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| Tags: tensors |
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#1
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Rambling
If i take a cube and unfold it in a way that it becomes a planar object then there is degeneracy in terms of dimension - The planar form for 3D is a Cross Crucifix) - the forth dimension of time added results in a 3D cross (This is not the only configuration) the form is a translation of the original shape. Question? What symbol *should* represent 11 dimensions? Kieran |
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#2
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"Aesop" wrote in message ... Rambling If i take a cube and unfold it in a way that it becomes a planar object then there is degeneracy in terms of dimension - The planar form for 3D is a Cross Crucifix) - the forth dimension of time added results in a 3D cross (This is not the only configuration) the form is a translation of the original shape. Question? What symbol *should* represent 11 dimensions? Kieran This is an object known as a 'tesseract' - unfolding results in an object one dimension lower, so it is a trick we can use to visualise higher dimensions. It is not possible to visualise an 11 dimensional one, but you can express it mathematically (via topology). There is some good information on this in the book 'Hyperspace' by Michio Kaku p.s. Salvador Dali featured the 3D tesseract you mention in his crucifiction painting |
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#3
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Aesop wrote: Rambling It shows... If i take a cube and unfold it in a way that it becomes a planar object Wrong. A cube is a 3-D object. It cannot be "unfolded" into a 2-D object. You are probably thinking about the *surface* of a cube. There are many topologically distinct ways that 6 squares can be arranged so that they can be folded up into the surface of a cube. then there is degeneracy in terms of dimension - The planar form for 3D is a Cross Crucifix) I don't know which definition of the word 'degeneracy' you are using here, http://www.onelook.com/?w=degeneracy&ls=a but in the mathematical sense http://mathworld.wolfram.com/Degenerate.html it does not apply to this situation. - the forth "fourth"? dimension of time added results in a 3D cross I infer you are referring to the shape depicted he http://en.wikipedia.org/wiki/Tesseract And where is the 'time' dimension of your 3-D cross? What does it add to the figure that was absent before it was added? (This is not the only configuration) the form is a translation of the original shape. "translation?" In which direction or into what language? Again your misuse of the words leads to miscommunication. Question? What symbol *should* represent 11 dimensions? The usual mathematical convention is a special font capital Roman R followed by a superscript representing the number of dimensions (in your case, "11"): http://mathworld.wolfram.com/Dimension.html Tom Davidson Richmond, VA |
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#4
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#5
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"tadchem" wrote in message oups.com... Aesop wrote: Rambling It shows... If i take a cube and unfold it in a way that it becomes a planar object Wrong. A cube is a 3-D object. It cannot be "unfolded" into a 2-D object. You are probably thinking about the *surface* of a cube. There are many topologically distinct ways that 6 squares can be arranged so that they can be folded up into the surface of a cube. then there is degeneracy in terms of dimension - The planar form for 3D is a Cross Crucifix) I don't know which definition of the word 'degeneracy' you are using here, http://www.onelook.com/?w=degeneracy&ls=a but in the mathematical sense http://mathworld.wolfram.com/Degenerate.html it does not apply to this situation. - the forth "fourth"? dimension of time added results in a 3D cross I infer you are referring to the shape depicted he http://en.wikipedia.org/wiki/Tesseract And where is the 'time' dimension of your 3-D cross? What does it add to the figure that was absent before it was added? (This is not the only configuration) the form is a translation of the original shape. "translation?" In which direction or into what language? Again your misuse of the words leads to miscommunication. Question? What symbol *should* represent 11 dimensions? The usual mathematical convention is a special font capital Roman R followed by a superscript representing the number of dimensions (in your case, "11"): http://mathworld.wolfram.com/Dimension.html Tom Davidson Richmond, VA Tom drop your red pen for a moment please and consider Degenerate Having declined or or deteriorated to a lower physical level (2D representation of a 3D object) Translation Any form that changes to another is 'translated' (Rather than the strict matematical sense) I am assuming, perhaps incorrectly, you have the intellect to think in english as well as mathematics I was thinking about the surface of the cube (granted - hangs head in shame) I am familiar with the R term - What I was thinking about was unfolding the 3D cross as I did the Cube and adding another dimension to the resulting 2D object making it a 5D representation of the original object (using the same scheme as with the cube - cross) My question was what would be the resulting shape for 11 dimensions Kieran |
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#6
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"Anthony Smales" wrote in message ... "Aesop" wrote in message ... Rambling If i take a cube and unfold it in a way that it becomes a planar object then there is degeneracy in terms of dimension - The planar form for 3D is a Cross Crucifix) - the forth dimension of time added results in a 3D cross (This is not the only configuration) the form is a translation of the original shape. Question? What symbol *should* represent 11 dimensions? Kieran This is an object known as a 'tesseract' - unfolding results in an object one dimension lower, so it is a trick we can use to visualise higher dimensions. It is not possible to visualise an 11 dimensional one, but you can express it mathematically (via topology). There is some good information on this in the book 'Hyperspace' by Michio Kaku p.s. Salvador Dali featured the 3D tesseract you mention in his crucifiction painting Man nailed to a 4 dimensional existence? |
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#7
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Aesop wrote: snip Degenerate Having declined or or deteriorated to a lower physical level (2D representation of a 3D object) Translation Any form that changes to another is 'translated' (Rather than the strict matematical sense) I am assuming, perhaps incorrectly, you have the intellect to think in english as well as mathematics I am educated in the contextual definitions of words in both fields - my mother was a proofreader for newspapers and my father was a physicist, my first undergraduate degree was in mathematics (I am now a chemist). You yourself established the context as mathematics, and I would have been presumptive to assume you were changing contexts in mid-discussion. Now that I have your admission, I can adapt. My wife does it to me all the time - but then she's just an engineer. I am familiar with the R term - What I was thinking about was unfolding the 3D cross as I did the Cube and adding another dimension to the resulting 2D object making it a 5D representation of the original object (using the same scheme as with the cube - cross) My question was what would be the resulting shape for 11 dimensions There are 11 distict *nets* for the 3-D cube (that is what your 'cross' shape obtained from unfolding the surface of cube onto a 2-D surface is called): http://mathworld.wolfram.com/Cube.html http://mathworld.wolfram.com/Net.html The tesseract (4-dimensional cube) has 261 "nets" http://mathworld.wolfram.com/Tesseract.html The number of nets grows rapidly with the order of the hypercube. The Online Encyclopedia of Integer Sequences http://www.research.att.com/cgi-bin/...i?Anum=A091159 does not give the number of nets for hypercubes beyond the tesseract, although they are calculable - not that I know how off the top of my head. The page http://mathworld.wolfram.com/Hypercube.html displays 2-dimensional projections of the hypercubes of orders (dimensionality) 2 through 7. Extrapolating from a study of these we can see the following: The 11-D hypercube will have 2^11 (2048) vertices (corners), with 11 edges meeting at each vertex from orthogonal (perpendicular) directions (total 11,264 edges), each edge shared by 10 square faces (total 28,160 square faces), and it gets complicated after that... HTH Tom Davidson Richmond, VA |
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#8
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"Aesop" wrote in message ... "Anthony Smales" wrote in message ... "Aesop" wrote in message ... Rambling If i take a cube and unfold it in a way that it becomes a planar object then there is degeneracy in terms of dimension - The planar form for 3D is a Cross Crucifix) - the forth dimension of time added results in a 3D cross (This is not the only configuration) the form is a translation of the original shape. Question? What symbol *should* represent 11 dimensions? Kieran This is an object known as a 'tesseract' - unfolding results in an object one dimension lower, so it is a trick we can use to visualise higher dimensions. It is not possible to visualise an 11 dimensional one, but you can express it mathematically (via topology). There is some good information on this in the book 'Hyperspace' by Michio Kaku p.s. Salvador Dali featured the 3D tesseract you mention in his crucifiction painting Man nailed to a 4 dimensional existence? I think its called 'Christus Hypercubus' here it is: http://mapage.noos.fr/dardelf2/museum5/Dali-corpus.jpg |
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#9
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"tadchem" wrote in message oups.com... Aesop wrote: snip Degenerate Having declined or or deteriorated to a lower physical level (2D representation of a 3D object) Translation Any form that changes to another is 'translated' (Rather than the strict matematical sense) I am assuming, perhaps incorrectly, you have the intellect to think in english as well as mathematics I am educated in the contextual definitions of words in both fields - my mother was a proofreader for newspapers and my father was a physicist, my first undergraduate degree was in mathematics (I am now a chemist). You yourself established the context as mathematics, and I would have been presumptive to assume you were changing contexts in mid-discussion. Now that I have your admission, I can adapt. My wife does it to me all the time - but then she's just an engineer. I am familiar with the R term - What I was thinking about was unfolding the 3D cross as I did the Cube and adding another dimension to the resulting 2D object making it a 5D representation of the original object (using the same scheme as with the cube - cross) My question was what would be the resulting shape for 11 dimensions There are 11 distict *nets* for the 3-D cube (that is what your 'cross' shape obtained from unfolding the surface of cube onto a 2-D surface is called): http://mathworld.wolfram.com/Cube.html http://mathworld.wolfram.com/Net.html The tesseract (4-dimensional cube) has 261 "nets" http://mathworld.wolfram.com/Tesseract.html The number of nets grows rapidly with the order of the hypercube. The Online Encyclopedia of Integer Sequences http://www.research.att.com/cgi-bin/...i?Anum=A091159 does not give the number of nets for hypercubes beyond the tesseract, although they are calculable - not that I know how off the top of my head. The page http://mathworld.wolfram.com/Hypercube.html displays 2-dimensional projections of the hypercubes of orders (dimensionality) 2 through 7. Extrapolating from a study of these we can see the following: The 11-D hypercube will have 2^11 (2048) vertices (corners), with 11 edges meeting at each vertex from orthogonal (perpendicular) directions (total 11,264 edges), each edge shared by 10 square faces (total 28,160 square faces), and it gets complicated after that... HTH Tom Davidson Richmond, VA So the Euler number, X would be : X = V - E + F X = 2048 - 11264 + 28160 = 18944 (Euler numbers of equivalent surfaces are equal) |
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#10
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"tadchem" wrote in message oups.com... Aesop wrote: snip Degenerate Having declined or or deteriorated to a lower physical level (2D representation of a 3D object) Translation Any form that changes to another is 'translated' (Rather than the strict matematical sense) I am assuming, perhaps incorrectly, you have the intellect to think in english as well as mathematics I am educated in the contextual definitions of words in both fields - my mother was a proofreader for newspapers and my father was a physicist, Being of - is no guarantee of being my first undergraduate degree was in mathematics (I am now a chemist). You yourself established the context as mathematics, No it was rambling and I would have been presumptive to assume you were changing contexts in mid-discussion. Now that I have your admission, I can adapt. My wife does it to me all the time - but then she's just an engineer. (private joke no doubt) I am familiar with the R term - What I was thinking about was unfolding the 3D cross as I did the Cube and adding another dimension to the resulting 2D object making it a 5D representation of the original object (using the same scheme as with the cube - cross) My question was what would be the resulting shape for 11 dimensions There are 11 distict *nets* for the 3-D cube (that is what your 'cross' shape obtained from unfolding the surface of cube onto a 2-D surface is called): http://mathworld.wolfram.com/Cube.html http://mathworld.wolfram.com/Net.html The tesseract (4-dimensional cube) has 261 "nets" http://mathworld.wolfram.com/Tesseract.html The number of nets grows rapidly with the order of the hypercube. The Online Encyclopedia of Integer Sequences http://www.research.att.com/cgi-bin/...es/eisA.cgi?An um=A091159 does not give the number of nets for hypercubes beyond the tesseract, although they are calculable - not that I know how off the top of my head. The page http://mathworld.wolfram.com/Hypercube.html displays 2-dimensional projections of the hypercubes of orders (dimensionality) 2 through 7. Extrapolating from a study of these we can see the following: The 11-D hypercube will have 2^11 (2048) vertices (corners), with 11 edges meeting at each vertex from orthogonal (perpendicular) directions (total 11,264 edges), each edge shared by 10 square faces (total 28,160 square faces), and it gets complicated after that... HTH Whats HTH? Tom Davidson Richmond, VA Kieran |
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