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Sunday, July 12, 2020

Observatory

From Wikipedia, the free encyclopedia

The Sphinx Observatory on a mountain top in the Swiss Alps at 3,571 m (11,716 ft)

An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geophysical, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Historically, observatories were as simple as containing an astronomical sextant (for measuring the distance between stars) or Stonehenge (which has some alignments on astronomical phenomena).

Astronomical observatories

Astronomical observatories are mainly divided into four categories: space-based, airborne, ground-based, and underground-based.

Ground-based observatories

Atacama Large Millimeter Array, Chile, at 5,058 m (16,594 ft)
 
Paranal Observatory, Chile, home of the VLT at 2,635 m (8,645 ft)
 
The Mauna Kea Observatories, Hawaii, home of several of the world's largest optical telescopes at 4,205 m (13,796 ft)

Ground-based observatories, located on the surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum. Most optical telescopes are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, and closed when the telescope is not in use. In most cases, the entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes usually do not have domes.

For optical telescopes, most ground-based observatories are located far from major centers of population, to avoid the effects of light pollution. The ideal locations for modern observatories are sites that have dark skies, a large percentage of clear nights per year, dry air, and are at high elevations. At high elevations, the Earth's atmosphere is thinner, thereby minimizing the effects of atmospheric turbulence and resulting in better astronomical "seeing". Sites that meet the above criteria for modern observatories include the southwestern United States, Hawaii, Canary Islands, the Andes, and high mountains in Mexico such as Sierra Negra. A newly emerging site which should be added to this list is Mount Gargash. With an elevation of 3600 m above sea level, it is the home to the Iranian National Observatory and its 3.4m INO340 telescope. Major optical observatories include Mauna Kea Observatory and Kitt Peak National Observatory in the US, Roque de los Muchachos Observatory and Calar Alto Observatory in Spain, and Paranal Observatory in Chile.

Specific research study performed in 2009 shows that the best possible location for ground-based observatory on Earth is Ridge A — a place in the central part of Eastern Antarctica. This location provides the least atmospheric disturbances and best visibility.

Radio observatories

Beginning in 1930s, radio telescopes have been built for use in the field of radio astronomy to observe the Universe in the radio portion of the electromagnetic spectrum. Such an instrument, or collection of instruments, with supporting facilities such as control centres, visitor housing, data reduction centers, and/or maintenance facilities are called radio observatories. Radio observatories are similarly located far from major population centers to avoid electromagnetic interference (EMI) from radio, TV, radar, and other EMI emitting devices, but unlike optical observatories, radio observatories can be placed in valleys for further EMI shielding. Some of the world's major radio observatories include the Socorro, in New Mexico, United States, Jodrell Bank in the UK, Arecibo in Puerto Rico, Parkes in New South Wales, Australia, and Chajnantor in Chile.

Highest astronomical observatories

Since the mid-20th century, a number of astronomical observatories have been constructed at very high altitudes, above 4,000–5,000 m (13,000–16,000 ft). The largest and most notable of these is the Mauna Kea Observatory, located near the summit of a 4,205 m (13,796 ft) volcano in Hawaiʻi. The Chacaltaya Astrophysical Observatory in Bolivia, at 5,230 m (17,160 ft), was the world's highest permanent astronomical observatory from the time of its construction during the 1940s until 2009. It has now been surpassed by the new University of Tokyo Atacama Observatory, an optical-infrared telescope on a remote 5,640 m (18,500 ft) mountaintop in the Atacama Desert of Chile. 

Ancient Indian observatory at Delhi
 
"El Caracol" observatory temple at Chichen Itza, Mexico
 
Remains of the Maragheh observatory (under dome) at Maragheh, Iran
 
 
The Estonian Tartu Observatory starting point of the Struve Geodetic Arc.
 
19th century Observatory Sydney, Australia (1872)
 
Ecuador's 1873-Quito Astronomical Observatory near the Equator
 
The 1962-built Solar observatory on Lomnický peak in Slovakia

Oldest astronomical observatories

The oldest proto-observatories, in the sense of a private observation post,
The oldest true observatories, in the sense of a specialized research institute, include:
The Hubble Space Telescope in Earth's orbit

Space-based observatories

Space-based observatories are telescopes or other instruments that are located in outer space, many in orbit around the Earth. Space telescopes can be used to observe astronomical objects at wavelengths of the electromagnetic spectrum that cannot penetrate the Earth's atmosphere and are thus impossible to observe using ground-based telescopes. The Earth's atmosphere is opaque to ultraviolet radiation, X-rays, and gamma rays and is partially opaque to infrared radiation so observations in these portions of the electromagnetic spectrum are best carried out from a location above the atmosphere of our planet. Another advantage of space-based telescopes is that, because of their location above the Earth's atmosphere, their images are free from the effects of atmospheric turbulence that plague ground-based observations. As a result, the angular resolution of space telescopes such as the Hubble Space Telescope is often much smaller than a ground-based telescope with a similar aperture. However, all these advantages do come with a price. Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope was serviced by the Space Shuttle while many other space telescopes cannot be serviced at all. The James Webb Space Telescope(JWST) will replace the Hubble Space Telescope in 2021.

SOFIA on board a Boeing 747SP

Airborne observatories

Airborne observatories have the advantage of height over ground installations, putting them above most of the Earth's atmosphere. They also have an advantage over space telescopes: The instruments can be deployed, repaired and updated much more quickly and inexpensively. The Kuiper Airborne Observatory and the Stratospheric Observatory for Infrared Astronomy use airplanes to observe in the infrared, which is absorbed by water vapor in the atmosphere. High-altitude balloons for X-ray astronomy have been used in a variety of countries.

Volcano observatories

A volcano observatory is an institution that conducts research and monitoring of a volcano. Among the best known are the Hawaiian Volcano Observatory and the Vesuvius Observatory. Mobile volcano observatories exist with the USGS VDAP (Volcano Disaster Assistance Program), to be deployed on demand.

Planetarium

From Wikipedia, the free encyclopedia

Inside a planetarium projection hall.
Inside the same hall during projection.
A planetarium under construction in Nishapur, near the Mausoleum of Omar Khayyam.
 
A planetarium (plural planetaria or planetariums) is a theatre built primarily for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation.

A dominant feature of most planetaria is the large dome-shaped projection screen onto which scenes of stars, planets, and other celestial objects can be made to appear and move realistically to simulate the complex 'motions of the heavens'. The celestial scenes can be created using a wide variety of technologies, for example precision-engineered 'star balls' that combine optical and electro-mechanical technology, slide projector, video and fulldome projector systems, and lasers. Whatever technologies are used, the objective is normally to link them together to simulate an accurate relative motion of the sky. Typical systems can be set to simulate the sky at any point in time, past or present, and often to depict the night sky as it would appear from any point of latitude on Earth.

Planetariums range in size from the 37 meter dome in St. Petersburg, Russia (called “Planetarium No 1”) to three-meter inflatable portable domes where attendees sit on the floor. The largest planetarium in the Western Hemisphere is the Jennifer Chalsty Planetarium at Liberty Science Center in New Jersey (27 meters in diameter). The Birla Planetarium in Kolkata, India is the largest by seating capacity (630 seats). Thereafter, the China Science and Technology Museum Planetarium in Beijing, China has the largest seating capacity (442 seats). In North America, the Hayden Planetarium at the American Museum of Natural History in New York City has the greatest number of seats (423).

The term planetarium is sometimes used generically to describe other devices which illustrate the solar system, such as a computer simulation or an orrery. Planetarium software refers to a software application that renders a three-dimensional image of the sky onto a two-dimensional computer screen. The term planetarian is used to describe a member of the professional staff of a planetarium.

History

Early

The Mark I projector installed in the Deutsches Museum in 1923 was the world's first planetarium projector.
 
The ancient Greek polymath Archimedes is attributed with creating a primitive planetarium device that could predict the movements of the Sun and the Moon and the planets. The discovery of the Antikythera mechanism proved that such devices already existed during antiquity, though likely after Archimedes' lifetime. Campanus of Novara (1220–1296) described a planetary equatorium in his Theorica Planetarum, and included instructions on how to build one. The Globe of Gottorf built around 1650 had constellations painted on the inside. These devices would today usually be referred to as orreries (named for the Earl of Orrery, an Irish peer: an 18th-century Earl of Orrery had one built). In fact, many planetaria today have what are called projection orreries, which project onto the dome a Sun with planets (usually limited to Mercury up to Saturn) going around it in something close to their correct relative periods.

The small size of typical 18th century orreries limited their impact, and towards the end of that century a number of educators attempted some larger scale simulations of the heavens. The efforts of Adam Walker (1730–1821) and his sons are noteworthy in their attempts to fuse theatrical illusions with educational aspirations. Walker's Eidouranion was the heart of his public lectures or theatrical presentations. Walker's son describes this "Elaborate Machine" as "twenty feet high, and twenty-seven in diameter: it stands vertically before the spectators, and its globes are so large, that they are distinctly seen in the most distant parts of the Theatre. Every Planet and Satellite seems suspended in space, without any support; performing their annual and diurnal revolutions without any apparent cause". Other lecturers promoted their own devices: R E Lloyd advertised his Dioastrodoxon, or Grand Transparent Orrery, and by 1825 William Kitchener was offering his Ouranologia, which was 42 feet (13 m) in diameter. These devices most probably sacrificed astronomical accuracy for crowd-pleasing spectacle and sensational and awe-provoking imagery.

The oldest, still working planetarium can be found in the Dutch town Franeker. It was built by Eise Eisinga (1744–1828) in the living room of his house. It took Eisinga seven years to build his planetarium, which was completed in 1781.

In 1905 Oskar von Miller (1855–1934) of the Deutsches Museum in Munich commissioned updated versions of a geared orrery and planetarium from M Sendtner, and later worked with Franz Meyer, chief engineer at the Carl Zeiss optical works in Jena, on the largest mechanical planetarium ever constructed, capable of displaying both heliocentric and geocentric motion. This was displayed at the Deutsches Museum in 1924, construction work having been interrupted by the war. The planets travelled along overhead rails, powered by electric motors: the orbit of Saturn was 11.25 m in diameter. 180 stars were projected onto the wall by electric bulbs.

While this was being constructed, von Miller was also working at the Zeiss factory with German astronomer Max Wolf, director of the Landessternwarte Heidelberg-Königstuhl observatory of the University of Heidelberg, on a new and novel design, inspired by Wallace W. Atwood's work at the Chicago Academy of Sciences and by the ideas of Walther Bauersfeld and Rudolf Straubel at Zeiss. The result was a planetarium design which would generate all the necessary movements of the stars and planets inside the optical projector, and would be mounted centrally in a room, projecting images onto the white surface of a hemisphere. In August 1923, the first (Model I) Zeiss planetarium projected images of the night sky onto the white plaster lining of a 16 m hemispherical concrete dome, erected on the roof of the Zeiss works. The first official public showing was at the Deutsches Museum in Munich on October 21, 1923.

After World War II

Opened in 1955, the Surveyor Germán Barbato Municipal Planetarium in Montevideo, Uruguay, is the oldest planetarium in Latin America and the southern hemisphere.

When Germany was divided into East and West Germany after the war, the Zeiss firm was also split. Part remained in its traditional headquarters at Jena, in East Germany, and part migrated to West Germany. The designer of the first planetaria for Zeiss, Walther Bauersfeld, also migrated to West Germany with the other members of the Zeiss management team. There he remained on the Zeiss West management team until his death in 1959.

The West German firm resumed making large planetaria in 1954, and the East German firm started making small planetaria a few years later. Meanwhile, the lack of planetarium manufacturers had led to several attempts at construction of unique models, such as one built by the California Academy of Sciences in Golden Gate Park, San Francisco, which operated 1952–2003. The Korkosz brothers built a large projector for the Boston Museum of Science, which was unique in being the first (and for a very long time only) planetarium to project the planet Uranus. Most planetaria ignore Uranus as being at best marginally visible to the naked eye.

A great boost to the popularity of the planetarium worldwide was provided by the Space Race of the 1950s and 60s when fears that the United States might miss out on the opportunities of the new frontier in space stimulated a massive program to install over 1,200 planetaria in U.S. high schools.

Early Spitz star projector

Armand Spitz recognized that there was a viable market for small inexpensive planetaria. His first model, the Spitz A, was designed to project stars from a dodecahedron, thus reducing machining expenses in creating a globe. Planets were not mechanized, but could be shifted by hand. Several models followed with various upgraded capabilities, until the A3P, which projected well over a thousand stars, had motorized motions for latitude change, daily motion, and annual motion for Sun, Moon (including phases), and planets. This model was installed in hundreds of high schools, colleges, and even small museums from 1964 to the 1980s.

A Goto E-5 projector.

Japan entered the planetarium manufacturing business in the 1960s, with Goto and Minolta both successfully marketing a number of different models. Goto was particularly successful when the Japanese Ministry of Education put one of their smallest models, the E-3 or E-5 (the numbers refer to the metric diameter of the dome) in every elementary school in Japan.

Phillip Stern, as former lecturer at New York City's Hayden Planetarium, had the idea of creating a small planetarium which could be programmed. His Apollo model was introduced in 1967 with a plastic program board, recorded lecture, and film strip. Unable to pay for this himself, Stern became the head of the planetarium division of Viewlex, a mid-size audio-visual firm on Long Island. About thirty canned programs were created for various grade levels and the public, while operators could create their own or run the planetarium live. Purchasers of the Apollo were given their choice of two canned shows, and could purchase more. A few hundred were sold, but in the late 1970s Viewlex went bankrupt for reasons unrelated to the planetarium business.

During the 1970s, the OmniMax movie system (now known as IMAX Dome) was conceived to operate on planetarium screens. More recently, some planetaria have re-branded themselves as dome theaters, with broader offerings including wide-screen or "wraparound" films, fulldome video, and laser shows that combine music with laser-drawn patterns.

Learning Technologies Inc. in Massachusetts offered the first easily portable planetarium in 1977. Philip Sadler designed this patented system which projected stars, constellation figures from many mythologies, celestial coordinate systems, and much else, from removable cylinders (Viewlex and others followed with their own portable versions).

When Germany reunified in 1989, the two Zeiss firms did likewise, and expanded their offerings to cover many different size domes.

Computerized planetaria

Bangabandhu Sheikh Mujibur Rahman Planetarium (Est.2003), Dhaka, Bangladesh uses Astrotec perforated aluminum curtain, GSS-Helios Space Simulator, Astrovision-70 and many other special effects projectors
 
In 1983, Evans & Sutherland installed the first digital planetarium projector displaying computer graphics (Hansen planetarium, Salt Lake City, Utah)—the Digistar I projector used a vector graphics system to display starfields as well as line art. This gives the operator great flexibility in showing not only the modern night sky as visible from Earth, but as visible from points far distant in space and time. The newest generations of planetaria, beginning with Digistar 3, offer fulldome video technology. This allows projection of any image the operator wishes.

A Sega Homestar home planetarium projector
 
A new generation of home planetaria was released in Japan by Takayuki Ohira in cooperation with Sega. Ohira is known for building portable planetaria used at exhibitions and events such as the Aichi World Expo in 2005. Later, the Megastar star projectors released by Takayuki Ohira were installed in several science museums around the world. Meanwhile, Sega Toys continues to produce the Homestar series intended for home use; however, projecting 60,000 stars on the ceiling makes it semi-professional.

In 2009 Microsoft Research and Go-Dome partnered on the WorldWide Telescope project. The goal of the project is to bring sub-$1000 planetaria to small groups of school children as well as provide technology for large public planetaria.

Technology

Planetarium domes range in size from 3 to 35 m in diameter, accommodating from 1 to 500 people. They can be permanent or portable, depending on the application.
  • Portable inflatable domes can be inflated in minutes. Such domes are often used for touring planetaria visiting, for example, schools and community centres.
  • Temporary structures using glass-reinforced plastic (GRP) segments bolted together and mounted on a frame are possible. As they may take some hours to construct, they are more suitable for applications such as exhibition stands, where a dome will stay up for a period of at least several days.
  • Negative-pressure inflated domes are suitable in some semi-permanent situations. They use a fan to extract air from behind the dome surface, allowing atmospheric pressure to push it into the correct shape.
  • Smaller permanent domes are frequently constructed from glass reinforced plastic. This is inexpensive but, as the projection surface reflects sound as well as light, the acoustics inside this type of dome can detract from its utility. Such a solid dome also presents issues connected with heating and ventilation in a large-audience planetarium, as air cannot pass through it.
  • Older planetarium domes were built using traditional construction materials and surfaced with plaster. This method is relatively expensive and suffers the same acoustic and ventilation issues as GRP.
  • Most modern domes are built from thin aluminium sections with ribs providing a supporting structure behind. The use of aluminium makes it easy to perforate the dome with thousands of tiny holes. This reduces the reflectivity of sound back to the audience (providing better acoustic characteristics), lets a sound system project through the dome from behind (offering sound that seems to come from appropriate directions related to a show), and allows air circulation through the projection surface for climate control.
The realism of the viewing experience in a planetarium depends significantly on the dynamic range of the image, i.e., the contrast between dark and light. This can be a challenge in any domed projection environment, because a bright image projected on one side of the dome will tend to reflect light across to the opposite side, "lifting" the black level there and so making the whole image look less realistic. Since traditional planetarium shows consisted mainly of small points of light (i.e., stars) on a black background, this was not a significant issue, but it became an issue as digital projection systems started to fill large portions of the dome with bright objects (e.g., large images of the sun in context). For this reason, modern planetarium domes are often not painted white but rather a mid grey colour, reducing reflection to perhaps 35-50%. This increases the perceived level of contrast.

A major challenge in dome construction is to make seams as invisible as possible. Painting a dome after installation is a major task, and if done properly, the seams can be made almost to disappear.

Traditionally, planetarium domes were mounted horizontally, matching the natural horizon of the real night sky. However, because that configuration requires highly inclined chairs for comfortable viewing "straight up", increasingly domes are being built tilted from the horizontal by between 5 and 30 degrees to provide greater comfort. Tilted domes tend to create a favoured "sweet spot" for optimum viewing, centrally about a third of the way up the dome from the lowest point. Tilted domes generally have seating arranged stadium-style in straight, tiered rows; horizontal domes usually have seats in circular rows, arranged in concentric (facing center) or epicentric (facing front) arrays.

Planetaria occasionally include controls such as buttons or joysticks in the arm rests of seats to allow audience feedback that influences the show in real time.

Often around the edge of the dome (the "cove") are:
  • Silhouette models of geography or buildings like those in the area round the planetarium building.
  • Lighting to simulate the effect of twilight or urban light pollution.
  • In one planetarium the horizon decor included a small model of a UFO flying.
Traditionally, planetaria needed many incandescent lamps around the cove of the dome to help audience entry and exit, to simulate sunrise and sunset, and to provide working light for dome cleaning. More recently, solid-state LED lighting has become available that significantly decreases power consumption and reduces the maintenance requirement as lamps no longer have to be changed on a regular basis.

The world's largest mechanical planetarium is located in Monico, Wisconsin. The Kovac Planetarium. It is 22 feet in diameter and weighs two tons. The globe is made of wood and is driven with a variable speed motor controller. This is the largest mechanical planetarium in the world, larger than the Atwood Globe in Chicago (15 feet in diameter) and one third the size of the Hayden.

Some new planetariums now feature a glass floor, which allows spectators to stand near the center of a sphere surrounded by projected images in all directions, giving the impression of floating in outer space. For example, a small planetarium at AHHAA in Tartu, Estonia features such an installation, with special projectors for images below the feet of the audience, as well as above their heads.

Traditional electromechanical/optical projectors

Traditional planetarium projection apparatus uses a hollow ball with a light inside, and a pinhole for each star, hence the name "star ball". With some of the brightest stars (e.g. Sirius, Canopus, Vega), the hole must be so big to let enough light through that there must be a small lens in the hole to focus the light to a sharp point on the dome. In later and modern planetarium star balls, the individual bright stars often have individual projectors, shaped like small hand-held torches, with focusing lenses for individual bright stars. Contact breakers prevent the projectors from projecting below the "horizon".

The star ball is usually mounted so it can rotate as a whole to simulate the Earth's daily rotation, and to change the simulated latitude on Earth. There is also usually a means of rotating to produce the effect of precession of the equinoxes. Often, one such ball is attached at its south ecliptic pole. In that case, the view cannot go so far south that any of the resulting blank area at the south is projected on the dome. Some star projectors have two balls at opposite ends of the projector like a dumbbell. In that case all stars can be shown and the view can go to either pole or anywhere between. But care must be taken that the projection fields of the two balls match where they meet or overlap.

Smaller planetarium projectors include a set of fixed stars, Sun, Moon, and planets, and various nebulae. Larger projectors also include comets and a far greater selection of stars. Additional projectors can be added to show twilight around the outside of the screen (complete with city or country scenes) as well as the Milky Way. Others add coordinate lines and constellations, photographic slides, laser displays, and other images.

Each planet is projected by a sharply focused spotlight that makes a spot of light on the dome. Planet projectors must have gearing to move their positioning and thereby simulate the planets' movements. These can be of these types:-
  • Copernican. The axis represents the Sun. The rotating piece that represents each planet carries a light that must be arranged and guided to swivel so it always faces towards the rotating piece that represents the Earth. This presents mechanical problems including:
    The planet lights must be powered by wires, which have to bend about as the planets rotate, and repeatedly bending copper wire tends to cause wire breakage through metal fatigue.
    When a planet is at opposition to the Earth, its light is liable to be blocked by the mechanism's central axle. (If the planet mechanism is set 180° rotated from reality, the lights are carried by the Earth and shine towards each planet, and the blocking risk happens at conjunction with Earth.)
  • Ptolemaic. Here the central axis represents the Earth. Each planet light is on a mount which rotates only about the central axis, and is aimed by a guide which is steered by a deferent and an epicycle (or whatever the planetarium maker calls them). Here Ptolemy's number values must be revised to remove the daily rotation, which in a planetarium is catered for otherwise. (In one planetarium, this needed Ptolemaic-type orbital constants for Uranus, which was unknown to Ptolemy.)
  • Computer-controlled. Here all the planet lights are on mounts which rotate only about the central axis, and are aimed by a computer.
Despite offering a good viewer experience, traditional star ball projectors suffer several inherent limitations. From a practical point of view, the low light levels require several minutes for the audience to "dark adapt" its eyesight. "Star ball" projection is limited in education terms by its inability to move beyond an earth-bound view of the night sky. Finally, in most traditional projectors the various overlaid projection systems are incapable of proper occultation. This means that a planet image projected on top of a star field (for example) will still show the stars shining through the planet image, degrading the quality of the viewing experience. For related reasons, some planetaria show stars below the horizon projecting on the walls below the dome or on the floor, or (with a bright star or a planet) shining in the eyes of someone in the audience.

However, the new breed of Optical-Mechanical projectors using fiber-optic technology to display the stars show a much more realistic view of the sky.

Digital projectors

A fulldome laser projection.

An increasing number of planetaria are using digital technology to replace the entire system of interlinked projectors traditionally employed around a star ball to address some of their limitations. Digital planetarium manufacturers claim reduced maintenance costs and increased reliability from such systems compared with traditional "star balls" on the grounds that they employ few moving parts and do not generally require synchronisation of movement across the dome between several separate systems. Some planetaria mix both traditional opto-mechanical projection and digital technologies on the same dome.

In a fully digital planetarium, the dome image is generated by a computer and then projected onto the dome using a variety of technologies including cathode ray tube, LCD, DLP, or laser projectors. Sometimes a single projector mounted near the centre of the dome is employed with a fisheye lens to spread the light over the whole dome surface, while in other configurations several projectors around the horizon of the dome are arranged to blend together seamlessly.

Digital projection systems all work by creating the image of the night sky as a large array of pixels. Generally speaking, the more pixels a system can display, the better the viewing experience. While the first generation of digital projectors were unable to generate enough pixels to match the image quality of the best traditional "star ball" projectors, high-end systems now offer a resolution that approaches the limit of human visual acuity.

LCD projectors have fundamental limits on their ability to project true black as well as light, which has tended to limit their use in planetaria. LCOS and modified LCOS projectors have improved on LCD contrast ratios while also eliminating the “screen door” effect of small gaps between LCD pixels. “Dark chip” DLP projectors improve on the standard DLP design and can offer relatively inexpensive solution with bright images, but the black level requires physical baffling of the projectors. As the technology matures and reduces in price, laser projection looks promising for dome projection as it offers bright images, large dynamic range and a very wide color space.

Show content

Artistic representations of the constellations projected during a planetarium show.

Worldwide, most planetaria provide shows to the general public. Traditionally, shows for these audiences with themes such as "What's in the sky tonight?", or shows which pick up on topical issues such as a religious festival (often the Christmas star) linked to the night sky, have been popular. Pre-recorded and live presentation formats are possible. Live format are preferred by many venues because a live expert presenter can answer on-the-spot questions raised by the audience.

Since the early 1990s, fully featured 3-D digital planetaria have added an extra degree of freedom to a presenter giving a show because they allow simulation of the view from any point in space, not only the earth-bound view which we are most familiar with. This new virtual reality capability to travel through the universe provides important educational benefits because it vividly conveys that space has depth, helping audiences to leave behind the ancient misconception that the stars are stuck on the inside of a giant celestial sphere and instead to understand the true layout of the solar system and beyond. For example, a planetarium can now 'fly' the audience towards one of the familiar constellations such as Orion, revealing that the stars which appear to make up a co-ordinated shape from our earth-bound viewpoint are at vastly different distances from Earth and so not connected, except in human imagination and mythology. For especially visual or spatially aware people, this experience can be more educationally beneficial than other demonstrations.

Music is an important element to fill out the experience of a good planetarium show, often featuring forms of space-themed music, or music from the genres of space music, space rock, or classical music.

Game studies

From Wikipedia, the free encyclopedia
 
Game studies, or ludology, is the study of games, the act of playing them, and the players and cultures surrounding them. It is a field of cultural studies that deals with all types of games throughout history. This field of research utilizes the tactics of, at least, folkloristics and cultural heritage, sociology and psychology, while examining aspects of the design of the game, the players in the game, and the role the game plays in its society or culture. Game studies is oftentimes confused with the study of video games, but this is only one area of focus; in reality game studies encompasses all types of gaming, including sports, board games, etc.

Before video games, game studies was rooted primarily in anthropology. However, with the development and spread of video games, games studies has diversified methodologically, to include approaches from sociology, psychology, and other fields.

There are now a number of strands within game studies: social science approaches explore how games function in society, and their interactions with human psychology, often using empirical methods such as surveys and controlled lab experiments. Humanities approaches emphasise how games generate meanings and reflect or subvert wider social and cultural discourses. These often use more interpretative methods, such as close reading, textual analysis, and audience theory, methods shared with other media disciplines such as television and film studies. Social sciences and humanities approaches can cross over, for example in the case of ethnographic or folkloristic studies, where fieldwork may involve patiently observing games to try to understand their social and cultural meanings. Game design approaches are closely related to creative practice, analysing game mechanics and aesthetics in order to inform the development of new games. Finally, industrial and engineering approaches apply mostly to video games and less to games in general, and examine things such as computer graphics, artificial intelligence, and networking.

History

It wasn't until Irving Finkel organized a colloquium in 1990 that grew into the International Board Game Studies Association, Gonzalo Frasca popularized the term ludology (from the Latin word for game, ludus) in 1999, the publication of the first issues of academic journals like Board Game Studies in 1998 and Game Studies in 2001, and the creation of the Digital Games Research Association in 2003, that scholars began to get the sense that the study of games could (and should) be considered a field in its own right. As a young field, it gathers scholars from different disciplines that had been broadly studying games, such as psychology, anthropology, economy, education, and sociology. The earliest known use of the term "ludology" occurred in 1982, in Mihaly Csikszentmihalyi's “Does Being Human Matter – On Some Interpretive Problems of Comparative Ludology.”

Social science

One of the earliest social science theories (1971) about the role of video games in society involved violence in video games, later becoming known as the catharsis theory. The theory suggests that playing video games in which you perform violent acts might actually channel latent aggression, resulting in less aggression in the players real lives. However, a meta-study performed by Craig A. Anderson and Brad J. Bushman, in 2001, examined data starting from the 1980s up until the article was published. The purpose of this study was to examine whether or not playing violent video games led to an increase in aggressive behaviors. They concluded that exposure to violence in video games did indeed cause an increase in aggression. However, it has been pointed out, and even stressed, by psychologist Jonathan Freedman that this research was very limited and even problematic since overly strong claims were made and the authors themselves seemed extremely biased in their writings. More recent studies, such as the one performed by Christopher J. Ferguson at Texas A&M International University have come to drastically different conclusions. In this study, individuals were either randomly assigned a game, or allowed to choose a game, in both the randomized and the choice conditions exposure to violent video games caused no difference in aggression. A later study (performed by the same people) looked for correlations between trait aggression, violent crimes, and exposure to both real life violence and violence in video games, this study suggests that while family violence and trait aggression are highly correlated with violent crime, exposure to video game violence was not a good predictor of violent crime, having little to no correlation, unless also paired with the above traits that had a much higher correlation. Over the past 15 years, a large number of meta-studies have been applied to this issue, each coming to its own conclusion, resulting in little consensus in the ludology community. It is also thought that even nonviolent video games may lead to aggressive and violent behaviour. Anderson and Dill seem to believe that it may be due to the frustration of playing video games that could in turn result in violent, aggressive behaviour.

Game designers Amy Jo Kim and Jane McGonigal have suggested that platforms which leverage the powerful qualities of video games in non-game contexts can maximize learning. Known as the gamification of learning, using game elements in non-game contexts extracts the properties of games from within the game context, and applies them to a learning context such as the classroom. 

Another positive aspect of video games is its conducive character towards the involvement of a person in other cultural activities. The probability of game playing increases with the consumption of other cultural goods (e.g., listening to music or watching television) or active involvement in artistic activities (e.g., writing or visual arts production). Video games by being complementary towards more traditional forms of cultural consumption, inhibit thus value from a cultural perspective.

More sociologically-informed research has sought to move away from simplistic ideas of gaming as either 'negative' or 'positive', but rather seeking to understand its role and location in the complexities of everyday life.

For example, it has been suggested that the very popular MMO World of Warcraft could be used to study the dissemination of infectious diseases because of the accidental spread of a plague-like disease in the gameworld.

"Ludology" vs "narratology"

A major focus in game studies is the debate surrounding narratology and ludology. Many ludologists believe that the two are unable to exist together, while others believe that the two fields are similar but should be studied separately. Many narratologists believe that games should be looked at for their stories, like movies or novels. The ludological perspective says that games are not like these other mediums due to the fact that a player is actively taking part in the experience and should therefore be understood on their own terms. The idea that a videogame is "radically different to narratives as a cognitive and communicative structure" has led the development of new approaches to criticism that are focused on videogames as well as adapting, repurposing and proposing new ways of studying and theorizing about videogames. A recent approach towards game studies starts with an analysis of interface structures and challenges the keyboard-mouse paradigm with what is called a "ludic interface".

Academics across both fields provide scholarly insight into the different sides of this debate. Gonzalo Frasca, a notable ludologist due to his many publications regarding game studies, argues that while games share many similar elements with narrative stories, that should not prevent games to be studied as games. He seeks not "to replace the narratologic approach, but to complement it."

Jesper Juul, another notable ludologist, argues for a stricter separation of ludology and narratology. Juul argues that games "for all practicality can not tell stories." This argument holds that narratology and ludology cannot exist together because they are inherently different. Juul claims that the most significant difference between the two is that in a narrative, events "have to" follow each other, whereas in a game the player has control over what happens.

Garry Crawford and Victoria K. Gosling argue in favor of narratives being an essential part of games as "it is impossible to isolate play from the social influences of everyday life, and in turn, play will have both intended and unintended consequences for the individual and society." The Last of Us is a video game released in 2013 that has been referred to as a narrative "masterpiece." Proponents of the narratology side of game studies argue that The Last of Us and similar games that have followed it and preceded it, serve as examples that games can in fact tell stories.

Janet Murray, in support of the Narratologist method of video game argues that "stories can be participatory." In this argument, Murray is linking the characteristics of video games to narratives to further her point that video games should be analyzed through narratology.

Michalis Kokonis argues in favor of Gonzalo Frasca's article entitled "Ludologists love stories too: notes from a debate that never took place," which aimed to list and explain the misunderstandings, mistakes, and prejudices surrounding the narratology vs. ludology debate. Kokonis noted that "endorsing his [Frasca] constructivist spirit we will have to agree that the so-called Narratology vs. Ludology Dilemma is a false one and that this debate will have to be resolved, as it is of no help to the cause of establishing Computer Games Study as an autonomous and independent academic field." 

Other areas of research

As is common with most academic disciplines, there are a number of more specialized areas or sub-domains of study.

Video game pre-history

An emerging field of study looks at the "pre-history" of video games, suggesting that the origins of modern digital games lie in: fairground attractions and sideshows such as shooting games; early "Coney Island"-style pleasure parks with elements such as large roller-coasters and "haunted house" simulations; nineteenth century landscape simulations such as dioramas, panoramas, planetariums, and stereographs; and amusement arcades that had mechanical game machines and also peep-show film machines.

Games and aging

In light of population ageing, there has been an interest into the use of games to improve the overall health and social connectedness of ageing players. For example, Adam Gazzaley and his team have designed NeuroRacer (a game that improves cognitive tasks outside of the game among its 60+ year old participants), while the AARP has organized a game jam to improve older people's social connections. Researchers such as Sarah Mosberg Iversen have argued that most of the academic work on games and ageing has been informed by notions of economical productivity, while Bob De Schutter and Vero Vanden Abeele have suggested a game design approach that is not focused on age-related decline but instead is rooted in the positive aspects of older age.

Virtual economies in gaming

Massive multiplayer online games can give economists clues about the real world. Markets based on digital information can be fully tracked as they are used by players, and thus real problems in the economy, such as inflation, deflation and even recession. The solutions the game designers come up with can therefore be studied with full information, and experiments can be performed where the economy can be studied as a whole. These games allow the economists to be omniscient, they can find every piece of information they need to study the economy, while in the real world they have to work with presumptions.

Former Finance Minister of Greece and Valve's in-house economist Yanis Varoufakis studied EVE Online and argued that video game communities give economists a venue for experimenting and simulating the economies of the future. Edward Castronova has studied virtual economies within a variety of games including Everquest and World of Warcraft.

Cognitive benefits

The psychological research into games has yielded theories on how playing video games may be advantageous for both children and for adults. Some theories claim that video games in fact help improve cognitive abilities rather than impede their development. These improvement theories include the improvement of visual contrast sensitivity. Other developments include the ability to locate something specific among various impediments. This is primarily done in first-person shooter games where the protagonist must look at everything in a first person view while playing. By doing this they increase their spatial attention due to having to locate something among an area of diversions. These games place the player in a high intensity environment where the player must remain observant of their surroundings in order to achieve their goal, e.g., shooting an enemy player, while impediments obstruct their gameplay in the virtual world.

Another cognitive enhancement provided by playing video games would be the improvement of brain functioning speed. This happens as the player is immersed in an unendingly changing environment where they are required to constantly think and problem solve while playing in order to do well in the game. This constant problem solving forces the brain to constantly run and so the speed of thought is sharpened greatly, because the need to think quickly is required to succeed. The attention span of the player is also benefited. High action video games, such as fighting or racing games, require the user's constant attention and in the process the skill of concentration is sharpened.

The overcoming of the condition known as dyslexia is also considered an improvement due to the continuous utilization of controllers for the video games. This continuous process helps to train the users to overcome their condition which impedes in their abilities of interpretation. The ability of hand-eye coordination is also improved thanks in part to video games, due to the need to operate the controller and view the screen displaying the content all at the same time. The coordination of the player is enhanced due the playing and continuous observation of a video game since the game gives high mental stimulation and coordination is important and therefore enhanced due to the constant visual and physical movement that is produced from the playing of the video game.

The playing of video games can also help increase a player's social skills. This is done by playing online multiplayer games which can require constant communication, this leads to socialization between players in order to achieve the goal within the game they may be playing. In addition it can help the users to meet new friends over their online games and at the same time communicate with friends they have already made in the past; those playing together online would only strengthen their already established bond through constant cooperation. Some video games are specifically designed to aid in learning, because of this another benefit of playing video games could be the educational value provided with the entertainment. Some video games present problem solving questions that the player must think on in order to properly solve, while action orientated video games require strategy in order to successfully complete. This process of being forced to think critically helps to sharpen the mind of the player.

Game culture

One aspect of game studies is the study of gaming culture. People who play video games are a subculture of their own. Gamers will often form communities with their own languages, attend conventions where they will dress up as their favorite characters, and have gaming competitions. One of these conventions, Gamescom 2018, had a record attendance with an estimated 370,000 attendees.

eSports is making a significant impact in gaming culture. In 2018, Newzoo, a marketing analytics company reported that 380 million people will watch eSports that year. Many gamers seek to form communities to meet new people and share their love of games. In 2014, Newzoo reported that 81% of gamers attend eSport to be a part of the gaming community. "61% of gamers attend live events and tournaments to connect with friends that they've met and played with online."

Throughout the years, there has been much research on the topic of game culture, specifically focusing on video games in relation to thinking, learning, gender, children, and war. When looking at game culture, multiplayer online games are usually the base for many research.

Demographics of Gamers (in the USA)

  • 75% of households have a gamer.
  • 65% of adults play video games.
  • 60% of adults play on smartphones, 52% play on a personal computer, and 49% play on a dedicated game console.
  • 32 is the average age of male gamers.
  • 34 is the average age of female gamers.
  • 54% of gamers are men. 46% are women.

Rydberg atom

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