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Luoyang

Luoyang is a city located in the confluence area of the Luo River and the Yellow River in the west of Henan province. Governed as a prefecture-level city, it borders the provincial capital of Zhengzhou to the east, Pingdingshan to the southeast, Nanyang to the south, Sanmenxia to the west, Jiyuan to the north, and Jiaozuo to the northeast. As of December 31, 2018, Luoyang had a population of 6,888,500 inhabitants with 2,751,400 people living in the built-up (or metro) area made of the city's five out of six urban districts (except the Jili District not continuously urbanized) and Yanshi District, now being conurbated. By the end of 2022, Luoyang Municipality had jurisdiction over 7 municipal districts, 7 counties and 1 development zone. The permanent population is 7.079 million.

Situated on the central plain of China, Luoyang is among the oldest cities in China and one of the cradles of Chinese civilization. It is the earliest of the Four Great Ancient Capitals of China.

Names
The name "Luoyang" originates from the city's location on the north or sunny ("yang") side of the Luo River. Since the river flows from west to east and the sun is to the south of the river, the sun always shines on the north side of the river. Luoyang has had several names over the centuries, including Luoyi (洛邑) and Luozhou (洛州), but Luoyang has been its primary name. It has also been called Dongdu during the Tang dynasty, Xijing  during the Song dynasty, or Jingluo. During the rule of Wu Zetian, the only female emperor in Chinese history, the city was known as Shendu. Luoyang was renamed Henanfu (河南府) during the Qing dynasty but regained its former name in 1912.

Classical era
The greater Luoyang area has been sacred ground since the late Neolithic period. This area at the intersection of the Luo River and Yi River was considered to be the geographical center of China. Because of this sacred aspect, several cities – all of which are generally referred to as "Luoyang" – have been built in this area. In 2070 BC, the Xia dynasty king Tai Kang moved the Xia capital to the intersection of the Luo and Yi and named the city Zhenxun (斟鄩). In 1600 BC, Tang of Shang defeated Jie, the final Xia dynasty king, and built Western Bo, (西亳), a new capital on the Luo River. The ruins of Western Bo are located in Luoyang Prefecture.

In 1036 BC a settlement named Chengzhou (成周) was constructed by the Duke of Zhou for the remnants of the captured Shang nobility. The Duke also moved the Nine Tripod Cauldrons to Chengzhou from the Zhou dynasty capital at Haojing. A second Western Zhou capital, Wangcheng (also: Luoyi) was built 15 km west of Chengzhou. Wangcheng became the capital of the Eastern Zhou dynasty in 771 BC. The Eastern Zhou dynasty capital was moved to Chengzhou in 510 BC. Later, the Eastern Han dynasty capital of Luoyang would be built over Chengzhou. Modern Luoyang is built over the ruins of Wangcheng, which are still visible today at Wangcheng Park.

Qin Shi Huang's chief minister, Lu Buwei, was given Luoyang. Lu began programs to develop and beautify Luoyang. It is said that Liu Bang visited Luoyang and considered making it his capital but was persuaded to reconsider by his ministers to turn to Chang'an instead for his capital.

Han dynasty
In 25 AD, Luoyang was declared the capital of the Eastern Han dynasty on November 27 by Emperor Guangwu of Han. The city walls formed a rectangle 4 km south to north and 2.5 km west to east, with the Gu River, a tributary of the Luo River just outside the northern eastern walls. The rectangular Southern Palace and the Northern Palace were 3 km apart and connected by The Covered Way. In 26, the Altar of the Gods of the Soils and Grains, the Altar of Heaven, and the Temple of the eminent Founder, Emperor Gao of Former Han were inaugurated. The Imperial University was restored in 29. In 48, the Yang Canal linked the capital to the Luo. In 56, main imperial observatory, the Spiritual Terrace, was constructed.

For several centuries, Luoyang was the focal point of China. In AD 68, the White Horse Temple, the first Buddhist temple in China, was founded in Luoyang. The temple still exists, though the architecture is of later origin, mainly from the 16th century. An Shigao was one of the first monks to popularize Buddhism in Luoyang.

The diplomat Ban Chao restored the Silk Road during the Eastern Han dynasty, thus making Luoyang the eastern terminus of the Silk Road during the Han dynasty.

In 166 AD, the first Roman mission, sent by "the king of Da Qin [the Roman Empire], Andun" (Marcus Aurelius Antoninus, r. 161–180 AD), reached Luoyang after arriving by sea in Rinan Commandery in what is now central Vietnam.

The late 2nd century saw China decline into anarchy:

"The decline was accelerated by the rebellion of the Yellow Turbans, who, although defeated by the Imperial troops in 184 AD, weakened the state to the point where there was a continuing series of rebellions degenerating into civil war, culminating in the burning of the Han capital of Luoyang on 24 September 189 AD. This was followed by a state of continual unrest and wars in China until a modicum of stability returned in the 220s, but with the establishment of three separate kingdoms, rather than a unified empire."

Wei and Jin dynasties
On April 4, 190 AD, Chancellor Dong Zhuo ordered his soldiers to ransack, pillage, and raze the city as he retreated from the coalition set up against him by regional lords all over China. The court was subsequently moved to the more defensible western city of Chang'an (modern Xi'an). Following a period of disorder, during which warlord Cao Cao held the last Han emperor Xian in Xuchang (196–220), Luoyang was restored to prominence when his son Cao Pi, Emperor Wen of the Wei dynasty, declared it his capital in 220 AD. The Jin dynasty, successor to Wei, was also established in Luoyang. At the height of Jin rule, Luoyang had a population of 600,000 and was probably the second largest city in the world after Rome.

During the Upheaval of the Five Barbarians in 311 AD, Western Jin was forced to move its capital to Jiankang (modern day Nanjing) and become Eastern Jin. The Xiongnu armies of Liu Cong destroyed Luoyang in the Disaster of Yongjia. Following the sack, it would take until 495 AD before the city was a major population hub again. The same fate befell Chang'an in 316 AD. Every single diaspora Sogdian and Indian living Luoyang at the time died due to the Xiongnu sack. A large battle between the forces of Liu Yao of Former Zhao and Shi Le of Later Zhao took place outside the remnants of the city in 328, with Shi obtaining a decisive victory, capturing Liu Yao and leading to the collapse of Former Zhao.

Northern Wei
In winter 416, Luoyang fell to Liu Yu's general Tan Daoji. In 422, Luoyang was captured by Northern Wei. Liu Song general Dao Yanzhi took the city back, but by 439 the Wei conquered the city definitively. In 493 AD, Emperor Xiaowen of the Northern Wei dynasty moved the capital from Datong to Luoyang, moving over 150,000 people to the site by 495, and started the construction of the rock-cut Longmen Grottoes. More than 30,000 Buddhist statues from the time of this dynasty have been found in the caves. Many of these sculptures were two-faced. At the same time, the Shaolin Temple was also built by the Emperor to accommodate an Indian monk on the Mont Song right next to Luoyang City. The Yongning Temple (永宁寺), the tallest pagoda in China, was also built in Luoyang. The city reached a population of 600,000 at its height during the Northern Wei. The city was destroyed by the warlord Gao Huan, who captured the city and forced its population to move to his capital at Ye in 534. The old city was the site of numerous battles between Western Wei (and its successor Northern Zhou) and Eastern Wei (and its successor Northern Qi) between 538 and 575

Sui and Tang dynasties
When Emperor Yang of Sui took control in 604 AD he founded the new Luoyang on the site of the existing city using a layout inspired by his father Emperor Wen of Sui's work in newly rebuilt Chang'an.

During the Tang dynasty, Luoyang was Dongdu (東都), the "Eastern Capital", and at its height had a population of around one million, second only to Chang'an, which, at the time, was the largest city in the world.

During an interval in the Tang dynasty, the first and the only empress in Chinese history – Empress Wu, moved the capital of her Zhou dynasty to Luoyang and named it as Shen Du (Capital of the God). She constructed the tallest palace in Chinese history, which is now in the site of Sui Tang Luoyang city. Luoyang was heavily damaged during the An Lushan Rebellion.

Epitaphs were found dating from the Tang dynasty of a Christian couple in Luoyang of a Nestorian Christian Sogdian woman, Lady An (安氏), who died in 821, and her Nestorian Christian Han Chinese husband, Hua Xian (花献), who died in 827. These Han Chinese Christian men may have married Sogdian Christian women because of a lack of Han Chinese women belonging to the Christian religion, limiting their choice of spouses among the same ethnicity. Another epitaph in Luoyang of a Nestorian Christian Sogdian woman also surnamed An was discovered and she was put in her tomb by her military officer son on 22 January, 815. This Sogdian woman's husband was surnamed He (和) and he was a Han Chinese man and the family was indicated to be multiethnic on the epitaph pillar. In Luoyang, the mixed raced sons of Nestorian Christian Sogdian women and Han Chinese men has many career paths available for them. Neither their mixed ethnicity nor their faith were barriers and they were able to become civil officials, a military officers and openly celebrated their Christian religion and support Christian monasteries. Central Asians like Sogdians were called "Hu" (胡) by the Chinese during the Tang dynasty. Central Asian "Hu" women were stereotyped as barmaids or dancers by Han in China. Occasionally, "Hu" women would be involved in prostitution as the "Hu" women in China were at times in occupations that doubled as illicit services.

During the short Five Dynasties and Ten Kingdoms period, Luoyang was the capital of the Later Liang (only for a few years before the court moved to Kaifeng) and Later Tang dynasty.

Later history
During the North Song dynasty, Luoyang was the 'Western Capital' and birthplace of Zhao Kuangyin, the founder of the Song dynasty. It served as a prominent cultural center, housing some of the most important philosophers. This prosperity was mainly caused by Luoyang undergoing new developments and reconstruction during this period.

During the Jurchen Jin dynasty, Luoyang was the "Middle Capital".

Since the Yuan dynasty, Luoyang was no longer the capital of China in the rest of the ancient dynasties. During the Yuan and Ming dynasties, Luoyang was razed and rebuilt twice. Its walls were destroyed by peasant rebels in the late Ming period. The city walls were then rebuilt during the Qing dynasty. The population was reduced to that of an average county. However, for one last time, Luoyang city was the capital of the Republic of China for a brief period of time during the Japanese invasion. By 1949, Luoyang's population was 75,000.

People's Republic of China
After the People's Republic of China was established, Luoyang was revived as a major heavy industrial hub. In the first five-year plan of China, 7 of 156 Soviet-aided major industrial programmes were launched in Luoyang's Jianxi District, including Dongfanghong Tractor Factory, Luoyang Mining Machines Factory and Luoyang Bearing Factory. Later, during the Third Front construction, a group of heavy industry factories was moved to or founded in Luoyang, including Luoyang Glass Factory. Industrial development significantly shifted Luoyang's demographic makeup, and about half of Luoyang's population are new immigrants after 1949 from outside the province or their descendants.

UNESCO World Heritage Site

 * Longmen Grottoes, added to the UNESCO World Heritage List in 2000
 * The Grand Canal – Huiluo Barn, Hanjia Barn, added to the UNESCO World Heritage List in 2014
 * Silk Roads – Han Wei Luoyang City Site, Dingding Gate Site of Sui Tang Luoyang City, Xin'an Hangu Guan Site, added to the UNESCO World Heritage List in 2014

Ancient city sites

 * Erlitou Site (Zhenxun) of Xia dynasty
 * Yanshi Shang City Site (Xibo) of Shang dynasty
 * Wangcheng Site of Eastern Zhou dynasty
 * Luoyang City Site of Han and Wei dynasty
 * Luoyang City Site of Sui and Tang dynasty

Administrative divisions
The prefecture-level city of Luoyang administers 7 districts and 7 counties:

 * Districts
 * Jianxi District
 * Xigong District
 * Laocheng District
 * Chanhe Hui District
 * Luolong District
 * Yanshi District
 * Mengjin District
 * Defunct District
 * Jili District, now part of Mengjin District
 * Counties
 * Xin'an County
 * Luoning County
 * Yiyang County
 * Yichuan County
 * Song County
 * Luanchuan County
 * Ruyang County

During the 2010 census, the 5 "built-up" urban districts held a population of 1,857,003, making it the fourth-largest city in Henan. The entire area of Luoyang's municipal government held 6,549,941 inhabitants total.

2021 administrative reorganization
With the 2017 designation of Zhengzhou as a National Central City, Henan Province in 2020 proposed a new development plan for Zhengzhou Metropolitan Area, which called for the development of Luoyang as a sub-central city. As part of this development, authorities decided to expand the urban area of Luoyang. This not only facilitated planning and coordinated use of resources and infrastructure in Luoyang, but also allowed for better integration towards Zhengzhou, as Yanshi, Jili and Mengjin previously separated the Luoyang urban area from Zhengzhou.

On 28 March 2021, the central government approved a major administrative reorganization of Luoyang city. Yanshi City was reorganized into an urban district (Yanshi District), while Jili District and Mengjin County were merged into Mengjin District. This reorganization effectively doubled the urban area of Luoyang.

Geography
As its name states, the Old Town of Luoyang is located on the north bank of the Luo, a southern tributary of the middle reaches of the Yellow River. The districts of the modern urban center include both banks and some of the surrounding mountains.

The countryside controlled by the municipal government includes still more rugged land: mountains comprise 45.51% of the total area; hills, 40.73%; and plains, 13.8%.

Climate
Luoyang has a highly continental dry-winter humid subtropical climate (Köppen climate classification: Cwa).

Culture
The Longmen Grottoes south of the city were listed on the UNESCO list of World Heritage Sites in November 2000. Guanlin—a series of temples built in honor of Guan Yu, a hero of the Three Kingdoms period—is nearby. The White Horse Temple is located 12 km east of the modern town.
 * Sites

The Luoyang Museum (established 1958) features ancient relics dating back to the Xia, Shang, and Zhou dynasties. The total number of exhibits on display is 1,700. China's only tomb museum, the Luoyang Ancient Tombs Museum, opened to the public in 1987 and is situated north of the modern town.

The Gaocheng Astronomical Observatory (also known as the Dengfeng Observatory or the Tower of Chou Kong) stands 80 km south-east of Luoyang. It was constructed in 1276 during the Yuan dynasty by Guo Shoujing as a giant gnomon for "the measurement of the sun's shadow". Prior to the Jesuit China Missions, it was used for establishing the summer and winter solstices in traditional Chinese astronomy.

Luoyang is the foundation of Confucianism, the birth of Taoism, the first transmission of Buddhism, the formation of metaphysics, and the origin of neo-Confucianism. All kinds of cultural thoughts are integrated and symbiosis here, and the compass, paper making and printing among the four great inventions of ancient China were born here. Luoyang is also the cultural root and ancestral lineage of the global Chinese, more than 100 million Hakka ancestral home in the world, 70% of China's clan name originated here, Heluo culture represented by "Hetu Luoshu" is the ancestral source of Chinese civilization.

Water Banquet, which is one of the famous banquets passed on for generations in the history of Chinese cuisine, consists of 8 cold and 16 warm dishes all cooked in various broths, gravies, or juices. The water here has two meanings: one is that all the hot dishes have soup-tang soup water; the other is that each dish is served after another smoothly just like flowing water. It comprises a wide selection of ingredients, simple and versatile, diverse tastes, sour, spicy, sweet and salty, comfortable and delicious.
 * Cuisine

Luoyang is also celebrated for the cultivation of peonies, its city flower. Since 1983, each mid-April the city hosts the Peony Culture Festival of Luoyang. More than 19 million tourists visited Luoyang during the 2014 festival.
 * Botany

"Spring in Luoyang", an ancient Chinese composition, became popular in Korea during the Goryeo dynasty (918–1392) and is still performed in its dangak (Koreanized) version Nakyangchun. Lou Harrison, an American composer, has also created an arrangement of the work.
 * Music

 * Dialect

Residents of Luoyang typically speak a dialect of Zhongyuan Mandarin. Although Luoyang's dialect was a prestige dialect of spoken Chinese from the Warring States period of the Zhou until the Ming dynasty, it differs from the Beijing form of Mandarin which became the basis of the standard modern dialect.

Asteroid (239200) 2006 MD13 is named after Luoyang.
 * Outer space

Education

 * Luoyang Institute of Science and Technology (洛阳理工学院)
 * Henan University of Science and Technology (河南科技大学)
 * Luoyang Normal University (洛阳师范学院)
 * PLA Foreign Language Institute, formerly known as the Luoyang PLA College of Foreign Languages (解放军洛阳外语学院)

Transportation
The city can be reached by highways, trains or planes. Long-distance buses are also an option although they generally tend to take longer. High-speed rail is the most common way to get into the city from either Xi'an or Zhengzhou. Luoyang has a bus system of around 30+ lines. Taxis are also a common sight in the city.

Subway
Line 1 of Luoyang Subway opened 28 March 2021. Line 2 opened on 26 December 2021.

Rail
The main station for conventional rail services is Luoyang railway station on the Longhai railway. Guanlin railway station on the Jiaozuo–Liuzhou railway has a far less frequent service, only seeing north–south trains or vice versa that don't stop at Luoyang railway station.
 * Conventional speed

Luoyang Longmen railway station sees high-speed services on the Zhengzhou–Xi'an high-speed railway.
 * High-speed

Road

 * 20231231 Wangcheng Avenue in Luoyang 02.jpg Lianyungang–Khorgas Expressway
 * G36 Nanjing–Luoyang Expressway
 * G55 Erenhot–Guangzhou Expressway
 * China National Highway 207
 * China National Highway 310

Air
Luoyang is served by Luoyang Beijiao Airport.

Twin towns and sister cities
Luoyang is twinned with:
 * 🇺🇸 La Crosse, Wisconsin, United States
 * 🇯🇵 Okayama, Okayama, Japan

Famous residents

 * Laozi, legendary founder of Taoism
 * The emperors of the Eastern Zhou dynasty
 * Guiguzi, geomancer and numerologist
 * The emperors of the Eastern Han dynasty
 * Xuanzang, Buddhist monk and hero of the Journey to the West
 * Liu Yuxi, poet
 * Emperor Taizu of Song, founder of the Song dynasty
 * Gao Hong, pipa player
 * Du Wei, soccer player
 * Wang Yibo, actor, singer, idol
 * Chen Dong, astronaut of Shenzhou 11 and Shenzhou 14
 * Meng Meiqi, singer, dancer (WJSN and Rocket Girls 101)

title: Luoyang


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Talk:Video game developer

Crunch time
Are the infos about "Crunch time" enough for its own article? -- Gebu (talk) 17:47, 22 January 2021 (UTC)

Semi-protected edit request on 17 June 2021
William Joseph Geraghty (talk) 16:27, 17 June 2021 (UTC) Who doesn't love playing video games? It's easy to get lost in fantasy worlds or get caught up in an epic quest. The games we love to play take months or even years to create. Behind the scenes, a team of skilled people work together to design, write, program, and test the games. If you want to be a part of this team, consider a career as a video game developer.

Video game developers design fun and interactive video games. A lot of pieces have to come together to make a game. For instance, there's the story, graphics, game mechanics, music, and AI. Developers' tasks depend on which of these areas they focus on.

Game designers plan every detail of the way a game is to be played. They decide on core features like structure, mechanics, and rules. They create design documents for how a player progresses through the game. These diagrams are like blueprints of the game. Designers also come up with the levels, missions, and challenges that players must complete. For example, if a player needs to solve a puzzle before moving on, a designer creates it.

Some designers come up with the whole concept for a game. They dream up the story, setting, and characters. In these cases, they may oversee the writers and artists who bring their ideas to life. They also have to pitch their concepts to clients or their employers.

Writers help create a compelling story for the game. They write the on-screen text, dialogue, and voiceovers. They also create character profiles and write any event scenes. Sometimes they write the script based on a plot they get from the designer.

Artists and animators come up with the look of a game. Artists create storyboards and concept art for the game. They also design characters and backgrounds. The work they do can help to establish the mood of the game. For example, dark colors and shadows can add to the gritty feel of a crime game. Artists may also create 3D models of characters using special software. This allows animators and programmers to bring the character to life.

Some artists focus on only one area of the game. For instance, some just design the environments in the game. Others may work on textures, making sure skin, hair, and fur look as real as possible.

Animators inject life into the characters by animating these models. They also design moving special effects, like ocean waves or laser beams. They are experts at making sure all the movements in the game are believable.

Of course, programmers are at the heart of the game development. They write the code that makes the game playable. They create the engine that the game runs on. They also make sure the on-screen action corresponds to players' input. The game needs to respond to the touch from a keyboard, mouse, or controller. When a player pushes the jump button, the right character better jump!

Programmers also deal with the game's AI (artificial intelligence). They program the logic and rules that tell the computer how to respond to the action inside the game. For example, when a player attacks an enemy, the computer responds with a counterattack. Programmers figure out all the possible outcomes of an interaction. They then program the computer to "play" the game with the player.

Programmers also handle the game physics. They make sure things move and fall the way they do in real life-or the way they should in the game's world.

Musicians or sound designers take care of the music. They also make sound effects, like fighting noises and scary voices. Their role is often unnoticed, but it is very important. Without sound effects, the game will not seem realistic.

Play testers play prototypes and unfinished games. They try to identify any bugs or problems with a game before it's released to the public. Producers or project managers oversee the entire process. They make sure the game is finished on time and on budget.
 * Red question icon with gradient background.svg Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format and provide a reliable source if appropriate. ScottishFinnishRadish (talk) 16:38, 17 June 2021 (UTC)

indie developer section has obsolete info?
the section says:

"other indie game developers create game software for a number of video-game publishers on several gaming platforms.[citation needed] In recent years this model has been in decline; larger publishers, such as Electronic Arts and Activision, increasingly turn to internal studios (usually former independent developers acquired for their development needs)"

The bold part seems highly suspect to me and the source for the last sentence is from 2004. Steam was first released in 2003 and xbox live arcade was only announced in 2004, so digital distribution was still in its infancy at the time, and AFAIK the affordable/free accessibility of quality game engines, assets, and other dev tools was just starting out (unity's first release was 2005), so the indie boom was a good ways off at the time. I'm pretty sure this claim is therefore crazy obsolete, esp given the insane glut of indie games and devs that eventually led to the 'indiepocalypse'.

(am not a regular contributor so i prob won't be back to continue conv. just thought i'd point this out in case one of you noble wiki editors agrees and feels like doing an update - else just delete this if i've somehow missed this trend and this is inaccurate). 192.131.249.109 (talk) 23:24, 15 August 2022 (UTC)

Should not be listed as a software developer as it creates confusion
A video game developer isn't one who writes code despite beliefs of this outside of the industry. A game developer is anyone who works to build a game. A game that could be physical and thus require zero programming at all. A video game developer is a subset of game developer specifically dealing with those who build games with electronics. This whole article seems to be focused on comparing it to software developers and programmers. As software developer points to https://en.wikipedia.org/wiki/Software_development#Workforce which then states "Other job titles for people with similar meanings include programmer, software analyst, or software engineer." which seems to suggest the whole blurb before it is only applying to software development companies. So either we should section off this page from software developer or include "producers, project managers, artists, or designers" in that similar meaning list. Either the term software developer on an individual level means "programmer" or means "anyone who builds software" but leaving it ambiguous means that the term video game developer is left ambiguous where the industry standard for the term is to include everyone on the team. If you go into a game's credits, you are a game developer. Let's have Wikipedia reflect the industry standard. MJBrune (talk) 22:02, 7 December 2023 (UTC)

 * On Wikipedia we follow what the source says - so we cannot change the article based on your opinion of what the term means, we have to follow the sources we cite. And since we don't use Wikipedia as a source for itself, it does not matter what other Wikipedia articles state. So - find us a source (which meets WP:RS) that gives the definition you propose, and we can perhaps cite it. - MrOllie (talk) 22:19, 7 December 2023 (UTC)
 * I don't know a great way to point this out because something like the "Game Developers Conference" doesn't just have engineering or programming talks. https://gdconf.com/ and https://jobs.gamedeveloper.com/ includes jobs for anyone who works in the games industry. I assume this isn't really enough as they aren't direct sources on the definition of who is a game developer.
 * That said I don't feel like the current sources https://www.google.com/books/edition/Game_Development_and_Production/m5exIODbtqkC?hl=en&gbpv=1 and "Creating Games in maps for happy wills Mechanics, Content, and Technology. Wellesley, Massachusetts: A K Peters. p. 25." actually reflect what is being said on the page. They are just saying the process of making games is still that of software development, where software development as a process is different than the term software developer. The only articles I can dig up to support this cite back to this Wikipedia article creating a circular dependency of citation. MJBrune (talk) 23:29, 7 December 2023 (UTC)

Wiki Education assignment: Science Writing
— Assignment last updated by Skylerkv (talk) 14:44, 2 April 2024 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Video game developer


text:
Talk:Apparent magnitude

Table of notable celestial objects - too extensive
It seems out of place to have such an extensive listing of objects. Perhaps this table should only include truly 'notable' objects, and have its own page (or just link to a website with a similar table) for the extended version? All Clues Key (talk) 02:20, 15 September 2012 (UTC)

 * Table modified in accordance with this suggestion. All Clues Key (talk) 17:30, 9 October 2012 (UTC)

 * I have reverted you severe castration of the list as unnecessary. If you do not like the long list you can simply ignore that section. I think it is useful to list sample objects at many apmags. -- Kheider (talk) 18:17, 9 October 2012 (UTC)

 * As I said above (and received no protests or disagreements to), the current list in unnecessarily extensive and detracted from the overall readability of the article. Hopefully other editors will voice their opinions, but it doesn't seem like this is the right place to include an exhaustive list of apparent magnitudes.  The purpose of the article is simply to explain what 'apparent magnitude' means and is.  That being the case, providing **some** common, important examples of apparent magnitude is very helpful.  A list that contains entries such as, "Sun as seen from Eris at aphelion", "Callirrhoe (small ~8 km satellite of Jupiter)", and "Jupiter if it were located 5000AU from the Sun" seems completely subjective, excessive, irrelevant and unaesthetic. All Clues Key (talk) 18:51, 10 October 2012 (UTC)

 * You agreed with yourself, and I have protested the excessive removals. Your castrated version of the list included no object dimmer than Messier 33 @ apmag 5.7. How do you know people do not want examples of objects that require a telescope to actually see? Most objects simply are not visible without a telescope and obviously will not be as notable as naked eye objects. Many amateurs consider objects such as Uranus, Ceres, M81, Neptune, Titan, Pluto, Eris, the moons of Pluto, and Halley's comet as notable. -- Kheider (talk) 20:28, 10 October 2012 (UTC)

 * I agree with Kheider. The lengthy list is most interesting. Rothorpe (talk) 21:14, 10 October 2012 (UTC)
 * It will likely be very subjective, but I wonder if there is anywhere that could reasonably hold a list of planetary moons by difficulty of seeing them. It's not just magnitude but also proximity to the planet: Mimas is brighter than Oberon, but harder to see. Double sharp (talk) 09:16, 2 October 2021 (UTC)

Photometric Reductions
How is this related, if at all, to photometric reductions? ~jp

Needs improvement
This article is quite poorly organised and in some places poorly explained. For a relatively important atronomy article it is a bit disappointing. 86.160.222.250 (talk) 21:04, 18 March 2013 (UTC)

The explicit relationship between apparent magnitude, m, and power flux in watts per square meter, F, when m and F pertain to the same bandpass, is

m = −2.5 log F − 18.98224

Example. The sun's bolometric apparent magnitude, as seen from Earth, is −26.8167

m = −26.8167

F = 10^[−0.4(m + 18.98224)]

F = 1360.8 watts per square meter

50.110.104.0 (talk) 12:35, 6 March 2024 (UTC)

Move large table down so that readers needn't scroll down many pages to find formulae
While the extensive table has its uses (discussed above), readers have to scroll down many pages to find formulae to calculate magnitude. As the table mainly provides examples, I think it's reasonable to move it to the bottom to detract from the rest of the page. cmɢʟee୯ ͡° ̮د ͡° ੭ 11:57, 13 August 2013 (UTC)

 * It might be useful to have a simpler set of examples of how magnitude relates to linear brightness. I've landed here as a rank amateur simply trying to find out what a magnitude difference (for a rotating asteroid lightcurve) of +/-0.4 means for actual luminance, and I'm still not entirely sure if I've got it right... in fact I've got two different answers, one around +/-0.832x the base figure, the other (more likely) of +/-0.692x. Something basic like what an 0.1 and 0.25 magnitude difference means alongside the 0.5, 1.0 and greater differences already noted (which don't seem to agree?!) as well as a straightforward method of working one to the other in both directions using a regular scientific calculator rather than some kind of advanced graphing model or scientific maths software package (how do you do log100 using Windows Calculator or a Casio FX-85? I've no idea... they just have basic "log" buttons that could mean anything) might do the trick...? This information is, after all, of use and interest to absolute beginners with an interest in astronomy, as well as doctors and professors of the art. 146.199.60.87 (talk) 18:29, 11 August 2019 (UTC)

 * Edit: or from a further reading of another part of the article, it could be simply described in terms of raising 2.512 to the power of the magnitude in question. EG, 2.512 ^ (-)0.4 = 1.445x (or 0.692x) ((to 3dp / 3.5sf, anyway)). For some reason that simple method isn't part of the discussion anywhere else. Though now I'm having difficulty figuring out how to reverse that to get a magnitude from the linear difference...?! 146.199.60.87 (talk) 19:08, 11 August 2019 (UTC)

 * Edit 2: Never mind, I'm being dumb / have a poor memory / may have had the calculator overlapping important parts of the screen. Simple terms, raise 100 to the power of (difference/5) to get the magnitude, and raise 2.511886... (ie, 100^0.2) to the power of the magnitude to get the difference. Sorted. Though it may still be worth putting that in such simple plain-English terms in the article because the formulae are rather offputting and not immediately comprehensible to the layman... 146.199.60.87 (talk) 19:16, 11 August 2019 (UTC)

 * 2.512, or however many decimal points you want, is an approximation. You will certainly see it discussed in many places, but there are simple ways to calculate magnitude/brightness differences that don't need any approximations.  Not to mention that raising 10 to the power of something has to be a better idea than raising 2.512(...) to the power of something.  The article doesn't seem to do itself any favours with explanations that seem to favour factoids for maths geeks over simple explanations for the average reader.  Lithopsian (talk) 19:40, 11 August 2019 (UTC)

 * BTW, in my in-my-head fashion, your calculation would be 10±0.4/2.5. Note that the result is not ± 0.692, but 0.692 or 1/0.692.  Lithopsian (talk) 19:45, 11 August 2019 (UTC)

Superbolide
Since a superbolide, as in a very bright meteor, or a "superbolid meteor", is defined as a bolide of high apparent magnitude (see Wiktionary on "superbolide"), I wonder if anyone has a scholarly source for at what magnitude a bolide is no longer a bolide and becomes a superbolide? Need it be brighter than the Sun? (App. Mag. approx. equal to -26) Or what? N2e (talk) 04:40, 21 November 2013 (UTC)

 * Maybe far too late an update, but the actual superbolide page says "In astronomy, it refers to a fireball about as bright as the full moon, and it is generally considered a synonym for a fireball", and further down the lede says it's usually considered anything of Mag -17 or above, or about 100x as bright as the full moon. So you've still got a bit of a range there, but at least it's been tied down somewhat. 146.199.60.87 (talk) 18:31, 11 August 2019 (UTC)

TZP
I removed a messed up part of a sentence. One part of what I removed said, "and then switched to using tabulated zero points" but I could find nothing using a Google search but pages that quoted this Wikipedia article. No one but a specially trained astronomer knows what a "tabulated zero points" is. Another part of what I removed was an external http reference, that was a dead link, leading to a page with nothing on it. If you have a reference to "tabulated zero points" and can explain what they are, in plain, non-technical, English, please do. I am really curious. Nick Beeson (talk) 21:25, 24 February 2015 (UTC)

 * It looks a bit better now; at least, from what's written, although I don't understand the actual methods used or what they mean, I can at least understand that a different method based upon using a certain celestial object as the measurement benchmark for "zero" (so other measurements may come out positive or negative in relation to it) is now preferred in some cases because of how the colour of different objects / the colorimetry of the observing equipment may affect the results. 146.199.60.87 (talk) 19:20, 11 August 2019 (UTC)

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Relation to implied distance
If true, could we note somewhere that 5 magnitudes fainter implies 10 times further away (since it is used in distance modulus) ? - Rod57 (talk) 19:22, 16 January 2017 (UTC)

 * That would seem self evident given that the inverse square law itself implies something that appears 100x fainter is likely 10x as far away, but it may still be worthy of exposition? 146.199.60.87 (talk) 18:33, 11 August 2019 (UTC)

Faintest object seen by hubble
The cite seems to say limiting magnitude 31.2 - it would help to have a quote for the 31.5 in the footnote, a search of the paper for the number 31.5 turns up a blank. Is it a typo? Robert Walker (talk) 10:01, 20 May 2018 (UTC)

Main Article Problems
There are many problems with this article page that need significant improvements or update. Fixes include:
 * Magnitude is a unit of measure of relative brightness.
 * The value is not dependant by observations from Earth. e.g. Planets still can have a different apparent magnitudes when viewed, say from Mars. It is the observer perspective not necessiarily from Earth
 * Apparent magnitude often is taken to mean apparent visual magnitude - specifically visible light seen by the human eye.
 * Apparent visual magnitude uses 'v' e.g. 4.5v with instrumental means like photometry uses 4.5V, etc.
 * There is no mention of photometric magnitude (different from visual magnitude and notable requires conversion from on system to another) Nor under Magnitude (astronomy) or Photometric system
 * Various contradictions with Magnitude (astronomy) or Photometric system (Main Strömgren photometric system (related to stellar classification isn't mentioned.
 * Added text also showing positive magnitudes, and exampled range of possible magnitudes with cite.
 * Added the definition of unit of brightness, based on the apparent bolometric magnitude. This has a value of energy measure in watts per square metre (which is measured with a bolometer), where apparent standard is a 0.0 magnitude star. A source for this is "IAU 2015 Resolution B2 on Recommended Zero Points for the Absolute and Apparent Bolometric Magnitude"

I have attempted an improvement in the Introduction, but from the fragmentary nature of the article's text is near impossible to repair.

History section

The History section is very confusing and is poorly cited. Various contradictions appear with Magnitude (astronomy)

 * Vega as a standard 0.0 magnitude is sometimes used for instrument calibrations (There are other ways e,g, Described here) How is this used in the southern hemisphere where Vega isn't visible or has intinction problems?
 * It says "The brightest stars in the night sky were said to be of first magnitude" The link to brightest stars is irrelevant, and only refers to stars above 1.0 (or 1.25 in some sources or 1.5 magnitude under Magnitude (astronomy))
 * A second paragraph should have something written about visual estimates of the brightness of stars made with the naked eye. These appear in older text books/ Some of these in the early 19th Century used comparison photometry. Magnitudes of such stars have 'v' attached. I.e. 3.5v.
 * There is little explanation to why surface temperature is related magnitude (It should be linked to the article on luminosity) Most of the text around Vega should probably be removed. The last paragraph has been mostly superseded and might be rightfully removed.
 * Energy is related to Wien curves
 * Variable star observers can estimate magnitudes to 0.11 magnitude and visual observers to about 0.3 magnitude
 * There is no mention of atmospheric extinction

Absolute magnitude section

Most of this should be simplified, summarised and condensed. It should plainly mention that apparent magnitude is independent of distance, while absolute magnitude is based on an arbitrarily set distance of 10 parsec.
 * I could not find the source of this statement: "Indeed, some L and T class stars have an estimated magnitude of well over 100, because they emit extremely little visible light, but are strongest in infrared."
 * The article mentions photographic magnitude, but there is not mention how this related apparent magnitudes.
 * The part about the Milky Way absolute magnitudes and redshifts or there correction appears irrelevant to the article.

Table of examples

Most of this listing is theoretical and difficult to understand. Suggest making a shorter Table with atypical values for bright star and planets. he labels should b changed from "planet Mercury" to Mercury (planet) which would make this more readable. (or even a separate column?)

NOTE: There also needs to be an explanation of usage. Many articles have odd usage, like "magnitude 6.0" or or a " the components are magnitudes 4.0 and 5.1 respectively" If magnitude is the unit measure of brightness, then the value must be followed by the unit measure. e.g, "6th magnitude' or "6.0v magnitude" or a "double star is 4.5v and 5.6v magnitude" must be correct. Using the plural of magnitude is also incorrect usage in this respect. Better usage would be "magnitude of 6.0" I find few examples of the reverse usage in the popular or astronomical literature. The claim "correct usage of magnitude as a unit,"  must be problematic? RfC??
 * This is explained here, where the IAU officially says: "5.17 Magnitude: The concept of apparent and absolute magnitude in connection with the brightness or luminosity of a star or other astronomical object will continue to be used in astronomy even though it is difficult to relate the scales of magnitude to photometric measures in the SI system. Magnitude, being the logarithm of a ratio, is to be regarded as a dimensionless quantity; the name may be abbreviated to mag without a full stop, and it should be written after the number.." Also it says: "The use of a superscript m is not recommended. The method of determination of a magnitude or its wavelength range may be indicated by appropriate letters in italic type as in U, B, V. The photometric system used should be clearly specified when precise magnitudes are given."

Arianewiki1 (talk) 08:27, 19 May 2019 (UTC)

Standard reference values section
The one thing that the Standard reference values section doesn't seem to discuss is standard reference values, although there is a table of standard fluxes in various passbands. The text of the section is just general chit-chat, very poorly-referenced. I can't think of a name for it. Should it just be dumped and written from scratch? Chopped up and farmed out to other places like the history section? Lithopsian (talk) 19:26, 7 June 2019 (UTC)

 * Agreed, it's a bit of a mess. It seems to be a general discussion of the difficulty and caveats involved in using a single magnitude value, or one biased towards a certain limited set of spectral bands, to describe all celestial objects; essentially it's just mistitled. The table is more in line with the title as is, but it's also pretty confusing (I recognise almost none of the units used, and I'm not sure why we can't just use watts or lux/lumen), and the only columns that seem to be directly relevant are the first (band designation) and one or other of the last two (luminous flux that's equal to zero magnitude in that particular band); the others could probably be dumped and just replaced with a link to an article about astronomical spectral bands, if one exists. 146.199.60.87 (talk) 19:27, 11 August 2019 (UTC)

Pre-photometric methods of determining magnitude...
The article mentions that magnitude determination was crude and subjective before the invention of photodetectors, but I do wonder if there would be a way of classifying things in a repeatable fashion to a certain arbitrary level of precision - say, 0.1 on a log2 scale? (Which would give us less than 100 steps from "too faint to see" up to "brightest known object other than the sun and moon", and it's entirely possible to rank printed or on-screen greyscales more finely than that, by eye, so long as you can compare between them, and the dynamic brightness of a VDU or piece of paper is far less than that of natural light)

There are various methods I could think of... for example, the earliest hour that a star becomes visible after sunset, especially if you make repeat measurements at the summer and/or winter solstice and equinoxes, using some way of excluding visual pollution from the horizon or nearby dwellings (e.g. the classic lensless paper tube "telescope", or the makeshift observatory of a building missing its roof - the latter of which, along with a parabolic support made of bricks, was something actually used by pre-optical-glass astronomers, especially in Arabia). Date and time was something much more easily measured even in antiquity, and the motion of the stars and planets themselves was used to measure such. Your determination could then be checked by seeing whether certain well known benchmark stars were or were not yet visible, and a ranked list drawn up and refined over time. Once you had sufficient entries, it would be enough to simply wait for the first moment the star / planet of interest became visible, and quickly check to see which other stars off the list in the general predicted neighbourhood were already visible, in order to add the as-yet unranked one into the catalogue in the right place...

Maybe it wouldn't be absolutely accurate, or mathematically precise other than in terms of direct comparison, but for the type of astronomy that was even possible (and thought relating to it) in the pre-telescopic age, it would likely have been more than sufficient, and still fairly scientifically valid. Astronomers of old weren't entirely stupid, after all, just limited in the equipment they had available. It's not beyond the realm of imagination to consider they might have come up with some clever scheme to repeatably determine the objective brightness of a star (after all, I just pulled one out of my ass, and I haven't had a lifetime of pondering on the meaning of the universe in an age long before multichannel TV and the internet); the brightening and darkening of the sky, on clear nights, in an age before any meaningful atmospheric or indeed much light pollution, would have been like the apocryphal clockwork, and something you could set your biological photometer by. 146.199.60.87 (talk) 19:41, 11 August 2019 (UTC)

 * And? None of this can go in the article without reliable references.  However, when you've published your phD thesis on the subject ... :) Lithopsian (talk) 19:47, 11 August 2019 (UTC)

Logarithmic or reverse?
Your last edit was a valiant attempt, but now you have "The magnitude scale is logarithmic..." while the next sentence begins "The magnitude scale is reverse logarithmic...". Your comment "not entirely convinced it is better" is well said :) Definitely a tough topic to introduce without confusing people. Might've been better to just revert the unregistered user's edit; what was there before was much clearer, in my opinion. Assambrew (talk) 08:19, 16 October 2020 (UTC)
 * I agree, obviously, but I thought there was some merit to the intent of the IP edit if not the grammar. I've changed it back, although I still think it could be improved.  The wording was contentious when it was added, but seemed to be the best that several editors could come up with at the time.  I made a couple of very small changes, hopefully improvements.  Lithopsian (talk) 13:20, 16 October 2020 (UTC)
 * Thanks. Yes, the IP edit was a valiant attempt as well. The 2nd paragraph of the Magnitude (astronomy) article is another try. Starting out with the math probably loses people; somewhere in the intro should be said that the scale was defined as a way to match the ancient historical system. Something like that anyway.
 * I re-added Polaris to the "List of apparent magnitudes"; I had added the other day, but it got reverted when you did your thing. No problem, I asked for it :) Assambrew (talk) 18:39, 16 October 2020 (UTC)
 * I added historical precedent before the math; figured the reader needed a reference point before diving in. Also modified the following paragraph some, didn't think it needed "100 times" twice. Assambrew (talk) 07:02, 19 October 2020 (UTC)

Discussion of apparent brightness
Just noticed that "apparent brightness," though redirecting here, isn't talked about at all, although the article seems to use it to mean something specific. Perhaps it could be brought up (or removed)? –LogStar100 (talk) 19:24, 3 February 2021 (UTC)
 * Good spot, but I wouldn't want to use this term in the article. It would add confusion.  "Apparent magnitude" is a defined scale (if not quite a unit), whereas "apparent brightness" is an adjective and a noun.  If you think the redirect is bad enough not to exist at all, that would be addressed at WP:RFC although I suspect it would fail.  Or find a better place to point the redirect.  However, there are quite a few articles that link to it.  I've edited half a dozen and dare say the rest should be changed because it is sloppy and in some cases misleading to use this wording.  Hipparcos may be the worst offender, discussing "apparent brightness" and "intrinsic brightness" in a very strange way not fully explained or supported by references.  I'm not sure what it is trying to say.  Might want to take a look at that and see what you think.  Lithopsian (talk) 21:07, 3 February 2021 (UTC)

Apparent magnitudes table error
The table "Standard apparent magnitudes and fluxes for typical bands" lists various bands. Jy column at first appears to follow the spectral black body curve, as would be expected, since the units are per Hz, and agnostic of the band width, however the Jy values for bands g,r,i,z are inconsistent with the above bands and appear to be in error.

Mercury maximum brightness at superior conjunction
This seems to me a little bit academic, because when Mercury is at superior conjunction, you can't see it. The same thing goes for the minimum brightness of Mercury (around inferior conjunction). Realistically, the most useful apparent magnitude of Mercury is going to be that around maximum elongation, right? Double sharp (talk) 09:13, 2 October 2021 (UTC)

First table, possible error
The table listing "Number of stars (other than the Sun) brighter than apparent magnitude in the night sky" seems not correct. If the number 9100 is correct, the numbers at the top should also include the magnitude on the respective rows and the stars on rows above, as the number 9100 from Bright Star Catalogue implies. That is, the second row in that column should say 5 rather than 4. (Maybe other lines should also be changed.) Fomalhaut76 (talk) 15:25, 20 March 2023 (UTC)
 * I suspect that table is correct, at least it matches the given references and my expectations. Someone seems to have misinterpreted the information and added four star names where there should only have been three (plus Sirius).  I have removed Vega, which is generally considered (see List of brightest stars) to have an apparent magnitude greater than zero, although it is slightly variable and sometimes brighter than magnitude 0.0.  Lithopsian (talk) 19:50, 20 March 2023 (UTC)

Relation to decibel
It is stated that the magnitude scale can be related to the decibel scale, as one magnitude step equals exactly 4 dB. I can see that this is mathematically correct, but is there anyone actually using decibel in this way? If no source to actual use of decibel related to apparent magnitude, then the statement should be deleted, as it does not convey any useful information. JakobT (talk) 08:13, 9 August 2023 (UTC)

Jupiter seen from its moons
It would be great if someone could add into the list the apparent magnitudes of Jupiter when seen from certain moons, a "full Jupiter" e.g. from Metis, the Galilean moons or Himalia. 2001:4BC9:1F98:112C:B897:9213:2412:1F13 (talk) 17:07, 8 October 2023 (UTC)

Historical inaccuracies
Hi! Both this page and Magnitude (astronomy) claim that Pogson defined magnitude zero to be based on Polaris = 2.0, and then astronomers switched to Vega = magnitude 0.0. I was curious about the history of magnitude, and fell down a rabbit hole of research, and then an wrote an article called The Cursed History of Star Brightness about my findings: I tracked down Pogson's original paper, and it actually defined magnitude 6.0. In fact, this page's history of magnitude section contains some errors in the large citation-free paragraphs.

Magnitude (astronomy) makes the same claim that astronomers defined magnitudes using Vega = 0.0, but cites page 182 of a book. That book, as seen on https://books.google.com/books?id=Ps_6zjUCR3wC&q=182#v=snippet&q=182&f=false here, does mention Vega's variability several pages after page 182, but it describes a model for the spectrum of Vega from 1991, far after Johnson's system was invented, and doesn't say that the model is used to calibrate magnitude zero.

This page also claimed that "Therefore, the magnitude scale was extrapolated to all wavelengths on the basis of the black-body radiation curve for an ideal stellar surface at $11,000 K$ uncontaminated by circumstellar radiation". It cites https://archive.today/20121204144725/http://www.astro.utoronto.ca/~patton/astro/mags.html, but that website doesn't mention anything about a black body spectrum. I've removed it in my edit, but if anyone does have a source for that claim I'd love to see it.

Since I found many primary sources while doing research for my article, I've edited this page to reflect what I understand is the correct history. If any of you Wikipedia editors have any comments, suggestions on how to rewrite it, or sources about the history of magnitude, please let me know! Explanaria (talk) 20:28, 23 May 2024 (UTC)

title: Talk:Apparent magnitude


text:
Logistic equation

Logistic equation can refer to:

 * Logistic map, a nonlinear recurrence relation that plays a prominent role in chaos theory
 * Logistic regression, a regression technique that transforms the dependent variable using the logistic function
 * Logistic differential equation, a differential equation for population dynamics proposed by Pierre François Verhulst

title: Logistic equation


text:
Talk:King (monarch)

shouldn't this redirect to monarch? Martin

 * Since the top of Monarch says so, yes -- Tarquin

shouldn't this still redirect to monarch? Martin

title: Talk:King (monarch)


text:
Ultra-wideband

Ultra-wideband (UWB, ultra wideband, ultra-wide band and ultraband) is a radio technology that can use a very low energy level for short-range, high-bandwidth communications over a large portion of the radio spectrum. UWB has traditional applications in non-cooperative radar imaging. Most recent applications target sensor data collection, precise locating, and tracking. UWB support started to appear in high-end smartphones in 2019.

Characteristics
Ultra-wideband is a technology for transmitting information across a wide bandwidth (>500 MHz). This allows for the transmission of a large amount of signal energy without interfering with conventional narrowband and carrier wave transmission in the same frequency band. Regulatory limits in many countries allow for this efficient use of radio bandwidth, and enable high-data-rate personal area network (PAN) wireless connectivity, longer-range low-data-rate applications, and the transparent co-existence of radar and imaging systems with existing communications systems.

Ultra-wideband was formerly known as pulse radio, but the FCC and the International Telecommunication Union Radiocommunication Sector (ITU-R) currently define UWB as an antenna transmission for which emitted signal bandwidth exceeds the lesser of 500 MHz or 20% of the arithmetic center frequency. Thus, pulse-based systems—where each transmitted pulse occupies the UWB bandwidth (or an aggregate of at least 500 MHz of a narrow-band carrier; for example, orthogonal frequency-division multiplexing (OFDM))—can access the UWB spectrum under the rules.

Theory
A significant difference between conventional radio transmissions and UWB is that conventional systems transmit information by varying the power level, frequency, or phase (or a combination of these) of a sinusoidal wave. UWB transmissions transmit information by generating radio energy at specific time intervals and occupying a large bandwidth, thus enabling pulse-position or time modulation. The information can also be modulated on UWB signals (pulses) by encoding the polarity of the pulse, its amplitude and/or by using orthogonal pulses. UWB pulses can be sent sporadically at relatively low pulse rates to support time or position modulation, but can also be sent at rates up to the inverse of the UWB pulse bandwidth. Pulse-UWB systems have been demonstrated at channel pulse rates in excess of 1.3 billion pulses per second using a continuous stream of UWB pulses (Continuous Pulse UWB or C-UWB), while supporting forward error-correction encoded data rates in excess of 675 Mbit/s.

A UWB radio system can be used to determine the "time of flight" of the transmission at various frequencies. This helps overcome multipath propagation, since some of the frequencies have a line-of-sight trajectory, while other indirect paths have longer delays. With a cooperative symmetric two-way metering technique, distances can be measured to high resolution and accuracy.

Real-time location
Ultra-wideband (UWB) technology is utilised for real-time locationing due to its precision and reliability. It plays a role in various industries such as logistics, healthcare, manufacturing, and transportation. UWB's centimeter-level accuracy is valuable in applications in which using traditional methods may be unsuitable, such as in indoor environments, where GPS precision may be hindered. Its low power consumption ensures minimal interference and allows for coexistence with existing infrastructure. UWB performs well in challenging environments with its immunity to multipath interference, providing consistent and accurate positioning. In logistics, UWB increases inventory tracking efficiency, reducing losses and optimizing operations. Healthcare makes use of UWB in asset tracking, patient flow optimization, and in improving care coordination. In manufacturing, UWB is used for streamlining inventory management and enhancing production efficiency through accurate tracking of materials and tools. UWB supports route planning, fleet management, and vehicle security in transportation systems.

UWB uses multiple techniques for location detection:

 * Time of flight (ToF)
 * Time difference of arrival (TDoA)
 * Two-way ranging (TWR)

Mobile devices with UWB capability
Apple launched the first three phones with ultra-wideband capabilities in September 2019, namely, the iPhone 11, iPhone 11 Pro, and iPhone 11 Pro Max. Apple also launched Series 6 of Apple Watch in September 2020, which features UWB, and their AirTags featuring this technology were revealed at a press event on April 20, 2021. The Samsung Galaxy Note 20 Ultra, Galaxy S21+, and Galaxy S21 Ultra also began supporting UWB, along with the Samsung Galaxy SmartTag+. The Xiaomi MIX 4 released in August 2021 supports UWB, and offers the capability of connecting to select AIoT devices.

The FiRa Consortium was founded in August 2019 to develop interoperable UWB ecosystems including mobile phones. Samsung, Xiaomi, and Oppo are currently members of the FiRa Consortium. In November 2020, Android Open Source Project received first patches related to an upcoming UWB API; "feature-complete" UWB support (exclusively for the sole use case of ranging between supported devices) was released in version 13 of Android.

Industrial applications

 * Automation and robotics: Its high data rate and low latency enable real-time communication and control between machines and systems. UWB-based communication protocols ensure reliable and secure data transmission, enabling precise coordination and synchronization of automated processes. This enhances manufacturing efficiency, reduces errors, and improves overall productivity. UWB can also be integrated into robotic systems to enable precise localization, object detection, and collision avoidance, further enhancing the safety and efficiency of industrial automation.
 * Worker safety and proximity sensing: Worker safety is a concern in industrial settings. UWB technology provides effective proximity sensing and worker safety solutions. By equipping workers with UWB-enabled devices or badges, companies can monitor their location and movement in real-time. UWB-based systems can detect potential collisions between workers and machinery, issuing timely warnings to prevent accidents. Moreover, UWB technology allows for the creation of safety zones and controlled access areas, ensuring the safe interaction of workers with hazardous equipment or restricted zones. This helps enhance workplace safety, reduce accidents, and protect employees from potential hazards.
 * Asset tracking and management: Efficient asset tracking and management are crucial for industrial operations. UWB enables precise and real-time tracking of assets within industrial facilities. By attaching UWB tags to equipment, tools, and inventory, companies can monitor their location, movement, and utilization. This enhances inventory management, reduces asset loss, minimizes downtime, and streamlines maintenance processes. UWB-based asset tracking systems provide accurate and reliable data, empowering businesses to optimize their resource allocation and improve overall operational efficiency.

Radar
Ultra-wideband gained widespread attention for its implementation in synthetic aperture radar (SAR) technology. Due to its high resolution capacities using lower frequencies, UWB SAR was heavily researched for its object-penetration ability. Starting in the early 1990s, the U.S. Army Research Laboratory (ARL) developed various stationary and mobile ground-, foliage-, and wall-penetrating radar platforms that served to detect and identify buried IEDs and hidden adversaries at a safe distance. Examples include the railSAR, the boomSAR, the SIRE radar, and the SAFIRE radar. ARL has also investigated the feasibility of whether UWB radar technology can incorporate Doppler processing to estimate the velocity of a moving target when the platform is stationary. While a 2013 report highlighted the issue with the use of UWB waveforms due to target range migration during the integration interval, more recent studies have suggested that UWB waveforms can demonstrate better performance compared to conventional Doppler processing as long as a correct matched filter is used.

Ultra-wideband pulse Doppler radars have also been used to monitor vital signs of the human body, such as heart rate and respiration signals as well as human gait analysis and fall detection. It serves as a potential alternative to continuous-wave radar systems since it involves less power consumption and a high-resolution range profile. However, its low signal-to-noise ratio has made it vulnerable to errors. A commercial example of this application is RayBaby, which is a baby monitor that detects breathing and heart rate to determine whether a baby is asleep or awake. Raybaby has a detection range of five meters and can detect fine movements of less than a millimeter.

Ultra-wideband is also used in "see-through-the-wall" precision radar-imaging technology,  precision locating and tracking (using distance measurements between radios), and precision time-of-arrival-based localization approaches. UWB radar has been proposed as the active sensor component in an Automatic Target Recognition application, designed to detect humans or objects that have fallen onto subway tracks.

Data transfer
Ultra-wideband characteristics are well-suited to short-range applications, such as PC peripherals, wireless monitors, camcorders, wireless printing, and file transfers to portable media players. UWB was proposed for use in personal area networks, and appeared in the IEEE 802.15.3a draft PAN standard. However, after several years of deadlock, the IEEE 802.15.3a task group was dissolved in 2006. The work was completed by the WiMedia Alliance and the USB Implementer Forum. Slow progress in UWB standards development, the cost of initial implementation, and performance significantly lower than initially expected are several reasons for the limited use of UWB in consumer products (which caused several UWB vendors to cease operations in 2008 and 2009).

Autonomous vehicles
UWB's precise positioning and ranging capabilities enable collision avoidance and centimeter-level localization accuracy, surpassing traditional GPS systems. Moreover, its high data rate and low latency facilitate seamless vehicle-to-vehicle communication, promoting real-time information exchange and coordinated actions. UWB also enables effective vehicle-to-infrastructure communication, integrating with infrastructure elements for optimized behavior based on precise timing and synchronized data. Additionally, UWB's versatility supports innovative applications such as high-resolution radar imaging for advanced driver assistance systems, secure key less entry via biometrics or device pairing, and occupant monitoring systems, potentially enhancing convenience, security, and passenger safety.

Regulation
In the U.S., ultra-wideband refers to radio technology with a bandwidth exceeding the lesser of 500 MHz or 20% of the arithmetic center frequency, according to the U.S. Federal Communications Commission (FCC). A February 14, 2002 FCC Report and Order authorized the unlicensed use of UWB in the frequency range from 3.1 to 10.6 GHz. The FCC power spectral density (PSD) emission limit for UWB transmitters is −41.3 dBm/MHz. This limit also applies to unintentional emitters in the UWB band (the "Part 15" limit). However, the emission limit for UWB emitters may be significantly lower (as low as −75 dBm/MHz) in other segments of the spectrum.

Deliberations in the International Telecommunication Union Radiocommunication Sector (ITU-R) resulted in a Report and Recommendation on UWB in November 2005. UK regulator Ofcom announced a similar decision on 9 August 2007.

There has been concern over interference between narrowband and UWB signals that share the same spectrum. Earlier, the only radio technology that used pulses was spark-gap transmitters, which international treaties banned because they interfere with medium-wave receivers. However, UWB uses much lower levels of power. The subject was extensively covered in the proceedings that led to the adoption of the FCC rules in the US, and in the meetings of the ITU-R leading to its Report and Recommendations on UWB technology. Commonly-used electrical appliances emit impulsive noise (for example, hair dryers), and proponents successfully argued that the noise floor would not be raised excessively by wider deployment of low power wideband transmitters.

Coexistence with other standards
In February 2002, the Federal Communications Commission (FCC) released an amendment (Part 15) that specifies the rules of UWB transmission and reception. According to this release, any signal with fractional bandwidth greater than 20% or having a bandwidth greater than 500 MHz is considered as an UWB signal. The FCC ruling also defines access to 7.5 GHz of unlicensed spectrum between 3.1 and 10.6 GHz that is made available for communication and measurement systems.

Narrowband signals that exist in the UWB range, such as IEEE 802.11a transmissions, may exhibit high PSD levels compared to UWB signals as seen by a UWB receiver. As a result, one would expect a degradation of UWB bit error rate performance.

Technology groups
• WiMedia Alliance

• Bluetooth SIG

• Wireless USB

• Wireless Gigabit Alliance

• WirelessHD

• Wireless FireWire

• TransferJet

• FM-UWB

• IEEE 802.15.3

• IEEE 802.15.4

• IEEE 802.15.4a

• IEEE 802.15.4f

• ISO/IEC 24730-61 LRP

• ISO/IEC 24730-62 HRP

• FiRa Consortium

title: Ultra-wideband


text:
Talk:Omar Abdel-Rahman

charges
To Admin/jeff the changes that i made at the start of the intro on the 19th century us law is already referenced along with the charge i was only toning down the biased slant of this article that makes it seem like they had something against this person. These charges where based on suspicion on the part of the US over-reaction machine and in international law and basic common law suspicion does not necessitate a crime so please be objective. In his case they had to refer to a 19th century treason law which is very broad just like the new NDAA act to charge him and i was just highlighting this fact which the other biased writers don't see. — Preceding unsigned comment added by 92.20.13.77 (talk) 03:43, 10 October 2012 (UTC)

Page moved
Moved this page because 'Sheik' is a title and shouldn't be in the page title. (ref: Walter Raleigh) Graft

Which prison is he in?
A New York Times article "Tape Tied to Al Qaeda Urges More Attacks in Iraq" (Sept 28, 2006) claims that he is in Springfield, Mo, USA.

Which prison is he really in?

 * ADX Florence. —Preceding unsigned comment added by 88.153.207.55 (talk) 11:30, 6 December 2008 (UTC)

---

The first sentence of the article reads:

"Sheikh Omar Abdel-Rahman (Arabic: عمر عبد الرحمن) (born May 3, 1938) is a blind Egyptian Muslim leader who is currently serving a life sentence at the Butner Medical Center which is part of the Butner Federal Correctional Institution in Butner, North Carolina, United States. "

Yet the last sentence in the "Activities in the US" subsection reads:

"He is currently an inmate at ADX Florence, Colorado."

Which is accurate?

--posted by trealistorm (Ylanne Sorrows) —Preceding unsigned comment added by Trealistorm (talk • contribs) 00:36, 12 April 2009 (UTC) He's all over the place, can't tell you how I know, but they don't want anyone to know where he is. —Preceding unsigned comment added by 66.170.16.194 (talk) 06:07, 8 March 2010 (UTC)

Better sources
This article has few sources its claims. Some links were gone or out of date, and not even from anywhere reliable. Since this is a newsworthy person and there should be plenty of references out there from news organizations, it shouldn't be hard. Wikipedia in general is moving in this direction.

The following link on the federal bureau of prisons demonstrates that as of 6/17/08, he is at Butner Federal Medical Center: http://www.bop.gov/iloc2/InmateFinderServlet?Transaction=NameSearch&needingMoreList=false&LastName=rahman&Middle=&FirstName=omar&Race=U&Sex=M&Age=&x=26&y=27 —Preceding unsigned comment added by Adamsjrcn (talk • contribs) 18:26, 17 June 2008 (UTC)

Not convicted of...
I removed this piece fo text: 'not convicted of conspiring to bomb New York landmarks including the United Nations and FBI offices on October 1, 1995 nor were they convicted of the World Trade Center bombing of 1993, rather they were convicted under the US Civil War era law'. Can someone please demonstate how mentioning things they weren't convicted is notable? Were they tried and found not guilty, or is this just a rhetorical device? Ashmoo 02:08, 27 January 2006 (UTC)

Proper transliteration, or lack therof
Jeez, that guy on the photo is the ugliest Santa ever seen! Ain't anybody a cute pic worthy of good ol' Umar "Handsome" abd al-Rahman?? And lest I forget: if nobody moves this article soon, some deeply hurt reindeer will - they got feelings too! Earnestly, speaking the contraction is ok, writing it is colloqial at best, poor from really, even if most English -and Arab- speakers don't know better - pls check Umar (name) and Harun al-Rashid. The wrong -though popular- form should become a redirect to the proper version.

The reader will then profit twofold: how to spell properly and how to become a pious man. --tickle me 15:25, 1 August 2006 (UTC)

Seditious conspiracy? Now that's a trumped up charge if I ever heard one...... just plain rediculous. I'm not saying he's innocent, I'm just saying we need more specific laws to fit specific crimes. Also, does the encyclopedia really need to turn into Fox News? Non-stop terror alerts are exactly what don't need.

AgentSpion 18:54, 14 December 2006 (UTC)

It is concerning that someone would remove information about the legal processes that Omar Abdel-Rahman, the subject of the biographic entry, has undergone. In my view, it would have been preferable to amend the entry to indicate that the subject had been charged with specific criminal offences but subsequently acquitted at trial. While I can understand not wishing to perpetuate rumours and innuendoes, e.g. 'it is alleged....", Mr Abdel-Rahman did actually face court concerning these matters. As Wikipedia is supposed to be a reference source, deleting factual information could be construed as a form of censorship, especially if it precludes the reader from further research avenues concerning the events in question. Beacon Intelligence (talk) 03:28, 1 June 2009 (UTC)

Claim associated with him
I've replaced the out of date Reuters source with an available one that I believe contains the same content. However, it doesn't seem to support the way the source is described, as a description of the 'will' of a person is far from an actual statement from them. Nimmo 11:02, 9 October 2007 (UTC)

question...
I question whether his sons' names are really Mohammed Omar Abdel-Rahman and Asim Abdulrahman. Arabic names don't have an inheritable lastname-surname. The first name of the father becomes the last name of the child. So each generation has a different last name.

If he followed the usual Arabic convention, and "Omar Abdel-Rahman" was his full name, wouldn't his son's names be Mohammed Omar and Asim Omar?

Cheers! Geo Swan (talk) 17:26, 18 July 2009 (UTC)

 * The names carry more than one generation, so you might be Abdullah son of Ahmed son of Muhammad son of Abdelrahim, thus Abdullah Ahmed Muhammad Abdelrahim (sometimes with the "bin" modifier). So his son Mohammed is correctly named Mohammed Omar Abdel-Rahman, while his son Asim is likely Asim Omar Abdel-Rahman in his full legal name. But "likely" isn't enough to warrant changing a WP article's name, imho. '' —Preceding unsigned comment added by Sherurcij (talk • contribs) 12:54, 2009 July 18

 * Okay, so in your example, Abdullah's name is parsed, Abdullah (Ahmed (Muhammad (Abdelrahim)))? And he would be plain old "Abdullah Ahmed", except his great-grandfather was somebody famous?  Geo Swan (talk) 14:40, 19 July 2009 (UTC)

from Al-Qaeda article
http://en.wikipedia.org/wiki/Al-Qaeda

According to Peter Bergen, known for conducting the first television interview with Osama bin Laden in 1997, the idea that "the CIA funded bin Laden or trained bin Laden ...[is] a folk myth. There's no evidence of this. ... Bin Laden had his own money, he was anti-American and he was operating secretly and independently. ... The real story here is the CIA didn't really have a clue about who this guy was until 1996 when they set up a unit to really start tracking him." But as Bergen himself admitted, in one "strange incident" the CIA did appear to give visa help to mujahideen-recruiter Omar Abdel-Rahman.

The CIA connection doesn't appear here. anyone think it should? Eyalmc (talk) 12:51, 8 August 2010 (UTC)

Possible status as Emir
In the book In the name of Osama bin Laden: Global Terrorism and the Bin Laden Brotherhood by Roland Jacquard, alleged Zawahiri operative Ahmed al-Sayed al-Najar is cited as saying that Abdel-Rahman had been appointed Emir by Egyptian Islamic Jihad and Gamaa Islamiya on the advice of Osama bin Laden, and his appointment was approved specifically by Mustapha Hamza and Rifai Taha.

Can any other sources back this up, put a date on this event, and describe what it means for Abdul-Rahman to be "Emir" in this context?

Timing is a problem. If this occurred after 1990, it raises the question of why Egyptian groups would give a leadership position to someone who was expelled from Egypt. If this occurred before 1990, it places Osama in a more active and authoritative position in worldwide terrorism than most sources suggest for him in that time. — Preceding unsigned comment added by Dturover (talk • contribs) 07:09, 9 November 2012 (UTC)

Bengazi connection
I work on the phone and spoke to a member of the US Defence dept. that told me that Bengazi was suppposed to be a kidnapping, which would have allowed Pres. Obama to release Omar Abdel Rahman in a trade with Pres. Morsi of Egypt without losing face. The military was told to stand down because of the "deal", but the Navy SEALS did not get the message and because they were attacking, the local Al Queda that were doing the kidnapping went berzerk and slaughtered everyone. Obviously, none of this can go public because Pres. Obama, Secy. of State Clinton, and several high ranking military officials would be destroyed. — Preceding unsigned comment added by 8.14.187.175 (talk) 23:22, 20 August 2013 (UTC)

Seditious conspiacy - looks like a guy who was pissed and said what he thought. Half of America could be in jail. 159.105.81.44 (talk) 14:30, 12 March 2014 (UTC)

Except, uh, "bombs"...--Quisqualis (talk) 21:45, 18 February 2017 (UTC)

"Youth" section
The entire section is unreferenced.

--105.101.7.203 (talk) 00:48, 21 January 2015 (UTC)

livingdead
which language wiki is Omar Abdel-Rahman reported as dead on? Can't see one. -- Callinus (talk) 04:02, 22 December 2015 (UTC)
 * (was reported) on Russian Wikipedia. -- Edgars2007  (talk/contribs) 17:34, 22 December 2015 (UTC)

Assessment comment
Substituted at 01:50, 30 April 2016 (UTC)

Removal of list of those who extended condolences
A significant portion of the page was taken up by a list of all those who extended condolences upon Omar Abdel-Rahman's death. It was bizarre and didn't seem very noteworthy, so I removed it. If there is significance, can the list be condensed and the significance be spelled out? The edit was here: https://en.wikipedia.org/w/index.php?title=Omar_Abdel-Rahman&type=revision&diff=771367551&oldid=771367196

Fogster (talk) 03:45, 21 March 2017 (UTC)

Arrest date correction for Abdel-Rahman
Regarding need of a citation for "Abdel-Rahman was arrested on 24 June 1993, along with nine of his followers":

https://timesmachine.nytimes.com/timesmachine/1993/06/27/276193.html?pageNumber=1 indicates "the Clinton Administration does not plan for now to arrest Mr. Abdel Rahman", but continues with "Six of the eight men arrested on Thursday ...", Thursday being 1993-06-24.

https://timesmachine.nytimes.com/timesmachine/1993/07/01/833293.html?pageNumber=23 indicates "A ninth suspect was arrested yesterday", so the ninth suspect was arrested 1993-06-30

https://timesmachine.nytimes.com/timesmachine/1993/07/03/issue.html indicates "Sheik Omar Abdel Rahman ... emerged from a Brooklyn mosque and surrendered to Federal authorities last night ... [He] walked on the arm of his lawyer shortly after 6 P.M. ... to a firehouse that had become a Federal command post" so his arrest date was 1993-07-02.

MgFrobozz (talk) 00:28, 1 December 2022 (UTC)

Article issues and classification

 * I think this article was premature -- or -- bot wrongly-assessed. There are "unsourced statements" (citation needed) from 2007, 2008, 2017, and 2022.
 * The B-class criteria #1 states; The article is suitably referenced, with inline citations. It has reliable sources, and any important or controversial material which is likely to be challenged is cited., and #4, The article is reasonably well-written.
 * Reassess the article to C-class. --  Otr500 (talk) 04:19, 17 March 2023 (UTC)

title: Talk:Omar Abdel-Rahman