Reflection symmetry
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Reflection symmetry, line symmetry, mirror symmetry, mirror-image symmetry, or bilateral symmetry is symmetry with respect to reflection.
In [[hfdhfhfhfhnnngfgngfntj The triangles with this symmetry are isosceles. The quadrilaterals with this symmetry are the kites and the isosceles trapezoids.
For each line or plane of reflection, the symmetry group is isomorphic with Cs (see point groups in three dimensions), one of the three types of order two (involutions), hence algebraically C2. The fundamental domain is a half-plane or half-space.
In certain contexts there is rotational symmetry anyway. Then mirror-image symmetry is equivalent with inversion symmetry; in such contexts in modern physics the term P-symmetry is used for both (P stands for parity).
For more general types of reflection there are corresponding more general types of reflection symmetry. Examples:
- with respect to a non-isometric affine involution (an oblique reflection in a line, plane, etc).
- with respect to circle inversion.
Mirrored symmetry is also found in the design of ancient structures, including Stonehenge.[1]
See also
References
- ^ Johnson, Anthony, Solving Stonehenge: The New Key to an Ancient Enigma. (Thames & Hudson, 2008) ISBN 978-0-500-05155-9
- Weyl, Hermann (1982). Symmetry. Princeton: Princeton University Press. ISBN 0-691-02374-3.
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