The iridescence of the Blue Morpho butterfly wings. The Menelaus Blue Morpho ( Morpho menelaus) is an iridescent tropical Butterfly of Central and South America.

Iridescence in soap bubbles. A soap bubble is a very thin film of Soap water that forms a Sphere with an iridescent Surface.

A fossil ammonite displaying iridescence. Ammonites are an extinct group of marine animals of the subclass Ammonoidea in the class Cephalopoda phylum

Iridescence is an optical phenomenon characterized as the property of surfaces in which hue changes according to the angle from which the surface is viewed (as may be seen of soap bubbles and butterfly wings). An optical phenomenon is any observable event which results from the interaction of Light and Matter. Hue is one of the main properties of a Color described with names such as " Red " " Yellow " etc A soap bubble is a very thin film of Soap water that forms a Sphere with an iridescent Surface. A butterfly is an Insect of the order Lepidoptera. Like all Lepidoptera butterflies are notable for their unusual life cycle with a

Iridescence is caused by multiple reflections from multi-layered, semi-transparent surfaces in which phase shift and interference of the reflections modulates the incident light (by amplifying or attenuating some frequencies more than others). The phase of an oscillation or wave is the fraction of a complete cycle corresponding to an offset in the displacement from a specified reference point at time t = 0 In physics interference is the addition ( superposition) of two or more Waves that result in a new wave pattern Amplitude modulation ( AM) is a technique used in electronic communication most commonly for transmitting information via a Radio Carrier wave This process is the functional analog of selective wavelength attenuation as seen with the Fabry-Pérot interferometer.

The word is derived in part from the Greek word iris (pl. irides), meaning "rainbow", which in turn derives from the goddess Iris of Greek mythology, who is the personification of the rainbow and acted as a messenger of the gods. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly Plural is a Grammatical number, typically referring to more than one of the Referent in the real world A rainbow is an optical and meteorological phenomenon that causes a spectrum of Light to appear in the Sky when the Sun In Greek mythology, Iris (Ἴρις is the personification of the Rainbow and messenger of the gods Greek mythology is the body of stories belonging to the ancient Greeks concerning their gods and Heroes the nature of the world and the origins and significance A rainbow is an optical and meteorological phenomenon that causes a spectrum of Light to appear in the Sky when the Sun Goniochromism is derived from the Greek words gonia which means angle, and chroma which means color. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly It is the property of certain surfaces to change their colour depending on the angle under which they are viewed. From a physics standpoint this is rather uncommon behaviour, and in man-made objects this is usually only found in paints that are specifically designed for the effect. Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. Paint is any Liquid, liquifiable or mastic composition which after application to a substrate in a thin layer is converted to an opaque Solid Examples are pearlescent paints or interference pigments, which are sometimes used for custom paintjobs on cars. Some specially woven fabrics or certain shampoos can also exhibit such behaviour. A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. Shampoo is a Hair care product used for the removal of oils, dirt skin particles Dandruff, environmental pollutants and other contaminant particles that Natural examples of goniochromism can be found in the appearance of certain insects, such as the Morpho butterfly, whose metallic-looking wings exhibit a colour shift depending on the observation angle. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described A Morpho butterfly may be one of over 80 species of the Genus Morpho.

Tapetum lucidum dissected from a calf's eye, appearing black and blue due to iridescence

Taxonomically, the most widespread distribution of iridescent tissue in animals may be the tapetum lucidum, present in the eyes of many vertebrate animals. The tapetum lucidum ( Latin: "bright tapestry" plural tapeta lucida) is a layer of tissue in the Eye of many Vertebrate animals that Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain

Because the apparent image changes with the angle of observation, iridescence is not fully reproduced by conventional still image photography; however, it can be reproduced by holography (which includes phase information). Holography (from the Greek, ὅλος - hólos whole + γραφή - grafē writing drawing is a technique that allows the

See also

• Dichroism
• Dichroic filter
• Thin-film optics
• Iridocyte

External links

• Living photonic crystals
• A 2.2 MB GIF animation of a morpho butterfly showing iridescence