In geometry, the mirror image of an object or two-dimensional figure is the virtual image formed by a plane mirror; it is of the same size as the original object, yet different, unless the object or figure has mirror-image symmetry (also known in the terminology of modern physics as a P-symmetry).
- The mirror-image of b is d or p (d and p are equal except for orientation).
- The tetrominos S and Z
- The mirror-image of a right hand is like a left hand.
- The mirror-image of a human body is roughly like a human body, but with internal differences; for a particular person there are also minor external differences, the most striking may be the hair if that is not symmetrically cut and combed.
- The 3D tetrominos left and right screw
- The two versions of the snub cube are mirror images of each other.
- The two isomers in the case of optical isomerism.
- Clothing is often approximately symmetric. However, for fastening the right to the left side (of a shirt, coat, flies, dress, etc.), often on the front side, but also on the back side, if buttons are used one side goes over the other; in the case of a zip fastener there is at least minor asymmetry, but often also one flap goes over the other. A belt, although often vertically symmetric, provides also asymmetry. A skirt may have a zip fastener on one side. There may also be asymmetry with regard to pockets, for example only one inner pocket.
- text or pictures on glass or textiles (a printed T-shirt worn inside out, a parasol)
- paper printed on one side, looked at from the other side, holding it to the light
Occasionally you can see a mirror image, even though you are aware of looking at the reflection of a reflection; this may be due to a third reflection.
A text is sometimes displayed in mirror image on the front side of a car, to be seen as a regular text in the rear view mirror of the car in front.
A special kind of "mirror image" of a text is with the letters in reversed order, while the individual letters are normal, see http://wikipedia.org.mirror.sytes.org/wiki/mirror_image . The real mirror image of that is with is with the letters in normal order, but each in mirror image.
See also Chirality, Left and right, handedness