INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN SOCIAL SCIENCE (IJRISS)
ISSN No. 2454-6186 | DOI: 10.47772/IJRISS | Volume IX Issue XI November 2025
positions of celestial objects and their relevance in time measurement. Ancient Egypt and Babylon are believed
to have used sundials around 3500 BCE. The oldest sundial in Asia and the world was found in Egypt. Great
civilizations of the past constructed various types and forms of sundials to determine time. Due to their desert
environments, the use of sundials was highly suitable during that era (Ibrahim & Safiai 2017).
During the heyday of early Islamic civilizations, various types of sundials were constructed for different
purposes, such as determining time and prayer times. In the history of Islamic civilization, the creation of
sundials is closely associated with an Islamic astronomer named Ibn al-Shatir. Ibn al-Shatir created a sundial to
be placed in the Umayyad Mosque Tower in Damascus. At the time, he was known as a muwaqqit (timekeeper).
His sundial was categorized as one of the earliest sundials based on straight lines. He divided the day into 12
hours, a concept that remains usable to this day. This concept was also employed by Syeikh Abdullah Fahim in
calculating prayer times.
c) Rubu‘ Mujayyab
Another instrument owned by Sheikh Abdullah Fahim is the rubu‘ mujayyab, a traditional astronomical
instrument shaped like a quarter or quadrant, more commonly known as an instrument used to measure angles,
determine time, establish prayer times, qibla direction, and the position of the sun. In geometric terms, this
instrument is referred to as a quadrant (sinus quadrant). Some even define the rubu‘ mujayyab as a traditional
celestial instrument in the form of a quadrant used for trigonometric calculations and angle measurement. This
instrument incorporates some of the functions found in an astrolabe (Safiai et al. 2020). The rubu‘ mujayyab is
a quarter-circle-shaped measuring tool. Some historians claim that the rubu‘ was one of the revolutionary
instruments created by al-Khawarizmi and Ibn Shatir. Its function is to assist in measuring geometric functions
to project the movement and positions of celestial objects. The rubu‘ is typically made of copper or wood, with
one of its surfaces marked with a scale. The rubu‘ mujayyab is a tool used to solve fundamental space-related
problems (issues related to celestial mapping) for a specific altitude. It uses degrees (°) in its operation and
involves data displayed on one of its surfaces. This instrument incorporates some of the functions found in an
astrolabe (Ibrahim & Safiai 2017).
In fact, the rubu‘ was used as a replacement for the astrolabe because the astrolabe had too many functions,
making it challenging for scientists to use to its full potential. Therefore, a quarter of the astrolabe's circle was
removed to create the rubu‘ mujayyab, which focused only on specific functions. Regarding its early history, the
exact origin of the rubu‘ is not known. Additionally, the books Durus al-Falakiyyah and Tibyan al-Miqat, which
specifically discuss the rubu‘, do not provide details about when, where, and how the development of the rubu‘
mujayyab took place (Ali 1992: 2; Madrasah al-Salafiyyah t.th.: 5). Sheikh Abdullah Fahim's rubu‘ mujayyab is
reported to still be kept in the office of the principal of Dairat al-Ma 'arif al-Wataniyyah, but the exact condition
of this instrument cannot be confirmed and is not known precisely. Furthermore, the method of storing the rubu‘
should also be taken into consideration, as it requires careful preservation due to its association with a famous
figure in Malaysia. He used the rubu‘ to calculate prayer times throughout the year and also to determine the
positions of constellations. The rubu‘ mujayyab, as a part of the astrolabe, also had a specific function for
determining the position of constellations, as the names of the constellations are inscribed along the curve of the
instrument's quadrant. Sheikh Abdullah Fahim once mentioned in Arabic: "am khair atana," which means a
good year is coming to us (Noor 2004).
Based on the chronological development, this demonstrates that the knowledge and use of the rubu‘ can be said
to have evolved and spread worldwide, including in Malaysia. This would not have been possible without the
diligence and dedication of Islamic astronomers who conducted observations and played a role in the
development of the rubu‘, including figures like al-Khawarizmi (770-840H) and Ibn Shatir (11th century).
Limitations
The primary limitation of this study is that the review was conducted through the mainstream of English and
Malay literature databases. This will automatically limit the search as many studies are published in native
languages across Muslim countries, such as Malaysia, Indonesia, Brunei.
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