The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, the largest among planetary satellites relative to the size of the planet that it orbits; the Moon is after Jupiter's satellite Io the second-densest satellite in the Solar System among those whose densities are known. The Moon is thought to have formed not long after Earth; the most accepted explanation is that the Moon formed from the debris left over after a giant impact between Earth and a Mars-sized body called Theia. The Moon is in synchronous rotation with Earth, thus always shows the same side to Earth, the near side; the near side is marked by dark volcanic maria that fill the spaces between the bright ancient crustal highlands and the prominent impact craters. After the Sun, the Moon is the second-brightest visible celestial object in Earth's sky, its surface is dark, although compared to the night sky it appears bright, with a reflectance just higher than that of worn asphalt.
Its gravitational influence produces the ocean tides, body tides, the slight lengthening of the day. The Moon's average orbital distance is 1.28 light-seconds. This is about thirty times the diameter of Earth; the Moon's apparent size in the sky is the same as that of the Sun, since the star is about 400 times the lunar distance and diameter. Therefore, the Moon covers the Sun nearly during a total solar eclipse; this matching of apparent visual size will not continue in the far future because the Moon's distance from Earth is increasing. The Moon was first reached in September 1959 by an unmanned spacecraft; the United States' NASA Apollo program achieved the only manned lunar missions to date, beginning with the first manned orbital mission by Apollo 8 in 1968, six manned landings between 1969 and 1972, with the first being Apollo 11. These missions returned lunar rocks which have been used to develop a geological understanding of the Moon's origin, internal structure, the Moon's history. Since the Apollo 17 mission in 1972, the Moon has been visited only by unmanned spacecraft.
Both the Moon's natural prominence in the earthly sky and its regular cycle of phases as seen from Earth have provided cultural references and influences for human societies and cultures since time immemorial. Such cultural influences can be found in language, lunar calendar systems and mythology; the usual English proper name for Earth's natural satellite is "the Moon", which in nonscientific texts is not capitalized. The noun moon is derived from Old English mōna, which stems from Proto-Germanic *mēnô, which comes from Proto-Indo-European *mḗh₁n̥s "moon", "month", which comes from the Proto-Indo-European root *meh₁- "to measure", the month being the ancient unit of time measured by the Moon; the name "Luna" is used. In literature science fiction, "Luna" is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of Earth's moon; the modern English adjective pertaining to the Moon is lunar, derived from the Latin word for the Moon, luna. The adjective selenic is so used to refer to the Moon that this meaning is not recorded in most major dictionaries.
It is derived from the Ancient Greek word for the Moon, σελήνη, from, however derived the prefix "seleno-", as in selenography, the study of the physical features of the Moon, as well as the element name selenium. Both the Greek goddess Selene and the Roman goddess Diana were alternatively called Cynthia; the names Luna and Selene are reflected in terminology for lunar orbits in words such as apolune and selenocentric. The name Diana comes from the Proto-Indo-European *diw-yo, "heavenly", which comes from the PIE root *dyeu- "to shine," which in many derivatives means "sky and god" and is the origin of Latin dies, "day"; the Moon formed 4.51 billion years ago, some 60 million years after the origin of the Solar System. Several forming mechanisms have been proposed, including the fission of the Moon from Earth's crust through centrifugal force, the gravitational capture of a pre-formed Moon, the co-formation of Earth and the Moon together in the primordial accretion disk; these hypotheses cannot account for the high angular momentum of the Earth–Moon system.
The prevailing hypothesis is that the Earth–Moon system formed after an impact of a Mars-sized body with the proto-Earth. The impact blasted material into Earth's orbit and the material accreted and formed the Moon; the Moon's far side has a crust, 30 mi thicker than that of the near side. This is thought to be; this hypothesis, although not perfect best explains the evidence. Eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, Jeff Taylor challenged fellow lunar scientists: "You have eighteen months. Go back to your Apollo data, go back to your computer, do whatever you have to, but make up your mind. Don't come to our conference unless you have something to say about the Moon's birth." At the 1984 conference at Kona, the giant impact hypothesis emerged as the most consensual theory. Before the conference, there were parti
Hanyu Pinyin abbreviated to pinyin, is the official romanization system for Standard Chinese in mainland China and to some extent in Taiwan. It is used to teach Standard Mandarin Chinese, written using Chinese characters; the system includes four diacritics denoting tones. Pinyin without tone marks is used to spell Chinese names and words in languages written with the Latin alphabet, in certain computer input methods to enter Chinese characters; the pinyin system was developed in the 1950s by many linguists, including Zhou Youguang, based on earlier forms of romanizations of Chinese. It was published by revised several times; the International Organization for Standardization adopted pinyin as an international standard in 1982, was followed by the United Nations in 1986. The system was adopted as the official standard in Taiwan in 2009, where it is used for international events rather than for educational or computer-input purposes, but "some cities and organizations, notably in the south of Taiwan, did not accept this", so it remains one of several rival romanization systems in use.
The word Hànyǔ means'the spoken language of the Han people', while Pīnyīn means'spelled sounds'. In 1605, the Jesuit missionary Matteo Ricci published Xizi Qiji in Beijing; this was the first book to use the Roman alphabet to write the Chinese language. Twenty years another Jesuit in China, Nicolas Trigault, issued his Xi Ru Ermu Zi at Hangzhou. Neither book had much immediate impact on the way in which Chinese thought about their writing system, the romanizations they described were intended more for Westerners than for the Chinese. One of the earliest Chinese thinkers to relate Western alphabets to Chinese was late Ming to early Qing dynasty scholar-official, Fang Yizhi; the first late Qing reformer to propose that China adopt a system of spelling was Song Shu. A student of the great scholars Yu Yue and Zhang Taiyan, Song had been to Japan and observed the stunning effect of the kana syllabaries and Western learning there; this galvanized him into activity on a number of fronts, one of the most important being reform of the script.
While Song did not himself create a system for spelling Sinitic languages, his discussion proved fertile and led to a proliferation of schemes for phonetic scripts. The Wade–Giles system was produced by Thomas Wade in 1859, further improved by Herbert Giles in the Chinese–English Dictionary of 1892, it was popular and used in English-language publications outside China until 1979. In the early 1930s, Communist Party of China leaders trained in Moscow introduced a phonetic alphabet using Roman letters, developed in the Soviet Oriental Institute of Leningrad and was intended to improve literacy in the Russian Far East; this Sin Wenz or "New Writing" was much more linguistically sophisticated than earlier alphabets, but with the major exception that it did not indicate tones of Chinese. In 1940, several thousand members attended a Border Region Sin Wenz Society convention. Mao Zedong and Zhu De, head of the army, both contributed their calligraphy for the masthead of the Sin Wenz Society's new journal.
Outside the CCP, other prominent supporters included Sun Fo. Over thirty journals soon appeared written in Sin Wenz, plus large numbers of translations, some contemporary Chinese literature, a spectrum of textbooks. In 1940, the movement reached an apex when Mao's Border Region Government declared that the Sin Wenz had the same legal status as traditional characters in government and public documents. Many educators and political leaders looked forward to the day when they would be universally accepted and replace Chinese characters. Opposition arose, because the system was less well adapted to writing regional languages, therefore would require learning Mandarin. Sin Wenz fell into relative disuse during the following years. In 1943, the U. S. military engaged Yale University to develop a romanization of Mandarin Chinese for its pilots flying over China. The resulting system is close to pinyin, but does not use English letters in unfamiliar ways. Medial semivowels are written with y and w, apical vowels with r or z.
Accent marks are used to indicate tone. Pinyin was created by Chinese linguists, including Zhou Youguang, as part of a Chinese government project in the 1950s. Zhou is called "the father of pinyin," Zhou worked as a banker in New York when he decided to return to China to help rebuild the country after the establishment of the People's Republic of China in 1949, he became an economics professor in Shanghai, in 1955, when China's Ministry of Education created a Committee for the Reform of the Chinese Written Language, Premier Zhou Enlai assigned Zhou Youguang the task of developing a new romanization system, despite the fact that he was not a professional linguist. Hanyu Pinyin was based on several existing systems: Gwoyeu Romatzyh of 1928, Latinxua Sin Wenz of 1931, the diacritic markings from zhuyin. "I'm not the father of pinyin," Zhou said years later. It's a lo
Simplified Chinese characters
Simplified Chinese characters are standardized Chinese characters prescribed in the Table of General Standard Chinese Characters for use in mainland China. Along with traditional Chinese characters, they are one of the two standard character sets of the contemporary Chinese written language; the government of the People's Republic of China in mainland China has promoted them for use in printing since the 1950s and 1960s to encourage literacy. They are used in the People's Republic of China and Singapore. Traditional Chinese characters are used in Hong Kong and the Republic of China. While traditional characters can still be read and understood by many mainland Chinese and the Chinese community in Malaysia and Singapore, these groups retain their use of simplified characters. Overseas Chinese communities tend to use traditional characters. Simplified Chinese characters may be referred to by their official name colloquially; the latter refers to simplifications of character "structure" or "body", character forms that have existed for thousands of years alongside regular, more complicated forms.
On the other hand, the official name refers to the modern systematically simplified character set, which includes not only structural simplification but substantial reduction in the total number of standardized Chinese characters. Simplified character forms were created by reducing the number of strokes and simplifying the forms of a sizable proportion of Chinese characters; some simplifications were based on popular cursive forms embodying graphic or phonetic simplifications of the traditional forms. Some characters were simplified by applying regular rules, for example, by replacing all occurrences of a certain component with a simplified version of the component. Variant characters with the same pronunciation and identical meaning were reduced to a single standardized character the simplest amongst all variants in form. Many characters were left untouched by simplification, are thus identical between the traditional and simplified Chinese orthographies; some simplified characters are dissimilar to and unpredictably different from traditional characters in those where a component is replaced by a simple symbol.
This has led some opponents of simplification to complain that the'overall process' of character simplification is arbitrary. Proponents counter that the system of simplification is internally consistent. Proponents have emphasized a some particular simplified characters as innovative and useful improvements, although many of these have existed for centuries as longstanding and widespread variants. A second round of simplifications was promulgated in 1977, but was retracted in 1986 for a variety of reasons due to the confusion caused and the unpopularity of the second round simplifications. However, the Chinese government never dropped its goal of further simplification in the future. In August 2009, the PRC began collecting public comments for a modified list of simplified characters; the new Table of General Standard Chinese Characters consisting of 8,105 characters was implemented for use by the State Council of the People's Republic of China on June 5, 2013. Although most of the simplified Chinese characters in use today are the result of the works moderated by the government of the People's Republic of China in the 1950s and 60s, character simplification predates the PRC's formation in 1949.
Cursive written text always includes character simplification. Simplified forms used in print are attested as early as the Qin dynasty. One of the earliest proponents of character simplification was Lufei Kui, who proposed in 1909 that simplified characters should be used in education. In the years following the May Fourth Movement in 1919, many anti-imperialist Chinese intellectuals sought ways to modernise China. Traditional culture and values such as Confucianism were challenged. Soon, people in the Movement started to cite the traditional Chinese writing system as an obstacle in modernising China and therefore proposed that a reform be initiated, it was suggested that the Chinese writing system should be either simplified or abolished. Lu Xun, a renowned Chinese author in the 20th century, stated that, "If Chinese characters are not destroyed China will die". Recent commentators have claimed that Chinese characters were blamed for the economic problems in China during that time. In the 1930s and 1940s, discussions on character simplification took place within the Kuomintang government, a large number of Chinese intellectuals and writers maintained that character simplification would help boost literacy in China.
In 1935, 324 simplified characters collected by Qian Xuantong were introduced as the table of first batch of simplified characters, but they were suspended in 1936. The PRC issued its first round of official character simplifications in two documents, the first in 1956 and the second in 1964. Within the PRC, further character simplification became associated with the leftists of the Cultural Revolution, culminating with the second-round simplified characters, which were promulgated in 1977. In part due to the shock and unease felt in the wake of the Cultural Revolution and Mao's death, the second-round of simplifications was poorly received. In 1986 the authorities retracted the second round completely. In the same year, the authorities promulgated a final list of simplifications, identical to the 1964 list except for six changes (including the restoration of three characters, simplified in the First Round: 叠, 覆, 像.
Chinese surnames are used by Han Chinese and Sinicized ethnic groups in Mainland China, Hong Kong, Malaysia, Taiwan, Singapore, Philippines and among overseas Chinese communities. In ancient times two types of surnames existed, namely xing or clan names, shi or lineage names. Chinese family names are patrilineal. Women do not change their surnames upon marriage, except in places with more Western influences such as Hong Kong. Traditionally Chinese surnames have been exogamous; the colloquial expressions laobaixing and bǎixìng are used in Chinese to mean "ordinary folks", "the people", or "commoners". Prior to the Warring States period, only the ruling families and the aristocratic elite had surnames. There was a difference between clan names or xing and lineage names or shi. Xing were surnames held by the noble clans, they are composed of a nü radical, taken by some as evidence they originated from matriarchal societies based on maternal lineages. Another hypothesis has been proposed by sinologist Léon Vandermeersch upon observation of the evolution of characters in oracular scripture from the Shang dynasty through the Zhou.
The "female" radical seems to appear at the Zhou period next to Shang sinograms indicating an ethnic group or a tribe. This combination seems to designate a female and could mean "lady of such or such clan"; the structure of the xing sinogram could reflect the fact that in the royal court of Zhou, at least in the beginning, only females were called by their birth clan name, while the men were designated by their title or fief. Prior to the Qin dynasty China was a fengjian society; as fiefdoms were divided and subdivided among descendants, so additional sub-surnames known as shi were created to distinguish between noble lineages according to seniority, though in theory they shared the same ancestor. In this way, a nobleman would hold a xing; the difference between xing and shi was blurring for women since the Spring and Autumn period. After the states of China were unified by Qin Shi Huang in 221 BC, surnames spread to the lower classes. Many shi surnames survive to the present day. According to Kiang Kang-Hu, there are 18 sources from which Chinese surnames may be derived, while others suggested at least 24.
These may be names associated with a ruling dynasty such as the various titles and names of rulers and dynasty, or they may be place names of various territories, towns and specific locations, the title of official posts or occupations, or names of objects, or they may be derived from the names of family members or clans, in a few cases, names of contempt given by a ruler. The following are some of the common sources: Xing: These were reserved for the central lineage of the royal family, with collateral lineages taking their own shi; the traditional description was what were known as the "Eight Great Xings of High Antiquity", namely Jiāng, Jī, Yáo, Yíng, Sì, Yún, Guī and Rèn, though some sources quote Jí as the last one instead of Rèn. Of these xings, only Jiang and Yao have survived in their original form to modern days as occurring surnames. Royal decree by the Emperor, such as Kuang. State name: Many nobles and commoners took the name of their state, either to show their continuing allegiance or as a matter of national and ethnic identity.
These are some of the most common Chinese surnames. Name of a fief or place of origin: Fiefdoms were granted to collateral branches of the aristocracy and it was natural as part of the process of sub-surnaming for their names to be used. An example is Marquis of Ouyangting, whose descendants took the surname Ouyang. There are some two hundred examples of this identified of two-character surnames, but few have survived to the present. Names of an ancestor: Like the previous example, this was a common origin with close to 500 or 600 examples, 200 of which are two-character surnames. An ancestor's courtesy name would be used. For example, Yuan Taotu took the second character of his grandfather's courtesy name Boyuan as his surname. Sometimes titles granted to ancestors could be taken as surnames. Seniority within the family: In ancient usage, the characters of meng, shu and ji were used to denote the first, second and fourth eldest sons in a family; these were sometimes adopted as surnames. Of these, Meng is the best known.
Occupation From official positions, such as Shǐ, Jí, Líng, Cāng, Kù, Jiàn, Shàngguān, Tàishǐ, Zhōngháng, Yuèzhèng, in the case of Shang's "Five Officials", namely Sīmǎ, Sītú, Sīkōng, Sīshì and Sīkòu.
The Qing dynasty the Great Qing, was the last imperial dynasty of China. It was established in 1636, ruled China proper from 1644 to 1912, it was succeeded by the Republic of China. The Qing multi-cultural empire lasted for three centuries and formed the territorial base for modern China, it was the fifth largest empire in world history. The dynasty was founded by the Manchu Aisin Gioro clan in Manchuria. In the late sixteenth century, Nurhaci a Ming Jianzhou Guard vassal, began organizing "Banners", military-social units that included Manchu and Mongol elements. Nurhaci formed the Manchu clans into a unified entity. By 1636, his son Hong Taiji began driving Ming forces out of the Liaodong Peninsula and declared a new dynasty, the Qing. In an unrelated development, peasant rebels led by Li Zicheng conquered the Ming capital, Beijing, in 1644. Rather than serve them, Ming general Wu Sangui made an alliance with the Manchus and opened the Shanhai Pass to the Banner Armies led by the regent Prince Dorgon.
He seized the capital. Resistance from the Southern Ming and the Revolt of the Three Feudatories led by Wu Sangui delayed the Qing conquest of China proper by nearly four decades; the conquest was only completed in 1683 under the Kangxi Emperor reign. The Ten Great Campaigns of the Qianlong Emperor from the 1750s to the 1790s extended Qing control into Inner Asia; the early Qing rulers maintained their Manchu customs, while their title was Emperor, they used "Bogd khaan" when dealing with the Mongols and they were patrons of Tibetan Buddhism. They governed using Confucian styles and institutions of bureaucratic government and retained the imperial examinations to recruit Han Chinese to work under or in parallel with Manchus, they adapted the ideals of the tributary system in dealing with neighboring territories. During the Qianlong Emperor reign the dynasty reached its apogee, but began its initial decline in prosperity and imperial control; the population rose to some 400 millions, but taxes and government revenues were fixed at a low rate guaranteeing eventual fiscal crisis.
Corruption set in, rebels tested government legitimacy, ruling elites failed to change their mindsets in the face of changes in the world system. Following the Opium Wars, European powers imposed "unequal treaties", free trade, extraterritoriality and treaty ports under foreign control; the Taiping Rebellion and the Dungan Revolt in Central Asia led to the deaths of some 20 million people, most of them due to famines caused by war. In spite of these disasters, in the Tongzhi Restoration of the 1860s, Han Chinese elites rallied to the defense of the Confucian order and the Qing rulers; the initial gains in the Self-Strengthening Movement were destroyed in the First Sino-Japanese War of 1895, in which the Qing lost its influence over Korea and the possession of Taiwan. New Armies were organized, but the ambitious Hundred Days' Reform of 1898 was turned back in a coup by the conservative Empress Dowager Cixi; when the Scramble for Concessions by foreign powers triggered the violently anti-foreign "Boxers", the foreign powers invaded China, Cixi declared war on them, leading to defeat and the flight of the Imperial Court to Xi'an.
After agreeing to sign the Boxer Protocol, the government initiated unprecedented fiscal and administrative reforms, including elections, a new legal code, abolition of the examination system. Sun Yat-sen and other revolutionaries competed with constitutional monarchists such as Kang Youwei and Liang Qichao to transform the Qing Empire into a modern nation. After the deaths of Cixi and the Guangxu Emperor in 1908, the hardline Manchu court alienated reformers and local elites alike by obstructing social reform; the Wuchang Uprising on 11 October 1911, led to the Xinhai Revolution. General Yuan Shikai negotiated the abdication of Puyi, the last emperor, on 12 February 1912. Nurhaci declared himself the "Bright Khan" of the Later Jin state in honor both of the 12th–13th century Jurchen Jin dynasty and of his Aisin Gioro clan, his son Hong Taiji renamed the dynasty Great Qing in 1636. There are competing explanations on the meaning of Qīng; the name may have been selected in reaction to the name of the Ming dynasty, which consists of the Chinese characters for "sun" and "moon", both associated with the fire element of the Chinese zodiacal system.
The character Qīng is associated with the water element. This association would justify the Qing conquest as defeat of fire by water; the water imagery of the new name may have had Buddhist overtones of perspicacity and enlightenment and connections with the Bodhisattva Manjusri. The Manchu name daicing, which sounds like a phonetic rendering of Dà Qīng or Dai Ching, may in fact have been derived from a Mongolian word "ᠳᠠᠢᠢᠴᠢᠨ, дайчин" that means "warrior". Daicing gurun may therefore have meant "warrior state", a pun, only intelligible to Manchu and Mongol people. In the part of the dynasty, however the Manchus themselves had forgotten this possible meaning. After conquering "China proper", the Manchus identified their state as "China", referred to it as Dulimbai Gurun in Manchu; the emperors equated the lands of the Qing state as "China" in both the Chinese and Manchu languages, defining China as a multi-ethnic state, rejecting the idea that "China" only meant Han areas. The Qing emperors proclaimed that bo
Liang Qichao, courtesy name Zhuoru, art name Rengong, was a Chinese scholar, journalist and reformist who lived during the late Qing dynasty and the early Republic of China. He inspired Chinese scholars with reform movements. Liang Qichao was born in a small village in Xinhui, Guangdong Province on February 23, 1873. Liang's father, Liang Baoying, was a farmer and local scholar, but a classical background that emphasized on tradition and education for ethnic rejuvenescence allowed him to be introduced to various literary works at six years old. By the age of nine, Liang started writing thousand-word essays and became a district-school student soon after. Liang had two wives: Wang Guiquan, they gave birth to nine children, all of whom became successful individuals through Liang's strict and effective education. Three of them were scientific personnel at the Chinese Academy of Sciences, including Liang Sicheng, the prominent historian of Chinese architecture. Liang passed the Xiucai degree provincial examination at the age of 11.
In 1884, he undertook the arduous task of studying for the traditional governmental exams. At the age of 16, he passed the Juren second level provincial exams and was the youngest successful candidate at that time. In 1890, Liang failed in his Jinshi degree national examinations in Beijing and never earned a higher degree, he took the exams along with a famous Chinese scholar and reformist. According to one popular narrative of Liang's failure to pass the Jinshi, the examiner was determined to flunk Kang for his heterodox challenge to existing institutions, but since the exams were all anonymous, he could only presume that the exam with the most unorthodox views was Kang's. Instead, Kang disguised himself by writing an examination eight-legged essay espousing traditionalist ideas and passed the exam while Liang's paper was assumed to be Kang's and picked out to be failed. Inspired by the book A short account of the maritime circuit, Liang became interested in western ideologies. After returning home, Liang went on to study with Kang Youwei, teaching at Wanmu Caotang in Guangzhou.
Kang's teachings about foreign affairs fuelled Liang's interest in reforming China. In 1895, Liang went to the capital Beijing again with Kang for the national examination. During the examination, he was a leader of the Gongche Shangshu movement. After failing to pass the examination for a second time, he stayed in Beijing to help Kang publish Domestic and Foreign Information, he helped to organise the Society for National Strengthening, where Liang served as secretary. For time, he was enlisted by the governor of Hunan, Chen Baozhen to edit reform-friendly publications, such as the Hunan Daily and the Hunan Journal; as an advocate of constitutional monarchy, Liang was unhappy with the governance of the Qing Government and wanted to change the status quo in China. He organized reforms with Kang Youwei by putting their ideas on paper and sending them to the Guangxu Emperor of the Qing dynasty; this movement is known as the Hundred Days' Reform. Their proposal asserted that China was in need of more than "self-strengthening", called for many institutional and ideological changes such as getting rid of corruption and remodeling the state examination system.
Liang thus was a major influence in the debates on democracy in China. This proposal soon ignited a frenzy of disagreement, Liang became a wanted man by order of Empress Dowager Cixi, the leader of the political conservative faction who took over the government as regent. Cixi opposed reforms at that time and along with her supporters, condemned the "Hundred Days' Reform" as being too radical. In 1898, the Conservative Coup ended all reforms, Liang fled to Japan, where he stayed for the next 14 years. While in Tokyo he befriended the influential politician and future Japanese Prime Minister Inukai Tsuyoshi. In Japan, he continued to advocate the democratic cause by using his writings to raise support for the reformers’ cause among overseas Chinese and foreign governments, he continued to emphasize the importance of individualism, to support the concept of a constitutional monarchy as opposed to the radical republicanism supported by the Tokyo-based Tongmeng Hui. During his time in Japan, Liang served as a benefactor and colleague to Phan Boi Chau, one of Vietnam's most important anti-colonial revolutionaries..
In 1899, Liang went to Canada, where he met Dr. Sun Yat-Sen among others to Honolulu in Hawaii. During the Boxer Rebellion, Liang was back in Canada, where he formed the "Chinese Empire Reform Association"; this organisation became the Constitutionalist Party which advocated constitutional monarchy. While Sun promoted revolution, Liang preached reform. In 1900-1901, Liang visited Australia on a six-month tour which aimed at raising support for a campaign to reform the Chinese empire in order to modernise China through adopting the best of Western technology and government systems, he gave public lectures to both Chinese and Western audiences around the country. This visit coincided with the Federation of the six British colonies into the new nation of Australia in 1901, he felt. He was feted by politicians, met the first Prime Minister of Australia, Edmund Barton, he returned to Japan that year. In 1903, Liang embar
A planet is an astronomical body orbiting a star or stellar remnant, massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, has cleared its neighbouring region of planetesimals. The term planet is ancient, with ties to history, science and religion. Five planets in the Solar System are visible to the naked eye; these were regarded by many early cultures as emissaries of deities. As scientific knowledge advanced, human perception of the planets changed, incorporating a number of disparate objects. In 2006, the International Astronomical Union adopted a resolution defining planets within the Solar System; this definition is controversial because it excludes many objects of planetary mass based on where or what they orbit. Although eight of the planetary bodies discovered before 1950 remain "planets" under the modern definition, some celestial bodies, such as Ceres, Pallas and Vesta, Pluto, that were once considered planets by the scientific community, are no longer viewed as such.
The planets were thought by Ptolemy to orbit Earth in epicycle motions. Although the idea that the planets orbited the Sun had been suggested many times, it was not until the 17th century that this view was supported by evidence from the first telescopic astronomical observations, performed by Galileo Galilei. About the same time, by careful analysis of pre-telescopic observational data collected by Tycho Brahe, Johannes Kepler found the planets' orbits were elliptical rather than circular; as observational tools improved, astronomers saw that, like Earth, each of the planets rotated around an axis tilted with respect to its orbital pole, some shared such features as ice caps and seasons. Since the dawn of the Space Age, close observation by space probes has found that Earth and the other planets share characteristics such as volcanism, hurricanes and hydrology. Planets are divided into two main types: large low-density giant planets, smaller rocky terrestrials. There are eight planets in the Solar System.
In order of increasing distance from the Sun, they are the four terrestrials, Venus and Mars the four giant planets, Saturn and Neptune. Six of the planets are orbited by one or more natural satellites. Several thousands of planets around other stars have been discovered in the Milky Way; as of 1 April 2019, 4,023 known extrasolar planets in 3,005 planetary systems, ranging in size from just above the size of the Moon to gas giants about twice as large as Jupiter have been discovered, out of which more than 100 planets are the same size as Earth, nine of which are at the same relative distance from their star as Earth from the Sun, i.e. in the circumstellar habitable zone. On December 20, 2011, the Kepler Space Telescope team reported the discovery of the first Earth-sized extrasolar planets, Kepler-20e and Kepler-20f, orbiting a Sun-like star, Kepler-20. A 2012 study, analyzing gravitational microlensing data, estimates an average of at least 1.6 bound planets for every star in the Milky Way.
Around one in five Sun-like stars is thought to have an Earth-sized planet in its habitable zone. The idea of planets has evolved over its history, from the divine lights of antiquity to the earthly objects of the scientific age; the concept has expanded to include worlds not only in the Solar System, but in hundreds of other extrasolar systems. The ambiguities inherent in defining planets have led to much scientific controversy; the five classical planets, being visible to the naked eye, have been known since ancient times and have had a significant impact on mythology, religious cosmology, ancient astronomy. In ancient times, astronomers noted how certain lights moved across the sky, as opposed to the "fixed stars", which maintained a constant relative position in the sky. Ancient Greeks called these lights πλάνητες ἀστέρες or πλανῆται, from which today's word "planet" was derived. In ancient Greece, China and indeed all pre-modern civilizations, it was universally believed that Earth was the center of the Universe and that all the "planets" circled Earth.
The reasons for this perception were that stars and planets appeared to revolve around Earth each day and the common-sense perceptions that Earth was solid and stable and that it was not moving but at rest. The first civilization known to have a functional theory of the planets were the Babylonians, who lived in Mesopotamia in the first and second millennia BC; the oldest surviving planetary astronomical text is the Babylonian Venus tablet of Ammisaduqa, a 7th-century BC copy of a list of observations of the motions of the planet Venus, that dates as early as the second millennium BC. The MUL. APIN is a pair of cuneiform tablets dating from the 7th century BC that lays out the motions of the Sun and planets over the course of the year; the Babylonian astrologers laid the foundations of what would become Western astrology. The Enuma anu enlil, written during the Neo-Assyrian period in the 7th century BC, comprises a list of omens and their relationships with various celestial phenomena including the motions of the planets.
Venus and the outer planets Mars and Saturn were all identified by Babylonian astronomers. These would remain the only known planets until the invention of the telescope in early modern times; the ancient Greeks did not attach as much significance to the planets as the Babylonians. The Pythagoreans, in the 6th and 5t