Astronomer, physicist and mechanic (B. 1100 – D. 1160?). His full name is Ebü’l-Feth Abdurrahman Mansûr el-Hazinî. Abdurrahman el-Hazini is sometimes confused with İbn Heysem, Ebu Ca’fer el-Hazin and Ebu’l-Fazl el-Hazinî n the sources. He was a slave of Byzantian origin, obtained a good opportunity of receiving a decent education in Merv city of Turkistan and was raised within the Islamic culture. As he was a slave, he was responsible for the treasure of his master in Merv palace, therefore he was known as el-Hazinî. Thanks to the means provided by his master he received the best education possible at that time. He was especially educated in philosophy and mathematics and raised himself in these fields in a perfect way. Later he conducted his studies and researches in Merv, which was a center of science and literature during the rule of Sultan Sencer, son of Melikşah (1118-57), benefiting from the support of the palace.
Hazinî prepared his catalogue of stars for Sultan Sencer, which introduced his name to the world of science and which is regarded as a most important and reliable work in the field of astronomy. He built a hydrostatic scales called “Mizanü’l-hikme”in order to use it in his treasury, which granted him a distinguished place among builders of scientific tools of all ages. Thanks to these scales, it was possible to find out whether metals and stones were pure and rates of mixture of metals in alloys with two elements. These scales were superior to its precedents in terms of sensitivity. Abdurrahman el-Hazinî was in the same time a devoted person who followed the path of riyazet (escaping from desires of ego which are not legitimate). He dressed in a simple way like a dervish, did not eat much and lived alone at his home. Once Sultan Sencer gave him 1000 dinars as a present but he did not accept this gift, saying that he had 10 dinars in his pocket and that this was sufficient for him for a long time.
Among his students, only Hasan es Semerkandi’s name is known. We do not have much information about the life of Abdurrahman el-Hazinî. His important and valuable works are not analyzed and researched sufficiently. He is very attached to researchers before him and quoted especially Birunî and Asfizarî. However, his deep knowledge about these issues is indisputable.
According to El-Hazinî, weight is a force in the body of object and causes it to move towards the center of earth. This depends on the specific weight of the object. Hazinî is one of twenty astronomers in the Islamic world to make original observations. His catalogue of stars started to be used after the ones of Birunî and Hayyam and after him the ones of Nasreddin et-Tusî, Kutbuddin eş-Şirazî, Kaşî and Uluğ Bey were used. El-Hazinî analyzed the relations between the velocity of fall ob objects and time and distance in a detailed way. Like Birunî, he detected specific weights of numerous fluids and mines, arranged tables to show these and built a special tool for these purposes. He made scientific explanations about scales, bascule, measuring tools and levers and gave wide knowledge about them in the book he wrote. In his work titled “Mizan’ül-Hikme” he wrote the history of physics.
El-Hazinî claimed that water had more intensity the more it approached the center of the world. He made experiments about it. The same hypothesis was extended by Roger Bacon (1214-94) hundred years later. He calculated latitudes and longitudes of great Seljuk Empire. He determined Qibla locations (T.N. the direction to pray for Muslims) for many places. Hazinî was an astute natural scientist and physicist. He made long researches about scales, which were called libra, snare, mushroom and“cerastium”. He turned the scales into a wonderful measuring device and called it “el-Mizan’ül Cami”. He called his book, which contained these issues “Kitabü Mizan'il Hikme”.
The famous historian of science Aldo Mieli compared intensity values of solid matters produced by Birunî and Hazinî with modern values. Hazinî used an “aerometer” to measure intensities. He developed the method to calculate the intensity of fluids and the weighing machine with five scales to calculate weights of objects in air.
Hazinî, by presenting that air had a weight and could be measured, had discussed and analyzed this issue before Torricelli. He said that air, like fluids, also had a weight and buoyancy and the weight of an object in air was decreased because of the buoyancy of air. This decreased weight of the object depended on the density of air. He expressed that “Law of Archimedes” not only concerned fluids, but also gases and that this was valid for all fluids. This and similar scientific researches of Hazinî built the fundaments for the discovery of barometer. So he pioneered Torricelli, Pascal, Boyle and other certain Western scientists and established the science of “fluid mechanics”.
Hazinî analyzed principles of light refraction and said that sun beams reached the world not in a direct and straight way, but after being refracted. Besides he researched gravity. He made numerous scientific experiments and showed in the end that all objects were drawn to the center of the earth under a gravitational force. He said that the difference of gravitation forces of objects depended on the distance between the falling object and center of gravity. He developed Birunî’s research and presented the principle of gravity between masses.
It is understood from Hazinî’s works that gravity was not discovered by Newton (1665) but by two Islamic scientists who lived 550 years before him. All these scientific conclusions Hazinî reached based on scientific experiments and comparisons. It is accurate to call Hazinî because of this characteristic ‘‘Master and pioneer of dynamics and hydrostatics and discoverer of fluid mechanics and principle of gravitation”.
Hazinî’s works were partially analyzed by M. Khanikov, translated into English and published in New Haven (America, 1859). Scientists who analyzed his works admitted and expressed their appreciation. His inventions in the field of physics are researched in modern universities of our day and enlighten their field. Most of authorities in the history of science admit that Hazinî was a master of physics of all ages and surpassed masters such as Avicenna, Birunî and İbn-i Heysem in this field.
Findings, principles and equations of Hazinî he introduced to the world of science are attributed to Western scientists such as Galileo, Keppler and Newton. However it is obvious that this is a mistake and error. As a matter of fact, numerous important works of Abdurrahman Hazinî were translated into Western languages in Medieval and European scientific environments benefited a lot from his scientific views. G. Sarton, a historian of science, evaluates Hazinî’s “Mizan-ül-Hikme” as the most prominent work of medieval Islamic brilliance, and regards it as a unique work for its age.
Hazinî used a water scales to measure fluids. With this tool he could measure fluids such as hot and cold water, sea water, vinegar, olive oil, cow milk, chicken egg, blood and urine in an accurate way. Hazinî has three important works known by environments of science.
Kitabü Mizanü'l-Hikme (1121), Ez-zicü'l-mu'teberu's-Senceri es-Sultani (about 1130), Risalefi’l-Alat (A small work about astronomical tools.), Cami-üt-Tevarih, Kitabünfil-fecriveş-Şafak, Kitab-üt-Tefhim.
REFERENCE: Saadettin Ökten / “Abdurrahman el-Hazininî” (Türkiye Diyanet Vakfı İslam Ansiklopedisi, c.1, s. 297, 1988), Yeni Rehber Ansiklopedisi (c. 9, s. 37-39), Çağını Aşanlar (Bilim ve Teknik, Şubat 1991), Abduurahman el Hazinî (davetci.com, erişim 18 Kasım 2011), İhsan Işık / Ünlü Bilim Adamları (Türkiye Ünlüleri Ansiklopedisi, C. 2, 2013) - Encyclopedia of Turkey’s Famous People (2013).