David Levy Posted March 9, 2016 Share Posted March 9, 2016 (edited) http://www.space.com/24073-how-big-is-the-universe.html "Today, that same spot is 46 billion light-years away, making the diameter of the observable universe a sphere around 92 billion light-years." So, the radius of the whole Universe is 46 BLY. Let's divide it to the following segments: 0 – 12 Bly 12 – 24 Bly 24 – 36 Bly 36 – 48 Bly If R = 12 Bly Than 0 – 12 Bly = R 0 – 24 Bly = 2R 0 – 36 Bly = 3R 0 – 48 Bly = 4R Therefore: 0 – 48 Bly = The whole Universe = 4R 0 – 12 Bly = The core of the Universe = R 36 – 48 Bly = Edge of the Universe 0 – 36 Bly = Not at the edge of the Universe. The Volume of the Core of the Universe is ref. to: R^3 The Volume of the whole Universe is: (4R)^3 = 64R^3 The Volume of not at the Edge of the Universe is (3R)^3 = 27R^3 The Volume of the Edge of the Universe is 64R^3 - 27R^3 = 37R^3 So, the chance to be at the core of the Universe is 1 : 64 = 0.015 = 1.5% The chance to be at the Edge of the Universe is 37 : 64 = 0.58 = 58% The chance to be not at the Edge of the Universe is 27 : 64 = 0.42 = 42% What can we learn from this simple statistical verification? Edited March 9, 2016 by David Levy -1 Link to comment Share on other sites More sharing options...
Strange Posted March 9, 2016 Share Posted March 9, 2016 http://www.space.com/24073-how-big-is-the-universe.html "Today, that same spot is 46 billion light-years away, making the diameter of the observable universe a sphere around 92 billion light-years." So, the radius of the whole Universe is 46 BLY. No, that is not the radius of the whole universe. It is as it very clearly states, the radius of the OBSERVABLE universe. I can't make any sense of your random equations. What can we learn from this simple statistical verification? That, as ever, you don't have a clue. 2 Link to comment Share on other sites More sharing options...
dimreepr Posted March 9, 2016 Share Posted March 9, 2016 (edited) http://www.space.com/24073-how-big-is-the-universe.html "Today, that same spot is 46 billion light-years away, making the diameter of the observable universe a sphere around 92 billion light-years." So, the radius of the whole Universe is 46 BLY. Let's divide it to the following segments: 0 – 12 Bly 12 – 24 Bly 24 – 36 Bly 36 – 48 Bly If R = 12 Bly Than 0 – 12 Bly = R 0 – 24 Bly = 2R 0 – 36 Bly = 3R 0 – 48 Bly = 4R Therefore: 0 – 48 Bly = The whole Universe = 4R 0 – 12 Bly = The core of the Universe = R 36 – 48 Bly = Edge of the Universe 0 – 36 Bly = Not at the edge of the Universe. The Volume of the Core of the Universe is ref. to: R^3 The Volume of the whole Universe is: (4R)^3 = 64R^3 The Volume of not at the Edge of the Universe is (3R)^3 = 27R^3 The Volume of the Edge of the Universe is 64R^3 - 27R^3 = 37R^3 So, the chance to be at the core of the Universe is 1 : 64 = 0.015 = 1.5% The chance to be at the Edge of the Universe is 37 : 64 = 0.58 = 58% The chance to be not at the Edge of the Universe is 27 : 64 = 0.42 = 42% What can we learn from this simple statistical verification? Nothing, since every point in the universe is at its centre Edited March 9, 2016 by dimreepr Link to comment Share on other sites More sharing options...
David Levy Posted March 9, 2016 Author Share Posted March 9, 2016 Nothing, since every point in the universe is at its centre How could it be? Let's assume that we are located at about 5 Bly from the edge of the Universe. So, in one side we should see that there are no more galaxies beyond 5 Bly, while on the other side we should see up to about 13 Bly. Hence, why do you claim that every point is at the center? No, that is not the radius of the whole universe. It is as it very clearly states, the radius of the OBSERVABLE universe. What is the size of the whole universe? Link to comment Share on other sites More sharing options...
Klaynos Posted March 9, 2016 Share Posted March 9, 2016 I wonder, can you please sure the universe (not observable universe) has an edge? Link to comment Share on other sites More sharing options...
David Levy Posted March 9, 2016 Author Share Posted March 9, 2016 I wonder, can you please sure the universe (not observable universe) has an edge? If it has a size, than it should have an edge. If it has no edge, then it is infinite. So simple. Link to comment Share on other sites More sharing options...
Klaynos Posted March 9, 2016 Share Posted March 9, 2016 If it has a size, than it should have an edge. If it has no edge, then it is infinite. So simple. The surface of a basketball has a size, please show me it's edge. Link to comment Share on other sites More sharing options...
David Levy Posted March 9, 2016 Author Share Posted March 9, 2016 (edited) The surface of a basketball has a size, please show me it's edge. We are discussing about the Volume. (Not the surface) Surface - has only two dimensions. Edited March 9, 2016 by David Levy Link to comment Share on other sites More sharing options...
Klaynos Posted March 9, 2016 Share Posted March 9, 2016 We are discussing about the Volume. (Not the surface) Surface - has only two dimensions. Ok, consider the surface volume of a hypersphere, please show me it's edge. You made a clear statement that things with size have an edge. Considering this with something we can actually conceptualise like a ball is a lot easier. Link to comment Share on other sites More sharing options...
David Levy Posted March 9, 2016 Author Share Posted March 9, 2016 Ok, consider the surface volume of a hypersphere, please show me it's edge. You made a clear statement that things with size have an edge. Considering this with something we can actually conceptualise like a ball is a lot easier. Do you claim that the Universe is a hypersphere? Why don't you like the idea that the Universe should have an edge? -1 Link to comment Share on other sites More sharing options...
Klaynos Posted March 9, 2016 Share Posted March 9, 2016 Do you claim that the Universe is a hypersphere? Why don't you like the idea that the Universe should have an edge? I have never seen any evidence that the universe has an edge. Even less than we are close to it. I strongly dislike the assertion that anything with size must have an edge. The claim is in fact false add shown, things can have size but no edge. Modern cosmology disagrees with your concept of the universe. 2 Link to comment Share on other sites More sharing options...
David Levy Posted March 9, 2016 Author Share Posted March 9, 2016 (edited) I strongly dislike the assertion that anything with size must have an edge. The claim is in fact false add shown, things can have size but no edge. If the Universe has three dimensions than by definition it has to have edge. If the Universe is hypersphere than it is O.K. to assume that it has no edge. But, you can't have them both in one Universe. I have never seen any evidence that the universe has an edge. Even less than we are close to it. Please choose one of the following options: 1. The Universe has no edge; therefore it has more than three dimensions. 2. The Universe has no edge, but it has only three dimensions, therefore it is infinite. 3. The Universe has three dimensions - it is not infinite - therefore it must have an edge. 4. ? Edited March 9, 2016 by David Levy -1 Link to comment Share on other sites More sharing options...
Phi for All Posted March 9, 2016 Share Posted March 9, 2016 If the Universe has three dimensions than by definition it has to have edge. I can travel all over the 3D Earth, drive through chunnels, spelunk through the middle (volume!), winding up back where I came from, and never see an edge. Your statement is false. Link to comment Share on other sites More sharing options...
dimreepr Posted March 9, 2016 Share Posted March 9, 2016 How could it be? Your mistake is to assume a finite universe. Link to comment Share on other sites More sharing options...
David Levy Posted March 9, 2016 Author Share Posted March 9, 2016 (edited) I can travel all over the 3D Earth, drive through chunnels, spelunk through the middle (volume!), winding up back where I came from, and never see an edge. Your statement is false. No, I disagree. The following is 2D: drive through chunnels The following is 3D: spelunk through the middle However, once you spelunk through the middle and continue more and more (in the same direction), you will get to the surface of the earth. if you continue with the same momentum/direction than you will find yourself out of the Earth. Edge! Edited March 9, 2016 by David Levy Link to comment Share on other sites More sharing options...
Phi for All Posted March 9, 2016 Share Posted March 9, 2016 if you continue with the same momentum/direction than you will find yourself out of the Earth. Edge! So you have to force me to break physical laws to make your statement true? Link to comment Share on other sites More sharing options...
swansont Posted March 9, 2016 Share Posted March 9, 2016 There is no evidence if the universe having an edge. You should not be making definitive statements to the contrary. If it has a size, than it should have an edge.[/size]If it has no edge, then it is infinite.[/size]So simple.[/size] This is moot, given your OP. The observable universe is finite, but it's not the same volume as somebody else's observable universe if they are not co-located with us. Which makes the rest of your OP meaningless. Link to comment Share on other sites More sharing options...
David Levy Posted March 9, 2016 Author Share Posted March 9, 2016 (edited) So you have to force me to break physical laws to make your statement true? What physical laws? So, Do you agree that the Universe has only three dimensions? If so - in any three dimensions there must be an edge. Why are you all against it? The observable universe is finite, but it's not the same volume as somebody else's observable universe if they are not co-located with us. I'm not sure that I fully understand this explanation. Would you kindly elaborate? In the following 2D example - The surface of a basketball has a size, please show me it's edge. If we go over the surface of the basketball, then, there will be no end as it is a close loop. Therefore, there is no edge. Actually, if we start at one point and walk in one direction, then we might get back to the same point. So, do you mean that the Universe is some sort of a close loop in three dimensions? Hence, can we assume that if we go in one direction, eventually we might get back to the same spot? Edited March 9, 2016 by David Levy Link to comment Share on other sites More sharing options...
swansont Posted March 9, 2016 Share Posted March 9, 2016 I'm not sure that I fully understand this explanation. Would you kindly elaborate? An observer a billion LY away sees a different 46 billion LY radius sphere, offset from ours by a billion LY. Not one that's 45 billion LY on one side. The observable universe is a subset of the whole universe Link to comment Share on other sites More sharing options...
Strange Posted March 9, 2016 Share Posted March 9, 2016 (edited) Let's assume that we are located at about 5 Bly from the edge of the Universe. There is no edge. What is the size of the whole universe? No one knows. Possibly infinite. Possibly not. If it has a size, than it should have an edge. If it has no edge, then it is infinite. So simple. So ignorant. We are discussing about the Volume. (Not the surface) Surface - has only two dimensions. It is an analogy: the same thing can be true in 3 dimensions. If the Universe has three dimensions than by definition it has to have edge. Not by any definition I am aware of. Please choose one of the following options: 1. The Universe has no edge; therefore it has more than three dimensions. 2. The Universe has no edge, but it has only three dimensions, therefore it is infinite. 3. The Universe has three dimensions - it is not infinite - therefore it must have an edge. 4. ? I'll go for 2 or 4 (as they are the ones supported by our current best theories). Forthe benefit of those who know nothing about modern science, 4 is: finite but unbounded. Edited March 9, 2016 by Strange 1 Link to comment Share on other sites More sharing options...
David Levy Posted March 10, 2016 Author Share Posted March 10, 2016 An observer a billion LY away sees a different 46 billion LY radius sphere, offset from ours by a billion LY. Not one that's 45 billion LY on one side. The observable universe is a subset of the whole universe Well I agree that an observer outside the Universe might see it differently from us. But, a 46 billion LY radius sphere is a 92 billion Ly diameter sphere. However - 92 billion Ly diameter sphere is a limited number. So, what the observer might see at the end of those 92 billion Ly? In the same token- I'll go for 2 or 4 (as they are the ones supported by our current best theories). Forthe benefit of those who know nothing about modern science, 4 is: finite but unbounded. Hence, do you agree about the following? "The Universe has only three dimensions, it is finite but it has no edge" So, what is the meaning of finite? Do you agree that if we go at one direction all the way, then at some point we will get to an end? If so, what shall we see? However, if there is no end – then why do we claim that it is finite? Link to comment Share on other sites More sharing options...
Mordred Posted March 10, 2016 Share Posted March 10, 2016 (edited) No there are some geometric shapes that have no edge that are finite one example is the 3 torus or a sphere. If you have a positive curvature constant however slight the Universe will be finite. However that curvature constant also means light beams will not travel "straight" but will travel with the curvature.(null geodesic) So with our measured curvature constant if you shot a laser that laser will follow the curvature (so will any craft). If you stop expansion it would take roughly 880 billion years to arrive back at its point of origin. However our universe is also extremely flat which implies an infinite universe. The measurement uncertainty favors the flat case but doesn't discount the positive curvature case It's a tricky concept to grasp but straight isn't straight in curved spacetime Edited March 10, 2016 by Mordred Link to comment Share on other sites More sharing options...
David Levy Posted March 10, 2016 Author Share Posted March 10, 2016 Thanks Mordred No there are some geometric shapes that have no edge that are finite one example is the 3 torus or a sphere. Well, I'm not sure that I fully understand the meaning of 3 torus or a sphere. However, if you claim that the Universe is a 3 torus or a sphere then, yes it could be that it is finite with no edge. But you have to prove that the Universe is 3 torus or a sphere and also explain what is it. If you have a positive curvature constant however slight the Universe will be finite. However that curvature constant also means light beams will not travel "straight" but will travel with the curvature.(null geodesic)So with our measured curvature constant if you shot a laser that laser will follow the curvature (so will any craft). Do you mean that there is a chance that eventually, the light will come back to the starting point? If yes, than it is a close loop - similar to the surface of the basketball. Then this is perfectly O.K. to assume that there is no end. However, if the light will travel with the curvature. to the infinite (in a finite universe), then at some point it must hit the end of the finite universe If you stop expansion it would take roughly 880 billion years to arrive back at its point of origin. I assume that this is a pure theory. Is it correct? If so, please try to distinguish between theory and evidence. However our universe is also extremely flat which implies an infinite universe. Is it also a theory or we have a clear evidence for that? The measurement uncertainty favors the flat case but doesn't discount the positive curvature caseIt's a tricky concept to grasp but straight isn't straight in curved spacetime So, do we have measurements results (evidences) which support a flat universe? If so, why do we consider about "positive curvature case"? Link to comment Share on other sites More sharing options...
Mordred Posted March 10, 2016 Share Posted March 10, 2016 The curvature time of transit is based on a paper from the South pole observatory. There was an arxiv paper on it around two years back. Nothing is ever conclusive in physics. So don't expect any conclusive answers. The WMAP and Planck data papers support the flat case. As far as the latter question is that there is always a margin of error in any complex analysis. Yes the light beam could theoretically return to Earth in the positive curvature case. However it will never do so due to rate of expansion. Here is a low math article on geometry. http://cosmology101.wikidot.com/universe-geometry Page 2 http://cosmology101.wikidot.com/geometry-flrw-metric/ Link to comment Share on other sites More sharing options...
David Levy Posted March 10, 2016 Author Share Posted March 10, 2016 Nothing is ever conclusive in physics. So don't expect any conclusive answers. Yes, I fully understand. But we can't say again - "sorry we don't know, however, based on what we don't know, it is clear that what you say is incorrect". The WMAP and Planck data papers support the flat case. As far as the latter question is that there is always a margin of error in any complex analysis. So, if the Universe is flat, then what does it means? How that might affect the idea that a finite Universe has no edge? The curvature time of transit is based on a paper from the South pole observatory. There was an arxiv paper on it around two years back. If it has a curvature time - then what does it mean? How this kind of phenomenon could affect the Universe from the first moment. Is it a constant phenomenon? Why we didn't add it in our formulas and calculations? Does it mean that Einstein and Friedman have missed something? Yes the light beam could theoretically return to Earth in the positive curvature case. However it will never do so due to rate of expansion. Here is a low math article on geometry. If that is correct, than could it be that the expansion is also in a the positive curvature case? Why the light can go in loop, while the expansion is not in the loop? So, could it be that we are living in some sort of a close loop universe? Link to comment Share on other sites More sharing options...
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