Sunset, also known as sundown, is the daily disappearance of the Sun below the horizon due to Earth’s rotation. As viewed from the Equator, the equinox Sun sets exactly due west in both Spring and Autumn. As viewed from the middle latitudes, the local summer sun sets to the southwest for the Northern Hemisphere, and to the northwest for the Southern Hemisphere.
The time of sunset is defined in astronomy as the moment when the upper limb of the Sun disappears below the horizon. Near the horizon, atmospheric refraction causes sunlight rays to be distorted to such an extent that geometrically the solar disk is already about one diameter below the horizon when a sunset is observed.
Sunset is distinct from twilight, which is divided into three stages, the first being civil twilight, which begins once the Sun has disappeared below the horizon, and continues until it descends to 6 degrees below the horizon; the second phase is nautical twilight, between 6 and 12 degrees below the horizon; and the third is astronomical twilight, which is the period when the Sun is between 12 and 18 degrees below the horizon. Dusk is at the very end of astronomical twilight, and is the darkest moment of twilight just before night. Night occurs when the Sun reaches 18 degrees below the horizon and no longer illuminates the sky.
Locations further North than the Arctic Circle and further South than the Antarctic Circle experience no full sunset or sunrise on at least one day of the year, when the polar day or the polar night persists continuously for 24 hours.
The time of sunset varies throughout the year, and is determined by the viewer’s position on Earth, specified by latitude and longitude, altitude, and time zone. Small daily changes and noticeable semi-annual changes in the timing of sunsets are driven by the axial tilt of Earth, daily rotation of the Earth, the planet’s movement in its annual elliptical orbit around the Sun, and the Earth and Moon’s paired revolutions around each other. During Winter and Spring, the days get longer and sunsets occur later every day until the day of the latest sunset, which occurs after the summer solstice. In the Northern Hemisphere, the latest sunset occurs late in June or in early July, but not on the Summer solstice of June 21. This date depends on the viewer’s latitude (connected with the Earth’s slower movement around the aphelion around July 4). Likewise, the earliest sunset does not occur on the winter solstice, but rather about two weeks earlier, again depending on the viewer’s latitude. In the Northern Hemisphere, it occurs in early December or late November (influenced by the Earth’s faster movement near its perihelion, which occurs around January 3).
Likewise, the same phenomenon exists in the Southern Hemisphere, but with the respective dates reversed, with the earliest sunsets occurring some time before June 21 in winter, and latest sunsets occurring some time after December 21 in summer, again depending on one’s southern latitude. For a few weeks surrounding both solstices, both sunrise and sunset get slightly later each day. Even on the equator, sunrise and sunset shift several minutes back and forth through the year, along with solar noon. These effects are plotted by an analemma.
Neglecting atmospheric refraction and the Sun’s non-zero size, whenever and wherever sunset occurs, it is always in the northwest quadrant from the March equinox to the September equinox, and in the southwest quadrant from the September equinox to the March equinox. Sunsets occur almost exactly due west on the equinoxes for all viewers on Earth. Exact calculations of the azimuths of sunset on other dates are complex, but they can be estimated with reasonable accuracy by using the analemma.
As sunrise and sunset are calculated from the leading and trailing edges of the Sun, respectively, and not the center, the duration of a daytime is slightly longer than nighttime (by about 10 minutes, as seen from temperate latitudes). Further, because the light from the Sun is refracted as it passes through the Earth’s atmosphere, the Sun is still visible after it is geometrically below the horizon. Refraction also affects the apparent shape of the Sun when it is very close to the horizon. It makes things appear higher in the sky than they really are. Light from the bottom edge of the Sun’s disk is refracted more than light from the top, since refraction increases as the angle of elevation decreases. This raises the apparent position of the bottom edge more than the top, reducing the apparent height of the solar disk. Its width is unaltered, so the disk appears wider than it is high. (In reality, the Sun is almost exactly spherical.) The Sun also appears larger on the horizon, an optical illusion, similar to the moon illusion.
Locations north of the Arctic Circle and south of the Antarctic Circle experience no sunset or sunrise at least one day of the year, when the polar day or the polar night persist continuously for 24 hours.
Evening twilight in Joshua Tree, California, displaying the separation of yellow colors in the direction from the Sun below the horizon to the observer, and the blue components scattered from the surrounding sky
Twilight in Paris
As a ray of white sunlight travels through the atmosphere to an observer, some of the colors are scattered out of the beam by air molecules and airborne particles, changing the final color of the beam the viewer sees. Because the shorter wavelength components, such as blue and green, scatter more strongly, these colors are preferentially removed from the beam.
At sunrise and sunset, when the path through the atmosphere is longer, the blue and green components are removed almost completely, leaving the longer wavelength orange and red hues we see at those times. The remaining reddened sunlight can then be scattered by cloud droplets and other relatively large particles to light up the horizon red and orange. The removal of the shorter wavelengths of light is due to Rayleigh scattering by air molecules and particles much smaller than the wavelength of visible light (less than 50 nm in diameter). The scattering by cloud droplets and other particles with diameters comparable to or larger than the sunlight’s wavelengths (> 600 nm) is due to Mie scattering and is not strongly wavelength-dependent. Mie scattering is responsible for the light scattered by clouds, and also for the daytime halo of white light around the Sun (forward scattering of white light).
A video time lapse of a sunset in Tokyo
Sunset colors are typically more brilliant than sunrise colors, because the evening air contains more particles than morning air. Sometimes just before sunrise or after sunset a green flash can be seen.
Ash from volcanic eruptions, trapped within the troposphere, tends to mute sunset and sunrise colors, while volcanic ejecta that is instead lofted into the stratosphere (as thin clouds of tiny sulfuric acid droplets), can yield beautiful post-sunset colors called afterglows and pre-sunrise glows. A number of eruptions, including those of Mount Pinatubo in 1991 and Krakatoa in 1883, have produced sufficiently high stratus clouds containing sulfuric acid to yield remarkable sunset afterglows (and pre-sunrise glows) around the world. The high altitude clouds serve to reflect strongly reddened sunlight still striking the stratosphere after sunset, down to the surface.
Some of the most varied colors at sunset can be found in the opposite or eastern sky after the Sun has set during twilight. Depending on weather conditions and the types of clouds present, these colors have a wide spectrum, and can produce unusual results.
Names of compass points
In some languages, points of the compass bear names etymologically derived from words for sunrise and sunset. The English words "orient" and "occident", meaning "east" and "west", respectively, are descended from Latin words meaning "sunrise" and "sunset". The word "levant", related e.g. to French "(se) lever" meaning "lift" or "rise" (and also to English "elevate"), is also used to describe the east. In Polish, the word for east wschód (vskhud), is derived from the morpheme "ws" – meaning "up", and "chód" – signifying "move" (from the verb chodzić – meaning "walk, move"), due to the act of the Sun coming up from behind the horizon. The Polish word for west, zachód (zakhud), is similar but with the word "za" at the start, meaning "behind", from the act of the Sun going behind the horizon. In Russian, the word for west, запад (zapad), is derived from the words за – meaning "behind", and пад – signifying "fall" (from the verb падать – padat’), due to the act of the Sun falling behind the horizon. In Hebrew, the word for east is ‘מזרח’, which derives from the word for rising, and the word for west is ‘מערב’, which derives from the word for setting.
The 16th-century astronomer Nicolaus Copernicus was the first to present to the world a detailed and eventually widely accepted mathematical model supporting the premise that the Earth is moving and the Sun actually stays still, despite the impression from our point of view of a moving Sun.
Sunset on Mars
Sunsets on other planets appear different because of differences in the distance of the planet from the Sun and non-existent or differing atmospheric compositions.
On Mars, the setting Sun appears about two-thirds the size as it appears from Earth, due to the greater distance between Mars and the Sun. The colors are typically hues of blue, but some Martian sunsets last significantly longer and appear far redder than is typical on Earth. The colors of the Martian sunset differ from those on Earth. Mars has a thin atmosphere, lacking oxygen and nitrogen, so the light scattering is not dominated by a Rayleigh Scattering process. Instead, the air is full of red dust, blown into the atmosphere by high winds, so its sky color is mainly determined by a Mie Scattering process, resulting in more blue hues than an Earth sunset. One study also reported that Martian dust high in the atmosphere can reflect sunlight up to two hours after the Sun has set, casting a diffuse glow across the surface of Mars.
A silhouette (English: /ˌsɪluˈɛt/ SIL-oo-ET, French: [silwɛt]) is the image of a person, animal, object or scene represented as a solid shape of a single colour, usually black, with its edges matching the outline of the subject. The interior of a silhouette is featureless, and the silhouette is usually presented on a light background, usually white, or none at all. The silhouette differs from an outline, which depicts the edge of an object in a linear form, while a silhouette appears as a solid shape. Silhouette images may be created in any visual artistic media, but were first used to describe pieces of cut paper, which were then stuck to a backing in a contrasting colour, and often framed.
Cutting portraits, generally in profile, from black card became popular in the mid-18th century, though the term silhouette was seldom used until the early decades of the 19th century, and the tradition has continued under this name into the 21st century. They represented a cheap but effective alternative to the portrait miniature, and skilled specialist artists could cut a high-quality bust portrait, by far the most common style, in a matter of minutes, working purely by eye. Other artists, especially from about 1790, drew an outline on paper, then painted it in, which could be equally quick.
From its original graphic meaning, the term silhouette has been extended to describe the sight or representation of a person, object or scene that is backlit, and appears dark against a lighter background. Anything that appears this way, for example, a figure standing backlit in a doorway, may be described as "in silhouette". Because a silhouette emphasises the outline, the word has also been used in the fields of fashion and fitness to describe the shape of a person’s body or the shape created by wearing clothing of a particular style or period.
The word silhouette is derived from the name of Étienne de Silhouette, a French finance minister who, in 1759, was forced by France’s credit crisis during the Seven Years’ War to impose severe economic demands upon the French people, particularly the wealthy. Because of de Silhouette’s austere economies, his name became synonymous with anything done or made cheaply and so with these outline portraits. Prior to the advent of photography, silhouette profiles cut from black card were the cheapest way of recording a person’s appearance.
The term silhouette, although existing from the 18th century, was not applied to the art of portrait-making until the 19th century. In the 18th and early 19th century, “profiles” or “shades” as they were called were made by one of three methods:
painted on ivory, plaster, paper, card, or in reverse on glass;
“hollow-cut” where the negative image was traced and then cut away from light colored paper which was then laid atop a dark background; and
“cut and paste” where the figure was cut out of dark paper (usually free-hand) and then pasted onto a light background. History
Attic Greek Black-figure Neck Amphora attributed to the Princeton Painter, ca. 550–540 BCE
The silhouette is closely tied in mythology to the origins of art. Pliny the Elder, in his Natural History (circa 77–79 AD) Books XXXIV and XXXV, recounts the origin of painting. In Chapter 5 of Book XXXV, he writes,
“We have no certain knowledge as to the commencement of the art of painting, nor does this enquiry fall under our consideration. The Egyptians assert that it was invented among themselves, six thousand years before it passed into Greece; a vain boast, it is very evident. As to the Greeks, some say that it was invented at Sicyon, others at Corinth; but they all agree that it originated in tracing lines round the human shadow […omnes umbra hominis lineis circumducta].“. In Chapter 15, he tells the story of Butades of Corinth:
“Butades, a potter of Sicyon, was the first who invented, at Corinth, the art of modelling portraits in the earth which he used in his trade. It was through his daughter that he made the discovery; who, being deeply in love with a young man about to depart on a long journey, traced the profile of his face, as thrown upon the wall by the light of the lamp [umbram ex facie eius ad lucernam in pariete lineis circumscripsit]. Upon seeing this, her father filled in the outline, by compressing clay upon the surface, and so made a face in relief, which he then hardened by fire along with other articles of pottery.”
In accord with the myth, Greek Black-figure pottery painting, also known as the black-figure style or black-figure ceramic (Greek, μελανόμορφα, melanomorpha, common between the 7th and 5th centuries BC) employs the silhouette and characteristic profile views of figures and objects on pottery forms. The pots themselves exhibit strong forms in outline that are indicators of their purpose, as well as being decorative. Profile portraits
The traditional method of making a silhouette portrait
S. John Ross, Sydney Royal Easter Show, c. 2004
For the depiction of portraits, the profile image has marked advantage over a full-face image in many circumstances, because it depends strongly upon the proportions and relationship of the bony structures of the face (the forehead, nose and chin) making the image is clear and simple. For this reason profile portraits have been employed on coinage since the Roman era. The early Renaissance period saw a fashion for painted profile portraits and people such as Federico da Montefeltro and Ludovico Sforza were depicted in profile portraits. The profile portrait is strongly linked to the silhouette.
Recent research at Stanford University indicates that where previous studies of face recognition have been based on frontal views, studies with silhouettes show humans are able to extract accurate information about gender and age from the silhouette alone. This is an important concept for artists who design characters for visual media, because the silhouette is the most immediately recognisable and identifiable shape of the character.
"Mister Bethany and Patience Wright, Anonymous engraving
Drawing a Silhouette by Johann Rudolph Schellenberg (1740–1806)
Rise of popularity and development in the nineteenth century
A silhouette portrait can be painted or drawn. However, the traditional method of creating silhouette portraits is to cut them from lightweight black cardboard, and mount them on a pale (usually white) background. This was the work of specialist artists, often working out of booths at fairs or markets, whose trade competed with that of the more expensive miniaturists patronised by the wealthy. A traditional silhouette portrait artist would cut the likeness of a person, freehand, within a few minutes. Some modern silhouette artists also make silhouette portraits from photographs of people taken in profile. These profile images are often head and shoulder length (bust), but can also be full length.
The work of the physiognomist Johann Caspar Lavater, who used silhouettes to analyse facial types, is thought to have promoted the art. The 18th century silhouette artist August Edouart cut thousands of portraits in duplicate. His subjects included French and British nobility and US presidents. Much of his personal collection was lost in a shipwreck. In England, the best known silhouette artist, a painter not a cutter, was John Miers, who travelled and worked in different cities, but had a studio on the Strand in London. He advertised "three minute sittings", and the cost might be as low as half a crown around 1800. Miers’ superior products could be in grisaille, with delicate highlights added in gold or yellow, and some examples might be painted on various backings, including gesso, glass or ivory. The size was normally small, with many designed to fit into a locket, but otherwise a bust some 3 to 5 inches high was typical, with half- or full-length portraits proportionately larger.
In America, silhouettes were highly popular from about 1790 to 1840.
The physionotrace apparatus invented by Frenchman Gilles-Louis Chrétien in 1783-84 facilitated the production of silhouette portraits by deploying the mechanics of the pantograph to transmit the tracing (via an eyepiece) of the subject’s profile silhouette to a needle moving on an engraving plate, from which multiple portrait copies could be printed. The invention of photography signaled the end of the silhouette as a widespread form of portraiture.
Maintaining the tradition
The skill was not lost, and travelling silhouette artists continued to work at state fairs into the 20th century. The popularity of the silhouette portrait is being reborn in a new generation of people who appreciate the silhouette as a nostalgic way of capturing a significant occasion. In the United States and the UK silhouette artists have websites advertising their services at weddings and other such functions. In England there is an active group of silhouette artists. In Australia, S. John Ross plied his scissors at agricultural shows for 60 years until his death in 2008. Other artists such as Douglas Carpenter produce silhouette images using pen and ink.
The silhouette in art, media and illustrations
A traditional paper-cut illustration by Wilhelm Gross
White on black by Hans Christian Andersen.
Since the late 18th century, silhouette artists have also made small scenes cut from card and mounted on a contrasting background like the portraits. These pictures, known as "paper cuts", were often, but not necessarily, silhouette images. Among 19th century artists to work in this way was the author Hans Christian Andersen. The modern artist Robert Ryan creates intricate images by this technique, sometimes using them to produce silk-screen prints.
In the late 19th and early 20th century several illustrators employed designs of similar appearance for making book illustrations. Silhouette pictures could easily be printed by blocks that were cheaper to produce and longer lasting than detailed black and white illustrations.
Silhouette pictures sometimes appear in books of the early 20th century in conjunction with colour plates. (The colour plates were expensive to produce and each one was glued into the book by hand.) Illustrators who produced silhouette pictures at this time include Arthur Rackham and William Heath Robinson. In breaking with literal realism, artists of the Vorticist, Futurist and Cubist movements employed the silhouette. Illustrators of the late 20th century to work in silhouette include Jan Pienkowski and Jan Ormerod. In the early 1970s, French artist Philippe Derome uses the black cut silhouette in his portraits of black people. In the 21st century, American artist Kara Walker develops this use of silhouette to present racial issues in confronting images.
Originating in the orient with traditions such as the shadow theatres of Indonesia, the shadow play became a popular entertainment in Paris during the 18th and 19th century. In the Paris of the late 19th century, the shadow theatre was particularly associated with the cabaret Le Chat Noir where Henri Rivière was the designer.
Since their pioneering use by Lotte Reiniger in silent films, silhouettes have been used for a variety of iconic, graphic, emotional, or conversely for distancing, effects in many movies. These include many of the opening credit sequences of the James Bond films. The opening sequence of the television series Alfred Hitchcock Presents features a silhouetted profile of Alfred Hitchcock stepping into a caricatured outline of himself, and in his movie Psycho the killer in the shower scene manifests as a terrifying silhouette. A scene from E.T. showing the central characters on a flying bicycle silhouetted against the full moon became a well-known movie poster. Harry Potter and the Deathly Hallows – Part 1 contains an animated sequence in silhouette illustrating a short story The Tale of the Three Brothers that is embedded in the film. The sequence was produced by Ben Hibon for Framestore, with artwork by Alexis Lidell.
Silhouettes have also been used by recording artists in music videos. One example is the video for "Buttons" by The Pussycat Dolls, in which Nicole Scherzinger is seen in silhouette. Michael Jackson used his own distinctive silhouette both on stage and in videos such as "You Rock My World". Early iPod commercials portrayed silhouetted dancers wearing an iPod and earbuds.
The cult television program, Mystery Science Theater 3000 features the three main characters of the series watching a movie as silhouettes at the bottom of the screen.
Theatre, film and photography
A Balinese shadow show puppet and its shadow
Shadow theatre designed by Henri Rivière for Le Chat Noir
Scene from the film noir, The Big Combo (1955) filmed by John Alton
The discipline of architecture that studies the shadows cast by or upon buildings is called Sciography.
The play of shadows upon buildings was very much in vogue a thousand years ago as evidenced by the surviving examples of "mukarnas" art where the shadows of 3 dimensional ornamentation with stone masonry around the entrance of mosques form pictures. As outright pictures were avoided in Islam, tessellations and calligraphic pictures were allowed, "accidental" silhouettes are a creative alternative.
Silhouette of trees against the blue sky.
Many photographers use the technique of photographing people, objects or landscape elements against the light, to achieve an image in silhouette. The background light might be natural, such as a cloudy or open sky, mist or fog, sunset or an open doorway (a technique known as contre-jour), or it might be contrived in a studio; see low-key lighting. Silhouetting requires that the exposure be adjusted so that there is no detail (underexposure) within the desired silhouette element, and overexposure for the background to render it bright; so a lighting ratio of 16:1 or greater is the ideal. The Zone System was an aid to film photographers in achieving the required exposure ratios. High contrast film, adjustment of film development, and/or high contrast photographic paper may be used in chemical-based photography to enhance the effect in the darkroom. With digital processing the contrast may be enhanced through the manipulation of the contrast curve for the image.
In graphic design
In media the term "to silhouette" is used for the process of separating or masking a portion of an image (such as the background) so that it does not show. Traditionally silhouettes have often been used in advertising, particularly in poster design, because they can be cheaply and effectively printed.
An advertisement for James Whitcomb Riley’s business, 1871
Poster for Palais der Friedrichstadt c. 1920
Poster for the Festival of Calanchi, San Marino, by Bradipone (2008)
Advertising postcard for Tiedtke’s store in Toledo, Ohio with a man in silhouetted profile
Advertising postcard for Tiedtke’s store in Toledo, Ohio
The fashionable silhouette of 1900
Fashion and fitness
The word "silhouette", because it implies the outline of a form, has been used in both fashion and fitness to describe the outline shape of the body from a particular angle, as altered by clothing in fashion usage, and clothed or unclothed where fitness is concerned, (e.g. a usage applied here by the Powerhouse Museum). Advertising for both these fields urges people, women in particular, to achieve a particular appearance, either by corsetry, diet or exercise. The term was in use in advertising by the early 20th century. Many gyms and fitness studios use the word "silhouette" either in their name or in their advertising.
Historians of costume also use the term when describing the effect achieved by the clothes of different periods, so that they might describe and compare the silhouette of the 1860s with that of the other decades of the 19th century. A desirable silhouette could be influenced by many factors. The invention of crinoline steel influenced the silhouette of women in the 1850s and 60s. The posture of the Princess Alexandra influenced the silhouette of English women in the Edwardian period. See advertisement left.
Because silhouettes give a very clear image, they are often used in any field where the speedy identification of an object is necessary. Silhouettes have many practical applications. They are used for traffic signs (see pic below). They are used to identify towns or countries with silhouettes of monuments or maps. They are used to identify natural objects such as trees, insects and dinosaurs. They are used in forensic science.
For interviews, some individuals choose to be videotaped in silhouette to mask their facial features and protect their anonymity, typically accompanied by a dubbed voice. This is done when the individuals may be endangered if it is known they were interviewed.
Computer vision researchers have been able to build computational models for perception that are capable of generating and reconstructing 3D shapes from single or multi-view depth maps or silhouettes
Silhouette of an aircraft
Main articles: Aircraft recognition and Jane’s Fighting Ships
Silhouettes of ships, planes, tanks, and other military vehicles are used by soldiers and sailors for learning to identify different craft.
Tagged: , Sunset , silhouettes , gateshead