text:
User talk:Jorgenev/MFD'd/Wikipedia:Recent Changes coefficient

something for meta? Martin

 * It is a little addendum to Are You a Wikipediholic Test, so I have put in the same namespace. - Patrick 01:34 19 Jul 2003 (UTC)

I don't really get this. Shouldn't it be the other way around? If you have a low C value you're adept at following up on recent changes. If you have a score(rate of addiction) of almost 1 then you are very slow at getting up to speed! Correct me if am wrong... You could reverse the c value by making the formula something like this n/(c-1)=time needed. Eruantalon
 * The larger c (below 1) the longer it takes, even my wrong version, which I have now corrected, had that right.--Patrick 23:40, 15 Apr 2005 (UTC)

 * If c<1, after being away for n hours it takes n/(c-1) hours to catch up.

This is impossible - for c<1, this results in a negative number. Daniel

 * You are right, my formula was wrong, but the way it was changed was not an improvement. I have corrected it now. To process the changes which occurred while you were away takes nc hours, but in the meantime there are more changes, taking nc2, etc. The sum of the geometric series is nc/(1-c).--Patrick 23:34, 15 Apr 2005 (UTC)

c=1 or more? So, essentially, c>1 would imply you're such a wikipedaholic that you can anticipate and react to changes before they're made. Yes, that is indeed scary. --Saforrest 23:30, 10 March 2006 (UTC)

Switch to watchlist
Perhaps, since RC is so overwhelming these days, we should be more concerned with one's watchlist? If one is keeping up with one's watchlist a good portion of the day, then that is addicted indeed. --maru  (talk)  contribs 06:55, 29 May 2006 (UTC)
 * Well that would not be too efficient as the number of watchlists users have varies considerably. -- S iva1979 Talk to me  20:34, 9 June 2006 (UTC)

My reversal
I have changed the old c to $$(c)^{-1}$$ as if you take less than 1 hour to catch up on the RC of 1 hour, you're anticipating and reacting to changes before they're made. 4 T C 14:58, 29 December 2009 (UTC)

 * No, you're not. The scenario is that you go away for an hour, then return and start to catch up. --Tango (talk) 09:23, 21 March 2010 (UTC)

Equation is wrong?
The expression given is negative for c>1. Is this a mistake? NotAnonymous0 (talk) 06:17, 21 March 2010 (UTC)

 * Yes. I've reverted the most recent change. There has been a very slow edit war on this page about the maths... people keep making it not make any sense and I keep fixing it... --Tango (talk) 09:22, 21 March 2010 (UTC)


text:
Talk:Hipparchos

Whats going on here? Pizza Puzzle

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

title: Talk:Hipparchos


text:
Al-Biruni

Abu Rayhan Muhammad ibn Ahmad al-Biruni (أبو الريحان البيروني; 973 – after 1050), known as al-Biruni, was a Khwarazmian Iranian scholar and polymath during the Islamic Golden Age. He has been called variously "Father of Comparative Religion", "Father of modern geodesy", Founder of Indology and the first anthropologist.

Al-Biruni was well versed in physics, mathematics, astronomy, and natural sciences, and also distinguished himself as a historian, chronologist, and linguist. He studied almost all the sciences of his day and was rewarded abundantly for his tireless research in many fields of knowledge. Royalty and other powerful elements in society funded al-Biruni's research and sought him out with specific projects in mind. Influential in his own right, Al-Biruni was himself influenced by the scholars of other nations, such as the Greeks, from whom he took inspiration when he turned to the study of philosophy. A gifted linguist, he was conversant in Khwarezmian, Persian, Arabic, Sanskrit, and also knew Greek, Hebrew, and Syriac. He spent much of his life in Ghazni, then capital of the Ghaznavids, in modern-day central-eastern Afghanistan. In 1017, he travelled to the Indian subcontinent and wrote a treatise on Indian culture entitled ("The History of India"), after exploring the Hindu faith practiced in India. He was, for his time, an admirably impartial writer on the customs and creeds of various nations, his scholarly objectivity earning him the title ("The Master") in recognition of his remarkable description of early 11th-century India.

Name
Al-Biruni's name is derived from the Persian word or  ("outskirts"), as he was born in an outlying district of Kath, the capital of the  Afrighid kingdom of Khwarazm. The city, now called Beruniy, is part of the autonomous republic of Karakalpakstan in northwest Uzbekistan.

His name was most commonly latinized as Alberonius.

Life
Al-Biruni spent the first twenty-five years of his life in Khwarezm where he studied Islamic jurisprudence, theology, grammar, mathematics, astronomy, medicine and philosophy and dabbled not only in the field of physics, but also in those of most of the other sciences. The Iranian Khwarezmian language, which was Biruni's mother tongue, survived for several centuries after Islam until the Turkification of the region – at least some of the culture of ancient Khwarezm endured – for it is hard to imagine that the commanding figure of Biruni, a repository of so much knowledge, should have appeared in a cultural vacuum. He was sympathetic to the Afrighids, who were overthrown by the rival dynasty of Ma'munids in 995. He left his homeland for Bukhara, then under the Samanid ruler Mansur II the son of Nuh II. There he corresponded with Avicenna, and there are extant exchanges of views between these two scholars.

In 998, he went to the court of the Ziyarid amir of Tabaristan, Qabus ((r. 977 – 981)). There he wrote his first important work, ("The remaining traces of past centuries", translated as "Chronology of ancient nations" or "Vestiges of the Past") on historical and scientific chronology, probably around 1000, though he later made some amendments to the book. He also visited the court of the Bavandid ruler Al-Marzuban. Accepting the definite demise of the Afrighids at the hands of the Ma'munids, he made peace with the latter who then ruled Khwarezm. Their court at Gorganj (also in Khwarezm) was gaining fame for its gathering of brilliant scientists.

In 1017, Mahmud of Ghazni captured Rey. Most scholars, including al-Biruni, were taken to Ghazni, the capital of the Ghaznavid dynasty. Biruni was made court astrologer and accompanied Mahmud on his invasions into India, living there for a few years. He was 44 when he went on the journeys with Mahmud of Ghazni. Biruni became acquainted with all things related to India. During this time he wrote his study of India, finishing it around 1030. Along with his writing, Al-Biruni also made sure to extend his study to science while on the expeditions. He sought to find a method to measure the height of the sun, and created a makeshift quadrant for that purpose. Al-Biruni was able to make much progress in his study over the frequent travels that he went on throughout the lands of India.

Belonging to the Sunni Ash'ari school, al-Biruni nevertheless also associated with Maturidi theologians. He was however, very critical of the Mu'tazila, particularly criticising al-Jahiz and Zurqan. He also repudiated Avicenna for his views on the eternality of the universe.

Astronomy

Of the 146 books written by al-Bīrūnī, 95 are devoted to astronomy, mathematics, and related subjects like mathematical geography. He lived during the Islamic Golden Age, when the Abbasid Caliphs promoted astronomical research, because such research possessed not only a scientific but also a religious dimension: in Islam worship and prayer require a knowledge of the precise directions of sacred locations, which can be determined accurately only through the use of astronomical data.

In carrying out his research, al-Biruni used a variety of different techniques dependent upon the particular field of study involved.

His major work on astrology is primarily an astronomical and mathematical text; he states: "I have begun with Geometry and proceeded to Arithmetic and the Science of Numbers, then to the structure of the Universe and finally to Judicial Astrology [sic], for no one who is worthy of the style and title of Astrologer [sic] who is not thoroughly conversant with these for sciences." In these earlier chapters he lays the foundations for the final chapter, on astrological prognostication, which he criticises. In a later work, he wrote a refutation of astrology, in contradistinction to the legitimate science of astronomy, for which he expresses wholehearted support. Some suggest that his reasons for refuting astrology relate to the methods used by astrologers being based upon pseudoscience rather than empiricism and also to a conflict between the views of the astrologers and those of the orthodox theologians of Sunni Islam.

He wrote an extensive commentary on Indian astronomy in the mostly translation of Aryabhatta's work, in which he claims to have resolved the matter of Earth's rotation in a work on astronomy that is no longer extant, his  ("Key to Astronomy"):

[T]he rotation of the earth does in no way impair the value of astronomy, as all appearances of an astronomic character can quite as well be explained according to this theory as to the other. There are, however, other reasons which make it impossible. This question is most difficult to solve. The most prominent of both modern and ancient astronomers have deeply studied the question of the moving of the earth, and tried to refute it. We, too, have composed a book on the subject called Miftah-ilm-alhai'a (Key to Astronomy), in which we think we have surpassed our predecessors, if not in the words, at all events in the matter.

In his major astronomical work, the Mas'ud Canon, Biruni observed that, contrary to Ptolemy, the Sun's apogee (highest point in the heavens) was mobile, not fixed. He wrote a treatise on the astrolabe, describing how to use it to tell the time and as a quadrant for surveying. One particular diagram of an eight-geared device could be considered an ancestor of later Muslim astrolabes and clocks. More recently, Biruni's eclipse data was used by Dunthorne in 1749 to help determine the acceleration of the Moon, and his data on equinox times and eclipses was used as part of a study of Earth's past rotation.

Refutation of Eternal Universe
Like later adherents of the Ash'ari school, such as al-Ghazali, al-Biruni is famous for vehemently defending the majority Sunni position that the universe had a beginning, being a strong supporter of creatio ex nihilo, specifically refuting the philosopher Avicenna in a multiple letter correspondence. Al-Biruni stated: ""Other people, besides, hold this foolish persuasion, that time has no terminus quo at all.""

He further stated that Aristotle, whose arguments Avicenna uses, contradicted himself when he stated that the universe and matter has a start whilst holding on to the idea that matter is pre-eternal. In his letters to Avicenna, he stated the argument of Aristotle, that there is a change in the creator. He further argued that stating there is a change in the creator would mean there is a change in the effect (meaning the universe has change) and that the universe coming into being after not being is such a change (and so arguing there is no change – no beginning – means Aristotle believes the creator is negated). Al-Biruni was proud of the fact that he followed the textual evidence of the religion without being influenced by Greek philosophers such as Aristotle.

Physics
Al-Biruni contributed to the introduction of the scientific method to medieval mechanics. He developed experimental methods to determine density, using a particular type of hydrostatic balance. Al-Biruni's method of using the hydrostatic balance was precise, and he was able to measure the density of many different substances, including precious metals, gems, and even air. He also used this method to determine the radius of the earth, which he did by measuring the angle of elevation of the horizon from the top of a mountain and comparing it to the angle of elevation of the horizon from a nearby plain.

In addition to developing the hydrostatic balance, Al-Biruni also wrote extensively on the topic of density, including the different types of densities and how they are measured. His work on the subject was very influential and was later used by scientists like Galileo and Newton in their own research.

Geography and geodesy
Bīrūnī devised a novel method of determining the Earth's radius by means of the observation of the height of a mountain. He carried it out at Nandana in Pind Dadan Khan (present-day Pakistan). He used trigonometry to calculate the radius of the Earth using measurements of the height of a hill and measurement of the dip in the horizon from the top of that hill. His calculated radius for the Earth of 3928.77 miles was 2% higher than the actual mean radius of 3847.80 miles. His estimate was given as 12,803,337 cubits, so the accuracy of his estimate compared to the modern value depends on what conversion is used for cubits. The exact length of a cubit is not clear; with an 18-inch cubit his estimate would be 3,600 miles, whereas with a 22-inch cubit his estimate would be 4,200 miles. One significant problem with this approach is that Al-Biruni was not aware of atmospheric refraction and made no allowance for it. He used a dip angle of 34 arc minutes in his calculations, but refraction can typically alter the measured dip angle by about 1/6, making his calculation only accurate to within about 20% of the true value.

In his Codex Masudicus (1037), Al-Biruni theorized the existence of a landmass along the vast ocean between Asia and Europe, or what is today known as the Americas. He argued for its existence on the basis of his accurate estimations of the Earth's circumference and Afro-Eurasia's size, which he found spanned only two-fifths of the Earth's circumference, reasoning that the geological processes that gave rise to Eurasia must surely have given rise to lands in the vast ocean between Asia and Europe. He also theorized that at least some of the unknown landmass would lie within the known latitudes which humans could inhabit, and therefore would be inhabited.

Pharmacology and mineralogy
Biruni wrote a pharmacopoeia, the ("Book on the Pharmacopoeia of Medicine"). It lists synonyms for drug names in Syriac, Persian, Greek, Baluchi, Afghan, Kurdi, and some Indian languages.

He used a hydrostatic balance to determine the density and purity of metals and precious stones. He classified gems by what he considered their primary physical properties, such as specific gravity and hardness, rather than the common practice of the time of classifying them by colour.

History and chronology
Biruni's main essay on political history, ("Book of nightly conversation concerning the affairs of Ḵᵛārazm") is now known only from quotations in Bayhaqī's Tārīkh-e Masʿūdī. In addition to this various discussions of historical events and methodology are found in connection with the lists of kings in his al-Āthār al-bāqiya and in the Qānūn as well as elsewhere in the Āthār, in India, and scattered throughout his other works. Al-Biruni's Chronology of Ancient Nations attempted to accurately establish the length of various historical eras.

History of religions
Biruni is widely considered to be one of the most important Muslim authorities on the history of religion. He is known as a pioneer in the field of comparative religion in his study of, among other creeds, Zoroastrianism, Judaism, Hinduism, Christianity, Buddhism and Islam. He assumed the superiority of Islam: "We have here given an account of these things in order that the reader may learn by the comparative treatment of the subject how much superior the institutions of Islam are, and how more plainly this contrast brings out all customs and usages, differing from those of Islam, in their essential foulness." However he was happy on occasion to express admiration for other cultures, and quoted directly from the sacred texts of other religions when reaching his conclusions. He strove to understand them on their own terms rather than trying to prove them wrong. His underlying concept was that all cultures are at least distant relatives of all other cultures because they are all human constructs. "Rather, what Al-Biruni seems to be arguing is that there is a common human element in every culture that makes all cultures distant relatives, however foreign they might seem to one another."

Al-Biruni divides Hindus into an educated and an uneducated class. He describes the educated as monotheistic, believing that God is one, eternal, and omnipotent and eschewing all forms of idol worship. He recognizes that uneducated Hindus worshiped a multiplicity of idols yet points out that even some Muslims (such as the Jabriyah) have adopted anthropomorphic concepts of God.

Anthropology
Al-Biruni wrote about the peoples, customs and religions of the Indian subcontinent. According to Akbar S. Ahmed, like modern anthropologists, he engaged in extensive participant observation with a given group of people, learnt their language and studied their primary texts, presenting his findings with objectivity and neutrality using cross-cultural comparisons. Akhbar S. Ahmed concluded that Al-Biruni can be considered as the first Anthropologist, others, however, have argued that he can hardly be considered an anthropologist in the conventional sense.

Indology
Al-Biruni's fame as an Indologist rests primarily on two texts. Al-Biruni wrote an encyclopedic work on India called Alberuni's India (variously translated as Verifying All That the Indians Recount, the Reasonable and the Unreasonable, or The book confirming what pertains to India, whether rational or despicable, in which he explored nearly every aspect of Indian life. During his journey through India, military and political history were not Al-Biruni's main focus: he decided rather to document the civilian and scholarly aspects of Hindu life, examining culture, science, and religion. He explored religion within a rich cultural context. He expressed his objectives with simple eloquence: He also translated the Yoga sutras of Indian sage Patanjali with the title :

"I shall not produce the arguments of our antagonists in order to refute such of them, as I believe to be in the wrong. My book is nothing but a simple historic record of facts. I shall place before the reader the theories of the Hindus exactly as they are, and I shall mention in connection with them similar theories of the Greeks in order to show the relationship existing between them."

An example of Al-Biruni's analysis is his summary of why many Hindus hate Muslims. Biruni notes in the beginning of his book how the Muslims had a hard time learning about Hindu knowledge and culture. He explains that Hinduism and Islam are totally different from each other. Moreover, Hindus in 11th century India had suffered waves of destructive attacks on many of its cities, and Islamic armies had taken numerous Hindu slaves to Persia, which – claimed Al-Biruni – contributed to Hindus becoming suspicious of all foreigners, not just Muslims. Hindus considered Muslims violent and impure, and did not want to share anything with them. Over time, Al-Biruni won the welcome of Hindu scholars. Al-Biruni collected books and studied with these Hindu scholars to become fluent in Sanskrit, discover and translate into Arabic the mathematics, science, medicine, astronomy and other fields of arts as practiced in 11th-century India. He was inspired by the arguments offered by Indian scholars who believed earth must be globular in shape, which they felt was the only way to fully explain the difference in daylight hours by latitude, seasons and Earth's relative positions with Moon and stars. At the same time, Al-Biruni was also critical of Indian scribes, who he believed carelessly corrupted Indian documents while making copies of older documents. He also criticized the Hindus on what he saw them do and not do, for example finding them deficient in curiosity about history and religion.

One of the specific aspects of Hindu life that Al-Biruni studied was the Hindu calendar. His scholarship on the topic exhibited great determination and focus, not to mention the excellence in his approach of the in-depth research he performed. He developed a method for converting the dates of the Hindu calendar to the dates of the three different calendars that were common in the Islamic countries of his time period, the Greek, the Arab/Muslim, and the Persian. Biruni also employed astronomy in the determination of his theories, which were complex mathematical equations and scientific calculation that allows one to convert dates and years between the different calendars.

The book does not limit itself to tedious records of battle because Al-Biruni found the social culture to be more important. The work includes research on a vast array of topics of Indian culture, including descriptions of their traditions and customs. Although he tried to stay away from political and military history, Biruni did indeed record important dates and noted actual sites of where significant battles occurred. Additionally, he chronicled stories of Indian rulers and told of how they ruled over their people with their beneficial actions and acted in the interests of the nation. His details are brief and mostly just list rulers without referring to their real names, and he did not go on about deeds that each one carried out during their reign, which keeps in line with Al-Biruni's mission to try to stay away from political histories. Al-Biruni also described the geography of India in his work. He documented different bodies of water and other natural phenomena. These descriptions are useful to today's modern historians because they are able to use Biruni's scholarship to locate certain destinations in modern-day India. Historians are able to make some matches while also concluding that certain areas seem to have disappeared and been replaced with different cities. Different forts and landmarks were able to be located, legitimizing Al-Biruni's contributions with their usefulness to even modern history and archeology.

The dispassionate account of Hinduism given by Al-Biruni was remarkable for its time. He stated that he was fully objective in his writings, remaining unbiased like a proper historian should. Biruni documented everything about India just as it happened. But, he did note how some of the accounts of information that he was given by natives of the land may not have been reliable in terms of complete accuracy, however, he did try to be as honest as possible in his writing. Edward C. Sachau compares it to "a magic island of quiet, impartial research in the midst of a world of clashing swords, burning towns, and plundered temples." Biruni's writing was very poetic, which may diminish some of the historical value of the work for modern times. The lack of description of battle and politics makes those parts of the picture completely lost. However, Many have used Al-Biruni's work to check facts of history in other works that may have been ambiguous or had their validity questioned.

Works
Most of the works of Al-Biruni are in Arabic although he seemingly wrote the in both Persian and Arabic, showing his mastery over both languages. Bīrūnī's catalogue of his own literary production up to his 65th lunar/63rd solar year (the end of 427/1036) lists 103 titles divided into 12 categories: astronomy, mathematical geography, mathematics, astrological aspects and transits, astronomical instruments, chronology, comets, an untitled category, astrology, anecdotes, religion, and books he no longer possesses.

Selection of extant works

 * Alberuni's India (A Critical Study of What India Says, Whether Accepted by Reason or Refused; تحقيق ما للهند من مقولة معقولة في العقل أو مرذولة), popularly called (The Book on India); English translations called  or Alberuni's India. The work is a compendium of India's religion and philosophy.
 * (Book of Instruction in the Elements of the Art of Astrology); in Persian.
 * The Remaining Signs of Past Centuries (الآثار الباقية عن القرون الخالية), a comparative study of calendars of cultures and civilizations, (including several chapters on Christian cults), which contains mathematical, astronomical, and historical information.
 * The Mas'udi Law (قانون مسعودي), an encyclopaedia of astronomy, geography, and engineering, dedicated to Mas'ud, son of the Ghaznavid sultan Mahmud of Ghazni.
 * Understanding Astrology (التفهيم لصناعة التنجيم), a question and answer style book about mathematics and astronomy, in Arabic and Persian.
 * Pharmacy, a work on drugs and medicines.
 * Gems (الجماهر في معرفة الجواهر), a geology manual about minerals and gems. Dedicated to Mawdud, son of Mas'ud.
 * A history of Mahmud of Ghazni and his father
 * A history of Khawarezm
 * (Epître de Berūnī)
 * (Epître de Berūnī)

Persian work
Biruni wrote most of his works in Arabic, the scientific language of his age, but is one of the most important of the early works of science in Persian, and is a rich source for Persian prose and lexicography. The book covers the Quadrivium in a detailed and skilled fashion.

Legacy
Following Al-Biruni's death, his work was neither built upon or referenced by scholars. Centuries later, his writings about India, which had become of interest to the British Raj, were revisited.

The lunar crater Al-Biruni and the asteroid 9936 Al-Biruni are named in his honour. Biruni Island in Antarctica is named after al-Biruni. In Iran, surveying engineers are celebrated on al-Biruni's birthday.

In June 2009, Iran donated a pavilion to the United Nations Office in Vienna—placed in the central Memorial Plaza of the Vienna International Center. Named the Scholars Pavilion, it features the statues of four prominent Iranian scholars: Avicenna, Abu Rayhan Biruni, Zakariya Razi (Rhazes) and Omar Khayyam.

In popular culture
A film about the life of Al-Biruni,, was released in the Soviet Union in 1974.

Irrfan Khan portrayed Al-Biruni in the 1988 Doordarshan historical drama Bharat Ek Khoj. He has been portrayed by Cüneyt Uzunlar in the Turkish television series Alparslan: Büyük Selçuklu on TRT 1.

title: Al-Biruni


text:
Angels of Light

Angels of Light was an American neofolk band that was formed circa 1998 by singer-songwriter and musician Michael Gira after he disbanded Swans, the group he had founded in 1982. The band has marked a distinctly different style for Gira since he left Swans, most noticeably being musically more melodic and less brutal than his previous efforts and with emphasis on acoustic instruments and folk and country influences.

Before the band was formed, Gira intended to call his post-Swans acoustic/song-based project The Pleasure Seekers. This name was discarded because there had been a group with the same name in the 1960s. The first two live performances of what would become the Angels of Light (the Tonic/Bowery Ballroom benefit shows) were billed as "Michael Gira with guests".

The revolving lineup up Angels of Light included a wide range of musicians from New York City and elsewhere, including Dana Schechter of Bee and Flower, Kid Congo Powers of The Cramps, Larry Mullins (a.k.a. Toby Dammit), Cassis Birgit Staudt of b-blush, Bliss Blood of The Moonlighters, Thor Harris of Shearwater, Swans guitarist Christoph Hahn, Phil Puleo of Cop Shoot Cop, and freak-folk musician Devendra Banhart. On The Angels of Light Sing 'Other People' and We Are Him, Gira was backed by Brooklyn band Akron/Family. Hahn, Harris and Puleo went on to join Gira in the new Swans lineup assembled in 2010. Shortly thereafter Swans released their first post-reunion LP My Father Will Guide Me up a Rope to the Sky.

All Angels of Light albums were released on Michael Gira's label Young God Records.

Discography
Studio albums
 * New Mother (1999)
 * How I Loved You (2001)
 * Everything Is Good Here/Please Come Home (2003)
 * The Angels of Light Sing 'Other People' (2005)
 * Akron/Family & Angels of Light (2005) – split album with Akron/Family.
 * We Are Him (2007)

Live albums
 * We Were Alive! (2002)

Singles
 * "Praise Your Name" (1999)

title: Angels of Light


text:
Abu Hanifa Dinawari

Abū Ḥanīfa Aḥmad ibn Dāwūd Dīnawarī (ابوحنيفه دينوری; died 895) was an Islamic Golden Age polymath: astronomer, agriculturist, botanist, metallurgist, geographer, mathematician, and historian.

Life
Of Persian stock, Dinawari was born in the (now ruined) town of Dinawar in modern-day western Iran. It had some importance due to its geographical location, serving as the entrance to the region of Jibal as well as a crossroad between the culture of Iran and that of the inhabitants on the other side of the Zagros Mountains. The birth date of Dinawari is uncertain; it is likely that he was born during the first or second decade of the 9th-century. He was instructed in the two main traditions of the Abbasid-era grammarians of al-Baṣrah and of al-Kūfah. His principal teachers were Ibn al-Sikkīt and his own father. He studied grammar, philology, geometry, arithmetic, and astronomy and was known to be a reliable traditionalist. His most renowned contribution is the Book of Plants, for which he is considered the founder of Arabic botany.

Dinawari's Kitāb al-akhbār al-ṭiwāl (General History), written from a Persian point of view, is possibly the earliest apparent effort to combine Iranian and Islamic history. While historians such as al-Tabari and Bal'ami devoted the introduction of their work to long discourses on the duration of the world, Dinawari attempted to establish the importance of Iranshahr ("land of Iran") as the centre of the world. In his work, Dinawari notably devoted much less space to the Islamic prophet Muhammad compared to that of Iran. Regardless, Dinawari was a devoted Muslim, as indicated by his commentary on the Qur'an. He concluded the history with the suppression of Babak Khorramdin's rebellion in 837, and the subsequent execution of the Iranian general Khaydhar ibn Kawus al-Afshin.

Besides having access to early Arabic sources, Dinawari also made use of Persian sources, including pre-Islamic epic romances. Fully acquainted with the Persian language, Dinawari occasionally inserted phrases from the language into his work.

Dinawari's spiritual successor was Hamza al-Isfahani (died after 961).

Works
The tenth century biographical encyclopaedia, al-Fihrist written by Al-Nadim, lists sixteen book titles by Dinawari:

Mathematics and natural sciences

 * 1) Kitâb al-kusuf ("Book of Solar Eclipses")
 * 2) Kitāb an-nabāt yufadiluh al-‘ulamā' fī ta’līfih (كتاب النبات يفضله العلماء في تأليفه), ‘Plants, valued by scholars for its composition'
 * 3) Kitāb Al-Anwā (كتاب الانواء) 'Tempest' (weather)
 * 4) Kitāb Al-qiblah wa'z-zawāl (كتاب القبلة والزوال) "Book of Astral Orientations"
 * 5) Kitāb ḥisāb ad-dūr (كتاب حساب الدور), "Arithmetic/Calculation of Cycles"
 * 6) Kitāb ar-rud ‘alā raṣd al-Iṣbhānī (كتاب الردّ على رصدٌ الاصفهانى) Refutation of Lughdah al-Iṣbhānī
 * 7) Kitāb al-baḥth fī ḥusā al-Hind (كتاب البحث في حسا الهند), "Analysis of Indian Arithmetic"
 * 8) Kitāb al-jam’ wa'l-tafrīq (كتاب الجمع والتفريق); "Book of Arithmetic/Summation and Differentiation"
 * 9) Kitāb al-jabr wa-l-muqabila (كتاب الجبر والمقابلة), "Algebra and Equation"
 * 10) Kitāb nuwādr al-jabr (كتاب نوادرالجبر), "Rare Forms of Algebra"

Social sciences and humanities

 * 1) Ansâb al-Akrâd ("Ancestry of the Kurds").
 * 2) Kitāb Kabīr  (كتاب كبير) "Great Book" [in history of sciences]
 * 3) Kitāb al-faṣāha (كتاب الفصاحة), "Book of Rhetoric"
 * 4) Kitāb al-buldān (كتاب البلدان), "Book of Cities (Regions) (Geography)"
 * 5) Kitāb ash-sh’ir wa-shu’arā’ (كتاب الشعر والشعراء), "Poetry and the Poets"
 * 6) Kitāb al-Waṣāyā (كتاب الوصايا), Commandments (wills);
 * 7) Kitāb ma yulahan fīh al’āmma (كتاب ما يلحن فيه العامّة), How the Populace Errs in Speaking;
 * 8) Islâh al-mantiq ("Improvement of Speech")
 * 9) Kitāb al-akhbār al-ṭiwāl (كتاب الاخبار الطوال), "General History"

Editions & translations
Dinawari's General History (Al-Akhbar al-Tiwal) has been edited and published numerous times (Vladimir Guirgass, 1888; Muhammad Sa'id Rafi'i, 1911; Ignace Krachkovsky, 1912; 'Abd al-Munim 'Amir & Jamal al-din Shayyal, 1960; Isam Muhammad al-Hajj 'Ali, 2001), but has not been translated in its entirety into a European language. Jackson Bonner has recently prepared an English translation of the pre-Islamic passages of al-Akhbar al-Tiwal.

Book of Plants
Al-Dinawari is considered the founder of Arabic botany for his Kitab al-Nabat (Book of Plants), which consisted of six volumes. Only the third and fifth volumes have survived, though the sixth volume has partly been reconstructed based on citations from later works. In the surviving portions of his works, 637 plants are described from the letters sin to ya. He describes the phases of plant growth and the production of flowers and fruit.

The first part of the Book of Plants describes astronomical and meteorological concepts as they relate to plants, including the planets and constellations, the sun and moon, the lunar phases indicating seasons and rain, anwa, and atmospheric phenomena such as winds, thunder, lightning, snow, and floods. The book also describes different types of ground, indicating which types are more convenient for plants and the qualities and properties of good ground.

Al-Dinawari quoted from other early Muslim botanical works that are now lost, such as those of al-Shaybani, Ibn al-Arabi, al-Bahili, and Ibn as-Sikkit.

title: Abu Hanifa Dinawari


text:
Madhhab

A madhhab (مَذْهَب,, pl. مَذَاهِب, ) refers to any school of thought within Islamic jurisprudence. The major Sunni madhhab are Hanafi, Maliki, Shafi'i and Hanbali. They emerged in the ninth and tenth centuries CE and by the twelfth century almost all jurists aligned themselves with a particular madhab. These four schools recognize each other's validity and they have interacted in legal debate over the centuries. Rulings of these schools are followed across the Muslim world without exclusive regional restrictions, but they each came to dominate in different parts of the world. For example, the Maliki school is predominant in North and West Africa; the Hanafi school in South and Central Asia; the Shafi'i school in East Africa and Southeast Asia; and the Hanbali school in North and Central Arabia. The first centuries of Islam also witnessed a number of short-lived Sunni madhhabs. The Zahiri school, which is considered to be endangered, continues to exert influence over legal thought. The development of Shia legal schools occurred along the lines of theological differences and resulted in the formation of the Ja'fari madhhab amongst Twelver Shias, as well as the Isma'ili and Zaidi madhhabs amongst Isma'ilis and Zaidis respectively, whose differences from Sunni legal schools are roughly of the same order as the differences among Sunni schools. The Ibadi legal school, distinct from Sunni and Shia madhhabs, is predominant in Oman. Unlike Sunnis, Shias, and Ibadis, non-denominational Muslims are not affiliated with any madhhab.

The transformations of Islamic legal institutions in the modern era have had profound implications for the madhhab system. With the spread of codified state laws in the Muslim world, the influence of the madhhabs beyond personal ritual practice depends on the status accorded to them within the national legal system. State law codification commonly drew on rulings from multiple madhhabs, and legal professionals trained in modern law schools have largely replaced traditional ulama as interpreters of the resulting laws. In the 20th century, some Islamic jurists began to assert their intellectual independence from traditional madhhabs. With the spread of Salafi influence and reformist currents in the 20th century; a handful of Salafi scholars have asserted independence from being strictly bound by the traditional legal mechanisms of the four schools. Nevertheless, the majority of Sunni scholarship continues to uphold post-classical creedal belief in rigorously adhering (Taqlid) to one of the four schools in all legal details.

The Amman Message, which was endorsed in 2005 by prominent Islamic scholars around the world, recognized four Sunni schools (Hanafi, Maliki, Shafi'i, Hanbali), two Shia schools (Ja'fari, Zaidi), the Ibadi school and the Zahiri school. The Muslim schools of jurisprudence are located in Pakistan, Iran, Bangladesh, India, Indonesia, Nigeria, Egypt, Turkey, Afghanistan, Kazakhstan, Russia, China, the Philippines, Algeria, Libya, Saudi Arabia and multiple other countries.

"Ancient" schools
According to John Burton, "modern research shows" that fiqh was first "regionally organized" with "considerable disagreement and variety of view". In the second century of Islam, schools of fiqh were noted for the loyalty of their jurists to the legal practices of their local communities, whether Mecca, Kufa, Basra, Syria, etc. (Egypt's school in Fustat was a branch of Medina's school of law and followed such practices—up until the end of the 8th century—as basing verdict on one single witness (not two) and the oath of the claimant. Its principal jurist in the second half of the 8th century was al-Layth b. Sa'd.) Al-Shafiʽi wrote that, "every capital of the Muslims is a seat of learning whose people follow the opinion of one of their countrymen in most of his teachings". The "real basis" of legal doctrine in these "ancient schools" was not a body of reports of Muhammad's sayings, doings, silent approval (the ahadith) or even those of his Companions, but the "living tradition" of the school as "expressed in the consensus of the scholars", according to Joseph Schacht.

Al-Shafi‘i and after
It has been asserted that madhahib were consolidated in the 9th and 10th centuries as a means of excluding dogmatic theologians, government officials and non-Sunni sects from religious discourse. Historians have differed regarding the times at which the various schools emerged. One interpretation is that Sunni Islam was initially split into four groups: the Hanafites, Malikites, Shafi'ites and Zahirites. Later, the Hanbalites and Jarirites developed two more schools; then various dynasties effected the eventual exclusion of the Jarirites; eventually, the Zahirites were also excluded when the Mamluk Sultanate established a total of four independent judicial positions, thus solidifying the Maliki, Hanafi, Shafi'i and Hanbali schools. During the era of the Islamic Gunpowders, the Ottoman Empire reaffirmed the official status of these four schools as a reaction to Shi'ite Persia. Some are of the view that Sunni jurisprudence falls into two groups: Ahl al-Ra'i ("people of opinions", emphasizing scholarly judgment and reason) and Ahl al-Hadith ("people of traditions", emphasizing strict interpretation of scripture).

10th century Shi'ite scholar Ibn al-Nadim named eight groups: Maliki, Hanafi, Shafi'i, Zahiri, Imami Shi'ite, Ahl al-Hadith, Jariri and Kharijite. Abu Thawr also had a school named after him. In the 12th century Jariri and Zahiri schools were absorbed by the Shafi'i and Hanbali schools respectively. Ibn Khaldun defined only three Sunni madhahib: Hanafi, Zahiri, and one encompassing the Shafi'i, Maliki and Hanbali schools as existing initially, noting that by the 14th-century historian the Zahiri school had become extinct,  only for it to be revived again in parts of the Muslim world by the mid-20th century.

Historically, the fiqh schools were often in political and academic conflict with one another, vying for favor with the ruling government in order to have their representatives appointed to legislative and especially judiciary positions.

Modern era
The transformations of Islamic legal institutions in the modern era have had profound implications for the madhhab system. Legal practice in most of the Muslim world has come to be controlled by government policy and state law, so that the influence of the madhhabs beyond personal ritual practice depends on the status accorded to them within the national legal system. State law codification commonly utilized the methods of takhayyur (selection of rulings without restriction to a particular madhhab) and talfiq (combining parts of different rulings on the same question). Legal professionals trained in modern law schools have largely replaced traditional ulema as interpreters of the resulting laws. Global Islamic movements have at times drawn on different madhhabs and at other times placed greater focus on the scriptural sources rather than classical jurisprudence. The Hanbali school, with its particularly strict adherence to the Quran and hadith, has inspired conservative currents of direct scriptural interpretation by the Salafi and Wahhabi movements. In the 20th century many Islamic jurists began to assert their intellectual independence from traditional schools of jurisprudence. Examples of the latter approach include networks of Indonesian ulema and Islamic scholars residing in Muslim-minority countries, who have advanced liberal interpretations of Islamic law.

Schools

Generally, Sunnis will follow one particular madhhab which varies from region to region, but also believe that ijtihad must be exercised by the contemporary scholars capable of doing so. Most rely on taqlid, or acceptance of religious rulings and epistemology from a higher religious authority in deferring meanings of analysis and derivation of legal practices instead of relying on subjective readings.

Experts and scholars of fiqh follow the usul (principles) of their own madhhab, but they also study the usul, evidences, and opinions of other madhahib.

Sunni
Sunni schools of jurisprudence are each named after the classical jurist who taught them. The four primary Sunni schools are the Hanafi, Shafi'i, Maliki and Hanbali rites. The Zahiri school remains in existence but outside of the mainstream, while the Jariri, Laythi, Awza'i, and Thawri schools have become extinct.

The extant schools share most of their rulings, but differ on the particular practices which they may accept as authentic and the varying weights they give to analogical reason and pure reason.

Orthodox Sunni schools
The 4 major and 1 minor schools of thought are accepted by most scholars in most parts of the world. The Zahiri is not always accepted.

Hanafi
The Hanafi school was founded by Abu Hanifa an-Nu‘man. It is followed by Muslims in the Levant, Central Asia, Afghanistan, Pakistan, most of India, Bangladesh, Northern Egypt, Iraq and Turkey and the Balkans and by most of the Muslim communities of Russia and China. There are movements within this school such as Barelvis and Deobandi, which are concentrated in South Asia.

Maliki
The Maliki school is based on the jurisprudence of Imam Malik ibn Anas. It has also been called "School of Medina" because the school was based in Medina and the Medinian community.

It is followed by Muslims in Nigeria, Algeria, North Africa, West Africa, United Arab Emirates, Kuwait, Bahrain, Upper Egypt, and in parts of Saudi Arabia.

The Murabitun World Movement follows this school as well. In the past, it was also followed in parts of Europe under Islamic rule, particularly Islamic Spain and the Emirate of Sicily.

Shafi'i
The Shafi'i school is based upon the jurisprudence of Imam Muhammad ibn Idris ash-Shafi'i. It is followed by Muslims in the Hejaz region of Saudi Arabia, Upper Egypt, Ethiopia, Eritrea, Swahili coast, Indonesia, Malaysia, Jordan, Palestine, Philippines, Singapore, Somalia, Sri Lanka, Thailand, Yemen, Kurdistan, and southern India (such as the Mappilas of Kerala and the Konkani Muslims). Most Chechens and Dagestani people also follow the Shafi'i school. It is the official school followed by the governments of Brunei and Malaysia. The Shafi'i school is also large in Iraq and Syria.

Hanbali
The Hanbali school is based on the jurisprudence of Imam Ahmad ibn Hanbal who had been a student of Imam al-Shafi.

It is followed by Muslims in Qatar, most of Saudi Arabia and minority communities in Syria and Iraq. There are movements that are highly influenced by Hanbali fiqh such as Salafism and Wahhabism concentrated in Saudi Arabia.

Zahiri
The Zahiri school was founded by Dawud al-Zahiri. It is followed by minority communities in Morocco and Pakistan. In the past, it was also followed by the majority of Muslims in Mesopotamia, Portugal, the Balearic Islands, North Africa and parts of Spain.

Ja'fari
Twelver Shia adhere to the Ja'fari theological school associated with Ja'far al-Sadiq. In this school, the time and space bound rulings of early jurists are taken more seriously, and the Ja'fari school uses the intellect instead of analogy when establishing Islamic laws, as opposed to common Sunni practice.

Subgroups

 * Usulism: forms the overwhelming majority within the Twelver Shia denomination. They follow a Marja-i Taqlid on the subject of taqlid and fiqh. They are concentrated in Iran, Pakistan, Azerbaijan, India, Iraq, and Lebanon.
 * Akhbarism: similar to Usulis, however reject ijtihad in favor of hadith. Concentrated in Bahrain.
 * Shaykhism: an Islamic religious movement founded by Shaykh Ahmad in the early 19th century Qajar dynasty, Iran, now retaining a minority following in Iran and Iraq. It began from a combination of Sufi and Shia and Akhbari doctrines. In the mid 19th-century many Shaykhis converted to the Bábí and Baháʼí religions, which regard Shaykh Ahmad highly.

Ismaili
Ismaili Muslims follow their own school in the form of the Daim al-Islam, a book on the rulings of Islam. It describes manners and etiquette, including Ibadat in the light of guidance provided by the Ismaili Imams. The book emphasizes what importance Islam has given to manners and etiquette along with the worship of God, citing the traditions of the first four Imams of the Shi'a Ismaili Fatimid school of thought.

Subgroups

 * Nizari: the largest branch (95%) of Ismaili, they are the only Shia group to have their absolute temporal leader in the rank of Imamate, which is invested in the Aga Khan. Nizārī Ismailis believe that the successor-Imām to the Fatimid caliph Ma'ad al-Mustansir Billah was his elder son al-Nizār. While Nizārī belong to the Ja'fari jurisprudence, they adhere to the supremacy of "Kalam", in the interpretation of scripture, and believe in the temporal relativism of understanding, as opposed to fiqh (traditional legalism), which adheres to an absolutism approach to revelation.
 * Tāyyebī Mustā'līyyah: the Musta'ali group of Ismaili Muslims differ from the Nizāriyya in that they believe that the successor-Imām to the Fatimid caliph, al-Mustansir, was his younger son al-Mustaʻlī, who was made Caliph by the Fatimad Regent Al-Afdal Shahanshah. In contrast to the Nizaris, they accept the younger brother al-Mustaʻlī over Nizār as their Imam. The Bohras are an offshoot of the Taiyabi, which itself was an offshoot of the Musta'ali. The Taiyabi, supporting another offshoot of the Musta'ali, the Hafizi branch, split with the Musta'ali Fatimid, who recognized Al-Amir as their last Imam. The split was due to the Taiyabi believing that At-Tayyib Abi l-Qasim was the next rightful Imam after Al-Amir. The Hafizi themselves however considered Al-Hafiz as the next rightful Imam after Al-Amir. The Bohras believe that their 21st Imam, Taiyab abi al-Qasim, went into seclusion and established the offices of the Da'i al-Mutlaq (الداعي المطلق), Ma'zoon (مأذون) and Mukasir (مكاسر). The Bohras are the only surviving branch of the Musta'ali and themselves have split into the Dawoodi Bohra, Sulaimani, Alavi Bohra, and other smaller groups.

Zaidi
Zaidi Muslims also follow their own school in the form of the teachings of Zayd ibn Ali and Imam Abu Hanifa. In terms of law, the Zaidi school is quite similar to the Hanafi school from Sunni Islam. This is likely due to the general trend of Sunni resemblance within Zaidi beliefs. After the passing of Muhammad, Imam Jafar al-Sadiq, Imam Zayd ibn Ali, Imams Abu Hanifa and Imam Malik ibn Anas worked together in Al-Masjid an-Nabawi in Medina along with over 70 other leading jurists and scholars. Jafar al-Sadiq and Zayd ibn Ali did not themselves write any books. But their views are Hadiths in the books written by Imams Abu Hanifa and Imam Malik ibn Anas. Therefore, the Zaydis to this day and originally the Fatimids, used the Hanafi jurisprudence, as do most Sunnis.

Ibadi
The Ibadi school of Islam is named after Abd-Allah ibn Ibadh, though he is not necessarily the main figure of the school in the eyes of its adherents. Ibadism is distinct from both Sunni and Shi'ite Islam not only in terms of its jurisprudence, but also its core beliefs. Ibadi Islam is mostly practiced in Oman, with Oman being the only country in the world where Ibadis form a sizable minority of the population. Other populations of Ibadis also reside in Libya, Algeria, Tunisia and Zanzibar in Tanzania.

Amman Message
The Amman Message was a statement, signed in 2005 in Jordan by nearly 200 prominent Islamic jurists, which served as a "counter-fatwa" against a widespread use of takfir (excommunication) by jihadist groups to justify jihad against rulers of Muslim-majority countries. The Amman Message recognized eight legitimate schools of Islamic law and prohibited declarations of apostasy against them.
 * 1) Hanafi (Sunni)
 * 2) Maliki (Sunni)
 * 3) Shafi'i (Sunni)
 * 4) Hanbali (Sunni)
 * 5) Ja'fari (Shia)
 * 6) Zaidiyyah (Shia)
 * 7) Ibadiyyah
 * 8) Zahiriyah

The statement also asserted that fatwas can be issued only by properly trained muftis, thereby seeking to delegitimize fatwas issued by militants who lack the requisite qualifications.

title: Madhhab


text:
Ismail al-Jazari

Badīʿ az-Zaman Abu l-ʿIzz ibn Ismāʿīl ibn ar-Razāz al-Jazarī (1136–1206, بَدِيعُ الزَّمانِ أَبُو العِزِّ بْنُ إسْماعِيلَ بْنِ الرَّزَّازِ الجَزَرِيّ, ) was a Muslim polymath: a scholar, inventor, mechanical engineer, artisan and artist from the Artuqid Dynasty of Jazira in Mesopotamia. He is best known for writing The Book of Knowledge of Ingenious Mechanical Devices (كتاب في معرفة الحيل الهندسية, also known as Automata) in 1206, where he described 50 mechanical devices, along with instructions on how to construct them. He is credited with the invention of the elephant clock.

Biography

Al-Jazari was born in the area of Upper Mesopotamia in 1136. Sources state his exact location is unknown, but they speculate he could have been born in Jazirat ibn Umar, where he got the name Jazari from or Al-Jazira which was used to denote Upper Mesopotamia. The only biographical information known about him is contained in his Book of Knowledge of Ingenious Mechanical Devices. Like his father before him, he served as chief engineer at the Artuklu Palace, the residence of the Mardin branch of the Artuqids which ruled across Upper Mesopotamia as vassals of the Zengid dynasty of Mosul and later of Ayyubid general Saladin. Little is known about his ethnic background, so he has been variously described as Arab,  Kurdish or Persian.

Al-Jazari was part of a tradition of artisans and was thus more a practical engineer than an inventor who appears to have been "more interested in the craftsmanship necessary to construct the devices than in the technology which lay behind them" and his machines were usually "assembled by trial and error rather than by theoretical calculation". His Book of Knowledge of Ingenious Mechanical Devices appears to have been quite popular as it appears in a large number of manuscript copies, and as he explains repeatedly, he only describes devices he has built himself. According to Mayr, the book's style resembles that of a modern "do-it-yourself" book.

Some of his devices were inspired by earlier devices, such as one of his monumental water clocks, which was based on that of a Pseudo-Archimedes. He also cites the influence of the Banū Mūsā brothers for his fountains, al-Saghani for the design of a candle clock, and Hibatullah ibn al-Husayn (d. 1139) for musical automata. Al-Jazari goes on to describe the improvements he made to the work of his predecessors, and describes a number of devices, techniques and components that are original innovations which do not appear in the works by his precessors.

1206 edition (Ahmet III 3472)
The Artuqid ruler Nasr al-Din Mahmud (r. 1201–1222) is known to have commisionned the first edition of Al-Jāmi‘ fī ṣinā‘at al-ḥiyal of Ibn al-Razzaz al-Jazari, in April 1206 at the Artuqid court. This manuscript is known as Ahmet III 3472, now in the Topkapı Sarayı Library. The miniatures are thought to reflect various aspects of the Artuqid court at the time. Ibn al-Razzaz al-Jazari was employed at the Artuqid court during the last quarter of the 12th century, and this is the earliest known manuscript of his opus.

Mechanisms and methods
The most significant aspect of al-Jazari's machines are the mechanisms, components, ideas, methods, and design features which they employ.

Camshaft
A camshaft, a shaft to which cams are attached, was described in 1206 by al-Jazari, who employed them in his automata, water clocks (such as the candle clock) and water-raising machines.

Crankshaft and crank-slider mechanism
The eccentrically mounted handle of the rotary quern-stone in fifth century BCE Spain that spread across the Roman Empire constitutes a crank. The earliest evidence of a crank and connecting rod mechanism dates to the 3rd century AD Hierapolis sawmill in the Roman Empire. The crank also appears in the mid-9th century in several of the hydraulic devices described by the Banū Mūsā brothers in their Book of Ingenious Devices.

In 1206, al-Jazari invented an early crankshaft, which he incorporated with a crank-connecting rod mechanism in his twin-cylinder pump. Like the modern crankshaft, al-Jazari's mechanism consisted of a wheel setting several crankpins into motion, with the wheel's motion being circular and the pins moving back-and-forth in a straight line. The crankshaft described by al-Jazari transforms continuous rotary motion into a linear reciprocating motion, and is central to modern machinery such as the steam engine, internal combustion engine and automatic controls.

He used the crankshaft with a connecting rod in two of his water-raising machines: the crank-driven saqiya chain pump and the double-action reciprocating piston suction pump. His water pump also employed the first known crank-slider mechanism.

Design and construction methods
English technology historian Donald Hill writes:

"We see for the first time in al-Jazari's work several concepts important for both design and construction: the lamination of timber to minimize warping, the static balancing of wheels, the use of wooden templates (a kind of pattern), the use of paper models to establish designs, the calibration of orifices, the grinding of the seats and plugs of valves together with emery powder to obtain a watertight fit, and the casting of metals in closed mold boxes with sand."

Escapement mechanism in a rotating wheel
Al-Jazari invented a method for controlling the speed of rotation of a wheel using an escapement mechanism.

Mechanical controls
According to Donald Hill, al-Jazari described several early mechanical controls, including "a large metal door, a combination lock and a lock with four bolts".

Water-raising machines
Al-Jazari invented five machines for raising water, as well as watermills and water wheels with cams on their axle used to operate automata, in the 12th and 13th centuries, and described them in 1206. It was in these water-raising machines that he introduced his most important ideas and components.

Saqiya chain pumps
The first known use of a crankshaft in a chain pump was in one of al-Jazari's saqiya machines. The concept of minimizing intermittent working is also first implied in one of al-Jazari's saqiya chain pumps, which was for the purpose of maximising the efficiency of the saqiya chain pump. Al-Jazari also constructed a water-raising saqiya chain pump which was run by hydropower rather than manual labour, though the Chinese were also using hydropower for chain pumps prior to him. Saqiya machines like the ones he described have been supplying water in Damascus since the 13th century up until modern times, and were in everyday use throughout the medieval Islamic world. Interestingly, the depiction of the chain in al-Jazari's pump appears to be in the form of a Möbius strip, from long before the Möbius strip was first identified as an object of study in mathematics.

Double-action suction pump with valves and reciprocating piston motion
Citing the Byzantine siphon used for discharging Greek fire as an inspiration, al-Jazari went on to describe his version of suction pipes, suction pump, double-action pump, and made early uses of valves and a crankshaft-connecting rod mechanism, when he developed a twin-cylinder reciprocating piston suction pump. This pump is driven by a water wheel, which drives, through a system of gears, an oscillating slot-rod to which the rods of two pistons are attached. The pistons work in horizontally opposed cylinders, each provided with valve-operated suction and delivery pipes. The delivery pipes are joined above the centre of the machine to form a single outlet into the irrigation system. This water-raising machine had a direct significance for the development of modern engineering. This pump is remarkable for three reasons:
 * The first known use of a true suction pipe (which sucks fluids into a partial vacuum) in a pump.
 * The first application of the double-acting principle.
 * The conversion of rotary to reciprocating motion via the crank-connecting rod mechanism.

Al-Jazari's suction piston pump could lift 13.6 metres of water, with the help of delivery pipes. It was not, however, any more efficient than the noria commonly used by the Muslim world at the time.

Water supply system
al-Jazari developed the earliest water supply system to be driven by gears and hydropower, which was built in 13th century Damascus to supply water to its mosques and Bimaristan hospitals. The system had water from a lake turn a scoop-wheel and a system of gears which transported jars of water up to a water channel that led to mosques and hospitals in the city.

Automata
Al-Jazari built automated moving peacocks driven by hydropower. He also created automatic doors as part of one of his elaborate water clocks, and invented water wheels with cams on their axle used to operate automata. According to Encyclopædia Britannica, the Italian Renaissance inventor Leonardo da Vinci may have been influenced by the classic automata of al-Jazari.

Mark E. Rosheim summarizes the advances in robotics made by Muslim engineers, especially al-Jazari, as follows:

"Unlike the Greek designs, these Arab examples reveal an interest, not only in dramatic illusion, but in manipulating the environment for human comfort. Thus, the greatest contribution the Arabs made, besides preserving, disseminating and building on the work of the Greeks, was the concept of practical application. This was the key element that was missing in Greek robotic science."

"The Arabs, on the other hand, displayed an interest in creating human-like machines for practical purposes but lacked, like other preindustrial societies, any real impetus to pursue their robotic science."

Drink-serving waitress
One of al-Jazari's humanoid automata was a waitress that could serve water, tea or drinks. The drink was stored in a tank with a reservoir from where the drink drips into a bucket and, after seven minutes, into a cup, after which the waitress appears out of an automatic door serving the drink.

Hand-washing automaton with flush mechanism
Al-Jazari invented a hand washing automaton incorporating a flush mechanism now used in modern flush toilets. This device is another example of humanoid automata. It consisted of a human figure, made from jointed copper, holding a pitcher resembling a peacock in its right hand. The pitcher is made from brass and holds within it a chamber, divided into two parts by a metal plate. This mechanism aided the pouring of the water from the spout so that it was smooth and would not splutter. The reservoir in which the water is held is situated within the right-hand side of the human figure. An axle is fitted into the right elbow of the human figure so as to allow the liquid to pour from the reservoir through the spout of the pitcher. The left arm of the figure had a fixed weight which would raise and lower the arm which would hold a towel, comb and mirror.

This automaton was designed to aid the king whilst he performed his ritual ablutions. A servant of the king would carry the figure and place it next to a basin that could hold liquid. The servant then turned a knob on the back of the figure which opened a valve resulting in the pouring of water from the right hand of the figure into the basin. When the reservoir is nearly empty and most of the water has been poured a mechanism is prompted and the left hand of the figure, holding the towel, comb and mirror, is extended out in the direction of the king so that he can dry himself and tend to his beard.

Peacock fountain with automated servants
Water and its usages holds particular importance in Islam; both as being an integral part of the pre-prayer washing processes wudu and ghusl, and a key feature in Islamic gardens – four fountains featuring in the Paradise Garden; the Islamic final resting place referenced in the Quran. Additionally, with Mesopotamia being a naturally drought-ridden place, machines relating to water held a significant function; in both a divine and practical sense.

An entire section of The Book of Knowledge of Ingenious Mechanical Devices was devoted to fountain mechanisms, titled: ‘On the construction in pools of fountains which change their shape, and of machines for the perpetual flute’.

Al-Jazari's "peacock fountain" was a more sophisticated hand washing device featuring humanoid automata as servants which offer soap and towels. Mark E. Rosheim describes it as follows:

"Pulling a plug on the peacock's tail releases water out of the beak; as the dirty water from the basin fills the hollow base a float rises and actuates a linkage which makes a servant figure appear from behind a door under the peacock and offer soap. When more water is used, a second float at a higher level trips and causes the appearance of a second servant figure – with a towel!" The basin of the "peacock fountain" formed the basin for performing wudu, and it would have been operated by a servant, who would have pulled the plug and positioned the peacock's beak; allowing the mechanism to release the water into the basin in front of the user.

However, whilst water moving objects such as the peacock fountain had ritualistic usage, there is suggestion that water-moving hydraulics were put to profane use. Ayhan Aytes suggests that: "Many of the devices also had additional functions that contradicted divine omnipotence. The most profane purpose of several of his hydraulic and pnuematic automata was to get guests at parties drunk as quickly as possible."

Musical robot band

Al-Jazari's work described fountains and musical automata, in which the flow of water alternated from one large tank to another at hourly or half-hourly intervals. This operation was achieved through his innovative use of hydraulic switching.

Al-Jazari created a musical automaton, which was a boat with four automatic musicians that floated on a lake to entertain guests at royal drinking parties. Professor Noel Sharkey has argued that it is quite likely that it was an early programmable automata and has produced a possible reconstruction of the mechanism; it has a programmable drum machine with pegs (cams) that bump into little levers that operated the percussion. The drummer could be made to play different rhythms and different drum patterns if the pegs were moved around.

The water-clock of the drummers

The water-clock of the drummers, which differs from the Musical robot band in that it lacks a flute-playing doll and instead has two trumpeters, consists of seven wood-jointed male figures, including the aforementioned trumpeters as well as two dolls playing cymbals and the rest playing other percussive instruments. The mechanism in this specific automaton serves as a clock by producing a musical output once every hour, illustrating Al-Jazari’s ability to create multi-faceted automata that functioned on a practical and entertainment level. The motion of the automaton is initiated at daybreak by another male doll, who stands at the edge of the frieze element of the design, moving across until he reaches a specific point at which a carved falcon leans forward dropping a ball from its beak onto a cymbal. All mechanical aspects of the automaton are then driven by water and a series of pistons and cables. Each hour water drains out of the main cistern to cause another bucket to tip over driving a water wheel that is connected to the musicians. The automaton is described to ‘perform a with a clamorous sound which is heard from afar’ and could play several different tunes. Like many other automatons by Al-Jazari, this was created to entertain guests at the royal palace.

Clocks
Al-Jazari constructed a variety of water clocks and candle clocks. These included a portable water-powered scribe clock, which was a meter high and half a meter wide, reconstructed successfully at the Science Museum in 1976 Al-Jazari also invented monumental water-powered astronomical clocks which displayed moving models of the Sun, Moon, and stars.

Candle clocks
According to Donald Hill, al-Jazari constructed the most sophisticated candle clocks known to date. Hill described one of al-Jazari's candle clocks as follows:

"The candle, whose rate of burning was known, bore against the underside of the cap, and its wick passed through the hole. Wax collected in the indentation and could be removed periodically so that it did not interfere with steady burning. The bottom of the candle rested in a shallow dish that had a ring on its side connected through pulleys to a counterweight. As the candle burned away, the weight pushed it upward at a constant speed. The automata were operated from the dish at the bottom of the candle. No other candle clocks of this sophistication are known."

Al-Jazari's candle clock also included a dial to display the time and, for the first time, employed a bayonet fitting, a fastening mechanism still used in modern times.

Elephant clock
The elephant clock described by al-Jazari in 1206 is notable for several innovations. It was the first clock in which an automaton reacted after certain intervals of time (in this case, a humanoid robot striking the cymbal and a mechanical robotic bird chirping) and the first water clock to accurately record the passage of the temporal hours to match the uneven length of days throughout the year.

Castle clock
Al-Jazari's largest astronomical clock was the "castle clock", which was a complex device that was about 11 ft high, and had multiple functions besides timekeeping. It included a display of the zodiac and the solar and lunar orbits, and an innovative feature of the device was a pointer in the shape of the crescent moon which travelled across the top of a gateway, moved by a hidden cart, and caused automatic doors to open, each revealing a mannequin, every hour.

Another feature of the device was five automata musicians who automatically play music when moved by levers operated by a hidden camshaft attached to a water wheel.

Al-Jazari invented water clocks that were driven by both water and weights. These included geared clocks and a portable water-powered scribe clock, which was a meter high and half a meter wide. The scribe with his pen was synonymous to the hour hand of a modern clock. Al-Jazari's famous water-powered scribe clock was reconstructed successfully at the Science Museum, London in 1976.

Miniature paintings
Alongside his accomplishments as an inventor and engineer, al-Jazari was also an accomplished artist. In The Book of Knowledge of Ingenious Mechanical Devices, he gave instructions of his inventions and illustrated them using miniature paintings, a medieval style of Islamic art.

title: Ismail al-Jazari


text:
RFA Sir Percivale

RFA Sir Percivale (L3036) was a Round Table class landing ship logistics (LSL) vessel belonging to the Royal Fleet Auxiliary of the United Kingdom.

Sir Percivale took part in the Falklands War and the 1991 Gulf War.

Background
She originally entered British Army service in 1968, managed for the Ministry of Transport by British India Steam Navigation Company, but was taken over by the Royal Fleet Auxiliary along with the other members of the class in 1970.

Falklands War
The first twelve years of the ship's life were quiet, with some time spent in the Pacific, until the Falklands War broke out in April 1982. Along with all the Navy's other amphibious assault shipping, Sir Percivale went south to participate in the recapture of the Falkland Islands. At this time, all the RFA ships were crewed by Hong Kong Chinese civilian sailors. She pioneered the supply runs to Teal Inlet and was the first British ship to re-enter Stanley Harbour. Unlike the Sir Galahad, Sir Tristram and Sir Lancelot, the ship emerged unscathed from the conflict.

1991-1999
The ship served in the Gulf War in 1991 and twice deployed to the Adriatic to support British operations in the Balkans.

In 1996 Sir Percivale took part in combined exercises with Jordan, followed by Green Wader 96, the first exercise of the then newly formed Amphibious Squadron of the Joint Rapid Deployment Force. In 1997, the ship took part in the large Ocean Wave 97 deployment to the far east and was present for the handover of Hong Kong to the Chinese. Following this ceremony, Sir Percivale escorted the ships of the former Hong Kong Squadron (3 Peacock class patrol vessel) to their new owners in the Philippines. During other parts of Ocean Wave, the ship took Royal Marines to Brunei, Singapore and Thailand for various exercises. 1998 saw further exercises as Sir Percivale took part in practice amphibious assaults in Norway, France and Spain.

2000-2004
In 2000, Sir Percivale was deployed to Sierra Leone to support British forces training the army of that country. In September 2000, the ship was alongside in Freetown when British forces who had been taken hostage were rescued in a raid by the Parachute Regiment and the SAS ("Operation Barras"). Since then the ship has been deployed during operations connected with Afghanistan in 2001 and Iraq in 2003.

The ship was to have a SLEP overhaul, but an equivalent overhaul of Sir Bedivere proved so costly that plans were abandoned and new ships were procured instead.

Sir Percivale was decommissioned on 17 August 2004 and was laid up alongside at Marchwood Military Port, Southampton.

The ship was sold to Leavesley International and scrapping commenced in Canada Dock, Liverpool on 16 December 2009.

title: RFA Sir Percivale


text:
RFA Sir Tristram

TV Sir Tristram (L3505) formerly RFA Sir Tristram, is a Round Table-class landing ship logistics that was converted to a Special Forces Training Vessel in 2008. She was launched in 1966, and accepted into British Army service in 1967. As with others of her class, she was transferred to the Royal Fleet Auxiliary in 1970, and was crewed by British officers and Hong Kong Chinese sailors. The ship saw service in the Falklands War of 1982, and was badly damaged at Fitzroy on 8 June.

Early service
From completion to early 1970 Sir Tristram was managed by British India Steam Navigation Company. In January 1972 Sir Tristram was part of an anti-invasion task force off British Honduras, together with HMS Fearless (L10), RFA Sir Bedivere and RFA Sir Geraint. In 1977 Sir Tristram was used as a guest ship for the Queens Silver Jubilee Fleet Review at Spithead in the Solent.

Falklands War
In April 1982 Sir Tristram was diverted from Belize to the Falkland Islands to take part in Operation Corporate, the British effort to retake the Falkland Islands.

On 8 June, while transporting men and equipment to Fitzroy Cove alongside the RFA Sir Galahad, Sir Tristram was attacked by Douglas A-4 Skyhawks of the Argentine Air Force's V Brigada Aérea (FAA), each loaded with three 500 lb Mark 82 bombs. At approximately 14:00 local time the decks were strafed and two crew were killed. A 500 lb bomb penetrated the deck, but failed to explode immediately, allowing the remaining crew to be evacuated. Following the later explosion, Sir Tristram was abandoned. Immediately following the end of the conflict, Sir Tristram was towed to Port Stanley, where she was used as an accommodation ship. Sir Tristram then returned to the United Kingdom in 1983 on a heavy lift ship and was extensively rebuilt.

Rebuilt
Following the rebuild, Sir Tristram re-entered active service in 1985, and saw service in the Gulf War, and the Balkan conflicts of the 1990s. The ship supported relief operations for Hurricane Mitch off Central America. In 2000 the ship was deployed to Sierra Leone in support of British operations there, followed by a cruise to the Baltic Sea in support of mine countermeasure vessels. In early 2001 Sir Tristram returned to Sierra Leone to take over from RFA Sir Percivale as the ship supporting British forces ashore there. In 2003 the ship was deployed as part of the largest British fleet for 20 years in support of the invasion of Iraq.

The ship was decommissioned on 17 December 2005 but continues to be used for training purposes by the Special Boat Service and other elements of the UK Special Forces group. She is now based at Portland Harbour.

title: RFA Sir Tristram


text:
John X of Constantinople

John X Kamateros (Ἰωάννης Καματηρός; died April or May 1206) was the Patriarch of Constantinople from 5 August 1198 to April/May 1206.

Life
John was a member of the Kamateros family to which belonged the Empress Euphrosyne Doukaina Kamatera, wife of Alexios III Angelos (r. 1195–1203). An educated man, well versed in classical literature, rhetoric and philosophy, he occupied a series of ecclesiastical posts reaching the post of chartophylax, which he held at the time of his elevation to the patriarchal throne.

In 1198–1200, he had an exchange of letters with Pope Innocent III on the issue of papal supremacy and the filioque clause. He disputed Rome's claim to primacy based on St. Peter, and asserted that in reality its primacy came from the fact that Rome was the old imperial capital. He intervened in the riots in Constantinople against the arrest of the banker Kalomodios, and secured his release, but during the coup of John Komnenos the Fat on 31 July 1200, he hid in a cupboard as the rebels seized control of the Hagia Sophia.

John remained in office after Alexios III's deposition in July 1203, and according to Western sources, both he and Alexios IV Angelos, threatened by the Fourth Crusade, acknowledged papal supremacy in the same year. After the capture of Constantinople during the Fourth Crusade in 1204, he initially fled to Didymoteichon in Thrace. In 1206, Theodore I Laskaris invited him to Nicaea, where he had established the Empire of Nicaea, a Byzantine Greek successor state, but John refused, perhaps because of his advanced age, and died in April or May of the same year.

The Crusaders then installed a Latin Patriarch in Constantinople, while Theodore simply created a new provisional seat of the Constantinoplitan Ecumenical Patriarchate in Nicaea, which was eventually restored in Constantinople with the rest of the Empire in 1261.

title: John X of Constantinople


text:
President of Guatemala

The president of Guatemala (Presidente de Guatemala), officially titled President of the Republic of Guatemala (Presidente de la República de Guatemala), is the head of state and head of government of Guatemala, elected to a single four-year term. The position of President was created in 1839.

Eligibility
Article 185 of the Constitution, sets the following requirements to qualify for the presidency:

 * be Guatemalan of origin who is a citizen in good standing;
 * be at least 40 years old.

A person who meets the above qualifications would, however, still be disqualified from holding the office of president if the individual:

 * Was the leader or the head of a coup d'état, armed revolution, or similar movement, that had altered the constitutional order, and as a result of their actions became the Head of Government;
 * Exercised the role of President or Vice President during an election, or at any point within the presidential period in which elections are conducted.
 * Are relatives of the incumbent president or vice president prior to the succeeding election;
 * Served as a Minister within the government, for any time in the six months before the election;
 * Served as a member of the Armed Forces unless they are on leave or have been in retirement for at least five years before the election;
 * Are ministers of any religion or cult;
 * Are magistrates of the Supreme Electoral Tribunal.

Term Limit
The President serves a four-year term and is prohibited from seeking re-election or extending their tenure. Moreover, a person who held the position of president for more than two years is barred from running for office again.

Executive powers
Article 183 of the Constitution, confers the following duties and competencies to the president:

 * Comply with and enforce the Constitution and laws.
 * Provide the defense and security of the Nation, as well as the preservation of public order.
 * Exercise the command of the Armed Forces of Guatemala with all the respective functions and attributions.
 * Exercise the command of the National Police.
 * Approve, promulgate, execute and enforce laws.
 * Dictate the provisions that are necessary in cases of serious emergency or public calamity, having to report to the Congress in its immediate sessions.
 * Submit proposals of laws to the Congress.
 * Exercise the right of veto with respect to the laws issued by the Congress, except in cases in which it is not necessary to sanction the executive branch in accordance with the Constitution.
 * Present annually to the Congress, at the beginning of its session, written report on the general situation of the Republic and of the business of its administration carried out during the previous year.
 * Submit annually to the Congress, for approval with no less than one hundred and twenty days prior to the date on which the fiscal year begins, through the Ministry of Public Finance, the draft budget that contains in detail the income and expenditures of the State. If the Congress is not in session, it must hold extraordinary sessions to hear about the project.
 * Submit for consideration of the Congress for approval, and before ratification, treaties and conventions of international character and contracts and concessions on public services.
 * To summon the Legislative Organism to extraordinary sessions when the interests of the Republic demand it.
 * Coordinate the development policy of the Nation through the Council of Ministers.
 * Preside over the Council of Ministers and exercise the function of hierarchical superior of the officials and employees of the Executive Organism.
 * Maintain the territorial integrity and dignity of the Nation.
 * Direct foreign policy and international relations, pronounce, ratify and denounce treaties and agreements in accordance with the Constitution.
 * Receive the diplomatic representatives, as well as issue and withdraw the exequatur to the patents of the consuls.
 * Administer public finances in accordance with the law.
 * Exonerate of fines and surcharges to the taxpayers who have incurred in them for not covering the taxes within the legal terms for acts or omissions in the administrative order.
 * Appoint and remove ministers of state, deputy ministers, secretaries and undersecretaries of the presidency, ambassadors and other officials that correspond to it according to the law.
 * Grant premiums, pensions and subsidies in accordance with the Law.
 * Award decorations to Guatemalans and foreigners.
 * Within the fifteen days following its conclusion, inform the Congress about the purpose of any trip that has taken place outside the national territory and about the results thereof.
 * Submit every four months to the Congress through the respective ministry an analytical report on the budget execution, for its knowledge and control.
 * Exercise all other functions assigned by the Constitution or the law.

Vacancies and succession
Article 189 of the Constitution establishes the presidential line of succession. If the president is temporarily absent, the vice president takes over the presidency. If the absence of the President is permanent, the vice president holds the presidency until the end of the constitutional period. In the event of a double vacancy, Congress has the authority to designate an acting president by a vote of two-thirds of the total number of deputies.

The State of Guatemala (1839-1847)
Note: Regarding the numbering of the terms, several reliable sources state that Jimmy Morales is the 50th president

Ten-Year Revolution (1944-1954)
The authoritarian regime of Jorge Ubico, which persisted since 1931, was overthrown by a revolution known as the  "Ten Years of Spring" on 4 July 1944. After more than a month of mass student and trade union protests, Ubico resigned and fled to Mexico, transferring powers to his First Deputy, Federico Ponce Vaides. Presidential elections were held on 4 July 1944, which declared Ponce as the president. However, the opposition rejected the results, and as a result, on 20 October 1944, a group of young officers overthrew Ponce, creating a military-civilian government called the Revolutionary Government Junta. A new constitution was adopted and elections were held, which resulted in the victory of Juan José Arévalo in 1944 and Jacobo Árbenz in 1950. During this period, Guatemala underwent numerous social and economic reforms, including large-scale land reform.

Military Governments (1954-1958)
Upon presenting his resignation, Jacobo Árbenz left Colonel Carlos Enrique Díaz, head of the Armed Forces, in charge of the presidency. Diaz's first measure was the integration of a provisional government board which he led alongside Colonels Elfego H. Monzón and José Ángel Sánchez. On 29 June, Díaz was forced to resign, leading to Monzón succeeding as the new chairman of the board. Monzón would assemble a new governing board and incorporate Colonel Castillo Armas, Juan Mauricio Dubois, Jose Luis Cruz Salazar, and Enrique Oliva.

The new board would dissolve after a popular plebiscite held on 10 October 1954 would allow Colonel Castillo Armas to assume the presidency. Under Armas' mandate, several reforms implemented during the Guatemalan Revolution were suspended, and political opponents, as well as unions and peasant organizations, were persecuted. Armas' assassination on 26 July 1957, would prompt Congress to appoint Luis Arturo González as acting president and condition him to call for elections within four months.

The planned election was held on 20 October 1957, but the results were later nullified due to allegations of fraud. President González would resign and cede power to a provisional governing board led by Óscar Mendoza Azurdia, Gonzalo Yurrita Nova, and Roberto Lorenzana. The new board would govern for two days before Congress would appoint Colonel Guillermo Flores Avendaño as acting president. President Avendaño would call for elections in January 1958.

title: President of Guatemala