![]() |
| If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|||||||
| Tags: shape, universe |
|
|
Thread Tools | Display Modes |
|
#1
|
|||
|
|||
|
Musings on NATURE Oct 9, 2003
Another world http://www.worldofescher.com/store/P5.html "Dear Jack and Saul-Paul, It is possible for a space to have zero curvature and still wrap around. One instance in three dims is flat metric on cartesian proudct of three circles. I suspect Dodec space has to have some curvature. Haven't had a chance to look at the Nature articles directly yet." Best, Lou K. George Ellis writes: "the Universe is finite" Does that contradict what Max Tegmark has written? No. See below. "it has a specific, rather rigid topology" He qualifies that by "if confirmed". That the universe may be "Poincare dodecahedral space" first of all is 3D not 2D and is a matter of metric independent "topology" in sense of the Felix Klein's 1872 "Erlanger Program" like a layered artichoke where geometry in the generalized sense is defined as the invariants of a given group of transformations between different frames of reference or perspectives or points of view as it were. Topology transformations are continuous transformations without cutting of holes of a continuum that leave certain global structures invariant and which do not at all respect the ds^2 = guv(x)dx^udx^v geometrodynamic invariant of Einstein's two relativity theories. There is also the issue of topology-changing catastrophes in the above context with cutting of holes. One can also consider discretums rather than continuums with finite groups of transformation which also arise in spaces that are defined using Galois fields of integers mod primes. Hermann Weyl showed a deep relation between discretums and continuums in his book on group theory and quantum theory. "What is its [the universe's] spatial curvature?" There are only 3 discrete possibilities. Restriction to "large scale" understood i.e. 10 megaparsecs k = 0 spatially flat like high school geometry where only one parallel to a line through a point not on the given line and never intersect k = -1 negative curvature where parallel lines diverge from each other and never intersect k = +1 positive curvature where parallel lines converge and intersect like the great circle geodesic longitudes on the surface of a sphere that intersect at the two poles. "geodesic" is the generalized "straight" for curved spaces. Inflation cosmology is like Handel's Messiah tenor aria "And the rough places plane" on the large scale of space. :-) Scale-dependence needs the "mother wavelet transform" generalization of the "Fourier transform". Modern quantum field theory and string theory are too dependent on the Fourier transform for propagators that define the difference between vacua (exotic or not) and real particles of matter and radiation. The value of k "depends on how well the amount of matter in the Universe, coupled with the driving force of dark energy, balances the Universe's kinetic energy of expansion. This is usually expressed in terms of the normalized density parameter Omega zero, which is unity for flat space sections, for positive spatial curvature Omega zero is greater than 1" "The second question is whether the universe is 'open' or 'closed' -- that is, is spatially infinite, containing an infinite amount of matter, or is spatially finite containing a finite amount of matter? Positively curved space sections are necessarily closed, but the converse does not necessarily follow: both flat and negatively curved space sections can be finite if their connectivity is more complicated than in Euclidean space, meaning that their topology is quite unusual." Enter the metrically engineered exotic vacuum Star Gate walled boundaries of space? See me talk about this in "Time Travel: The Art Of The Possible" http://www.dvdworldonline.com/DVD/Sc...yageHomeSE.asp "For example in a flat toroidal space, as you exit right you enter left, and space is finite." This means the 2D boundary wall is an exotic vacuum /\zpf =/= 0 Star Gate portal so that space is something like an Escher drawing or a giant Pong Video Game in the sky. To be continued. On Saturday, October 11, 2003, at 11:03 AM, Jack Sarfatti wrote: Thanks Saul-Paul. I have the 9 Oct 2003 issue of Nature on this in front of me and hopefully I will soon be able to understand what Ellis is actually proposing here in some detail. :-) George Ellis has a paper with references on p. 566 and more detailed paper on p. 593 by Luminet et-al so that should clear this all up soon. He is proposing a "finite" universe so how to square that circle with the "spatially flat" universe is the issue. I suppose that's where the periodic boundary conditions come in? It's like we are living inside a big spatial box that is expanding and accelerating but that we come to an "edge" i.e. a 2D wall and get instantly transported to an opposite wall many billions of light years on the opposite side of the universe? Rather like we are simulations in the "Destiny Matrix" Cosmic Computer Program after all? :-) On Saturday, October 11, 2003, at 08:42 AM, S-P & M-M Sirag wrote: Jack, I'm forwarding this message on the POSSIBLY dodecahedral universe from my friend Lou Kauffman, who is a well known topologist. This is the best information I now have on this new wrinkle in cosmololgy, since I have yet to see the 8 October issue of *Nature*. Be sure and check out the jpg's. For me the most intriguing aspect of this development is that the universe could have the topology of an A-D-E classified gravitational instanton, especially of type E6, E7, or E8. The "infinity" of these three instantons are, respectively, SU(2)/TD, SU(2)/OD, and SU(2)/ID. Note that the topology of SU(2)/ID is exactly that of a dodecahedron with opposite faces identified. Yes, interesting indeed. I need to understand in some detail how Ellis et-al make those inferences from the statistics of the WMAP data. One thing I am confused on is are they talking about 2D boundaries of 3D spacelike geometries? By "faces" do you mean literally 2D or a 3D generalization? Also it should be noted that these gravitational instantons (C^2/TD, C^2/OD, and C^2/ID) are also the identity fibers of the catastrophe bundle of types E6, E7, and E8. If one wonders where these catastrophe bundles are geometrically located, the answer is: inside the Lie algebras of types E6, E7, and E8, which are vector spaces of (complex) dimensions (respectively) 78, 133, and 248. Since E8 x E8 is also implicated in the heterotic string theory and E7 is implicated in membrane theory, this development in cosmology MAY have something to say about string theory. What I need to understand is how all this powerful math relates to the relatively simple math of the standard large scale cosmology of the ~ isotropic homogeneous FRW metric with /\ term that the precision cosmologists use to analyze the WMAP data and come to conclusions like k = 0 (universe is spatially flat on large scale). For more information see my paper "Notes on Hyperspace" which I have as a pdf, and also my 1998 paper "Hyperspace Platonics" (which unfortunately I don't have in pdf form). Send me the word.doc for Mac and I will make it pdf. Note also that the gravitational instanton idea is closely related to the Penrose twistor space. See especially *Twistor Geometry and Field Theory* by R.S. Ward and Raymond O. Wells Jr (Cambridge, 1990). See also P.B. Kronheimer's papers J. Differential Geometry 29, 685-698 (1989); 32, 473-490 (1990). Peter Kronheimer's Ph.D. thesis (advised by Michael Atiyah at Oxford) proved in detail the A-D-E classification of a class of gravitational instantons. I hope you can see why I continue to study what I call ADEX theory, the application of the A-D-E series of Coxeter graphs to mathematics and physics. Incidentally the X stands for the vast object (reality, I think) which underlies the entire set of A-D-E classifications. The X also stands for the classification of objects beyond the A-D-E series. In fact the three E graphs (E6, E7, & E8) are doorways into this set of graphs beyond A-D-E. There is an especially interesting X9 graph which abuts directly to E7 (by adding two nodes). This X9 graph is: *--*--*--*--*--*--* | * | * Saul-Paul ---------- From: Louis H Kauffman To: RWGRAY Subject: the shape of the universe Date: Sat, Oct 11, 2003, 12:13 AM Dear Folks, I have included some images and information from the web as three jpegs. The Nature article is in fact coauthored by Jeff Weeks. Best, Lou On Fri, 10 Oct 2003, Louis H Kauffman wrote: Dear Bob, The issue of structure of 3d universe as a whole is very interesting. In the abstract it is certainly possible for space to curve back on itself so that if one goes far enough "out" then one comes back to the starting point, just like going around the world. Yes, but it is my understanding from March and April APS and April 2003 Physics Today et-al that this possibility has been ruled out by the actual data from WMAP, type 1a supernovae etc? Is George Ellis challenging this? Or, is what he proposes somehow consistent with it. I thought the data confirms k = 0 FRW metric consistent with chaotic inflationary models (Max Tegmark May 2003 Scientific American)? We understand this effect for surfaces partly because we can stand outside them and see they have this property (like looking at the modes of circulation on a torus), but also because we can imagine a situation with no boundary but continual periodicity like a tv game where the objects move off screen left and reapear on screen right. That is the sort of description that the dodecahedral "identify by 1/5 twist the opposite faces" description uses. In that description a ray of light heading for one face flies right through and comes in again via the opposite face. But the "faces" are not there. That is just a way to describe the periodicity, and it is traces of this periodicity that are supposed to be inherent in the astronomical data. Oh, this helps. What I get from this is that 1) they are talking about 3D spacelike geometries. Are these "faces" like 2D boundaries that are like star gate portals? You pass through the 2D wall in your starship and instantly come out many light years across to the opposite edge of the 3D universe? Is that the picture that we are trapped inside a finite box with mirror faces that are star gates. The "box" is spatially flat on large scale consistent with k = 0? Or am I misunderstanding here? If so, these 2D boundary faces or "walls" in space would have to be exotic vacuum for sure. (I don't think the universe is small enough for any direct evidence of the periodicity. It must be quite indirect evidence that these guys are using, and this is going to make the result quite speculative.) So one wants more global descriptions of the space. One way to get a global description is to describe the manifold as a locus of solutions to systems of equations in a higher dimesional Euclidean space. In the case of the dodec space there is such a description of it in terms of equations in 6 dimensional Euclidean space written as 3 complex variables (X,Y,Z). Note that each complex variable has two real coords, making the space 6 diml. The dodec space is then described as the locus of solutions to the equations: X^2 + Y^3 + Z^5 = 0 |X|^2 + |Y|^2 + |Z|^2 = 1. Of course, if the universe were dodec space, this does not mean that the geometric universe is actually sitting inside flat 6 space, but that could be a useful way to model it. In general, if we are going to think about a boundaryless closed universe we might as well represent its curvature and dynamics in terms of embedding in some higher dimensional space. Theorems of John Nash and others tell us that abstract manifolds can be so modeled, and such models were the starting point for studying manifolds to begin with. Now for the sake of Science Fiction we have to ask, if Universe is really inside a 6 (or higher) space, then can't we figure out how to get off the Universe into the higher dims, just like we got off the surface of the earth into outer space. Here we have the next stage in space exploration: Voyages into higher space! The the vibrations of our familiar Universe will be seen as part of the panoply of quantum vibrating string and higher dimensional membrane interactions in the higher space. And THAT space, what if that space is itself closed and bounded and suffering dynamics in an even higher dimension... Fractal seeds of an infinite hierarchy of membrane universes. And we need not stop at finite dimensions. Let them all be enfolded in infinite and unfolding dimensions extending to the uncountable cardinals, the incaccessible cardinals and beyond, beyond logic, beyond paradox beyond conceptualization into the absolute.... And think of it man, all spiralling up out of void, into self-reference, distinction, triality, the trefoil knot, the quintessence of the trefoil knot, the dodec space, the enfoldment of the dodec in perfect six and ... But we seem to have reentered the periodicity. Time does not have a stop, but this letter does stop. Here. Love, Lou By Dr David Whitehouse BBC News Online science editor Leonardo da Vinci had the right idea More precisely, we may inhabit a dodecahedral cosmos. It is, according to the scientists, the best way to account for the latest satellite observations. Dodecahedrons, and similar shapes, have long fascinated mankind. Plato believed that the Universe was made up of them. Leonardo da Vinci also studied them, as did the great astronomer Kepler, who thought the structure of the Solar System was based on geometrical shapes. Further observations, especially from space probes yet to be launched, may settle the matter, and may at last reveal the hidden geometry of the Universe. Ripples in the sky The Cosmic Microwave Background (CMB) radiation, the "echo" of the Big Bang, contains a wealth of data about the early history of the Universe, as well as its large-scale structure. If only we had precise enough observations of it to discriminate between competing ideas of what the Universe is like. The scientists were writing in Nature magazine Will it expand forever? Is space infinite? Such profound questions may have their answers in the CMB. Specifically, the answers may be found in the ripples in the CMB - miniscule, regular, fluctuations in its strength over the sky. Data from the US space agency's Wilkinson Microwave Anisotropy Probe (WMAP), which maps the CMB, suggests that at the very largest scales its temperature fluctuations seen across the sky are smaller than would be produced by an infinite Universe. It seems the WMAP data shows the Universe is too small for large fluctuations to be seen in the microwave background radiation. Positively curved space sections Astronomers from the US and France suggest that space itself is not big enough to support such waves. A small, cosmologically speaking, finite Universe, however, made of curved pentagons joined together into a sphere, would fit the observations. The answer could be in the CMB Writing a commentary in Nature, George Ellis of the University of Cape Town, says we live in a Universe "with positively curved space sections and a non-standard topology". Indeed, a dodecahedral Universe, were you able to traverse it, would have some interesting properties. If you went out to the edge of the dodecahedron, you would come back in through the opposite face. More precise observations made by WMAP and by its successor, the Planck satellite, to be launched in 2007, will tell scientists if the cosmos does have such a shape, or if it is even stranger. |
| Ads |
| Thread Tools | |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| The observable Universe is a dodecahedron in shape | a_plutonium@hotmail.com | Physics - General Discussion | 7 | August 1st 05 07:47 AM |
| Shape of the Universe | Jack Sarfatti | Physics - General Discussion | 0 | October 12th 03 02:04 AM |
| Shape of Universe | Jack Sarfatti | Physics - General Discussion | 0 | October 12th 03 12:33 AM |
| Shape of spacetime vs. shape of universe | Jose B. Almeida | Physics - General Discussion | 0 | August 23rd 03 02:37 PM |
| Shape of spacetime vs. shape of universe | David Rutherford | Current Physics Research (Moderated) | 2 | August 20th 03 06:55 AM |