reflection

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(rĭ-flĕk'shən) pronunciation
n.
  1. The act of reflecting or the state of being reflected.
  2. Something, such as light, radiant heat, sound, or an image, that is reflected.
    1. Mental concentration; careful consideration.
    2. A thought or an opinion resulting from such consideration.
  3. An indirect expression of censure or discredit: a reflection on his integrity.
  4. A manifestation or result: Her achievements are a reflection of her courage.
  5. Anatomy.
    1. The folding of a membrane from the wall of a cavity over an organ and back to the wall.
    2. The folds so made.
reflectional re·flec'tion·al adj.


is now the dominant form, although reflexion is the older.

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Change in the direction of propagation of a wave that strikes a boundary between different media through which it cannot pass. When a wave strikes such a boundary it bounces back, or is reflected, just as a ball bounces off the floor. The angle of incidence is the angle between the path of the wave and a line perpendicular to the boundary. The angle of reflection is the angle between the same line and the path of the reflected wave. All reflected waves obey the law of reflection, which states that the angle of reflection is equal to the angle of incidence. The reflectivity of a material is the fraction of energy of the oncoming wave that is reflected by it.

For more information on reflection, visit Britannica.com.

(1) A characteristic of light (see reflective).

(2) A feature of some programming languages and scripting languages that allows them to change their own structure at runtime. It typically refers to interpreted languages that can, for example, accept source code as input, which modifies the program's original behavior when executed. A compiler may also provide meta-data that can be used for reflection at runtime. See also reflection mapping.

(3) (Reflection) A family of connectivity software from Attachmate Corporation that runs under Windows. Reflection products include terminal emulation for Unix, HP, OpenVMS, IBM and X Window as well as NFS support for clients and NT servers. The Reflection line was originally the flagship product offering of WRQ, Inc., which Attachmate acquired in 2005.

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noun

  1. Something that is reflected: image. See show/hide.
  2. Imitative reproduction, as of the style of another: echo, imitation, reflex, repetition. See same/different/compare.
  3. The act or process of thinking: brainwork, cerebration, cogitation, contemplation, deliberation, excogitation, meditation, rumination, speculation, thought. See thoughts.
  4. An implied criticism: reproach, slur. See praise/blame.

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n

Definition: criticism
Antonyms: praise

The change of direction which a ray of light, sound, or radiant heat undergoes when it strikes a surface; also see law of reflection.


Reflections exercise an enduring fascination for photographers; but they are harder to photograph than to resist. The most usual problem with reflections in water, apart from ripples destroying the resolution, is determining the ideal exposure: the reflection is almost always darker than the object reflected, though there are a few lighting conditions where this is not so. If the disparity is too great, a graduated grey filter can prove a useful remedy. If there is too great an expanse of smooth, featureless water in the foreground, tossing in a pebble or two to create ripples can be useful.

Reflections in other materials—glass, mirrors, chrome automobile trim, and more—are often let down by lack of depth of field; this can sometimes be used creatively, throwing either the reflector or the reflected subject out of focus. For a plane surface, a reflection is at the same effective distance as the subject from the reflective surface. In other words, if the reflector is a metre from the camera, and the subject reflected is 3 metres (10 ft) from the reflector, then the effective distance of the subject from the camera is 1 + 3 = 4 metres. For curved reflectors, the effective distance may well vary.

— Roger W. Hicks

See also polarized light
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reflection, return of a wave from a surface that it strikes into the medium through which it has traveled. The general principles governing the reflection of light and sound are similar, for both normally travel in straight lines and both are wave phenomena. Objects are visible because of the light reflected from their surfaces, and their color depends on their ability to reflect light of a certain wavelength and to absorb that of other wavelengths. The reflection of sound waves from a surface is called an echo.

The Laws of Reflection

The reflection of light follows certain definite laws. A ray of light striking a reflecting surface at right angles to it is returned directly along the path it has followed in reaching the surface. When, however, a ray strikes a reflecting surface at any other angle, it is reflected at an angle in an opposite direction. The incoming ray is called the incident ray. Its direction is usually described by the angle of incidence, which is the angle that it makes with the normal, or line perpendicular to the reflecting surface at the point of reflection. The angle formed by the reflected ray and the normal is called the angle of reflection and is equal to the angle of incidence. Furthermore, the reflected ray is always in the same plane as the incident ray, and this plane is perpendicular to the surface.

The Degree and Types of Reflection

Not all surfaces reflect light in the same way or to the same degree. The measure of the fraction of light that is reflected by a material is called its reflectance. Metals in general have high values of reflectance; silver, for example, has a reflectance of about 96%. Smooth surfaces give regular reflection, also called specular reflection, in which incident parallel rays remain parallel after reflection. Rough or uneven surfaces give diffuse reflection, since the reflected rays are scattered and not parallel. For example, reflection by a mirror is regular; by a highly polished but uneven piece of metal, it is diffused. Reflection of light is also brought about under certain conditions by the surfaces of transparent media through which light normally passes. An example is seen in the blazing glare of sunlight on a window or an automobile windshield when the sun's rays strike it at a very oblique angle.

A corner reflector returns a ray that is exactly parallel to the incident ray back to the incident ray's point of origin, or very close to it. The reflector is formed by intersecting three mutually perpendicular planes, with the centerpoint therefore being located at the mutual point of intersection. Such a device can be utilized as a radar target or marker for range finding and surveying. For increased visibility at night microscopic corner reflectors can be incorporated into reflective paint for road signs and incorporated into the lenses of bicycle and motorcycle reflectors. Several U.S. Apollo missions and one Soviet Lunakhod lunar probe deployed corner reflector arrays on the lunar surface. When the arrays are illuminated by laser beams originating from the earth, precise measurements of the roundtrip travel time of the light permit the calculation of the earth-moon distance to an accuracy of 6 in. (15 cm). Such measurements also are used to determine the moon's orbit with greater accuracy, to record perturbations in the moon's motion caused by meteorite impacts, and to ascertain the length of an earth day.

The phenomenon called total internal reflection is observed when light passing from one medium (e.g., a glass prism or water) to a less dense medium (e.g., air) reaches the boundary between the two media and is thrown back into the denser medium instead of passing outward as would be expected. This occurs when the light strikes at an oblique angle, greater than a certain degree. Up to that degree, refraction (not reflection) takes place, and the greatest angle at which refraction is possible is called the critical angle; if the angle of incidence exceeds this angle, total reflection occurs. The fire of a faceted diamond is due to total internal reflection. Internal reflection accounts in part for a number of natural phenomena. Rays of sunlight striking raindrops are refracted on entering them and then undergo internal reflection; since the sunlight is broken up into its colors, a rainbow appears. A mirage is also partially the result of internal reflection.


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A cynical view of the world by Ambrose Bierce


n.

An action of the mind whereby we obtain a clearer view of our relation to the things of yesterday and are able to avoid the perils that we shall not again encounter.


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reflection

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pronunciation

IN BRIEF: n. - The image of something as seen in a mirror; A remark expressing careful consideration.

pronunciation What we are doing to the forests of the world is but a mirror reflection of what we are doing to ourselves and to one another. — Gandhi

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A bouncing of light off a surface. People see themselves in mirrors through reflection. (Compare refraction.)

A turning or bending back, such as the folds produced when a membrane passes over the surface of an organ and then passes back to the body wall that it lines.


n

The act of elevating and folding back the mucoperiosteum, thereby exposing the underlying bone.

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categories related to 'reflection'

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Random House Word Menu by Stephen Glazier
For a list of words related to reflection, see:

Translations:

Reflection

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Dansk (Danish)
n. - tilbagekastning, refleksion, genskær, eftertanke

idioms:

  • on reflection    ved nærmere eftertanke

Nederlands (Dutch)
bezinning, aanmerking, (af-/be)spiegeling, weerkaatsing

Français (French)
n. - (lit, fig) reflet, image, réflexion, pensée, remarque, idée (que), critique

idioms:

  • on reflection    à la réflexion

Deutsch (German)
n. - Reflexion, Nachdenken, Spiegelung, Spiegelbild

idioms:

  • on reflection    bei weiterem Nachdenken

Ελληνική (Greek)
n. - αντανάκλαση, συλλογισμός, στοχασμός, (βαθιά) σκέψη, επίκριση, αμφισβήτηση, είδωλο, εικόνα

idioms:

  • on reflection    μετά από σκέψη

Italiano (Italian)
riflessione

idioms:

  • on reflection    ripensandoci

Português (Portuguese)
n. - reflexão (f), comentário (m)

idioms:

  • on reflection    refletindo, considerando

Русский (Russian)
обдумывание, отражение

idioms:

  • on reflection    по размышлении

Español (Spanish)
n. - reflexión, meditación, reflejo

idioms:

  • on reflection    pensándolo mejor

Svenska (Swedish)
n. - spegelbild, eftertanke

中文(简体)(Chinese (Simplified))
反射, 反射光, 回声, 回响, 映象, 倒影

idioms:

  • on reflection    考虑后

中文(繁體)(Chinese (Traditional))
n. - 反射, 反射光, 回聲, 回響, 映象, 倒影

idioms:

  • on reflection    考慮後

한국어 (Korean)
n. - 반사 , 숙고 , 비난, 꼭 닮은 것

日本語 (Japanese)
n. - 反射, 反響, 反射光, 映像, 生き写し, 意見, 熟考, 反省, 非難

idioms:

  • on reflection    よく考えて

العربيه (Arabic)
‏(الاسم) إنعكاس, , صورة منعكسه, تفكير‏

עברית (Hebrew)
n. - ‮השתקפות, מחשבה, בבואה, החזרה, רעיון, הערה, דופי, אשמה, פגיעה‬


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