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| | The term Symmetry arises in a number of contexts, and has several, related meanings<ref> Intial definitions from: http://www.m-w.com/dictionary/symmetry</ref> : | | The term Symmetry arises in a number of contexts, and has several, related meanings<ref> Intial definitions from: http://www.m-w.com/dictionary/symmetry</ref> : |
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| − | * It may refer to an object which has balanced proportions, and the beauty of form arising from those balanced proportions, notably a face, or an animal, e.g a racehorse. | + | * It may refer to an object which has balanced proportions, and the beauty of form arising from those balanced proportions, notably a face, or an animal, e.g a tiger, as in Blake's poem: |
| | + | TIGER, tiger, burning bright |
| | + | In the forests of the night, |
| | + | What immortal hand or eye |
| | + | Could frame thy fearful symmetry? |
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| | * It may refer to the property of being mathematically symmetrical, especially relating to a correspondence in size, shape, and relative position of parts on opposite sides of a dividing line or median plane or about a center or axis; sometimes the term [[bilateral symmetry]] is used in this context. | | * It may refer to the property of being mathematically symmetrical, especially relating to a correspondence in size, shape, and relative position of parts on opposite sides of a dividing line or median plane or about a center or axis; sometimes the term [[bilateral symmetry]] is used in this context. |
| | * It may refer to an [[isometry|isometric transformation]] or [[rigid body motion]] of a geometric figure, which determines a one-to-one mapping onto itself, and which preserves angles and distances. There are four such kinds of [[isomorphism]]:[[Rotation]]s, [[Reflection]]s, [[Translation]]s and [[Glide-Reflection]]s | | * It may refer to an [[isometry|isometric transformation]] or [[rigid body motion]] of a geometric figure, which determines a one-to-one mapping onto itself, and which preserves angles and distances. There are four such kinds of [[isomorphism]]:[[Rotation]]s, [[Reflection]]s, [[Translation]]s and [[Glide-Reflection]]s |