![]() Hence, the reversal is somewhat misleadingly called a "lateral inversion". Although a plane mirror reverses an object only in the direction normal to the mirror surface, this turns the entire three-dimensional image seen in the mirror inside-out, so there is a perception of a left-right reversal. Thus reflection is a reversal of the coordinate axis perpendicular ( normal) to the mirror's surface. If a point of an object has coordinates ( x, y, z) then the image of this point (as reflected by a mirror in the y, z plane) has coordinates (− x, y, z). In general, an object and its mirror image are called enantiomorphs. That is an example of chirality (chemistry). ![]() In chemistry, two versions (isomers) of a molecule, one a "mirror image" of the other, are called enantiomers if they are not "superposable" (the correct technical term, though the term "superimposable" is also used) on each other. ![]() More fundamentally in geometry and mathematics they form the principal objects of Coxeter group theory and reflection groups. In physics, mirror images are investigated in the subject called geometrical optics. A three-dimensional object is reversed in the direction perpendicular to the mirror surface. The term then relates to structural as well as visual aspects. The concept of reflection can be extended to three-dimensional objects, including the inside parts, even if they are not transparent. In three dimensions A symmetrical urn and its mirror image So, in these examples the mirror does not actually cause the observed reversals. Again we perceive a left-right reversal due to a change in our orientation. Then we compare the object with its reflection by turning ourselves 180°, towards the mirror. Another example is when we stand with our backs to the mirror and face an object that is in front of the mirror. In this example, it is the change in orientation rather than the mirror itself that causes the observed reversal. If we first look at an object that is effectively two-dimensional (such as the writing on a card) and then turn the card to face a mirror, the object turns through an angle of 180° and we see a left-right reversal in the mirror. Two-dimensional mirror images can be seen in the reflections of mirrors or other reflecting surfaces, or on a printed surface seen inside-out. In geometry, the mirror image of an object or two-dimensional figure is the virtual image formed by reflection in a plane mirror it is of the same size as the original object, yet different, unless the object or figure has reflection symmetry (also known as a P-symmetry).
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