Encyclopedia - Light: Encyclopedia Ii - Light - Refraction
All light propagates at a finite speed. Even moving observers always measure the same value of c, the speed of light in vacuum, as c = 29...   » Read the article

Encyclopedia - Refractive Index: Encyclopedia Ii - Refractive Index - The Speed Of Light
The speed of all electromagnetic radiation in vacuum is the same, approximately 3×108 meters per second, and is denoted by c. Therefore,...   » Read the article

Encyclopedia - Refractive Index: Encyclopedia Ii - Refractive Index - Anisotropy
The refractive index of certain media may be different depending on the polarization and direction of propagation of the light through th...   » Read the article

Encyclopedia - Light: Encyclopedia - Light
Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific context,...   » Read the article

Article - Indigo Children: Poetry For And About Indigos - Girl Indigo
Girl Indigo   Shattered glass sparkles through a broken window refracting reflections into backlit hallways deep, deep inside, fl...   » Read the article

Encyclopedia - Birefringence: Encyclopedia - Birefringence
Birefringence, or double refraction, is the decomposition of a ray of light into two rays (the ordinary ray and the extraordinary ray) w...   » Read the article

Encyclopedia - Lens Anatomy: Encyclopedia - Lens Anatomy
The lens or crystalline lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to focus...   » Read the article

Encyclopedia - Caustics: Encyclopedia - Caustics
The word caustics, meaning "to burn" or "burning", may refer to: Caustic (substance), a substance that 'eats away' or chemically burns o...   » Read the article

Encyclopedia - Cornea: Encyclopedia - Cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber and provides most of an eye's optic...   » Read the article

Encyclopedia - Telescope: Encyclopedia - Telescope
A telescope (from the Greek tele = 'far' and skopein = 'to look or see'; teleskopos = 'far-seeing') is an optical tool which gathers and ...   » Read the article

Encyclopedia - Darkfield Microscope: Encyclopedia - Darkfield Microscope
A Darkfield microscope uses a method whereby the sample being viewed is actually in front of a dark background and light is being angled ...   » Read the article

Encyclopedia - Chromatic Aberration: Encyclopedia - Chromatic Aberration
Chromatic aberration is caused by the dispersion of the lens material, the variation of its refractive index n with the wavelength of lig...   » Read the article

Encyclopedia - X-ray Microscope: Encyclopedia - X-ray Microscope
An X-ray microscope uses electromagnetic radiation in the soft X-ray band to produce images of very small objects. Unlike visible light m...   » Read the article

Encyclopedia - Allvar Gullstrand: Encyclopedia - Allvar Gullstrand
Allvar Gullstrand (born June 5, 1862 in Landskrona – died July 28, 1930 in Stockholm) was a Swedish ophthalmologist. He was professor (...   » Read the article

Encyclopedia - Zone Plate: Encyclopedia - Zone Plate
A Zone plate is a device used to focus light. Unlike lenses however, zone plates use diffraction instead of refraction. Created by August...   » Read the article

Encyclopedia - Myopia: Encyclopedia - Myopia
Myopia is a refractive defect of the eye in which light focuses in front of the retina. Those with myopia are often described as nearsig...   » Read the article

Encyclopedia - Aberration In Optical Systems: Encyclopedia - Aberration In Optical Systems
Aberration in optical systems (lenses, prisms, mirrors or series of them intended to produce a sharp image) generally leads to blurring o...   » Read the article

Encyclopedia - Silk: Encyclopedia - Silk
Silk is a natural protein fibre that can be woven into textiles. It is obtained from the cocoon of the silkworm larva, in the process kno...   » Read the article

Encyclopedia - Refractive Index: Encyclopedia Ii - Refractive Index - Dispersion And Absorption
In real materials, the polarization does not respond instantaneously to an applied field. This causes dielectric loss, which can be expre...   » Read the article

Encyclopedia - Refractive Index: Encyclopedia Ii - Refractive Index - Applications
The refractive index of a material is the most important property of any optical system that uses refraction. It is used to calculate the...   » Read the article

Encyclopedia - Telescope: Encyclopedia Ii - Telescope - Types
Telescopes are broadly classified into two main types. Optical telescopes Radio telescopes Optical telescopes are also divided into two...   » Read the article

Encyclopedia - Telescope: Encyclopedia Ii - Telescope - Types
The telescopes are broadly classified into two main categories. Optical telescopes Radio telescopes The optical telescopes are again di...   » Read the article

Encyclopedia - Angle Of Refraction: Encyclopedia Ii - Angle Of Refraction - Derivation And Meaning Of The Angle Of Refraction
There are several ways to derive Snell's Law, and therefore the Angle of Refraction. The first way it was discovered was by an applicatio...   » Read the article

Encyclopedia - Dispersion Optics: Encyclopedia Ii - Dispersion Optics - Material Dispersion In Optics
In optics, the phase velocity of a wave v in a given uniform medium is given by: where c is the speed of light in a vacuum and n is th...   » Read the article

Encyclopedia - Refracting Telescope: Encyclopedia Ii - Refracting Telescope - Technical Difficulties
Refractors are criticized for their relatively high-degree of residual chromatic and spherical aberration. In very large apertures, there...   » Read the article

Encyclopedia - History Of Telescopes: Encyclopedia Ii - History Of Telescopes - Achromatic Telescope
The historical sequence of events now brings us to the discovery of the achromatic telescope. The first person who succeeded in making ac...   » Read the article

Encyclopedia - Numerical Aperture: Encyclopedia Ii - Numerical Aperture - Fiber Optics
Multimode optical fiber will only propagate light that enters the fiber within a certain cone, known as the acceptance cone of the fiber....   » Read the article

Encyclopedia - Visual System: Encyclopedia Ii - Visual System - Eye
The eye is a complex biological device. The functioning of a CCD camera makes an apt metaphor for the workings of the eye, which takes vi...   » Read the article

Encyclopedia - Aether Drag Hypothesis: Encyclopedia Ii - Aether Drag Hypothesis - Historical Importance
The aether drag hypothesis is historically important because it was one of the reasons why Newton's corpuscular theory of light was repla...   » Read the article

Encyclopedia - Optical Telescope: Encyclopedia Ii - Optical Telescope - How It Works
For detailed information on specific designs of reflecting and refracting telescopes, see the main articles on Reflecting telescopes and ...   » Read the article

Encyclopedia - Skygazing: Encyclopedia Ii - Skygazing - The Observation With A Reflecting Telescope
A reflecting telescope is constituted not of lenses but of mirrors. It being less costly to manufacture, one can, for the price of a refr...   » Read the article

Encyclopedia - Green Flash: Encyclopedia Ii - Green Flash - Explanation
Its explanation lies in refraction of light (as in a prism) in the atmosphere and is enhanced by atmospheric layering. Whilst we would ex...   » Read the article

Encyclopedia - Luminiferous Aether: Encyclopedia Ii - Luminiferous Aether - The History Of Light And Aether
See also timeline of luminiferous aether. Isaac Newton had assumed that light was made up of numerous small particles, in order to explai...   » Read the article

Encyclopedia - Snell's Law: Encyclopedia Ii - Snell's Law - Overview
In the diagram on the right, two media of refractive indices n1 (on the left) and n2 (on the right) meet at a surface or interface (verti...   » Read the article

Encyclopedia - Telescope: Encyclopedia Ii - Telescope - History
The first telescopes may have been Assyrian crystal lenses. Article Though the Visby lenses tentatively suggest that the technology was k...   » Read the article

Encyclopedia - Telescope: Encyclopedia Ii - Telescope - Telescope Mountings
A simple telescope mount is an altitude-azimuth or altazimuth mount. It is similar to that of a surveying transit. A fork rotates in azim...   » Read the article

Encyclopedia - Telescope: Encyclopedia Ii - Telescope - History
The first telescopes may have been Assyrian crystal lenses. Article The Visby lenses tentatively suggest that the technology was known to...   » Read the article

Encyclopedia - Telescope: Encyclopedia Ii - Telescope - Telescope Mountings
A simple telescope mount is an altitude-azimuth or altazimuth mount. It is similar to that of a surveying transit. A fork rotates in azim...   » Read the article

Encyclopedia - Telescope: Encyclopedia Ii - Telescope - Imperfect Images
No telescope can form a perfect image. Even if a reflecting telescope could have a perfect mirror, or a refracting telescope could have a...   » Read the article

Encyclopedia - Telescope: Encyclopedia Ii - Telescope - Research Telescopes
Most large research telescopes can operate as either a cassegrain telescope (longer focal length, and a narrower field with higher magnif...   » Read the article

Encyclopedia - Telescope: Encyclopedia Ii - Telescope - Research Telescopes
Most large research telescopes can operate as either a Cassegrain telescope (longer focal length, and a narrower field with higher magnif...   » Read the article

Encyclopedia - Faster-than-light: Encyclopedia Ii - Faster-than-light - Terminology
In the context of this article, FTL actually refers to the transmission of information or matter faster than c, a constant equal to the s...   » Read the article

Encyclopedia - 3d Computer Graphics: Encyclopedia Ii - 3d Computer Graphics - Reflection And Shading Models
Modern 3D computer graphics rely heavily on a simplified reflection model called Phong reflection model (not to be confused with Phong sh...   » Read the article

Encyclopedia - Angular Resolution: Encyclopedia Ii - Angular Resolution - Microscope Case
The resolution D depends on the angular aperture α: . Here α is the collecting angle of the lens, which depends on the width of objec...   » Read the article

Encyclopedia - Alhazen: Encyclopedia Ii - Alhazen - Works
Alhazen was a pioneer in optics, engineering and astronomy. According to Giambattista della Porta, Alhazen was the first to explain the a...   » Read the article

Encyclopedia - Zone Plate: Encyclopedia Ii - Zone Plate - Applications
Zone plate - Physics. There are many wavelengths of light outside of the visible area of the electromagnetic spectrum where traditional...   » Read the article

Encyclopedia - Bioluminescence: Encyclopedia Ii - Bioluminescence - Characteristics Of The Phenomenon
Bioluminescence is a form of luminescence, or "cold light" emission; less than 20% of the light is generated by thermal radiation. It sho...   » Read the article

Encyclopedia - Ray Tracing: Encyclopedia Ii - Ray Tracing - Genesis And Description Of Ray Tracing
Ray tracing describes a realistic method for rendering images (or frames) constructed in 3D computer graphics environments. It works by t...   » Read the article

Encyclopedia - Ray Tracing: Encyclopedia Ii - Ray Tracing - Genesis And Description Of Ray Tracing
Ray tracing describes a realistic method for rendering images (or frames) constructed in 3D computer graphics environments. It works by t...   » Read the article

Encyclopedia - Ray Tracing: Encyclopedia Ii - Ray Tracing - Genesis And Description Of Ray Tracing
Ray tracing describes a realistic method for rendering images (or frames) constructed in 3D computer graphics environments. It works by t...   » Read the article

Encyclopedia - Microscope: Encyclopedia Ii - Microscope - Optical Resolution
A lens magnifies by bending light (see refraction). Optical microscopes are restricted in their ability to resolve features by a phenomen...   » Read the article

Encyclopedia - Microscope: Encyclopedia Ii - Microscope - Optical Resolution
A lens magnifies by bending light (see refraction). Optical microscopes are restricted in their ability to resolve features by a phenomen...   » Read the article

Encyclopedia - Binoculars: Encyclopedia Ii - Binoculars - Optical Construction
When light strikes an interface between two materials of different refractive index (e.g., at an air-glass interface), some of the light ...   » Read the article

Encyclopedia - Léon Foucault: Encyclopedia Ii - Léon Foucault - Middle Years
In the 1840s, he contributed to the Comptes Rendus a description of an electromagnetic regulator for the electric arc lamp, and, in conju...   » Read the article

Encyclopedia - 3dmark: Encyclopedia Ii - 3dmark - 3dmark 06
The following is shown in the screenshot below. HDR rendering. Complex HDR post processing. Dynamic soft shadows for all objects. Water ...   » Read the article

Encyclopedia - Kerr Effect: Encyclopedia Ii - Kerr Effect - Kerr Electro-optic Effect
The Kerr electro-optic effect, or DC Kerr effect, is the special case in which the electric field is a slowly-varying external field appl...   » Read the article

Encyclopedia - Birefringence: Encyclopedia Ii - Birefringence - Examples Of Birefringent Materials
Many plastics are birefringent, because their molecules are 'frozen' in an stretched conformation when the plastic is moulded or extruded...   » Read the article

Encyclopedia - Biosensor: Encyclopedia Ii - Biosensor - Principles Of Detection
Optical and piezoelectric biosensors are both evanescent wave techniques. Optical biosensors are based on the phenomenon of surface plasm...   » Read the article

Encyclopedia - Optics: Encyclopedia Ii - Optics - Classical Optics
Before Max Planck suggested that light is quantized, optics consisted mainly of the application of electromagnetism and its high frequenc...   » Read the article

Encyclopedia - Optical Fiber: Encyclopedia Ii - Optical Fiber - Optical Description
Optical fiber is a cylindrical structure that transmits light along its axis. The fiber consists of a core surrounded by a cladding laye...   » Read the article

Encyclopedia - Jan Marek Marci: Encyclopedia Ii - Jan Marek Marci - Work
Marci's studies covered the mechanics of colliding bodies, epilepsy, and the refraction of light, among other topics. Marci at some time ...   » Read the article

Encyclopedia - Faraday Effect: Encyclopedia Ii - Faraday Effect - Faraday Rotation In The Interstellar Medium
The Faraday effect is imposed on light over the course of its propagation from its origin to the Earth, through the interstellar medium. ...   » Read the article

Encyclopedia - Eyeglass Prescription: Encyclopedia Ii - Eyeglass Prescription - Lens Strength
The values indicated in the "sphere" and "cylinder" columns of an eyeglass prescription specify the optical power of the lenses in diopte...   » Read the article

Encyclopedia - Headlight: Encyclopedia Ii - Headlight - Types Of Headlights
A light source (filament or arc) is placed at or near the focus of a reflector, which may be parabolic or of non-parabolic complex shap...   » Read the article

Encyclopedia - Headlight: Encyclopedia Ii - Headlight - Types Of Headlights
A light source (filament or arc) is placed at or near the focus of a reflector, which may be parabolic or of non-parabolic complex shape...   » Read the article

Encyclopedia - Thallium: Encyclopedia Ii - Thallium - Applications
The odorless and tasteless thallium sulfate was widely used in the past as a rat poison and ant killer. In the United States and many oth...   » Read the article

Encyclopedia - Newton's Aether Model: Encyclopedia Ii - Newton's Aether Model - Problems With Newton's Aether
Newton's model had two major shortcomings: Newton's aether model - 1: Lightspeeds. Critically, Newton had mistakenly inverted the relat...   » Read the article

Encyclopedia - Numerical Aperture: Encyclopedia Ii - Numerical Aperture - General Optics
In most areas of optics, and especially in microscopy, the numerical aperture of an optical system such as an objective lens is defined b...   » Read the article

Encyclopedia - Optical Fiber: Encyclopedia Ii - Optical Fiber - Optical Description
An optical fiber (american spelling) or fibre (english spelling) is a cylindrical dielectric waveguide that transmits light along its axi...   » Read the article

Encyclopedia - History Of Telescopes: Encyclopedia Ii - History Of Telescopes - Reflecting Telescopes
Until Newton's discovery of the different refrangibility of light of different colours, it was generally supposed that object-glasses of ...   » Read the article

Encyclopedia - Germanium: Encyclopedia Ii - Germanium - Applications
Unlike most semiconductors, germanium has a small band gap, allowing it to efficiently respond to infrared light. It is therefore used in...   » Read the article

Encyclopedia - Marble: Encyclopedia Ii - Marble - Kinds Of Marble
Some historically important kinds of marble, named after the locations of their quarries, include: Paros (Greece) Penteli (Greece) Carra...   » Read the article

Encyclopedia - Ammolite: Encyclopedia Ii - Ammolite - Properties
The chemical composition of ammolite is variable, and aside from aragonite may include calcite, silica, pyrite, or other minerals. The sh...   » Read the article

Encyclopedia - Strontium Titanate: Encyclopedia Ii - Strontium Titanate - Properties
Strontium titanate is both much denser (specific gravity 4.88 for natural, 5.13 for synthetic) and much softer (Mohs hardness 6–6.5 for...   » Read the article

Encyclopedia - Material Properties Of Diamond: Encyclopedia Ii - Material Properties Of Diamond - Optical Properties
The luster of a diamond is described as adamantine, which simply means diamond-like. It is the highest luster possible bar that of metal ...   » Read the article

Encyclopedia - Optical Fiber: Encyclopedia Ii - Optical Fiber - Optical Description
An optical fiber (american spelling) or fibre (english spelling) is a cylindrical dielectric waveguide that transmits light along its axi...   » Read the article

Encyclopedia - Aberration In Optical Systems: Encyclopedia Ii - Aberration In Optical Systems - Chromatic Or Colour Aberration
In optical systems composed of lenses, the position, magnitude and errors of the image depend upon the refractive indices of the glass em...   » Read the article

Encyclopedia - History Of Telescopes: Encyclopedia Ii - History Of Telescopes - Refracting Telescopes
There is an archeological finding of lenses is from Gotlandia in Sweden. These so-called Visby lenses can be dated to the second half of ...   » Read the article

Encyclopedia - Polar Night: Encyclopedia Ii - Polar Night - Kinds Of Polar Night
Various kinds of polar night exist. This is because polar night is the period during which no twilight occurs; but there are various kind...   » Read the article

Encyclopedia - Optical Fiber: Encyclopedia Ii - Optical Fiber - Optical Description
Optical fiber is a cylindrical dielectric waveguide that transmits light along its axis. The fiber consists of a core surrounded by a cla...   » Read the article

Encyclopedia - Nuclear Explosion: Encyclopedia Ii - Nuclear Explosion - Other Phenomena
As the fireball rises through still air, it takes on the flow pattern of a vortex ring with incandescent material in the vortex core as s...   » Read the article

Encyclopedia - Game Boy Advance Sp: Encyclopedia Ii - Game Boy Advance Sp - Criticism
The frontlight, although an improvement over the previous lack of light, has been criticized for giving a "washed-out" look to many games...   » Read the article

Encyclopedia - Eye Surgery: Encyclopedia Ii - Eye Surgery - Types Of Eye Surgeries
Eye surgery - Cataract surgery. Main article: Cataract surgery A cataract is an opacification or cloudiness of the eye's crystalline ...   » Read the article

Encyclopedia - Atmospheric Reentry: Encyclopedia Ii - Atmospheric Reentry - Blunt Body Entry Vehicles
These four shadowgraph images represent early re-entry vehicle concepts. A shadowgraph is a process that makes visible the disturbances t...   » Read the article

Encyclopedia - Atmospheric Reentry: Encyclopedia Ii - Atmospheric Reentry - Blunt Body Entry Vehicles
These four shadowgraph images represent early re-entry vehicle concepts. A shadowgraph is a process that makes visible the disturbances t...   » Read the article

Encyclopedia - Atmospheric Reentry: Encyclopedia Ii - Atmospheric Reentry - Blunt Body Entry Vehicles
These four shadowgraph images represent early re-entry vehicle concepts. A shadowgraph is a process that makes visible the disturbances t...   » Read the article

Encyclopedia - Eye Examination: Encyclopedia Ii - Eye Examination - Basic Examination
Eye examination - External examination. External examination of eyes consists of inspection of the eyelids, surrounding tissues and pal...   » Read the article

Encyclopedia - Total Internal Reflection: Encyclopedia Ii - Total Internal Reflection - Frustrated Total Internal Reflection
While it is true that the creation of an evanescent wave does not affect the conservation of energy under ordinary conditions, i.e. the e...   » Read the article

Encyclopedia - Reflection Physics: Encyclopedia Ii - Reflection Physics - Specular Mirror-like Reflection
A mirror provides the most common model for specular light reflection and consists of a glass sheet in front of a metallic coating where ...   » Read the article

Encyclopedia - Refracting Telescope: Encyclopedia Ii - Refracting Telescope - Notable Refracting Telescopes
The 50 cm refractor at Nice Observatory. 20 inch refractor at the Observatories at Chabot Space and Science Center in Oakland, California...   » Read the article

Encyclopedia - Birefringence: Encyclopedia Ii - Birefringence - Biaxial Birefringence
Biaxial birefringence, also known as trirefringence, describes an anisotropic material that has more than one axis of anisotropy. For suc...   » Read the article

Encyclopedia - Refractive Surgery: Encyclopedia Ii - Refractive Surgery - Techniques
Refractive surgery - Flap procedures. Consists in cutting a flap in the cornea in order to access the tissue underneath. Automated Lam...   » Read the article

Encyclopedia - Optical Spectrum: Encyclopedia Ii - Optical Spectrum - Historical Use Of The Term
Two of the earliest explanations of the optical spectrum came from Newton, when he wrote his Optiks, and from Goethe, in his *Theory of C...   » Read the article

Encyclopedia - Light: Encyclopedia Ii - Light - Theories About Light
Light - Early Greek ideas. In 55 BC Lucretius, continuing the ideas of earlier atomists, wrote that light and heat from the Sun were co...   » Read the article

Encyclopedia - Light: Encyclopedia Ii - Light - Theories About Light
Light - Early Greek ideas. In 55 BC Lucretius, continuing the ideas of earlier atomists, wrote that light and heat from the Sun were co...   » Read the article

Encyclopedia - Light: Encyclopedia Ii - Light - Measurement Of Light
The following quantities and units are used to measure the quantity or "brightness" of light. edit edit Sometimes confusingly called "in...   » Read the article

Encyclopedia - Light: Encyclopedia Ii - Light - Visible Electromagnetic Radiation
Visible light is the portion of the electromagnetic spectrum between the frequencies of 380 THz (3.8×1014 hertz) and 750 ...   » Read the article

Encyclopedia - Light: Encyclopedia Ii - Light - Light Sources
There are many sources of light. The most common light sources are thermal: a body at a given temperature emits a characteristic spectrum...   » Read the article

Encyclopedia - Light: Encyclopedia Ii - Light - Speed Of Light
Although some people speak of the "velocity of light", the word velocity should be reserved for vector quantities, that is, those with bo...   » Read the article

Encyclopedia - Light: Encyclopedia Ii - Light - Color And Wavelengths
The different wavelengths are detected by the human eye and then interpreted by the brain as colors, ranging from red at the longest wave...   » Read the article