WiMax

WiMax, in full worldwide interoperability for microwave access, communication technology for wirelessly delivering high-speed Internet service to large geographical areas.

Part of a “fourth generation,” or 4G, of wireless-communication technology, WiMax far surpasses the 30-metre (100-foot) wireless range of a conventional Wi-Fi local area network (LAN), offering a metropolitan area network with a signal radius of about 50 km (30 miles). Ultimately, WiMax proponents hope to establish a global area network in which signals could reach, for instance, the entire continental United States, including the many rural and suburban areas to which land-based broadband providers do not run cable.

WiMax operates over radio waves on a tower-receiver model. A single WiMax tower can provide coverage over about 8,000 square km (3,000 square miles) and also connect to other towers via a line-of-sight microwave link to broaden coverage further. A roof-mounted antenna dish can receive information at the fastest data-transfer rates, or an internal receiver chip in a personal computer, mobile telephone, or other device can communicate without a line of sight at lower speeds. Under optimal conditions, WiMax offers data-transfer rates of up to 75 megabits per second (Mbps), which is superior to conventional cable-modem and DSL connections. However, the bandwidth must be split among multiple users and thus yields lower speeds in practice.

The development of WiMax began in the early 21st century. The American integrated circuit manufacturer Intel Corporation invested substantially in creating receiver chipsets and was a vocal proponent of the technology. Technical hurdles to achieving optimal speed and coverage, combined with competition from rival schemes, hampered the development of early networks. In 2008 American wireless service providers Sprint Nextel Corporation and Clearwire Corporation both early WiMax adopters completed an agreement to merge their WiMax efforts, with a goal of spreading their 4G coverage throughout the United States in the following few years.

YouTube

Primary Contributor: William L. Hosch

YouTube, Web site for sharing videos. It was registered on Feb. 15, 2005, by Steve Chen, Chad Hurley, and Jawed Karim, three former employees of the American e-commerce company PayPal. They had the idea that ordinary people would enjoy sharing their “home videos.” The company is headquartered in San Bruno, Calif.

Shortly after the site opened on a limited (“beta”) basis in May 2005, it was attracting some 30,000 visitors per day. By the time YouTube was officially launched on Dec. 15, 2005, it was serving more than two million video views each day. By January 2006 that number had increased to more than 25 million views. The number of videos available at the site surpassed 25 million in March 2006, with more than 20,000 new videos uploaded on a daily basis. By the summer of 2006, YouTube was serving more than 100 million videos per day, and the number of videos being uploaded to the site showed no sign of slowing down.

The immense growth in traffic at YouTube created its own set of problems. The company continually had to purchase more computer equipment and more broadband connections to the Internet. In addition, YouTube was forced to allocate more financial resources for potential litigation, as many media companies discovered that some of the videos uploaded to YouTube contained copyrighted material. With limited success in commercializing its Web site or containing its growing costs, YouTube began looking for a buyer.

In 2005 the American search engine company Google Inc. had launched a video service, Google Video, but it failed to generate much traffic, and Google was prompted to purchase YouTube for $1.65 billion in stock in November 2006. Rather than merging the Web sites, however, Google continued YouTube’s operation as before. To reduce the risk of copyright-infringement lawsuits, Google negotiated deals with a number of entertainment companies that would allow copyrighted video material to appear on YouTube and would give YouTube users the right to include certain copyrighted songs in their videos. It also agreed to remove tens of thousands of copyrighted video files from YouTube. In November 2008 Google reached an agreement with Metro-Goldwyn-Mayer, Inc. (MGM), to show some of the studio’s full-length movies and television shows, the broadcasts being free to watch, with advertisements running alongside the programs.

Sony Ericsson Elm J10i2

Sony Ericsson Elm J10i2

Sony-Ericsson Elm J10i2 is a GSM phone. Sony-Ericsson Elm J10i2, a CandyBar mobile comes with a great list of features. Sony-Ericsson Elm J10i2 price is optimal and it is a great buy.

The Sony Ericsson Elm J10i2 is an eco-friendly mobile phone focusing on green technology. The Sony-Ericsson Elm J10i2 key features include GreenHeart technology, Widget Manager for integrating social networks like Facebook and Twitter, aGPS and Wisepilot for finding your way, dedicated standby search integrated with Google search, Music recognition etc. The Sony-Ericsson Elm J10i2 display screen has a 240 X 320 pixels resolution with 262 K colors. This internet and java enabled multimedia phone has an internal memory range of up to 280 mb extendable to 16 GB with microSD support. The Sony-Ericsson Elm J10i2 can make both audio and video calls.

The Sony Ericsson Elm J10i2 uses the GSM/GPRS/EDGE networks at 850/900/1800/1900 operating frequencies, and 900/1200 frequencies with UMTS/HSPA. The Sony Ericsson Elm J10i2 has a powerful camera with 5 mega-pixel sensor and 4X digital zoom. The mobile phone has excellent video recording capabilities and is equipped with both photoflash and Video Light. The Sony Ericsson Elm J10i2 camera uses advanced technologies like Smile Detection, Photo FIX, Face Detection, Auto Focus etc. Other supporting features include Send to the web, subscribe to photo feeds, and geo tagging of images.

The Sony Ericsson Elm J10i2 has a wonderful music system including MegaBass and TrackID. The media player is supported with Bluetooth A2DP for fast sharing of multimedia. Internet browsing in the Sony-Ericsson Elm J10i2 is enhanced with the Access NetFront Web Browser with support for standard protocols, images and video. Entertainment features of the Sony Ericsson Elm J10i2 further include FM Radio with RDS, YouTube, Video Streaming, Video Clip, Walk Mate, Tracker, Java and 3D games.

Depending upon the type of usage and network, the Sony Ericsson Elm J10i2 has a talktime between 4-10 hrs and Standby time between 430-446 hours. The maximum time for video calls is 3 hours before the battery needs recharge. A feature checklist of the Sony-Ericsson Elm J10i2 is given under the "specifications" tab on this page for further reference.

General	2G Network
	GSM 850 / 900 / 1800 / 1900
3G Network	HSDPA 2100
	HSDPA 900 / 2100
Announced	2009, December
Status	Available. Released 2010, March
Size	Dimensions
	110 x 45 x 14 mm
Weight	90 g
Display	Type
	TFT, 16M colors
Size	240 x 320 pixels, 2.2 inches
	Accelerometer sensor for UI auto-rotate
Sound	Alert types
	Vibration, MP3 ringtones
Speakerphone	Yes
Memory	Phonebook
	1000 entries, Photocall
Call records	Yes
Internal	280 MB
Card slot	microSD, up to 8GB
Data	GPRS
	Class 10 (4+1/3+2 slots), 32 - 48 kbps
EDGE	Class 10, 236.8 kbps
3G	HSDPA 7.2 Mbps; HSUPA, 2 Mbps
WLAN	Wi-Fi 802.11 b/g, DLNA
Bluetooth	Yes, v2.1 with A2DP
Infrared port	No
USB	Yes, USB v2.0
Camera	Primary
	5 MP, 2592 x 1944 pixels, autofocus, LED flash, check quality
Features	Geo-tagging, face, smile detection, video calling
Video	Yes, VGA@30fps, video light
Secondary	No
Features	Messaging
	SMS (threaded view), MMS, Email, Push Email, IM
Browser	WAP 2.0/HTML (NetFront), RSS reader
Radio	Stereo FM radio with RDS
Games	Yes, incl. motion-based + downloadable
Colors	Metal Black, Pearly Rose
GPS	Yes, with A-GPS support; Wisepilot navigation
Java	Yes, MIDP 2.0
	Noise cancellation with dedicated microphone
	HD Voice ready
	Splash resistant
	- MP3/eAAC+/WAV player
	SensMe, Track ID
	MP5/H.263/H.264 player
	Google Maps
	Picture editor/blogging
	YouTube, Facebook, MySpace, Twitter applications
	Widget Manager
	Organizer
	Eco friendly materials
	Walkmate, CO2 Calculator
	Voice memo/dial
	T11
Battery	Standard battery, Li-Po 1000 mAh (BST-43)
Stand-by	Up to 430 h (2G) / Up to 446 h (3G)
Talk time	Up to 10 h (2G) / Up to 4 h (3G)
Misc	SAR EU
	1.24 W/kg (head)

Sachin Tendulkar

Sachin Tendulkar, in full Sachin Ramesh Tendulkar  (b. April 24, 1973, Bombay [Mumbai], India), Indian professional cricket player, considered by many to be one of the greatest batsmen of all time. In 2005 he became the first cricketer to score 35 centuries (100 runs in a single innings) in Test (international) play.
Tendulkar was given his first bat when he was 11. As a 14-year-old, he used it to score 329 out of a world-record stand of 664 in a school match. A year later he scored a century on his first-class debut for Bombay (Mumbai), and at 16 years 205 days he became India’s youngest Test cricketer, making his debut against Pakistan in Karachi in November 1989. When he was 18 he scored two centuries in Australia (148 in Sydney and 114 in Perth), and in 1994 he scored 179 against the West Indies. In August 1996, at age 23, Tendulkar was made captain of his country’s team.

Although India was defeated in the semifinals of the 1996 World Cup, Tendulkar emerged as the tournament’s top run scorer, with 523 runs. In 1997 he was chosen for the Rajiv Gandhi Khel Ratna Award, the highest award given to an Indian athlete, for his outstanding performance in the 1997–98 season. India was defeated by Australia in the 1999 World Cup, failing to advance past the round of six, and was soundly defeated by both Australia and South Africa in series later that year. In the 2003 World Cup, however, Tendulkar helped his team advance as far as the finals. Though India was again defeated by Australia, Tendulkar, who averaged 60.2, was named the man of the tournament.

Tendulkar made history in December 2005 when he scored his record-breaking 35th century in Test play against Sri Lanka. The feat was accomplished in a total of 125 Tests and allowed Tendulkar to surpass the prolific Indian run scorer Sunil Gavaskar. In June 2007 Tendulkar reached another major milestone when he became the first player to record 15,000 runs in one-day international (ODI) play, and in January 2010 he became the first batsman to score 13,000 runs in Test play. One month later he scored a historic “double century” in a contest against South Africa, becoming the first man in history to record 200 runs in a single innings of ODI play. Throughout his long career Tendulkar was consistently ranked among the game’s best batsmen. He was often likened to Australia’s Don Bradman in his single-minded dedication to scoring runs and the certainty of his strokeplay off both front and back foot.

Manmohan Singh

Manmohan Singh,  (b. September 26, 1932, Gah, West Punjab, India [now in Pakistan]), Indian economist and politician, who became prime minister of India in 2004. A Sikh, he was the first non-Hindu to occupy the office.

Singh attended Punjab University and the University of Cambridge in Great Britain. He later earned a doctorate in economics from the University of Oxford. In the 1970s he was named to a series of economic advisory posts with the Indian government and became a frequent consultant to prime ministers. Singh also worked at the Reserve Bank of India, serving as director (1976–80) and governor (1982–85). When he was named finance minister in 1991, the country was on the verge of an economic collapse. Singh devalued the rupee, lowered taxes, privatized state-run industries, and encouraged foreign investment, reforms that helped transform the country’s economy and spark an economic boom. A member of the Indian National Congress, he joined the Rajya Sabha (upper house of Parliament) in 1991. Singh, who served as finance minister until 1996, ran for the Lok Sabha (lower house) in 1999 but was defeated.

Congress won the May 2004 parliamentary elections, defeating the ruling Bharatiya Janata Party. Congress’s leader, Sonia Gandhi (widow of former prime minister Rajiv Gandhi), declined the prime ministership, instead recommending Singh for the post. Singh subsequently formed a government and took office. His stated goals included helping improve conditions for India’s poor (who generally had not benefited from the country’s economic growth), securing peace with neighbouring Pakistan, and improving relations between India’s various religious groups.

Singh presided over a rapidly expanding economy, but rising fuel costs precipitated a marked increase in inflation that threatened the government’s ability to provide subsidies for the country’s poor. In an effort to meet India’s growing energy demands, Singh in 2005 entered into negotiations with U.S. Pres. George W. Bush for a nuclear cooperation pact. The deal called for India to receive fuel technology for nuclear plants and to be given the ability to purchase nuclear fuel on the world market. Abroad, the prospective cooperation agreement was resisted by those who were upset over India’s refusal to sign the Treaty on the Non-proliferation of Nuclear Weapons; in India, Singh was criticized for fostering too close a relationship with the United States, which, his critics believed, would use the deal to leverage power in the Indian government. By 2008 progress on the deal prompted members of the government’s Parliamentary majority communist parties in particular to denounce Singh’s government and ultimately push for a confidence vote in Parliament in late July 2008. Singh’s government narrowly survived the vote, but the process was marred by allegations on both sides of corruption and the purchasing of votes. In the parliamentary elections of May 2009, Congress increased its number of seats in the legislature, and Singh took office as prime minister for a second time.

DNA

DNA, abbreviation of deoxyribonucleic acid, organic chemical of complex molecular structure that is found in all prokaryotic and eukaryotic cells and in many viruses. DNA codes genetic information for the transmission of inherited traits.

A brief treatment of DNA follows. For full treatment, see genetics: DNA and the genetic  code.The chemical DNA was first discovered in 1869, but its role in genetic inheritance was not demonstrated until 1943. In 1953, James Watson and Francis Crick determined that the structure of DNA is a double-helix polymer, a spiral consisting of two DNA strands wound around each other. Each strand is composed of a long chain of monomer nucleotides. The nucleotide of DNA consists of a deoxyribose sugar molecule to which is attached a phosphate group and one of four nitrogenous bases: two purines (adenine and guanine) and two pyrimidines (cytosine and thymine). The nucleotides are joined together by covalent bonds between the phosphate of one nucleotide and the sugar of the next, forming a phosphate-sugar backbone from which the nitrogenous bases protrude. One strand is held to another by hydrogen bonds between the bases; the sequencing of this bonding is specific i.e., adenine bonds only with thymine, and cytosine only with guanine.

The configuration of the DNA molecule is highly stable, allowing it to act as a template for the replication of new DNA molecules, as well as for the production (transcription) of the related RNA (ribonucleic acid) molecule. A segment of DNA that codes for the cell’s synthesis of a specific protein is called a gene.

DNA replicates by separating into two single strands, each of which serves as a template for a new strand. The new strands are copied by the same principle of hydrogen-bond pairing between bases that exists in the double helix. Two new double-stranded molecules of DNA are produced, each containing one of the original strands and one new strand. This “semiconservative” replication is the key to the stable inheritance of genetic traits.
Within a cell, DNA is organized into dense protein-DNA complexes called chromosomes. In eukaryotes, the chromosomes are located in the nucleus, although DNA also is found in mitochondria and chloroplasts. In prokaryotes, which do not have a membrane-bound nucleus, the DNA is found as a single circular chromosome in the cytoplasm. Some prokaryotes, such as bacteria, and a few eukaryotes have extrachromosomal DNA known as plasmids, which are autonomous, self-replicating genetic material. Plasmids have been used extensively in recombinant DNA technology to study gene expression.

The genetic material of viruses may be single- or double-stranded DNA or RNA. Retroviruses carry their genetic material as single-stranded RNA and produce the enzyme reverse transcriptase, which can generate DNA from the RNA strand.

Great Wall of China

Great Wall of China, Chinese (Pinyin) Wanli Changcheng or (Wade-Giles romanization) Wan-li Ch’ang-ch’eng (“10,000-Li Long Wall”), Defensive wall, northern China.

One of the largest building-construction projects ever carried out, it runs (with all its branches) about 4,500 mi (7,300 km) east to west from the Bo Hai (Gulf of Chihli) to a point deep in Central Asia. Large parts of the fortification date from the 7th to the 4th century bce. In the 3rd century bce the emperor Shihuangdi connected existing defensive walls into a single system fortified by watchtowers. These served both to guard the rampart and to communicate with the capital, Xianyang (near modern Xi’an) by signal smoke by day and fire by night. Originally constructed partly of masonry and earth, it was faced with brick in its eastern portion. It was rebuilt in later times, especially in the 15th and 16th centuries. The basic wall is about 23–26 ft (7–8 m) high; at intervals towers rise above it to varying heights. It was designated a UNESCO World Heritage site in 1987.

Great Wall of China, Chinese (Pinyin) Wanli Changcheng or (Wade-Giles romanization) Wan-li Ch’ang-ch’eng (“10,000-Li Long Wall”), extensive bulwark erected in ancient China, one of the largest building-construction projects ever undertaken. The Great Wall actually consists of numerous walls many of them parallel to each other built over some two millennia across northern China and southern Mongolia. The most extensive and best-preserved version of the wall dates from the Ming dynasty (1368–1644) and runs for some 5,500 miles (8,850 km) east to west from Mount Hu near Dandong, southeastern Liaoning province, to Jiayu Pass west of Jiuquan, northwestern Gansu province. This wall often traces the crestlines of hills and mountains as it snakes across the Chinese countryside, and about one-fourth of its length consists solely of natural barriers such as rivers and mountain ridges. Nearly all of the rest (about 70 percent of the total length) is actual constructed wall, with the small remaining stretches constituting ditches or moats. Although lengthy sections of the wall are now in ruins or have disappeared completely, it is still one of the more remarkable structures on Earth. The Great Wall was designated a UNESCO World Heritage site in 1987.

Large parts of the fortification system date from the 7th through the 4th century bce. In the 3rd century bce Shihuangdi (Qin Shihuang), the first emperor of a united China (under the Qin dynasty), connected a number of existing defensive walls into a single system. Traditionally, the eastern terminus of the wall was considered to be Shanhai Pass in eastern Hebei province along the coast of the Bo Hai (Gulf of Chihli), and the wall’s length without its branches and other secondary sections was thought to extend for some 4,160 miles (6,700 km). However, government-sponsored investigations that began in the 1990s revealed sections of wall in Liaoning, and aerial and satellite surveillance eventually proved that this wall stretched continuously through much of the province. The greater total length of the Ming wall was announced in 2009.

History of construction

The Great Wall developed from the disparate border fortifications and castles of individual Chinese kingdoms. For several centuries these kingdoms probably were as concerned with protection from their near neighbours as they were with the threat of barbarian invasions or raids.

Early building

About the 7th century bce the state of Chu started to construct a permanent defensive system. Known as the “Square Wall,” this fortification was situated in the northern part of the kingdom’s capital province. From the 6th to the 4th century other states followed Chu’s example. In the southern part of the Qi state an extensive perimeter wall was gradually created using existing river dikes, newly constructed bulwarks, and areas of impassable mountain terrain. The Qi wall was made mainly of earth and stone and terminated at the shores of the Yellow Sea. In the Zhongshan state a wall system was built to thwart invasion from the states of Zhao and Qin in the southwest. There were two defensive lines in the Wei state: the Hexi (“West of the [Yellow] River”) and Henan (“South of the River”) walls. The Hexi Wall was a fortification against the Qin state and western nomads. Built during the reign of King Hui (370–335 bce), it was expanded from the dikes on the Luo River on the western border. It started in the south near Xiangyuan Cave, east of Mount Hua, and ended at Guyang in what is now the Inner Mongolia Autonomous Region. Henan Wall, built to protect Daliang (the capital, now Kaifeng), was repaired and extended in King Hui’s later years. The Zheng state also built a wall system, which was rebuilt by the Han state after it conquered Zheng. The state of Zhao completed a southern wall and a northern wall; the southern wall was built mainly as a defense against the Wei state.

After administrative reorganization was carried out by Shang Yang (died 338 bce), the Qin state grew politically and militarily to become the strongest among the seven states, but it was frequently raided by the Donghu and Loufan, two nomadic peoples from the north. Therefore, the Qin erected a wall that started from Lintiao, went north along the Liupan Mountains, and ended at the Huang He (Yellow River).

In the Yan state two separate defensive lines were prepared the Northern Wall and the Yishui Wall in an effort to defend the kingdom from attacks by northern groups such as the Donghu, Linhu, and Loufan, as well as by the Qi state in the south. The Yishui Wall was expanded from the dike of the Yi River as a defense line against Qi and Zhao, its two main rival states. It began southwest of Yi City, the capital, and ended south of Wen’an. In 290 bce the Yan state built the Northern Wall along the Yan Mountains, starting from the northeast in the area of Zhangjiakou in Hebei, passing over the Liao River, and extending to the ancient city of Xiangping (modern Liaoyang). This was the last segment of the Great Wall to be erected during the Zhanguo (Warring States) period.

In 221 bce Shihuangdi, the first Qin emperor, completed his annexation of Qi and thus unified China. He ordered removal of the fortifications set up between the previous states because they served only as obstacles to internal movements and administration. In addition, he sent Gen. Meng Tian to garrison the northern border against incursions of the nomadic Xiongnu and to link the existing wall segments in Qin, Yan, and Zhao into the so-called “10,000-Li Long Wall” (2 li equal approximately 0.6 mile [1 km]). This period of construction began about 214 bce and lasted a decade. Hundreds of thousands of soldiers and conscripted workers laboured on the project. With the fall of the Qin dynasty after Shihuangdi’s death, however, the wall was left largely ungarrisoned and fell into disrepair.

The Han through Yuan dynasties

During the reign of the Han emperor Wudi (141–87 bce), the wall was strengthened as part of an overall campaign against the Xiongnu. From that period the Great Wall also contributed to the exploitation of farmland in northern and western China and to the growth of the trade route that came to be known as the Silk Road. In 121 bce a 20-year project of construction was started on the Hexi Wall (generally known as the Side Wall) between Yongdeng (now in Gansu) in the east and Lake Lop Nur (now in Xinjiang) in the west. According to Juyan Hanjian (“Juyan Correspondence of the Han”), the strongpoints set up along the wall included “a beacon every 5 li, a tower every 10 li, a fort every 30 li, and a castle every 100 li.”
The main work on the wall during the Dong (Eastern) Han period (25–220 ce) took place during the reign of Liu Xiu (Guangwudi), who in 38 ordered the repair of four parallel lines of the Great Wall in the area south of the Hexi Wall. The Great Wall served not only for defense but also to centralize control of trade and travel.

During the Bei (Northern) Wei dynasty (386–534/535 ce), the Great Wall was repaired and extended as a defense against attacks from the Juan-juan and Khitan tribes in the north. According to Wei shu: Mingyuandi Ji (“History of Wei: Chronicle of Emperor Mingyuan”), in 417, the eighth year of the reign of Mingyuandi (409–423), a part of the Great Wall was built south of Changchuan, from Chicheng (now in Hebei) to Wuyuan (now in Inner Mongolia) in the west, extending more than 620 miles (1,000 km). During the reign of Taiwudi (423–452), a lower and thinner wall of rammed earth was built around the capital as a complement to the Great Wall. Starting from Guangling in the east, it extended to the eastern side of the Huang He, forming a circle around Datong. In 549, after the Dong Wei kingdom moved its capital east to Ye, it also built a segment of the Great Wall in the area of contemporary Shanxi province.

In order to strengthen its northern frontier and prevent invasion from the west by the Bei Zhou, the Bei Qi kingdom (550–577) launched several big construction projects that were nearly as extensive in scope as the building projects of the Qin dynasty. In 552 a segment was built on the northwestern border, and only three years later the emperor ordered the recruitment of 1.8 million workers to repair and extend other sections. The construction took place between the south entrance of Juyong Pass (near modern Beijing) and Datong (in Shanxi). In 556 a new fortification was set up in the east and extended to the Yellow Sea. The following year a second wall was built inside the Great Wall within modern Shanxi, beginning in the vicinity of Laoying east of Pianguan, extending to the east beyond Yanmen Pass and Pingxing Pass, and ending in the area around Xiaguan in Shanxi. In 563 the emperor Wuchengdi of the Bei Qi had a segment repaired along the Taihang Mountains. That is the part of the Great Wall found today in the area around Longguan, Guangchang, and Fuping (in Shanxi and Hebei). In 565 the inner wall built in 557 was repaired, and a new wall was added that started in the vicinity of Xiaguan, extended to the Juyong Pass in the east, and then joined to the outer wall. The segments repaired and added during the Bei Qi period totaled some 900 miles (1,500 km), and towns and barracks were established at periodic intervals to garrison the new sections. In 579, in order to prevent invasions of the Bei Zhou kingdom by the Tujue (a group of eastern Turks) and the Khitan, the emperor Jing started a massive rebuilding program on areas of the wall located in the former Bei Qi kingdom, starting at Yanmen in the west and ending at Jieshi in the east.

During the Sui dynasty (581–618) the Great Wall was repaired and improved seven times in an effort to defend the country against attacks from the Tujue. After the Tang dynasty (618–907) replaced the Sui, the country grew much stronger militarily, defeating the Tujue in the north and expanding beyond the original frontier. Thus, the Great Wall gradually lost its significance as a fortification, and there was no need for repairs or additions. During the Song dynasty (960–1279), however, the Liao and Jin peoples in the north were a constant threat. The Song rulers were forced to withdraw to the south of the lines of the Great Wall built by the Qin, Han, and Northern dynasties. Many areas on both sides of the wall were subsequently taken over by the Liao (907–1125) and Jin dynasties (1115–1234). When the Song rulers had to retreat even farther to the south of the Yangtze River (Chang Jiang) repairs to the wall or extensions of it were no longer feasible. Limited repairs were carried out once (1056) during Liao times but only in the area between the Yazi and Huntong rivers.

In 1115, after the Jin dynasty was established, work was performed on two defensive lines at Mingchang. The old wall there previously called the Wushu Wall, or Jinyuan Fort—ran westward from a point north of Wulanhada, then wound through the Hailatu Mountains, turning to the north and then to the west again, finally ending at the Nuanshui River. The second of the lines was the new Mingchang Wall, also called the Inner Jin Wall or the Jin Trench, which was constructed south of the old wall. It started in the west from a bend in the Huang He and ended at the Sungari (Songhua) River.

During the Yuan (Mongol) dynasty (1206–1368), the Mongols controlled all of China, as well as other parts of Asia and sections of Europe. As a defensive structure the Great Wall was of little significance to them; however, some forts and key areas were repaired and garrisoned in order to control commerce and to limit the threat of rebellions from the Chinese (Han) and other nationalities.

The Ming dynasty to the present

Rulers during the Ming dynasty (1368–1644) ceaselessly maintained and strengthened the Great Wall to prevent another Mongolian invasion. The majority of the work took place along the old walls built by the Bei Qi and Bei Wei.

Most of the Great Wall that stands today is the result of work done during the reign of the Hongzhi emperor (1487–1505). Starting west of Juyong Pass, this part of the wall was split into south and north lines, respectively named the Inner and Outer walls. Along the wall were many strategic “passes” (i.e., fortresses) and gates. Among them were Juyong, Daoma, and Zijing passes, the three closest to the Ming capital Beijing. Together they were referred to as the Three Inner Passes. Farther west were Yanmen, Ningwu, and Piantou passes, known as the Three Outer Passes. Both the Inner and Outer passes were of key importance in protecting the capital and were usually heavily garrisoned.

After the Qing (Manchu) dynasty (1644–1911/12) replaced the Ming, there was a change in ruling strategy called huairou (“mollification”), wherein the Qing tried to pacify the leaders and peoples of Mongolia, Tibet, and other nationalities by not interfering with local social, cultural, or religious life. Because of the success of that strategy, the Great Wall was repaired less frequently, and it gradually fell into ruin.

Design of the fortifications

The Great Wall had three major components: passes, signal towers (beacons), and walls.

Passes

Passes were major strongholds along the wall, usually located at such key positions as intersections with trade routes. The ramparts of many passes were faced with huge bricks and stones, with dirt and crushed stones as filler. The bastions measured some 30 feet (10 metres) high and 13 to 16 feet (4 to 5 metres) wide at the top. Within each pass were access ramps for horses and ladders for soldiers. The outside parapet was crenellated, and the inside parapet, or yuqiang (nüqiang), was a low wall about 3 feet (1 metre) high that prevented people and horses from falling off the top. In addition to serving as an access point for merchants and other civilians, the gate within the pass was used as an exit for the garrison to counterattack raiders or to send out patrols. Under the gate arch there was typically a huge double door of wood. Bolts and locker rings were set in the inner panel of each door. On top of each gate was a gate tower that served as a watchtower and command post. Usually it stood one to three stories (levels) high and was constructed either of wood or of bricks and wood. Built outside the gate, where an enemy was most likely to attack, was a wengcheng, a semicircular or polygonal parapet that shielded the gate from direct assault. Extending beyond the most strategic wengchengs was an additional line of protection, the luocheng, which was often topped by a tower used to watch those beyond the wall and to direct troop movements in battles waged there. Around the gate entrance there was often a moat that was formed in the process of digging earth to build the fortifications.

Signal towers

Signal towers were also called beacons, beacon terraces, smoke mounds, mounds, or kiosks. They were used to send military communications: beacon (fires or lanterns) during the night or smoke signals in the daytime; other methods such as raising banners, beating clappers, or firing guns were also used. Signal towers, often built on hilltops for maximum visibility, were self-contained high platforms or towers. The lower levels contained rooms for soldiers, as well as stables, sheepfolds, and storage areas.

Walls

The wall itself was the key part of the defensive system. It usually stood 21.3 feet (6.5 metres) wide at the base and 19 feet (5.8 metres) at the top, with an average height of 23 to 26 feet (7 to 8 metres), or a bit lower on steep hills. The structure of the wall varied from place to place, depending on the availability of building materials. Walls were made of tamped earth sandwiched between wooden boards, adobe bricks, a brick and stone mixture, rocks, or pilings and planks. Some sections made use of existing river dikes; others used rugged mountain terrain such as cliffs and gorges to take the place of man-made structures.

In the western deserts the walls were often simple structures of rammed earth and adobe; many eastern ramparts, such as those near Badaling, were faced with stone and included a number of secondary structures and devices. On the inner side of such walls, placed at small intervals, were arched doors called juan, which were made of bricks or stones. Inside each juan were stone or brick steps leading to the top of the battlement. On the top, on the side facing outward, stood 7-foot- (2-metre-) high crenels called duokou. On the upper part of the duokou were large openings used to watch and shoot at attackers, and on the lower part were small openings, or loopholes, through which defenders could also shoot. At intervals of about 650 to 1,000 feet (200 to 300 metres) there was a crenellated platform rising slightly above the top of the wall and protruding from the side that faced attackers. During battle the platform provided a commanding view and made it possible to shoot attackers from the side as they attempted to scale the wall with ladders. On several platforms were simply structured huts called pufang, which provided shelter for the guards during storms. Some platforms, as with signal towers, had two or three stories and could be used to store weapons and ammunition. Those at Badaling commonly had two stories, with accommodations for more than 10 soldiers on the lower level. There were also drainage ditches on the walls to shield them from damage by excessive rainwater.

Military administration

Each major stronghold along the wall was hierarchically linked to a network of military and administrative commands. During the rule of Shihuangdi, 12 prefectures were established along the wall, and in the Ming period the whole fortification was divided into 9 defense areas, or zones. A post chief (zongbingguan) was assigned to each zone. Together they were known as the Nine Border Garrisons.

Tradition and conservation

The Great Wall has long been incorporated into Chinese mythology and popular symbolism, and in the 20th century it came to be regarded as a national symbol. Above the East Gate (Dongmen) at Shanhai Pass is an inscription attributed to the medieval historian Xiao Xian, which is translated as “First Pass Under Heaven,” referring to the traditional division between Chinese civilization and the barbarian lands to the north.
Despite the wall’s cultural significance, roadways have been cut through it at several points, and vast sections have suffered centuries of neglect. In the 1970s a segment near Simatai (68 miles [110 km] northeast of Beijing) was dismantled for building materials, but it was subsequently rebuilt. Other areas have also been restored, including just northwest of Jiayu Pass at the western limit of the wall; at Huangya Pass, some 105 miles (170 km) north of Tianjin; and at Mutianyu, about 55 miles (90 km) northeast of Beijing. The best-known section, at Badaling (43 miles [70 km] northwest of Beijing), was rebuilt in the late 1950s; it now attracts thousands of national and foreign tourists every day. Portions of the wall around Shanhai Pass and at Mount Hu, the eastern terminus, also had been rebuilt by 2000.

Mir

Primary Contributor: David M. Harland

Mir, Soviet/Russian modular space station, the core module (base block) of which was launched into Earth orbit by the U.S.S.R. in 1986. Over the next decade additional modules were sent aloft on separate launch vehicles and attached to the core unit, creating a large habitat that served as a versatile space laboratory for more than 14 years.
Mir (Russian: “Peace” or “World”) was the third generation of space stations developed by the Soviet Union. Its core module resembled its simpler predecessors in the Salyut series but had additional docking ports (a total of six) that accommodated not only a succession of manned spacecraft and cargo ferries but also permanently attached expansion modules equipped for scientific research.

Mir’s core module was launched on Feb. 20, 1986. It had the form of a stepped cylinder about 13 metres (43 feet) long and 4.2 metres (13.8 feet) in diameter at its widest point. The module had a docking port at each end and four ports sited radially at its forward end. On March 13, 1986, cosmonauts Leonid Kizim and Vladimir Solovyov were sent aloft aboard a Soyuz T spacecraft to rendezvous with Mir and become its first occupants. Between March 1987 and April 1996, five expansion modules were added to the core unit Kvant 1 (1987), an astrophysics observatory; Kvant 2 (1989), containing supplementary life-support equipment and a large airlock; Kristall (1990), a materials-sciences laboratory; and Spektr (1995) and Priroda (1996), two science modules containing remote-sensing instruments for ecological and environmental studies of Earth. With the exception of its first occupants, Mir’s cosmonaut crews traveled between the station and Earth in upgraded Soyuz TM spacecraft, and supplies were transported by robotic Progress cargo ferries.

Mir supported human habitation from March 14, 1986, to June 15, 2000, which included an uninterrupted stretch of occupancy of almost 10 years. It hosted more than 100 people from 12 countries, including a series of U.S. astronauts in 1995–98 as part of a Mir–space shuttle cooperative endeavour. Between January 1994 and March 1995, Mir cosmonaut-physician Valery Polyakov set an endurance record of 438 continuous days in space, longer than the approximately nine months estimated for a manned voyage to the planet Mars.
Designed for only a five-year life, the aging Mir suffered a series of equipment failures and accidents in 1996–97 but remained in service. On March 23, 2001, the abandoned Mir made a controlled reentry, with the surviving pieces falling into the Pacific Ocean. (See also Energia.)
David M. Harland A chronology of missions to Mir is shown in the table.

Chronology of manned missions to Mir space station
	mission	country	crew	dates	notes
	Soyuz T-15/Mir/Salyut 7	U.S.S.R.	Leonid Kizim; Vladimir Solovyov	March 13–July 16, 1986	first spaceflight between two space stations
	Soyuz TM-2/Mir	U.S.S.R.	Aleksandr Laveykin; Yury Romanenko	Feb. 5–July 30, 1987 (Dec. 29 [Romanenko])	new space endurance record (Romanenko; 326 days 12 hours); addition of Kvant 1 module to Mir
	Soyuz TM-3/Mir	U.S.S.R.	Aleksandr Viktorenko; Aleksandr Pavlovich Aleksandrov; Muhammed Faris	July 22–30, 1987 (Dec. 29 [Aleksandrov])	first Syrian astronaut (Faris)
	Soyuz TM-4/Mir	U.S.S.R.	Vladimir Titov; Musa Manarov; Anatoly Levchenko	Dec. 21, 1987–Dec. 21, 1988 (Dec. 29, 1987 [Levchenko])	new space endurance record (Titov and Manarov; 365 days 23 hours)
	Soyuz TM-5/Mir	U.S.S.R.	Anatoly Solovyov; Viktor Savinkyh; Aleksandr Panayatov Aleksandrov	June 7–17, 1988	second Bulgarian astronaut (Aleksandrov)
	Soyuz TM-6/Mir	U.S.S.R.	Vladimir Lyakhov; Valery Polyakov; Abdul Ahad Mohmand	Aug. 29–Sept. 7, 1988 (April 4, 1989 [Polyakov])	first Afghan astronaut (Mohmand)
	Soyuz TM-7/Mir	U.S.S.R.	Aleksandr Volkov; Sergey Krikalyov; Jean-Loup Chrétien	Nov. 26, 1988–April 27, 1989 (Dec. 21, 1988 [Chrétien])	Mir was left unoccupied after crew returned to Earth
	Soyuz TM-8/Mir	U.S.S.R.	Aleksandr Viktorenko; Aleksandr Serebrov	Sept. 5, 1989–Feb. 19, 1990	addition of Kvant 2 module to Mir
	Soyuz TM-9/Mir	U.S.S.R.	Anatoly Solovyov; Aleksandr Balandin	Feb. 11–Aug. 9, 1990	addition of Kristall module to Mir
	Soyuz TM-10/Mir	U.S.S.R.	Gennady Manakov; Gennady Strekalov	Aug. 1–Dec. 10, 1990	crew performed spacewalk to fix damaged hatch on Kvant 2
	Soyuz TM-11/Mir	U.S.S.R.	Viktor Afanasiyev; Musa Manarov; Akiyama Toyohiro	Dec. 2, 1990–May 26, 1991 (Dec. 10, 1990 [Akiyama])	first Japanese citizen in space (Akiyama)
	Soyuz TM-12/Mir	U.S.S.R.	Anatoly Artsebarsky; Sergey Krikalyov; Helen Sharman	May 18, 1991–Oct. 10, 1991 (March 25, 1992 [Krikalyov]; May 26, 1991 [Sharman])	first British astronaut (Sharman)
	Soyuz TM-13/Mir	U.S.S.R.	Aleksandr Volkov; Toktar Aubakirov; Franz Viehböck	Oct. 2, 1991–March 25, 1992 (Oct. 10, 1991 [Aubakirov; Viehböck]	first Austrian astronaut (Viehböck)
	Soyuz TM-14/Mir	Russia	Aleksandr Viktorenko; Aleksandr Kalery; Klaus-Dietrich Flade	March 17–Aug. 10, 1992 (March 25 [Flade])	first Russian spaceflight after breakup of the U.S.S.R.
	Soyuz TM-15/Mir	Russia	Anatoly Solovyov; Sergey Avdeyev; Michel Tognini	July 27, 1992–Feb. 1, 1993 (Aug. 10, 1992 [Tognini])	crew performed spacewalks to extend lifetime of Mir
	Soyuz TM-16/Mir	Russia	Gennady Manakov; Aleksandr Poleshchuk	Jan. 24–July 22, 1993	placed docking target on Mir for use by space shuttle Atlantis
	Soyuz TM-17/Mir	Russia	Vasily Tsibliyev; Aleksandr Serebrov; Jean-Pierre Haigneré	July 1, 1993–Jan. 14, 1994 (July 22, 1993 [Haigneré])	slight collision with Mir
	Soyuz TM-18/Mir	Russia	Viktor Afanasiyev; Yury Usachyov; Valery Polyakov	Jan. 8–July 9, 1994 (March 22, 1995 [Polyakov])	new space endurance record (Polyakov; 437 days 18 hours)
	Soyuz TM-19/Mir	Russia	Yury Malenchenko; Talgat Musabayev	July 1–Nov. 4, 1994	Malenchenko performed first manual docking of Progress resupply ship
	Soyuz TM-20/Mir	Russia	Aleksandr Viktorenko; Elena Kondakova; Ulf Merbold	Oct. 4, 1994–March 22, 1995 (Nov. 4, 1994 [Merbold])	first woman to make a long-duration spaceflight (Kondakova)
	STS-63 (Discovery)	U.S.	James Wetherbee; Eileen Collins; Bernard Harris; Michael Foale; Janice Voss; Vladimir Titov	Feb. 3–11, 1995	demonstrated shuttle orbiter’s ability to approach and maneuver around Mir
	Soyuz TM-21/Mir	Russia	Vladimir Dezhurov; Gennady Strekalov; Norman Thagard	March 14–July 7, 1995	first American to fly on Russian spacecraft (Thagard); addition of Spektr module to Mir
	STS-71 (Atlantis)/Mir	U.S.	Robert Gibson; Charles Precourt; Ellen Baker; Gregory Harbaugh; Bonnie Dunbar; Anatoly Solovyov; Nikolay Budarin	June 27–July 7, 1995 (Sept. 11, 1995 [Solovyov, Budarin])	first space shuttle visit to Mir
	Soyuz TM-22/Mir	Russia	Yury Gidzenko; Sergei Avdeyev; Thomas Reiter	Sept. 3, 1995–Feb. 29, 1996	first German to walk in space (Reiter)
	STS-74 (Atlantis)/Mir	U.S.	Kenneth Cameron; James Halsell; Chris Hadfield; Jerry Ross; William McArthur	Nov. 12–20, 1995	attached docking module to Mir
	Soyuz TM-23/Mir	Russia	Yury Onufriyenko; Yury Usachyov	Feb. 21–Sept. 2, 1996	addition of Priroda module to Mir
	STS-76 (Atlantis)/Mir	U.S.	Kevin Chilton; Richard Searfoss; Ronald Sega; Michael Clifford; Linda Godwin; Shannon Lucid	March 22–31, 1996 (Sept. 26 [Lucid])	delivered supplies to Mir
	Soyuz TM-24/Mir	Russia	Valery Korzun; Aleksandr Kaleri; Claudie André-Deshays	Aug. 17, 1996–March 2, 1997 (Sept. 2, 1996 [André-Deshays])	first French woman in space (André-Deshays)
	STS-79 (Atlantis)/Mir	U.S.	William Readdy; Terrence Wilcutt; Jerome Apt; Thomas Akers; Carl Walz; John Blaha	Sept. 16–26, 1996 (Jan. 22, 1997 [Blaha])	conducted experiments in Spacelab Double Module
	STS-81 (Atlantis)/Mir	U.S.	Michael Baker; Brent Jett; Peter Wisoff; John Grunsfeld; Marsha Ivins; Jerry Linenger	Jan. 12–22, 1997 (May 24, 1997 [Linenger])	returned with first plants to complete a full life cycle in space
	Soyuz TM-25/Mir	Russia	Vasily Tsibliyev; Aleksandr Lazutkin; Reinhold Ewald	Feb. 10–Aug. 14, 1997 (March 2 [Ewald])	fire seriously damaged Mir’s oxygen generation system (Feb. 23); collision with Progress punctured Spektr module (June 25)
	STS-84 (Atlantis)/Mir	U.S.	Charles Precourt; Eileen Collins; Jean-François Clervoy; Carlos Noriega; Edward Lu; Yelena Kondakova; Michael Foale	May 15–24, 1997 (Oct. 6 [Foale])	carried Biorack research facility, which conducted microgravity experiments
	Soyuz TM-26/Mir	Russia	Anatoly Solovyov; Pavel Vinogradov	Aug. 5, 1997–Feb. 19, 1998	Mir’s oxygen generation system repaired
	STS-86 (Atlantis)/Mir	U.S.	James Wetherbee; Michael Bloomfield; Vladimir Titov; Scott Parazynski; Jean-Loup Chrétien; Wendy Lawrence; David Wolf	Sept. 25–Oct. 6, 1997 (Jan. 31, 1998 [Wolf])	carried Spacehab module, which included replacement computer for Mir
	STS-89 (Endeavour)/Mir	U.S.	Terrence Wilcutt; Joe Edwards; James Reilly; Michael Anderson; Bonnie Dunbar; Salizhan Sharipov; Andrew Thomas	Jan. 22–31, 1998 (June 12 [Thomas])	carried experiments in protein crystal growth
	Soyuz TM-27/Mir	Russia	Talgat Musabayev; Nikolay Budarin; Leopold Eyharts	Jan. 29–Aug. 25, 1998 (Feb. 19 [Eyharts])	unsuccessful attempt to repair Spektr solar panel
	STS-91 (Discovery)/Mir	U.S.	Charles Precourt; Dominic Gorie; Franklin Chang-Díaz; Wendy Lawrence; Janet Kavandi; Valery Ryumin	June 2–12, 1998	final space shuttle mission to Mir
	Soyuz TM-28/Mir	Russia	Gennady Padalka; Sergey Avdeyev; Yury Baturin	Aug. 13, 1998–Feb. 28, 1999 (Aug. 28, 1999 [Avdeyev]; Aug. 25, 1998 [Baturin])	first Russian politician in space (Baturin)
	Soyuz TM-29/Mir	Russia	Viktor Afanasiyev; Jean-Pierre Haigneré; Ivan Bella	Feb. 20–Aug. 28, 1999 (Feb. 28 [Bella])	first Slovak astronaut (Bella)
	Soyuz TM-30/Mir	Russia	Sergey Zalyotin; Aleksandr Kaleri	April 4–June 16, 2000	last occupants of Mir

Amitabh Bachchan

Amitabh Bachchan,  (b. October 11, 1942, Allahabad, India), Indian film actor, perhaps the most popular star in the history of India’s cinema, known primarily for his roles in action films.

Bachchan, the son of the renowned Hindi poet Harivansh Rai Bachchan, attended Sherwood College in Nainital and the University of Delhi. He worked as a business executive in Calcutta (Kolkata) and performed in theatre before embarking on a film career. Bachchan made his big-screen debut in Saat Hindustani (1969; “Seven Indians”) and achieved his first success with Zanjeer (1973; “Chain”). A string of action films followed, including Deewar (1975; “Wall”), Sholay (1975; “Embers”), and Don (1978). Nicknamed “Big B,” Bachchan personified a new type of action star in Indian films, that of the “angry young man,” rather than the romantic hero. He was often compared to Clint Eastwood although, unlike Eastwood and other American action stars, Bachchan was renowned for his versatility, and many of his roles showcased his talents at singing, dancing, and comedy.

By the end of the 1970s, Bachchan had appeared in more than 35 films and was regarded as India’s top film star. His popularity was such that he became something of a cultural phenomenon, drawing large crowds of screaming fans wherever he went. A near-fatal accident on the set of his film Coolie in 1982 touched off a national prayer vigil for his recovery. His subsequent films, however, did poorly at the box office, and Bachchan entered politics at the encouragement of his friend Indian Prime Minister Rajiv Gandhi. In 1984 he was elected to India’s parliament by an overwhelming majority, but he resigned his seat in 1989 after being implicated in a bribery scandal that toppled Gandhi’s government.

Bachchan returned to film and won the National Award for his portrayal of a mafia don in Agneepath (1990; “Path of Fire”). He later headed Amitabh Bachchan Corporation Ltd., an entertainment venture that specialized in film production and event management. The business was plagued by financial difficulties, however, and Bachchan eventually returned to performing. His later movies include the crime drama Hum (1991); Mohabbatein (2000; Love Stories), a musical that was a major box-office success; and Black (2005), which was inspired by Helen Keller’s life story. In the drama Paa (2009), he played a boy who suffers from an aging disease similar to progeria. By the early 21st century, Bachchan had appeared in more than 175 films. In addition, from 2000 to 2006 he hosted the television game show Kaun Banega Crorepati, the Indian version of the American and British hit Who Wants to Be a Millionaire? His easygoing nature and charisma helped make the show one of India’s top television programs.

Amy Tan

Amy Tan, in full Amy Ruth Tan  (b. Feb. 19, 1952, Oakland, Calif., U.S.),  American author of novels about Chinese American women and the immigrant experience.

Tan grew up in California and in Switzerland and studied English and linguistics at San Jose State University (B.A., 1973; M.A., 1974) and the University of California, Berkeley. She was a highly successful freelance business writer in 1987 when she took her Chinese immigrant mother to revisit China. There Tan, for the first time, met two of her half sisters, a journey and a meeting that inspired part of her first novel, The Joy Luck Club (1989; film 1993). The novel relates the experiences of four Chinese mothers, their Chinese American daughters, and the struggles of the two disparate cultures and generations to relate to each other.

Her second novel, The Kitchen God’s Wife (1991), was inspired by her mother’s history; it concerns a Chinese mother who accepts American ways clumsily and her relationship to her thoroughly Americanized daughter. In The Hundred Secret Senses (1995), an American woman gradually learns to appreciate her Chinese half sister and the knowledge she imparts. Tan again explored the complex relationships of mothers and daughters in The Bonesetter’s Daughter (2001), in which a woman cares for her mother, who is afflicted with Alzheimer disease. In Saving Fish from Drowning (2005), an idiosyncratic San Francisco art dealer narrates the story of a group of tourists traveling through China and Myanmar (Burma). Tan also published the collection of essays The Opposite of Fate: A Book of Musings (2003) and the children’s stories The Moon Lady (1992) and The Chinese Siamese Cat (1994; adapted as a television series in 2001).

Coming Soon!!!

Britannia news. Work under progress.

Encouraging Entrepreneurship Through the Startup Visa Act

The U.S. education system, with all its flaws, is widely regarded as having the best higher education institutions in the world. The American taxpayer is a primary contributor to the stability of this system, in part by financing public institutions, and in part by financing numerous domestic student loans. This financing is then used to support the training and retention of faculty, benefiting both private and public universities. Naturally, then, it is desirable that the brilliant and creative minds that are honed by our tax dollar-backed institutions remain in the U.S. after their graduation, to benefit our domestic economy by increasing productivity and creating American jobs. While it may seem trivial that an American citizen would do so, that is far from being the case for a foreign national. With immigration reform hanging in the air, our greatest loss may be foreign entrepreneurs. When at least one key founder of 25.3% of technology and engineering companies started in the U.S. from 1995 to 2005 is foreign-born, and approximately one million skilled workers are stuck in an immigration limbo, something in our immigration process must change.

With the recent explosive growth of the Internet ecosystem (or the World’s Town Square as Secretary Clinton recently coined it), there are countless opportunities for entrepreneurs to develop new products and services. While not all of these innovations will pan out to become the next Facebook, Amazon, Zynga, or Twitter, those that do will create American jobs and increase our GDP. And while before it could cost hundreds of thousands of dollars or more to develop and market a software product, now, innovative, game-changing technologies such as Twitter, Tumblr, and Groupon can be built within months for a fraction of the cost. Given a proposed $3.2 trillion federal budget and our present deficit and given that more new jobs are created by startups than by large companies, what better way to raise additional tax revenues than fostering the creation of more productive American jobs?

Unfortunately, it is extremely difficult for a foreign entrepreneur to pursue a business opportunity domestically. Since foreign entrepreneurs do not have an established firm to sponsor them for an employment visa, they must secure investors first, even when their startup costs are relatively minuscule. To put this into perspective, the current EB-5 visa enables investors from other countries to obtain a visa in exchange for starting a business in the U.S. with at least $1M in capital (or $500K in economically targeted areas), and the creation of at least 10 domestic jobs. For many foreign entrepreneurs, this is an impossible hurdle. As a result, many foreign entrepreneurs are faced with a critical choice: (i) cave in to the current system, work for an established firm, and forgo their passion to pursue a business opportunity; or (ii) go back to their home country to pursue the development of their innovation there. If a foreign national is from another developed or emerging economy, their decision may not be in our favor.

This is where the Startup Visa Act comes in. The bill, sponsored by Senators John Kerry (D-Mass.) and Richard Lugar (R-Ind.), and supported by notables from the technology sector such as Brad Feld, Paul Graham, David McClure, Eric Ries, Vivek Wadhwa (although with some reservations), and Fred Wilson, aims to alleviate some of these issues. The Startup Visa Act grants a temporary work visa to any foreign-born entrepreneur who is able to obtain an investment of at least $100,000 from a venture capitalist or a qualified “super angel” investor in an equity financing of no less than $250,000. To gain permanent residency, the entrepreneur must create five new U.S. jobs within two years, raise more than $1 million in venture capital, or generate sales of more than $1 million annually.

While the bill has its shortcomings, it is an important step in the right direction. It still has major flaws. For instance, it assumes that all startups raise venture capital the Kauffman Foundation has found that 84% of the Inc. 500 list of the fastest-growing private companies raised no venture capital. It also increases the bargaining power of investors, as they would now have control over an entrepreneur’s legal status, hence reducing the overall incentive to innovate. Clearly, then, the bottom line is that while this is an important step, there is more to be done if we want to keep these entrepreneurs here, and this is what we need to work towards:

(1) We need to sway foreign nationals in favor of innovating here rather than in their home country;
(2) We need to eliminate any additional barriers that startups face in hiring key employees when compared to larger and more established firms; and
(3) We need to resolve the backlog of one million foreign doctors, scientists, engineers, and other high-skilled workers that are stuck in an immigration limbo.

Pluto

Primary Contributor: Tobias Chant Owen

Pluto, large, distant member of the solar system that formerly was regarded as the outermost and smallest planet. It also was considered the most recently discovered planet, having been found in 1930. In August 2006 the International Astronomical Union (IAU), the organization charged by the scientific community with classifying astronomical objects, voted to remove Pluto from the list of planets and give it the new classification of dwarf planet. The change reflects astronomers’ realization that Pluto is a large member of the Kuiper belt, a collection of debris of ice and rock left over from the formation of the solar system and now revolving around the Sun beyond Neptune’s orbit. (For the IAU’s distinction between planet and dwarf planet and further discussion of the change in Pluto’s classification, see planet.)

Pluto is not visible in the night sky to the unaided eye. Its largest moon, Charon, is close enough in size to Pluto that it has become common to refer to the two bodies as a double system. Pluto is designated by the symbol ♇.

Pluto is named for the god of the underworld in Roman mythology (the Greek equivalent is Hades). It is so distant that the Sun’s light, which travels about 300,000 km (186,000 miles) per second, takes more than five hours to reach it. An observer standing on Pluto’s surface would see the Sun as an extremely bright star in the dark sky, providing Pluto on average 1/1,600 of the amount of sunlight that reaches Earth. Pluto’s surface temperature therefore is so cold that common gases such as nitrogen and carbon monoxide exist there as ices.

Basic data for Pluto
mean distance from Sun	5,910,000,000 km (39.5 AU)
eccentricity of orbit	0.251
inclination of orbit to ecliptic	17.1°
Plutonian year (sidereal period of revolution)	247.69 Earth years
visual magnitude at mean opposition	15.1
mean synodic period*	366.74 Earth days
mean orbital velocity	4.72 km/s
radius	1,172 km
mass	1.2 x 1022 kg
mean density	about 2 g/cm3
mean surface gravity	58 cm/s
escape velocity	1.1 km/s
rotation period (Plutonian sidereal day)	6.3873 Earth days (retrograde)
Plutonian mean solar day**	6.3874 Earth days
inclination of equator to orbit (obliquity)	120°
mean surface temperature	about 40 K (-387 °F, -233 °C)
surface pressure (near perihelion)	about 10-5 bar
number of known moons	3
*Time required for Pluto to return to the same position in the sky relative to the Sun as seen from Earth. **Smallness of deviation from sidereal day is due to Pluto’s huge orbit.

Because of Pluto’s remoteness and small size, the best telescopes on Earth and in Earth orbit have been able to resolve little detail on its surface. Indeed, such basic information as its radius and mass have been difficult to determine; most of what is known about Pluto has been learned since the late 1970s as an outcome of the discovery of Charon. Pluto has yet to be visited by spacecraft, though the U.S. spacecraft New Horizons departed Earth for the Pluto-Charon system in 2006 and will arrive there in July 2015; many key questions about it and its environs can be answered only by close-up robotic observations.

Basic astronomical data

Pluto’s mean distance from the Sun, about 5.9 billion km (3.7 billion miles or 39.5 astronomical units), gives it an orbit larger than that of the outermost planet, Neptune. (One astronomical unit [AU] is the average distance from Earth to the Sun about 150 million km [93 million miles].) Its orbit, compared with those of the planets, is atypical in several ways. It is more elongated, or eccentric, than any of the planetary orbits and more inclined (at 17.1°) to the ecliptic, the plane of Earth’s orbit, near which the orbits of most of the planets lie. In traveling its eccentric path around the Sun, Pluto varies in distance from 29.7 AU, at its closest point to the Sun (perihelion), to 49.5 AU, at its farthest point (aphelion). Because Neptune orbits in a nearly circular path at 30.1 AU, Pluto is for a small part of each revolution actually closer to the Sun than is Neptune. Nevertheless, the two bodies will never collide, because Pluto is locked in a stabilizing 3:2 resonance with Neptune i.e., it completes two orbits around the Sun in exactly the time it takes Neptune to complete three. This gravitational interaction affects their orbits such that they can never pass closer than about 17 AU. The last time Pluto reached perihelion occurred in 1989; for about 10 years before that time and again afterward, Neptune was more distant than Pluto from the Sun.

Observations from Earth have revealed that Pluto’s brightness varies with a period of 6.3873 Earth days, which is now well established as its rotation period (sidereal day). Of the planets, only Mercury, with a rotation period of almost 59 days, and Venus, with 243 days, turn more slowly. Pluto’s axis of rotation is tilted at an angle of 120° from the perpendicular to the plane of its orbit, so that its north pole actually points 30° below the plane. (By convention, above the plane is taken to mean in the direction of Earth’s and the Sun’s north poles; below, in the opposite direction. For comparison, Earth’s north polar axis is tilted 23.5° away from the perpendicular, above its orbital plane.) Pluto thus rotates nearly on its side in a retrograde direction (opposite the direction of rotation of the Sun and most of the planets); an observer on its surface would see the Sun rise in the west and set in the east.

Compared with the planets, Pluto is also anomalous in its physical characteristics. Pluto has a radius less than half that of Mercury; it is only about two-thirds the size of Earth’s Moon. Next to the outer planets the giants Jupiter, Saturn, Uranus, and Neptune it is strikingly tiny. When these characteristics are combined with what is known about its density and composition, Pluto appears to have more in common with the large icy moons of the outer planets than with any of the planets themselves. Its closest twin is Neptune’s moon Triton, which suggests a similar origin for these two bodies (see below Origin of Pluto and its moons). For additional orbital and physical data about Pluto, see the table.

The atmosphere

Although the detection of methane ice on Pluto’s surface in the 1970s (see below The surface and interior) gave scientists confidence that the body had an atmosphere, direct observation of it had to wait until the next decade. Discovery of its atmosphere was made in 1988 when Pluto passed in front of (occulted) a star as observed from Earth. The star’s light gradually dimmed just before it disappeared behind Pluto, demonstrating the presence of a thin, greatly distended atmosphere. Because Pluto’s atmosphere must consist of vapours in equilibrium with their ices, small changes in temperature should have a large effect on the amount of gas in the atmosphere. During the years surrounding Pluto’s perihelion in 1989, when Pluto was slightly less cold than average, more of its frozen gases vaporized; the atmosphere was then at or near its thickest, making it a favourable time to study the body. Astronomers in the year 2000 estimated a surface pressure in the range of a few to several tens of microbars (one microbar is one-millionth of sea-level pressure on Earth). At aphelion, when Pluto is receiving the least sunlight, its atmosphere may not be detectable at all.

Observations made during occultations cannot provide direct information about atmospheric composition, but they can allow determination of the ratio of mean molecular weight to temperature. Using reasonable assumptions about the atmospheric temperature, scientists have calculated that each particle i.e., each atom or molecule of Pluto’s atmosphere has a mean molecular weight of approximately 25 atomic mass units. This implies that significant amounts of gases heavier than methane, which has a molecular weight of 16, must also be present. Molecular nitrogen, with a molecular weight of 28, must in fact be the dominant constituent, because nitrogen ice was discovered on the surface (see below The surface and interior) and is known to be more volatile than methane ice. Nitrogen is also the main constituent of the atmospheres of both Triton and Saturn’s largest satellite, Titan, as well as of Earth.

Although ongoing Earth-based observations will add to knowledge about the atmosphere and other aspects of Pluto, major new insights will likely require a close-up visit from a spacecraft. Scientists looked to the U.S. New Horizons spacecraft mission, launched in 2006, to Pluto, Charon, and the outer solar system beyond to provide much of the needed data. The mission plan called for a nine-year flight to the Pluto-Charon system followed by a 150-day flyby for investigation of the surfaces, atmospheres, interiors, and space environment of the two bodies.

The surface and interior

Observations of Pluto show that its colour is slightly reddish, although much less red than Mars or Jupiter’s moon Io. Thus, the surface of Pluto cannot be composed simply of pure ices, a conclusion supported by the observed variation in brightness caused by its rotation. Its average reflectivity, or albedo, is 0.55 (i.e., it returns 55 percent of the light that strikes it), compared with 0.1 for the Moon and 0.8 for Triton.

The first crude infrared spectroscopic measurements (see spectroscopy), made in 1976, revealed the presence of solid methane on Pluto’s surface. Using new ground-based instrumentation available in the early 1990s, observers discovered ices of water, carbon monoxide, and molecular nitrogen. Although nitrogen’s spectral signature is intrinsically very weak, it is now clear that this substance must be the dominant surface constituent. The methane is present both as patches of pure methane ice and as a frozen “solution” of methane in the nitrogen ice. The nature of the dark, reddish material remains to be determined; some mixture of organic compounds produced by photochemical reactions in atmospheric gases or surface ices seems a likely possibility. Brightness fluctuations observed from 1954 to 1986 when Pluto and Charon mutually eclipsed one another (see below Pluto’s moons) revealed that Pluto’s south polar region was unusually bright. Scientists find such variation in Pluto’s surface striking because, with the exception of Saturn’s mysterious moon Iapetus, all the other icy bodies in the outer solar system exhibit much more uniform surfaces. A subsequent brightness map based on observations taken with the Earth-orbiting Hubble Space Telescope from 2002 to 2003 revealed seasonal changes as winter approached in the southern hemisphere. The north polar region became brighter, and the south polar region became darker.

The same Pluto-Charon eclipses have allowed astronomers to estimate the masses and radii of the two bodies. From this information their densities have been calculated to fall between 1.92 and 2.06 grams per cubic cm for Pluto and between 1.51 and 1.81 grams per cubic cm for Charon. These values suggest that both bodies are composed of a significant fraction of materials such as silicate rock and organic compounds denser than water ice (which has a density of 1 gram per cubic cm). It is customary to assume that Pluto, like the icy moons of Jupiter and Saturn, has an inner rocky core surrounded by a thick mantle of water ice. The frozen nitrogen, carbon monoxide, and methane observed on its surface are expected to be in the form of a relatively thin layer, similar to the layer of water on Earth’s surface. Such a model, however, requires verification by spacecraft observations.

The surface temperature of Pluto has proved very difficult to measure. Observations made in 1983 from the Earth-orbiting Infrared Astronomical Satellite (IRAS) suggest values in the range of 45 to 58 K (−379 to −355 °F, −228 to −215 °C), whereas measurements from Earth’s surface at millimetre wavelengths imply a slightly lower range of 35 to 50 K (−397 to −370 °F, −238 to −223 °C). The temperature certainly must vary over the surface, depending on the reflectivity at a given location and the angle of the noon Sun there. The solar energy falling on Pluto is also expected to decrease by a factor of roughly three as it moves from perihelion to aphelion.

Pluto’s moons

Pluto possesses three known moons. Charon, by far the largest, is fully half the size of Pluto. It revolves around Pluto more accurately, the two bodies revolve around a common centre of mass at a distance of about 19,640 km (12,200 miles), equal to about eight Pluto diameters. (By contrast, Earth’s Moon is a little more than one-fourth the size of Earth and is separated from the latter by about 30 Earth diameters.) Charon’s period of revolution is exactly equal to the rotation period of Pluto itself; in other words, Charon is in synchronous orbit around Pluto. As a result, Charon is visible from only one hemisphere of Pluto. It remains above the same location on Pluto’s surface, never rising or setting (just as do communications satellites in geostationary orbits over Earth; see spaceflight: Earth orbit). In addition, as with most moons in the solar system, Charon is in a state of synchronous rotation i.e., it always presents the same face to Pluto.
Charon is somewhat less reflective (has a lower albedo about 0.35) than Pluto and is more neutral in colour. Its spectrum reveals the presence of water ice, which appears to be the dominant surface constituent. There is no hint of the solid methane that is so obvious on its larger neighbour. The observations to date were not capable of detecting ices of nitrogen or carbon monoxide, but, given the absence of methane, which is less volatile, they seem unlikely to be present. As discussed above in the section The surface and interior, Charon’s density implies that the moon contains materials such as silicates and organic compounds that are denser than water ice. The disposition of these materials inside Charon is even more speculative than it is for Pluto. For additional data about Charon, see the table.

Data for Pluto’s moon Charon
mean distance from centre of Pluto (orbital radius)	19,640 km
orbital period (sidereal period)	6.3873 Earth days
eccentricity of orbit	close to zero
rotation period	same as orbital period (synchronous)
inclination of orbit to Pluto’s equator	close to zero
radius	625 km
mass	1.8 x 1021 kg
mean density	about 1.7 g/cm3

Scientists have exploited the presence of Charon to reveal several characteristics of Pluto that would not otherwise be known, particularly its mass and size. Much of this information was acquired through the extraordinary coincidence that in 1985, just seven years after Charon’s discovery, it began a five-year period of mutual eclipse events with Pluto in which the moon alternately crossed the disk of (transited) and was hidden (was occulted, or was eclipsed) by Pluto, as seen from Earth, every 6.4 days. These events occur when Earth passes through Charon’s orbital plane around Pluto, which happens only twice during Pluto’s 248-year orbit around the Sun. Careful observations of these events allowed determinations of the radii of Pluto and Charon and of the masses of both bodies that were more precise than heretofore possible. In addition, monitoring the changes in the total brightness of the two bodies as they blocked each other permitted astronomers to estimate their individual overall albedos and even to create maps depicting brightness differences over their surfaces.
Pluto’s other two moons, called Hydra and Nix (provisionally designated S/2005 P1 and S/2005 P2, respectively, on their discovery), are much smaller than Charon 72 and 88 km (45 and 55 miles) in diameter, respectively. They revolve around Pluto outside Charon’s path in nearly circular orbits (like Charon) and in the same orbital plane as Charon. The orbital radius of Hydra is about 65,210 km (40,520 miles); of Nix, 49,240 km (30,600 miles). It appears that for every 12 orbits completed by Charon, Hydra makes about 2 orbits (for a ratio of 6:1 in their orbital periods), while Nix makes nearly 3 orbits (for a 4:1 ratio); this also means that the orbital periods of Hydra and Nix are in a 3:2 ratio. These relationships of the orbital periods, which are approximately in the ratios of small whole numbers, suggest that the small moons are in stable dynamic resonances with Charon and with each other that is, all three bodies pass one another periodically, interacting via gravity in a way that tends to maintain the regularity of their encounters.

Discoveries of Pluto and its moons

When Pluto was found, it was considered the third planet to be discovered, after Uranus and Neptune, as opposed to the six planets that have been visible in the sky to the naked eye since ancient times. The existence of a ninth planet had been postulated beginning in the late 19th century on the basis of apparent perturbations of the orbital motion of Uranus, which suggested that a more-distant body was gravitationally disturbing it. Astronomers later realized that these perturbations were spurious the gravitational force from Pluto’s small mass is not strong enough to have been the source of the suspected disturbances. Thus, Pluto’s discovery was a remarkable coincidence attributable to careful observations rather than to accurate prediction of the existence of a hypothetical planet.

The search for the expected planet was supported most actively at the Lowell Observatory in Flagstaff, Ariz., U.S., in the early 20th century. It was initiated by the founder of the observatory, Percival Lowell, an American astronomer who had achieved notoriety through his highly publicized claims of canal sightings on Mars. After two unsuccessful attempts to find the planet prior to Lowell’s death in 1916, an astronomical camera built specifically for this purpose and capable of collecting light from a wide field of sky was put into service in 1929, and a young amateur astronomer, Clyde Tombaugh, was hired to carry out the search. On Feb. 18, 1930, less than one year after he began his work, Tombaugh found Pluto in the constellation Gemini. The object appeared as a dim “star” of the 15th magnitude that slowly changed its position against the fixed background stars as it pursued its 248-year orbit around the Sun. Although Lowell and other astronomers had predicted that the unknown planet would be much larger and brighter than the object Tombaugh found, Pluto was quickly accepted as the expected ninth planet. The symbol invented for it, ♇, stands both for the first two letters of Pluto and for the initials of Percival Lowell.

Charon was discovered in 1978 on images of Pluto that had been recorded photographically at the U.S. Naval Observatory station in Flagstaff, fewer than 6 km (3.7 miles) from the site of Pluto’s discovery. These images were being recorded by James W. Christy and Robert S. Harrington in an attempt to obtain more-accurate measurements of Pluto’s orbit. The new satellite was named after the boatman in Greek mythology who ferries dead souls to Hades’ realm in the underworld.

Prior to the discovery of Charon, Pluto was thought to be larger and more massive than it actually is; there was no way to determine either quantity directly. Even in the discovery images, Charon appears as an unresolved bump on the side of Pluto, an indication of the observational difficulties posed by the relative nearness of the two bodies, their great distance from Earth, and the distorting effects of Earth’s atmosphere. Only near the end of the 20th century, with the availability of the Hubble Space Telescope and Earth-based instruments equipped with adaptive optics that compensate for atmospheric turbulence, did astronomers first resolve Pluto and Charon into separate bodies.

A team of nine astronomers working in the United States discovered Pluto’s two small moons, Hydra and Nix, in 2005 in images made with the Hubble Space Telescope during a concerted search for objects traveling around Pluto as small as 25 km (16 miles) in diameter. To confirm the orbits, the astronomers checked Hubble images of Pluto and Charon made in 2002 for surface-mapping studies and found faint but definite indications of two objects moving along the orbital paths calculated from the 2005 images.

Origin of Pluto and its moons

Before the discovery of Charon, it was popular to assume that Pluto was a former moon of Neptune that had somehow escaped its orbit. This idea gained support from the apparent similarity of the dimensions of Pluto and Triton and the near coincidence in Triton’s orbital period (5.9 days) and Pluto’s rotation period (6.4 days). It was suggested that a close encounter between these two bodies when they were both moons led to the ejection of Pluto from the Neptunian system and caused Triton to assume the retrograde orbit that is presently observed.

Astronomers found it difficult to establish the likelihood that all these events would have occurred, and the discovery of Charon provided information that further refuted the theory. Because the revised mass of Pluto is only half that of Triton, Pluto clearly could not have caused the reversal of Triton’s orbit. Also, the fact that Pluto has a proportionally large moon of its own makes the escape idea implausible. Current thinking favours the idea that Pluto and Charon instead formed as two independent bodies in the solar nebula, the gaseous cloud from which the solar system condensed (see solar system: Origin of the solar system). A collision between Pluto and a proto-Charon could have produced a debris ring around Pluto that accreted by gravitational attraction to form the present moon. This scenario is similar to the currently favoured model for the formation of the Moon as a result of the collision of a Mars-sized body with Earth (see Moon: Origin and evolution). Just as the Moon appears to be deficient in volatile elements relative to Earth as a consequence of its high-temperature origin, so also can the absence of methane on Charon, along with the relatively high densities of both Pluto and Charon, be explained by a similar process.

Astronomers have argued that Pluto’s two small moons also are products of the same collision that resulted in the present Charon. The alternative scenario that they formed independently elsewhere in the outer solar system and were later gravitationally captured by the Pluto-Charon system does not appear likely given the combination of circular coplanar orbits and multiple dynamic resonances that currently exist for the two small bodies and Charon. Rather, these conditions suggest that material in the ring of debris that was ejected from the collision accreted into all three moons and possibly into others yet to be found.

This collision scenario implies that at the time the Pluto-Charon system formed, about 4.6 billion years ago, the outer solar nebula contained many icy bodies with the same approximate dimensions as these two. The bodies themselves are thought to have been built up from smaller entities that today would be recognized as the nuclei of comets. Triton is presumably another of these large icy planetesimals, captured into orbit by Neptune in the planet’s early history. Chiron, a small body orbiting the Sun between Saturn and Uranus and believed to be a giant comet nucleus, and Phoebe, a moon of Saturn, represent somewhat smaller examples of such objects.

Most of these icy planetesimals were incorporated into the cores of the giant planets during their formation. Many others, however, are thought to have remained as the unconsolidated debris that makes up the Kuiper belt a thick disk-shaped region, flattened toward the plane of the solar system, that lies beyond Neptune’s orbit and, significantly, includes the outer part of Pluto’s orbit. Billions more icy objects were scattered to the outermost reaches of the solar system during the formation of Uranus and Neptune; they are believed to form the Oort cloud, a huge spherical shell surrounding the solar system at a distance of some 50,000 AU. After more than a thousand Kuiper belt objects (KBOs) were directly observed starting in the early 1990s, astronomers came to the conclusion that Pluto and Charon likely are large members of the Kuiper belt and that bodies such as Chiron, Neptune’s moon Triton, and a number of other icy moons of the outer planets originated as KBOs. In fact, like Pluto, there is one group of KBOs having highly eccentric orbits inclined to the plane of the solar system and exhibiting the same stabilizing 3:2 orbital resonance with Neptune. In recognition of this affinity, astronomers named this group of objects Plutinos (“little Plutos”).

Pluto’s status as a solar system member

Prior to the removal of Pluto from the official list of planets, astronomers had never established a rigorous scientific definition of a solar system planet, nor had they agreed on a minimum mass, radius, or mechanism of origin for a body to qualify as one. The traditional “instinctive” distinctions between the larger planetary bodies of the solar system, their moons, and small bodies such as asteroids and comets were made when their differences had seemed more profound and clear-cut and when the nature of the small bodies as remnant building blocks of the planets was dimly perceived. This early, disjointed conception of the solar system was in some ways analogous to the situation described by the Indian fable of the blind men, each of whom identified a different object after touching a different part of the same elephant. It later became clear that the original groupings of the components of the solar system required reclassification under a set of more-complex, interrelated definitions.

If Pluto had been discovered in the context of the Kuiper belt rather than as an isolated entity, it might never have been ranked with the eight planets. Indeed, in the decades after Pluto’s discovery, some astronomers continued to question its planetary status in view of its small size, icy composition, and anomalous orbital characteristics. Moreover, about the turn of the 21st century, astronomers observed several KBOs that are each roughly the size of Charon and one, named Eris, that is slightly larger than Pluto itself. Because Pluto was no longer unique in the outer reaches of the solar system, it became incumbent on astronomers either to admit additional members into the planetary ranks or to exclude Pluto. In 2006 the IAU voted to take the latter course while establishing the category of dwarf planets to recognize the larger, more-massive members of a given population of objects having similar compositions and origins and occupying the same orbital “neighbourhood.” Thus, Pluto, Eris, and Ceres Ceres, with a diameter of some 940 km (585 miles), is the largest object in the asteroid belt were designated dwarf planets. In June 2008 the IAU created a subcategory within the dwarf planet category, called plutoids, for all dwarf planets that are farther from the Sun than Neptune that is, bodies that are large KBOs. Pluto and Eris are plutoids; Ceres, because of its location in the asteroid belt, is not. Since then, two more KBOs, Makemake and Haumea, have been designated dwarf planets and plutoids.