This article deals with varieties of epistemological methods in calculating days of lunar calendar, mainly on the beginning date of months. Examining different methods in Indonesian Islamic-scape, it argues that there are three epistemological models which are rooted at Islamic classical epistemologies; the ahl al-hadith, the ahl al-ra‎y, and the intuitive sufi. The ahl al-hadith emphasizes on the empirical rukyatul-hilal, whereas the ahl al-ra’y strongly concerns on the mathematically rational method. The sufi, not so popular in Indonesia but influential in (...) some sufi circles, deploys the intuitive kashf method. In some cases, these three are however intertwined and in contradiction one to another. The article futher argues that different method-in-use is strongly influenced the local spesificties of diverse Indonesian Muslim’s backgrounds, and groupings. (shrink)

The fasting and Eid al-Fitr celebration has a strong public dimension for their traditional characteristics in Islamic communal celebrations. This study used field research from interviews with the two largest mass organisations in Indonesia, Nahdlatul Ulama and Muhammadiyah, and the statements of mass media. This research shows that contestation of religious symbols is not something that needs to be debated but it should broaden the understanding of the differences that must be respected in order to build brotherhood not, division. Contestation (...) of religious symbols between the hisab [astronomical calculations] and the ru'yat [sighting a new crescent moon] is a competition between religious organisations, to strengthen their position, social legitimacy and religious authority in the public sphere. The government has to take the initiative to compromise the policy between the two Islamic organisations to reach a methodological agreement in order to minimise social tensions.CONTRIBUTION: This article proposed that understanding the ru'yat and hisab as a symbol of contestation becomes an attribute of religious organisations and part of organisational behaviour and culture. (shrink)

It was a strange posthumous fate that awaited the Englishman Robert of Ketton : he was to be both best known and most strenuously criticized for a work that he surely viewed as a sideline to his own interests and career. By trade Robert was a Latin translator of Arabic scientific and mathematical works, one of those remarkable twelfth-century men who, as his contemporary Petrus Alfonsi put it, were willing “to traverse distant provinces and withdraw into remote regions so as (...) to be able to attain fuller knowledge of the astronomical art.” Like other contemporary translators, such as the Italian Gerard of Cremona , Robert had left his birthplace—in his case Rutlandshire—and traveled to Spain in order to have access to the great works of Arabic astronomy and mathematics that could be found in the still very Arab Iberian Peninsula. By 1141 we find him and his close friend Herman of Carinthia studying and translating scientific works together in northeastern Spain, and in later years his astronomical interests and ecclesiastical responsibilities led him to travel widely in Spain and England. As a scientific translator, he is perhaps best known for his Liber algebrae et Almucabola, a Latin version of al-Khwarazmī's great manual of algebra, Al-Kitāb al-mukhtaṣar fī ḥisāb al-jabr wa-al-muqābalah. (shrink)

Dans le cadre des algorithmes numériques introduits et élaborés par les mathématiciens arabes, à partir du ixe siècle, figure l'algorithme de l'extraction de la racine carrée d'un entier naturel. Cet algorithme a été étudié chez plusieurs d'entre eux et surtout bien expliqué par alBaġdādī dans le chapitre « Comment extraire la racine des nombres entiers » de son livre « La complétion du calcul », Al-takmila fī al-ḥisāb 1. Dans ce chapitre, al-Baġdādī expose son travail pédagogiquement en six sections traitant (...) de plusieurs manières différentes le problème de l'extraction de la racine carrée d'un entier 2. À la même époque, dans un texte isolé intitulé « Sur la cause de la racine, de son doublement et de son déplacement 3 », Ibn al-Hayṯam donne une justification géométrique de l'algorithme en se basant sur des notions algébriques précises. (shrink)

En este artículo se lleva a cabo una descripción detallada del ms. 80 de la Zāwiya Ḥamzawīya. Es un maŷmū‛ recopilado, en su mayor parte, por un mismo copista del que desconocemos su nombre completo, aunque no el de su padre: ‛Umar b. Aḥmad b. Abī-l-Qāsim al-Šarīf. El maŷmu‛ contiene 427 folios con textos de variado contenido, predominando los de carácter astronómico. Entre otras obras, incluye una copia del Kitāb fī-l-‛amal bi-l-asturlāb de Abū-l-Ṣalt de Denia; el Kitāb min ‛ilm al-awqāt (...) bi-l-ḥisāb de Ibn al-Bannā de Marrākuš; el Tanbīh al-anām ‛alà mā yaḥduṯu fī ayyām al-‛ām de al-Ŷādīrī, así como su Urŷuza Rawḍat al-Azhār; y la única copia del Kitāb al-nuŷūm de ‛Abd. al-Mālik b. Ḥabīb. (shrink)

This article deals with varieties of epistemological methods in calculating days of lunar calendar (hijri), mainly on the beginning date of months. Examining different methods in Indonesian Islamic-scape, it argues that there are three epistemological models which are rooted at Islamic classical epistemologies; the ahl al-hadith (textualist), the ahl al-ra‎y (contextualist), and the intuitive sufi. The ahl al-hadith emphasizes on the empirical rukyatul-hilal (witnessing the moon), whereas the ahl al-ra’y strongly concerns on the mathematically rational method. The sufi, not so (...) popular in Indonesia but influential in some sufi circles, deploys the intuitive kashf (uncovering) method. In some cases, these three are however intertwined and in contradiction one to another. The article futher argues that different method-in-use is strongly influenced the local spesificties of diverse Indonesian Muslim’s backgrounds, and groupings. (shrink)