Iridescence

	Email		Print
	Bookmark		Link

Iridescence

Iridescence is an optical phenomenon

Optical phenomenon

An optical phenomenon is any observable event which results from the interaction of light and matter. See also list of optical topics and optics....
in which hue

Hue

Hue is one of the main properties of a color described with names such as "red", "yellow", etc. The two other main properties are lightness and colorfulness....
changes with the angle from which a surface is viewed.

Discussion

Ask a question about 'Iridescence'

Start a new discussion about 'Iridescence'

Answer questions from other users

Full Discussion Forum

Encyclopedia

Soap Bubble Foliage Background Iridescent Colours Traquair 040801

Iridescence is an optical phenomenon

Optical phenomenon

An optical phenomenon is any observable event which results from the interaction of light and matter. See also list of optical topics and optics....
in which hue

Hue

Soap bubble

A soap bubble is a very thin film of soap water that forms a sphere with an iridescence surface. Soap bubbles usually last for only a few moments before bursting: either on their own or on contact with another object....
s and butterfly

Butterfly

A butterfly is an insect of the Order Lepidoptera. Like all Lepidoptera, butterflies are notable for their unusual Biological life cycle with a larval caterpillar stage, an inactive pupal stage, and a spectacular metamorphosis into a familiar and colourful winged adult form....
wings.

Iridescence is caused by multiple reflections from multi-layered, semi-transparent surfaces in which phase shift

Phase (waves)

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....
and interference

Interference

In physics, interference is the addition of two or more waves that result in a new wave pattern.Interference usually refers to the interaction of waves which are correlated or Coherence with each other, either because they come from the same source or because they have the same or nearly the same frequency....
of the reflections modulates

Amplitude modulation

Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave....
the incident light (by amplifying or attenuating some frequencies more than others). This process is the functional analog of selective wavelength attenuation as seen with the Fabry-Pérot interferometer

Fabry-Pérot interferometer

File:Fabry Perot Etalon Rings Fringes.pngIn optics, a Fabry-P?rot interferometer or etalon is typically made of a transparent plate with two Reflection surfaces, or two parallel highly reflecting mirrors....
.

Etymology

The word iridescence is derived in part from the Greek

Greek language

Greek is an Indo-European languages native to the southern Balkan peninsula, the language of the Greek people. It forms an independent branch within Indo-European....
word iris (pl.

Plural

Plural is a grammatical number, typically referring to more than one of the referent in the real world. In the English language, singular and plural are the only grammatical numbers....
irides), meaning "rainbow

Rainbow

A rainbow is an optics and meteorology phenomenon that causes a optical spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere....
", which in turn derives from the goddess Iris

Iris (mythology)

In Greek mythology, Iris is the personification of the rainbow and messenger of the gods. As the sun unites Earth and heaven, Iris links the gods to humanity....
of Greek mythology

Greek mythology

Greek mythology is the body of myths and legends belonging to the Ancient Greece concerning their List of Greek mythological figures#Immortals and Greek hero cult, Cosmology#Metaphysical cosmology, and the origins and significance of their own cult and ritual practices....
, who is the personification of the rainbow

Rainbow

Greek language

Greek is an Indo-European languages native to the southern Balkan peninsula, the language of the Greek people. It forms an independent branch within Indo-European....
words gonia, which means angle, and chroma, which means color.

Examples

Iridescence is the property of certain surfaces to change their colour depending on the angle under which they are viewed. From a physics

Physics

Physics is the natural science which examines basic concepts such as energy, force, and spacetime and all that derives from these, such as mass, charge, matter and its Motion ....
standpoint this is rather uncommon behaviour, and in man-made objects this is usually only found in paint

Paint

Paint is any liquid, liquifiable, or mastic composition which after application to a Substrate in a thin layer is converted to an opaque solid film....
s that are specifically designed for the effect. Examples are pearlescent paints or interference pigments, which are sometimes used for custom paintjobs on cars. Some specially woven fabrics or certain shampoo

Shampoo

Shampoo is a hair care product used for the removal of sebum, dirt, skin particles, dandruff, environmental pollutants and other contaminant particles that gradually build up in hair....
s can also exhibit such behaviour. Natural examples of goniochromism can be found in the appearance of certain insect

Insect

Insects are the biggest class of arthropods and the only ones with wings. They are the most diverse group of animals on the planet. They are most diverse at the equator and their diversity declines toward the poles....
s, such as the Morpho butterfly, whose metallic-looking wings exhibit a colour shift depending on the observation angle.

A very common and popular example is the inside of an abalone

Abalone

Abalone are medium-sized to very large edible sea snails, marine gastropod mollusks in the family Haliotidae and the genus Haliotis....
shell.

Under certain conditions, window film will exhibit iridescence. This phenomenon usually occurs at night, when the source of illumination within a building is fluorescent lighting.

The amount of iridescence may vary from almost imperceptible to very visible, and most frequently occurs when the film is constructed using one or more layers of sputtered metal, though it can occur in non-reflective films as well.

When iridescence does occur in window film, the only way to stop it is to prevent the fluorescent light from illuminating the film.

Calf Eye Posterior With Retina Detached 2005 Oct 13

Taxonomically, the most widespread distribution of iridescent tissue in animals may be the tapetum lucidum

Tapetum lucidum

The tapetum lucidum is a layer of tissue in the eye of many vertebrate animals, that lies immediately behind or sometimes within the retina. It Reflection visible light back through the retina, increasing the light available to the Photoreceptor cell....
, present in the eye

Eye

Eyes are Organ that detect light, and send signals along the optic nerve to the visual system and other areas of the brain. Complex optical systems with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system....
s of many vertebrate animals.

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

Holography

A hologram is a picture that changes when looked at from different angles.Holography is a technique that allows the light scattered from an object to be recorded and later reconstructed so that it appears as if the object is in the same position relative to the recording medium as it was when recorded....
(which includes phase information).

External links

of a morpho butterfly showing iridescence