2022 Posted January 2, 2022 4 minutes ago, Genady said: We can measure geometrical features of the space. The point is, we will find that they do not fit Euclidean theorems. I wasn't questioning that. Only that "space is factually, measurably curved". I was just trying to clarify what you meant.
Genady Posted January 2, 2022 Posted January 2, 2022 13 minutes ago, zapatos said: I wasn't questioning that. Only that "space is factually, measurably curved". I was just trying to clarify what you meant. Ah, I see. Sure. The definition of "space being curved" is that its geometry is not Euclidean. The curvature in Euclidean geometry is 0. 1
beecee Posted January 2, 2022 Posted January 2, 2022 (edited) 2 hours ago, Marius said: If its not an actual bending of anything then why do mainstream scientists keep pretending that it is ('matter tells space how to curve, and space tells matter how to move'), and keep giving the same fabric sheet example over and over ? And how is the aberration in the video an accurate description of reality ? Do you seriously think that it has anything to do with reality ? Where do you think you are, the Matrix ? You seem rather agressive. Is this anything to do with your other nonsense being closed? As MigL has said, We mainly use Newtonian to obtain "correct "results in most space endeavours, because the answers/calcs fall within acceptable zones of precision. The far more precise and far more complicated equations of GR are just not needed in these circumstances. 40 minutes ago, MigL said: For the orbits of Jupiter and Saturn, Newtonian gravity gives essentially the same results as GR. The only anomaly is the procession of the orbit of Mercury, which is much deeper in the Sun's gravitational well, and subject to much greater 'curvature' on the time axis. Since GR essentially reduces to Newtonian gravity at the lo mass/lo energy limit, only a fool would attemt to solve the set of EFEs for outer planetary orbits when Newtonian gravity will suffice. Even NASA uses Newtonian gravity models to land rovers on Mars and 'sling-shot' Voyager around outer planets. What does that have to do with comprehending GR ? Can you grasp that? 2 hours ago, Marius said: So now you explain Einstein's gravity with Newton's law, are you fucking joking ? Einstein contradicts Newton, he says gravity is not a force but a curvature of space-time, while Newton says gravity is a force in a flat space ! Calm down! Let me try and explain. Newtonian gives acceptable results in most Earthly calculations and also most space endeavours undertaken througout the solar system. But it does have its recognised zone of applicability, as most theories do. Outside that zone, ( as in the perhelion shift of Mercury) we need and use GR, which if we needed to, we could also use instead of Newtonian. The ease though of Newtonian and the acceptable precision see it as sufficient. Einstein's GR describes or models gravity in a different manner to Newtonian, and more accurately, but gives us the same answer as the less precise Newtonian. Please research what a scientific theory/model is, and the how both Newtonian and GR are essentially correct. Remember what I have attempted to explain to you elswhere...first know thourghly that which you are attempting to invalidate before displaying your ignorance on that model.. Edited January 2, 2022 by beecee
swansont Posted January 2, 2022 Posted January 2, 2022 8 hours ago, Marius said: Its not, they are actually observed to be in the same plane. This contradicts the aberration that gravity is caused by a curvature of space-time and planets orbit on the curved space. As does the flat geometry of the universe in general. There is nothing curved or bent. The “plane” has an extent of several degrees, which is much, much larger than any geometry introduced by GR. There is no contradiction. https://en.wikipedia.org/wiki/Orbital_inclination#Observations_and_theories ! Moderator Note The approach of “I don’t understand GR, therefore it is wrong” is fatally flawed. There are two options: 1. Present evidence to support your claims, and an alternate model if you are proposing an alternative 2. Ask questions to fix your knowledge deficiencies What you can’t do is merely assert that mainstream physics is wrong. Not here, at least. 1
Janus Posted January 2, 2022 Posted January 2, 2022 13 hours ago, Marius said: If its not an actual bending of anything then why do mainstream scientists keep pretending that it is ('matter tells space how to curve, and space tells matter how to move'), and keep giving the same fabric sheet example over and over ? And how is the aberration in the video an accurate description of reality ? Do you seriously think that it has anything to do with reality ? Where do you think you are, the Matrix ? They say it this way when trying to communicate the idea of non-euclidean spacetime to a general populace that has no idea what non-euclidean geometry is. The animation is not meant to represent "reality", it is a "translation" of non-euclidean geometry using euclidean geometry. It is an attempt to represent an abstract concept in a way that is easier to visualize.
studiot Posted January 2, 2022 Posted January 2, 2022 It is important to distinguish the measure and the measurand in all circumstances. That is the ruler is not the same as that which is being measured. Failure to do this leads to much misunderstanding. Here are two 'straight line' graphs. Or are they ? Straight is the one dimensional version of not curved or zero curvature.
Markus Hanke Posted January 3, 2022 Posted January 3, 2022 On 1/2/2022 at 9:40 AM, Marius said: And you comprehend it ? If so, then can you make a calculation of the orbit of planets Jupiter and Saturn around the sun using Einsteins General Relativity gravity equations, and prove that they orbit in the same plane ? Not Newton, Einstein !!! The geodesic equations used to obtain free fall orbits are a system of differential equations - meaning any exact solution depends explicitly on initial and boundary conditions. The planets are (roughly) all in the ecliptic plane, because they all formed from the same protoplanetary accretion disk, meaning they all share one common boundary condition. So yes, GR handles this just fine, and so does Newton. The maths of how to obtain orbits in GR for simple Schwarzschild metrics are found in any undergrad GR text; I’ve worked through these calculations myself, and, while cumbersome and tedious, they demonstrably yield the correct results. On 1/2/2022 at 9:40 AM, Marius said: This actual curvature of space is what in his and the mainstream opinion causes the light of stars to be bend near the sun (gravitational lensing), and the planets to orbit around the sun. It’s curvature of spacetime, not just space. In fact, for situations such as planets and stars, gravitation is mostly due to the time part of the metric. Spatial curvature gives you tidal forces, but the ‘downward force’ of gravity is overwhelmingly (by a factor of c^2) due to time dilation, in conjunction with the principle of extremal ageing. Of course, in the geodesic equation you don’t really separate these effects; there’s just a trajectory in spacetime. On 1/2/2022 at 9:12 AM, Marius said: are you fucking joking If you were to take the emotion out of your posts, then people would take you more seriously. Some of the points you make and questions you ask are valid and worthy of discussion, but your approach to argumentation is off-putting and unscientific. You’re sabotaging yourself here.
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