Tuesday, 29 November 2011
Sunday, 27 November 2011
Thales of Miletus
SCIENTIST THALES OF MILETUS:
Thales of Miletus was the son of Examyes and Cleobuline. His parents are said by some to be from Miletus but others report that they were Phoenicians. J Longrigg writes in [1]:-
But the majority opinion considered him a true Milesian by descent, and of a distinguished family.
Thales seems to be the first known Greek philosopher, scientist and mathematician although his occupation was that of an engineer. He is believed to have been the teacher of Anaximander (611 BC - 545 BC) and he was the first natural philosopher in the Milesian School. However, none of his writing survives so it is difficult to determine his views or to be certain about his mathematical discoveries. Indeed it is unclear whether he wrote any works at all and if he did they were certainly lost by the time of Aristotle who did not have access to any writings of Thales. On the other hand there are claims that he wrote a book on navigation but these are based on little evidence. In the book on navigation it is suggested that he used the constellation Ursa Minor, which he defined, as an important feature in his navigation techniques. Even if the book is fictitious, it is quite probable that Thales did indeed define the constellation Ursa Minor.
Proclus, the last major Greek philosopher, who lived around 450 AD, wrote:-
[Thales] first went to Egypt and thence introduced this study [geometry] into Greece. He discovered many propositions himself, and instructed his successors in the principles underlying many others, his method of attacking problems had greater generality in some cases and was more in the nature of simple inspection and observation in other cases.
There is a difficulty in writing about Thales and others from a similar period. Although there are numerous references to Thales which would enable us to reconstruct quite a number of details, the sources must be treated with care since it was the habit of the time to credit famous men with discoveries they did not make. Partly this was as a result of the legendary status that men like Thales achieved, and partly it was the result of scientists with relatively little history behind their subjects trying to increase the status of their topic with giving it an historical background.
Certainly Thales was a figure of enormous prestige, being the only philosopher before Socrates to be among the Seven Sages. Plutarch, writing of these Seven Sages, says that (see [8]):-
[Thales] was apparently the only one of these whose wisdom stepped, in speculation, beyond the limits of practical utility, the rest acquired the reputation of wisdom in politics.
This comment by Plutarch should not be seen as saying that Thales did not function as a politician. Indeed he did. He persuaded the separate states of Ionia to form a federation with a capital at Teos. He dissuaded his compatriots from accepting an alliance with Croesus and, as a result, saved the city.
It is reported that Thales predicted an eclipse of the Sun in 585 BC. The cycle of about 19 years for eclipses of the Moon was well known at this time but the cycle for eclipses of the Sun was harder to spot since eclipses were visible at different places on Earth. Thales's prediction of the 585 BC eclipse was probably a guess based on the knowledge that an eclipse around that time was possible. The claims that Thales used the Babylonian saros, a cycle of length 18 years 10 days 8 hours, to predict the eclipse has been shown by Neugebauer to be highly unlikely since Neugebauer shows in [11] that the saros was an invention of Halley. Neugebauer wrote [11]:-
... there exists no cycle for solar eclipses visible at a given place: all modern cycles concern the earth as a whole. No Babylonian theory for predicting a solar eclipse existed at 600 BC, as one can see from the very unsatisfactory situation 400 years later, nor did the Babylonians ever develop any theory which took the influence of geographical latitude into account.
After the eclipse on 28 May, 585 BC Herodotus wrote:-
... day was all of a sudden changed into night. This event had been foretold by Thales, the Milesian, who forewarned the Ionians of it, fixing for it the very year in which it took place. The Medes and Lydians, when they observed the change, ceased fighting, and were alike anxious to have terms of peace agreed on.
Longrigg in [1] even doubts that Thales predicted the eclipse by guessing, writing:-
... a more likely explanation seems to be simply that Thales happened to be the savant around at the time when this striking astronomical phenomenon occurred and the assumption was made that as a savant he must have been able to predict it.
There are several accounts of how Thales measured the height of pyramids. Diogenes Laertius writing in the second century AD quotes Hieronymus, a pupil of Aristotle [6] (or see [8]):-
Hieronymus says that [Thales] even succeeded in measuring the pyramids by observation of the length of their shadow at the moment when our shadows are equal to our own height.
This appears to contain no subtle geometrical knowledge, merely an empirical observation that at the instant when the length of the shadow of one object coincides with its height, then the same will be true for all other objects. A similar statement is made by Pliny (see [8]):-
Thales discovered how to obtain the height of pyramids and all other similar objects, namely, by measuring the shadow of the object at the time when a body and its shadow are equal in length.
Plutarch however recounts the story in a form which, if accurate, would mean that Thales was getting close to the idea of similar triangles:-
... without trouble or the assistance of any instrument [he] merely set up a stick at the extremity of the shadow cast by the pyramid and, having thus made two triangles by the impact of the sun's rays, ... showed that the pyramid has to the stick the same ratio which the shadow [of the pyramid] has to the shadow [of the stick]
Of course Thales could have used these geometrical methods for solving practical problems, having merely observed the properties and having no appreciation of what it means to prove a geometrical theorem. This is in line with the views of Russell who writes of Thales contributions to mathematics in [12]:-
Thales is said to have travelled in Egypt, and to have thence brought to the Greeks the science of geometry. What Egyptians knew of geometry was mainly rules of thumb, and there is no reason to believe that Thales arrived at deductive proofs, such as later Greeks discovered.
On the other hand B L van der Waerden [16] claims that Thales put geometry on a logical footing and was well aware of the notion of proving a geometrical theorem. However, although there is much evidence to suggest that Thales made some fundamental contributions to geometry, it is easy to interpret his contributions in the light of our own knowledge, thereby believing that Thales had a fuller appreciation of geometry than he could possibly have achieved. In many textbooks on the history of mathematics Thales is credited with five theorems of elementary geometry:-
A circle is bisected by any diameter.
The base angles of an isosceles triangle are equal.
The angles between two intersecting straight lines are equal.
Two triangles are congruent if they have two angles and one side equal.
An angle in a semicircle is a right angle.
What is the basis for these claims? Proclus, writing around 450 AD, is the basis for the first four of these claims, in the third and fourth cases quoting the work History of Geometry by Eudemus of Rhodes, who was a pupil of Aristotle, as his source. The History of Geometry by Eudemus is now lost but there is no reason to doubt Proclus. The fifth theorem is believed to be due to Thales because of a passage from Diogenes Laertius book Lives of eminent philosophers written in the second century AD [6]:-
Pamphile says that Thales, who learnt geometry from the Egyptians, was the first to describe on a circle a triangle which shall be right-angled, and that he sacrificed an ox (on the strength of the discovery). Others, however, including Apollodorus the calculator, say that it was Pythagoras.
A deeper examination of the sources, however, shows that, even if they are accurate, we may be crediting Thales with too much. For example Proclus uses a word meaning something closer to 'similar' rather than 'equal- in describing (ii). It is quite likely that Thales did not even have a way of measuring angles so 'equal- angles would have not been a concept he would have understood precisely. He may have claimed no more than "The base angles of an isosceles triangle look similar". The theorem (iv) was attributed to Thales by Eudemus for less than completely convincing reasons. Proclus writes (see [8]):-
[Eudemus] says that the method by which Thales showed how to find the distances of ships from the shore necessarily involves the use of this theorem.
Heath in [8] gives three different methods which Thales might have used to calculate the distance to a ship at sea. The method which he thinks it most likely that Thales used was to have an instrument consisting of two sticks nailed into a cross so that they could be rotated about the nail. An observer then went to the top of a tower, positioned one stick vertically (using say a plumb line) and then rotating the second stick about the nail until it point at the ship. Then the observer rotates the instrument, keeping it fixed and vertical, until the movable stick points at a suitable point on the land. The distance of this point from the base of the tower is equal to the distance to the ship.
Although theorem (iv) underlies this application, it would have been quite possible for Thales to devise such a method without appreciating anything of 'congruent triangles'.
As a final comment on these five theorems, there are conflicting stories regarding theorem (iv) as Diogenes Laertius himself is aware. Also even Pamphile cannot be taken as an authority since she lived in the first century AD, long after the time of Thales. Others have attributed the story about the sacrifice of an ox to Pythagoras on discovering Pythagoras's theorem. Certainly there is much confusion, and little certainty.
Our knowledge of the philosophy of Thales is due to Aristotle who wrote in his Metaphysics :-
Thales of Miletus taught that 'all things are water'.
This, as Brumbaugh writes [5]:-
...may seem an unpromising beginning for science and philosophy as we know them today; but, against the background of mythology from which it arose, it was revolutionary.
Sambursky writes in [15]:-
It was Thales who first conceived the principle of explaining the multitude of phenomena by a small number of hypotheses for all the various manifestations of matter.
Thales believed that the Earth floats on water and all things come to be from water. For him the Earth was a flat disc floating on an infinite ocean. It has also been claimed that Thales explained earthquakes from the fact that the Earth floats on water. Again the importance of Thales' idea is that he is the first recorded person who tried to explain such phenomena by rational rather than by supernatural means.
It is interesting that Thales has both stories told about his great practical skills and also about him being an unworldly dreamer. Aristotle, for example, relates a story of how Thales used his skills to deduce that the next season's olive crop would be a very large one. He therefore bought all the olive presses and then was able to make a fortune when the bumper olive crop did indeed arrive. On the other hand Plato tells a story of how one night Thales was gazing at the sky as he walked and fell into a ditch. A pretty servant girl lifted him out and said to him "How do you expect to understand what is going on up in the sky if you do not even see what is at your feet". As Brumbaugh says, perhaps this is the first absent-minded professor joke in the West!
Thales of Miletus was the son of Examyes and Cleobuline. His parents are said by some to be from Miletus but others report that they were Phoenicians. J Longrigg writes in [1]:-
But the majority opinion considered him a true Milesian by descent, and of a distinguished family.
Thales seems to be the first known Greek philosopher, scientist and mathematician although his occupation was that of an engineer. He is believed to have been the teacher of Anaximander (611 BC - 545 BC) and he was the first natural philosopher in the Milesian School. However, none of his writing survives so it is difficult to determine his views or to be certain about his mathematical discoveries. Indeed it is unclear whether he wrote any works at all and if he did they were certainly lost by the time of Aristotle who did not have access to any writings of Thales. On the other hand there are claims that he wrote a book on navigation but these are based on little evidence. In the book on navigation it is suggested that he used the constellation Ursa Minor, which he defined, as an important feature in his navigation techniques. Even if the book is fictitious, it is quite probable that Thales did indeed define the constellation Ursa Minor.
Proclus, the last major Greek philosopher, who lived around 450 AD, wrote:-
[Thales] first went to Egypt and thence introduced this study [geometry] into Greece. He discovered many propositions himself, and instructed his successors in the principles underlying many others, his method of attacking problems had greater generality in some cases and was more in the nature of simple inspection and observation in other cases.
There is a difficulty in writing about Thales and others from a similar period. Although there are numerous references to Thales which would enable us to reconstruct quite a number of details, the sources must be treated with care since it was the habit of the time to credit famous men with discoveries they did not make. Partly this was as a result of the legendary status that men like Thales achieved, and partly it was the result of scientists with relatively little history behind their subjects trying to increase the status of their topic with giving it an historical background.
Certainly Thales was a figure of enormous prestige, being the only philosopher before Socrates to be among the Seven Sages. Plutarch, writing of these Seven Sages, says that (see [8]):-
[Thales] was apparently the only one of these whose wisdom stepped, in speculation, beyond the limits of practical utility, the rest acquired the reputation of wisdom in politics.
This comment by Plutarch should not be seen as saying that Thales did not function as a politician. Indeed he did. He persuaded the separate states of Ionia to form a federation with a capital at Teos. He dissuaded his compatriots from accepting an alliance with Croesus and, as a result, saved the city.
It is reported that Thales predicted an eclipse of the Sun in 585 BC. The cycle of about 19 years for eclipses of the Moon was well known at this time but the cycle for eclipses of the Sun was harder to spot since eclipses were visible at different places on Earth. Thales's prediction of the 585 BC eclipse was probably a guess based on the knowledge that an eclipse around that time was possible. The claims that Thales used the Babylonian saros, a cycle of length 18 years 10 days 8 hours, to predict the eclipse has been shown by Neugebauer to be highly unlikely since Neugebauer shows in [11] that the saros was an invention of Halley. Neugebauer wrote [11]:-
... there exists no cycle for solar eclipses visible at a given place: all modern cycles concern the earth as a whole. No Babylonian theory for predicting a solar eclipse existed at 600 BC, as one can see from the very unsatisfactory situation 400 years later, nor did the Babylonians ever develop any theory which took the influence of geographical latitude into account.
After the eclipse on 28 May, 585 BC Herodotus wrote:-
... day was all of a sudden changed into night. This event had been foretold by Thales, the Milesian, who forewarned the Ionians of it, fixing for it the very year in which it took place. The Medes and Lydians, when they observed the change, ceased fighting, and were alike anxious to have terms of peace agreed on.
Longrigg in [1] even doubts that Thales predicted the eclipse by guessing, writing:-
... a more likely explanation seems to be simply that Thales happened to be the savant around at the time when this striking astronomical phenomenon occurred and the assumption was made that as a savant he must have been able to predict it.
There are several accounts of how Thales measured the height of pyramids. Diogenes Laertius writing in the second century AD quotes Hieronymus, a pupil of Aristotle [6] (or see [8]):-
Hieronymus says that [Thales] even succeeded in measuring the pyramids by observation of the length of their shadow at the moment when our shadows are equal to our own height.
This appears to contain no subtle geometrical knowledge, merely an empirical observation that at the instant when the length of the shadow of one object coincides with its height, then the same will be true for all other objects. A similar statement is made by Pliny (see [8]):-
Thales discovered how to obtain the height of pyramids and all other similar objects, namely, by measuring the shadow of the object at the time when a body and its shadow are equal in length.
Plutarch however recounts the story in a form which, if accurate, would mean that Thales was getting close to the idea of similar triangles:-
... without trouble or the assistance of any instrument [he] merely set up a stick at the extremity of the shadow cast by the pyramid and, having thus made two triangles by the impact of the sun's rays, ... showed that the pyramid has to the stick the same ratio which the shadow [of the pyramid] has to the shadow [of the stick]
Of course Thales could have used these geometrical methods for solving practical problems, having merely observed the properties and having no appreciation of what it means to prove a geometrical theorem. This is in line with the views of Russell who writes of Thales contributions to mathematics in [12]:-
Thales is said to have travelled in Egypt, and to have thence brought to the Greeks the science of geometry. What Egyptians knew of geometry was mainly rules of thumb, and there is no reason to believe that Thales arrived at deductive proofs, such as later Greeks discovered.
On the other hand B L van der Waerden [16] claims that Thales put geometry on a logical footing and was well aware of the notion of proving a geometrical theorem. However, although there is much evidence to suggest that Thales made some fundamental contributions to geometry, it is easy to interpret his contributions in the light of our own knowledge, thereby believing that Thales had a fuller appreciation of geometry than he could possibly have achieved. In many textbooks on the history of mathematics Thales is credited with five theorems of elementary geometry:-
A circle is bisected by any diameter.
The base angles of an isosceles triangle are equal.
The angles between two intersecting straight lines are equal.
Two triangles are congruent if they have two angles and one side equal.
An angle in a semicircle is a right angle.
What is the basis for these claims? Proclus, writing around 450 AD, is the basis for the first four of these claims, in the third and fourth cases quoting the work History of Geometry by Eudemus of Rhodes, who was a pupil of Aristotle, as his source. The History of Geometry by Eudemus is now lost but there is no reason to doubt Proclus. The fifth theorem is believed to be due to Thales because of a passage from Diogenes Laertius book Lives of eminent philosophers written in the second century AD [6]:-
Pamphile says that Thales, who learnt geometry from the Egyptians, was the first to describe on a circle a triangle which shall be right-angled, and that he sacrificed an ox (on the strength of the discovery). Others, however, including Apollodorus the calculator, say that it was Pythagoras.
A deeper examination of the sources, however, shows that, even if they are accurate, we may be crediting Thales with too much. For example Proclus uses a word meaning something closer to 'similar' rather than 'equal- in describing (ii). It is quite likely that Thales did not even have a way of measuring angles so 'equal- angles would have not been a concept he would have understood precisely. He may have claimed no more than "The base angles of an isosceles triangle look similar". The theorem (iv) was attributed to Thales by Eudemus for less than completely convincing reasons. Proclus writes (see [8]):-
[Eudemus] says that the method by which Thales showed how to find the distances of ships from the shore necessarily involves the use of this theorem.
Heath in [8] gives three different methods which Thales might have used to calculate the distance to a ship at sea. The method which he thinks it most likely that Thales used was to have an instrument consisting of two sticks nailed into a cross so that they could be rotated about the nail. An observer then went to the top of a tower, positioned one stick vertically (using say a plumb line) and then rotating the second stick about the nail until it point at the ship. Then the observer rotates the instrument, keeping it fixed and vertical, until the movable stick points at a suitable point on the land. The distance of this point from the base of the tower is equal to the distance to the ship.
Although theorem (iv) underlies this application, it would have been quite possible for Thales to devise such a method without appreciating anything of 'congruent triangles'.
As a final comment on these five theorems, there are conflicting stories regarding theorem (iv) as Diogenes Laertius himself is aware. Also even Pamphile cannot be taken as an authority since she lived in the first century AD, long after the time of Thales. Others have attributed the story about the sacrifice of an ox to Pythagoras on discovering Pythagoras's theorem. Certainly there is much confusion, and little certainty.
Our knowledge of the philosophy of Thales is due to Aristotle who wrote in his Metaphysics :-
Thales of Miletus taught that 'all things are water'.
This, as Brumbaugh writes [5]:-
...may seem an unpromising beginning for science and philosophy as we know them today; but, against the background of mythology from which it arose, it was revolutionary.
Sambursky writes in [15]:-
It was Thales who first conceived the principle of explaining the multitude of phenomena by a small number of hypotheses for all the various manifestations of matter.
Thales believed that the Earth floats on water and all things come to be from water. For him the Earth was a flat disc floating on an infinite ocean. It has also been claimed that Thales explained earthquakes from the fact that the Earth floats on water. Again the importance of Thales' idea is that he is the first recorded person who tried to explain such phenomena by rational rather than by supernatural means.
It is interesting that Thales has both stories told about his great practical skills and also about him being an unworldly dreamer. Aristotle, for example, relates a story of how Thales used his skills to deduce that the next season's olive crop would be a very large one. He therefore bought all the olive presses and then was able to make a fortune when the bumper olive crop did indeed arrive. On the other hand Plato tells a story of how one night Thales was gazing at the sky as he walked and fell into a ditch. A pretty servant girl lifted him out and said to him "How do you expect to understand what is going on up in the sky if you do not even see what is at your feet". As Brumbaugh says, perhaps this is the first absent-minded professor joke in the West!
THALES OF MILETUS
THALES OF MILETUS
THALES OF MILETUS
THALES OF MILETUS
THALES OF MILETUS
THALES OF MILETUS
THALES OF MILETUS
THALES OF MILETUS
THALES OF MILETUS
THALES OF MILETUS
Ancient Greek Philosophers - Thales of Miletus
Thales of Miletus one of the Seven Sages
Jābir ibn Hayyān
SCIENTIST JABIR IBN HAYYAN
Abu Musa Jābir ibn Hayyān (Arabic: جابر بن حيان), (Persian: جابر بن حيان) (born c. 721 in Tous–died c. 815 in Kufa)[1] was a prominent polymath: a chemist and alchemist, astronomer and astrologer, engineer, geologist, philosopher, physicist, and pharmacist and physician. He is considered by some to be the "father of chemistry."[2] His ethnic background have been under debate:.[3] Born and educated in Tus, located in Iran's Persian heartland of Khorasan, he later traveled to Kufa. While mentioned as being of Persian ethnicity, other sources, without providing independent documentation, state that he was an Arab; "Muslim" and "Arab" are erroneously used interchangeably by some such sources.[4] [5][6] Jābir is held to be the first practical alchemist.[7]
As early as the tenth century, the identity and exact corpus of works of Jābir was in dispute in Islamic circles.[8] His name was Latinised as "Geber" in the Christian West and in 13th century Europe an anonymous writer produced a non-trivial body of alchemical and metallurgical writings under the pen-name Geber. This person is usually referred to as Pseudo-Geber.
Contents
1 Biography
1.1 Early references
1.2 Life and background
2 The Jabirian corpus
2.1 People
2.2 Theories
2.3 Laboratory equipment and material
2.3.1 Alcohol and the Mineral Acids
2.4 Legacy
2.5 Quotation
3 The Geber Problem
3.1 The Pseudo-Geber corpus
3.2 English translations of Jābir and the pseudo-Geber
4 Popular culture
5 See also
6 References
7 External links
Biography
Early references
Abu Musa (sometimes Abu AbdAllah) Jabir ibn Haiyan al-Azdl (al-Tusl, al-Artusl, al-Harram, al-Sufi, also al-Kufi or al-Tartusi)[9] In 987 Ibn al-Nadim compiled the Kitab al-Fihrist which mentions Jabir as a spiritual leader and a companion to Jafar al-Sadiq (he is not listed among the students of Jafar but many of the writings of the Jabirian corpus are dedicated to Jafar). In an other reference al-Nadim reports that a group philosophers claimed Jabir was one of their own members. Another group, reported by al-Nadim, says only The Large Book of Mercy is genuine and that the rest are pseudographical. Their assertions are rejected by al-Nadim.[10] Joining al-Nadim in asserting a real Jabir; Ibn-Wahshiyya ("Jaber ibn Hayyn al-Sufi ...book on poison is a great work..") Rejecting a real Jabir; (the philosopher c.970) Abu Sulayman al-Mantiqi claims the real author is one al-Hasan ibn al-Nakad al-Mawili. 14th century critic of Arabic literature, Jamal al-Din ibn Nubata al-Misri declares all the writings attributed to Jabir doubtful.[9]
Life and background
Jabir was a Natural Philosopher who lived mostly in the 8th century, he was born in Tus (Iran), Khorasan, in Iran (Persia),[1] then ruled by the Umayyad Caliphate. In some sources, he is reported to have been the son of Hayyan al-Azdi, a pharmacist of the Arabian Azd tribe who emigrated from Yemen to Kufa (in present-day Iraq) during the Umayyad Caliphate.[11][12] Jābir became an alchemist at the court of Caliph Harun al-Rashid, for whom he wrote the Kitab al-Zuhra ("The Book of Venus", on "the noble art of alchemy").[citation needed] Hayyan had supported the Abbasid revolt against the Umayyads, and was sent by them to the province of Khorasan (present days Afghanistan, Iran, and part of North western Pakistan) to gather support for their cause. He was eventually caught by the Ummayads and executed. His family fled to Yemen,[11][13] where Jābir grew up and studied the Quran, mathematics and other subjects.[11] Jābir's father's profession may have contributed greatly to his interest in alchemy.
After the Abbasids took power, Jābir went back to Kufa. He began his career practicing medicine, under the patronage of a Vizir (from the noble Persian family Barmakids) of Caliph Harun al-Rashid.
Jābir may have been a student of the celebrated Islamic teacher and sixth Imam Ja'far al-Sadiq and Harbi al-Himyari.[14][8] His connections to the Barmakid cost him dearly in the end. When that family fell from grace in 803, Jābir was placed under house arrest in Kufa, where he remained until his death.
The Jabirian corpus
In total, nearly 3,000 treatises and articles are credited to Jabir ibn Hayyan.[15] Following the pioneering work of Paul Kraus, who demonstrated that a corpus of some several hundred works ascribed to Jābir were probably a medley from different hands,[9][16] mostly dating to the late ninth and early tenth centuries, many scholars believe that many of these works consist of commentaries and additions by his followers,[citation needed] particularly of an Ismaili persuasion.[17]
The scope of the corpus is vast: cosmology, music, medicine, magic, biology, chemical technology, geometry, grammar, metaphysics, logic, artificial generation of living beings, along with astrological predictions, and symbolic Imâmî myths.[9]
The 112 Books dedicated to the Barmakids, viziers of Caliph Harun al-Rashid. This group includes the Arabic version of the Emerald Tablet, an ancient work that proved a recurring foundation of and source for alchemical operations. In the Middle Ages it was translated into Latin (Tabula Smaragdina) and widely diffused among European alchemists.
The Seventy Books, most of which were translated into Latin during the Middle Ages. This group includes the Kitab al-Zuhra ("Book of Venus") and the Kitab Al-Ahjar ("Book of Stones").
The Ten Books on Rectification, containing descriptions of alchemists such as Pythagoras, Socrates, Plato and Aristotle.
The Books on Balance; this group includes his most famous 'Theory of the balance in Nature'.
Jābir states in his Book of Stones (4:12) that "The purpose is to baffle and lead into error everyone except those whom God loves and provides for". His works seem to have been deliberately written in highly esoteric code (see steganography), so that only those who had been initiated into his alchemical school could understand them. It is therefore difficult at best for the modern reader to discern which aspects of Jābir's work are to be read as symbols (and what those symbols mean), and what is to be taken literally. Because his works rarely made overt sense, the term gibberish is believed to have originally referred to his writings (Hauck, p. 19).
People
Jābir's interest in alchemy was probably inspired by his teacher Ja'far al-Sadiq. Ibn Hayyan was deeply religious, and repeatedly emphasizes in his works that alchemy is possible only by subjugating oneself completely to the will of Allah and becoming a literal instrument of Allah on Earth, since the manipulation of reality is possible only for Allah. The Book of Stones prescribes long and elaborate sequences of specific prayers that must be performed without error alone in the desert before one can even consider alchemical experimentation.
Jābir professes to draw his inspiration from earlier writers, Legendary and historic, on the subject.[18] In his writings, Jābir pays tribute to Egyptian and Greek alchemists Zosimos, Democritus, Hermes Trismegistus, Agathodaimon, but also Plato, Aristotle, Galen, Pythagoras, and Socratesas well as the commentators Alexander of Aphrodisias Simplicius, Porphyry and others.[9] A huge pseudo-epigraphic literature of alchemical books was composed in Arabic, among which the names of Persian authors also appear like Jāmāsb, Ostanes, Mani, testifying that alchemy-like operations on metals and other substances were also practiced in Persia. The great number of Persian technical names (zaybaq = mercury, nošāder = sal-ammoniac) also corroborates the idea of an important Iranian roots of medieval alchemy.[19] Ibn al-Nadim reports a dialogue between Aristotle and Ostanes, the Persian alchemist of Achaemenid era, which is in Jabirian corpus under the title of Kitab Musahhaha Aristutalis.[20] Ruska had suggested that the Sasanian medical schools played an important role in the spread of interest in alchemy.[19] He emphasizes the long history of alchemy, "whose origin is Arius ... the first man who applied the first experiment on the [philosopher's] stone... and he declares that man possesses the ability to imitate the workings of Nature" (Nasr, Seyyed Hussein, Science and Civilization of Islam).
Theories
Jābir's alchemical investigations ostensibly revolved around the ultimate goal of takwin — the artificial creation of life. The Book of Stones includes several recipes for creating creatures such as scorpions, snakes, and even humans in a laboratory environment, which are subject to the control of their creator. What Jābir meant by these recipes is unknown.
Jābir's alchemical investigations were theoretically grounded in an elaborate numerology related to Pythagorean and Neoplatonic systems. The nature and properties of elements was defined through numeric values assigned the Arabic consonants present in their name, ultimately culminating in the number 17.
By Jabirs' time Aristotelian physics, had become Neoplatonic. Each Aristotelian element was composed of these qualities: fire was both hot and dry, earth, cold and dry, water cold and moist, and air, hot and moist. This came from the elementary qualities which are theoretical in nature plus substance. In metals two of these qualities were interior and two were exterior. For example, lead was cold and dry and gold was hot and moist. Thus, Jābir theorized, by rearranging the qualities of one metal, a different metal would result. Like Zosimos, Jabir believed this would require a catalyst, an al-iksir, the elusive elixir that would make this transformation possible — which in European alchemy became known as the philosopher's stone.[9]
According to Jabir's mercury-sulfur theory, metals differ from each in so far as they contain different proportions of the sulfur and mercury. These are not the elements that we know by those names, but certain principles to which those elements are the closest approximation in nature.[21] Based on Aristotle's "exhalation" theory the dry and moist exhalations become sulfur and mercury (sometimes called "sophic" or "philosophic" mercury and sulfur). The sulfur-mercury theory is first recorded in a 7th century work Secret of Creation credited (falsely) to Balinus (Apollonius of Tyana). This view becomes wide spread.[22] In the Book of Explanation Jabir says
the metals are all, in essence, composed of mercury combined and coagulated with sulphur [that has risen to it in earthy, smoke-like vapors]. They differ from one another only because of the difference of their accidental qualities, and this difference is due to the difference of their sulphur, which again is caused by a variation in the soils and in their positions with respect to the heat of the sun
Holmyard says that Jabir proves by experiment that these are not ordinary sulfur and mercury.[11]
The seeds of the modern classification of elements into metals and non-metals could be seen in his chemical nomenclature. He proposed three categories:[23]
"Spirits" which vaporise on heating, like arsenic (realgar, orpiment), camphor, mercury, sulfur, sal ammoniac, and ammonium chloride.
"Metals", like gold, silver, lead, tin, copper, iron, and khar-sini
Non-malleable substances, that can be converted into powders, such as stones.
The origins of the idea of chemical equivalents might be traced back to Jabir, in whose time it was recognized that "a certain quantity of acid is necessary in order to neutralize a given amount of base."[24] Jābir also made important contributions to medicine, astronomy/astrology, and other sciences. Only a few of his books have been edited and published, and fewer still are available in translation.
Laboratory equipment and material
Ambix, cucurbit and retort of Zosimus, from Marcelin Berthelot, Collection of ancient greek alchemists (3 vol., Paris, 1887-1888).
Jabirian corpus is renowned for its contributions to alchemy. It shows a clear recognition of the importance of experimentation, "The first essential in chemistry is that thou shouldest perform practical work and conduct experiments, for he who performs not practical work nor makes experiments will never attain to the least degree of mastery."[25] He is credited with the use of over twenty types of now-basic chemical laboratory equipment,[26] such as the alembic[27] and retort, and with the description of many now-commonplace chemical processes – such as crystallisation, various forms of alchemical "distilation", and substances citric acid (the sour component of lemons and other unripe fruits), acetic acid (from vinegar) and tartaric acid (from wine-making residues), arsenic, antimony and bismuth, sulfur, and mercury[25][26] that have become the foundation of today's chemistry.[28]
Jabir applied his chemical knowledge to the improvement of many manufacturing processes, such as making steel and other metals, preventing rust, engraving gold, dyeing and waterproofing cloth, tanning leather, and the chemical analysis of pigments and other substances. He noted the use of manganese dioxide in glassmaking, to counteract the green tinge produced by iron — a process that is still used today. According to Ismail al-Faruqi and Lois Lamya al-Faruqi, "In response to Jafar al-Sadik's wishes, [Jabir ibn Hayyan] invented a kind of paper that resisted fire, and an ink that could be read at night. He invented an additive which, when applied to an iron surface, inhibited rust and when applied to a textile, would make it water repellent."[29]
Alcohol and the Mineral Acids
According to Forbes "no proof was ever found that the Arabs knew alcohol or any mineral acid in a period before they were discovered in Italy, whatever the opinion of some modern authors may be on this point."[30] Fractional distillation of alcohol first occurs about 1100 probably in Salerno. Magister Salernus (died 1167) provides one of the earliest direct recipes.[30] Directions to make sulfuric acid, nitric acid and aqua regis appear in Liber Fornacum, De inventione perfectionis, and the Summa.[30]
Legacy
The crater Geber on the Moon is named after him.
He paved the way for most of the later alchemists, including al-Kindi, al-Razi, al-Tughrai and al-Iraqi, who lived in the 9th-13th centuries. His books strongly influenced the medieval European alchemists[28] and justified their search for the philosopher's stone.[31][32]
In the Middle Ages, Jabir's treatises on alchemy were translated into Latin and became standard texts for European alchemists. These include the Kitab al-Kimya (titled Book of the Composition of Alchemy in Europe), translated by Robert of Chester (1144); and the Kitab al-Sab'een (Book of Seventy) by Gerard of Cremona (before 1187). Marcelin Berthelot translated some of his books under the fanciful titles Book of the Kingdom, Book of the Balances, and Book of Eastern Mercury. Several technical Arabic terms introduced by Jabir, such as alkali, have found their way into various European languages and have become part of scientific vocabulary.
Max Meyerhoff states the following on Jabir ibn Hayyan: "His influence may be traced throughout the whole historic course of European alchemy and chemistry."[28]
The historian of chemistry Erick John Holmyard gives credit to Jābir for developing alchemy into an experimental science and he writes that Jābir's importance to the history of chemistry is equal to that of Robert Boyle and Antoine Lavoisier. The historian Paul Kraus, who had studied most of Jābir's extant works in Arabic and Latin, summarized the importance of Jābir to the history of chemistry by comparing his experimental and systematic works in chemistry with that of the allegorical and unintelligible works of the ancient Greek alchemists.[33] The word gibberish is theorized to be derived from the Latinised version off Jābir's name,[34] in reference to the incomprehensible technical jargon often used by alchemists, the most famous of whom was Jābir.[35] Other sources such as the Oxford English Dictionary suggest the term stems from gibber; however, the first known recorded use of the term "gibberish" was before the first known recorded use of the word "gibber" (see Gibberish).
Quotation
"My wealth let sons and brethren part. Some things they cannot share: my work well done, my noble heart — these are mine own to wear."[36]
The Geber Problem
The identity of the author of works attributed to Jabir has long been discussed.[8] According to a famous controversy,[37] pseudo-Geber has been considered as the unknown author of several books in Alchemy.[38] This was first independently suggested, on textual and other grounds, by the nineteenth-century historians Hermann Kopp and Marcellin Berthelot.[39] Jabir, by reputation the greatest chemist of Islam, has long been familiar to western readers under the name of Geber, which is the medieval rendering of the Arabic Jabir, the Geber of the Middle Ages.[40] The works in Latin corpus were considered to be translations until the studies of Kopp, Hoefer, Berthelot, and Lippman. Although they reflect earlier Arabic alchemy the are not direct translations of "Jabir" but are the work of a 13th century Latin alchemist.[41] Eric Holmyard says in his book Makers of Chemistry Clarendon press.(1931) [1].)
There are, however, certain other Latin works, entitled The Sum of Perfection, The Investigation of Perfection, The Invention of Verity, The Book of Furnaces, and The Testament, which pass under his name but of which no Arabic original is known. A problem which historians of chemistry have not yet succeeded in solving is whether these works are genuine or not.
However by 1957 AD when he (Holmyard) wrote Alchemy. Courier Dover Publications. p. 134. ISBN 978-0-486-26298-7. Holmyard had abandoned the idea of an Arabic original. (although they are based on "Islamic" alchemical theories)
The question at once arises whether the Latin works are genuine translations from the Arabic, or written by a Latin author and, according to common practice, ascribed to Jabir in order to heighten their authority. That they are based on Muslim alchemical theory and practice is not questioned, but the same may be said of most Latin treatises on alchemy of that period; and from various turns of phrase it seems likely that their author could read Arabic. But the general style of the works is to clear and systematic to find a close parallel in any of the known writings of the Jabirian corpus, and we look in vain in them for any references to the characteristically Jabirian ideas of "balance" and the alphabetic numerology. Indeed for their age they have a remarkably matter of fact air about them, theory being stated with a minimum of prolixity and much precise practical detail being given. The general impression they convey is that they are the product of an occidental rather than an oriental mind, and a likely guess would be that they were written by a European scholar, possibly in Moorish Spain. Whatever their origin, they became the principal authorities in early Western alchemy and held that position for two or there centuries.
The question of Geber's identity, whether he is the original Jābir or a "pseudo-Geber" adopting his name, is still in dispute(1962).[42]
It is said that Geber, the Latinized form of "Jābir," was adopted presumably because of the great reputation of a supposed 8th-century alchemist by the name of Jābir ibn Hayyān.[43] About this historical figure, however, there is considerable uncertainty(1910).[44]
This is sometimes called the "Geber-Jābir problem".[45]
It is possible that some of the facts mentioned in the Latin works, ascribed to Geber and dating from the twelfth century and later, must also be placed to Jabir's credit. It is important to consider that it is impossible to reach definite conclusions until all the Arabic writings ascribed to Jābir have been properly edited and discussed.[40]
The Pseudo-Geber corpus
The Latin corpus consists of books with an author named "Geber" for which researchers have failed to find a text in Arabic. Although these books are heavily influenced by Arabic books written by Jābir, the "real" Geber, and by Al Razi and others, they were never written in Arabic. They are in Latin only, they date from about the year 1310, and their author is called Pseudo-Geber:
Summa perfectionis magisterii ("The Height of the Perfection of Mastery").[46]
Liber fornacum ("Book of Stills"),
De investigatione perfectionis ("On the Investigation of Perfection"), and
De inventione veritatis ("On the Discovery of Truth").
Testamentum gerberi
The 2nd, 3rd and 4th books listed above "are merely extracts from or summaries of the Summa Perfectionis Magisterii with later additions."[47]
English translations of Jābir and the pseudo-Geber
E. J. Holmyard (ed.) The Arabic Works of Jabir ibn Hayyan, translated by Richard Russel in 1678. New York, E. P. Dutton (1928); Also Paris, P. Geuther.
Syed Nomanul Haq, Names, Natures and Things: The Alchemists Jabir ibn Hayyan and his Kitab al-Ahjar (Book of Stones), [Boston Studies in the Philosophy of Science p. 158] (Dordrecht: Kluwer Academic Publishers, 1994), ISBN 0-7923-3254-7.
Donald Routledge Hill, 'The Literature of Arabic Alchemy' in Religion: Learning and Science in the Abbasid Period, ed. by M.J.L. Young, J.D. Latham and R.B. Serjeant (Cambridge University Press, 1990) pp. 328–341, esp. pp 333–5.
William Newman, New Light on the Identity of Geber, Sudhoffs Archiv, 1985, Vol.69, pp. 76–90.
Geber and William Newman The Summa Perfectionis of Pseudo-Geber: A Critical Edition, Translation and Study ISBN 9004094664
Popular culture
Geber is mentioned in Paulo Coelho's 1993 bestseller, The Alchemist.[48]
There is a villain in the Japanese manga and anime series Bio Booster Armor Guyver by the name of Jearvill bun Hiyern (translated in various ways), who is most likely named after ibn Hayyan.
Jabbir is said to be the creator of a (fictional) mystical chess set in Katherine Neville's novels The Eight and The Fire
In S.H.I.E.L.D, Jabir appears as the 8th century leader of the organization.
Abu Musa Jābir ibn Hayyān (Arabic: جابر بن حيان), (Persian: جابر بن حيان) (born c. 721 in Tous–died c. 815 in Kufa)[1] was a prominent polymath: a chemist and alchemist, astronomer and astrologer, engineer, geologist, philosopher, physicist, and pharmacist and physician. He is considered by some to be the "father of chemistry."[2] His ethnic background have been under debate:.[3] Born and educated in Tus, located in Iran's Persian heartland of Khorasan, he later traveled to Kufa. While mentioned as being of Persian ethnicity, other sources, without providing independent documentation, state that he was an Arab; "Muslim" and "Arab" are erroneously used interchangeably by some such sources.[4] [5][6] Jābir is held to be the first practical alchemist.[7]
As early as the tenth century, the identity and exact corpus of works of Jābir was in dispute in Islamic circles.[8] His name was Latinised as "Geber" in the Christian West and in 13th century Europe an anonymous writer produced a non-trivial body of alchemical and metallurgical writings under the pen-name Geber. This person is usually referred to as Pseudo-Geber.
Contents
1 Biography
1.1 Early references
1.2 Life and background
2 The Jabirian corpus
2.1 People
2.2 Theories
2.3 Laboratory equipment and material
2.3.1 Alcohol and the Mineral Acids
2.4 Legacy
2.5 Quotation
3 The Geber Problem
3.1 The Pseudo-Geber corpus
3.2 English translations of Jābir and the pseudo-Geber
4 Popular culture
5 See also
6 References
7 External links
Biography
Early references
Abu Musa (sometimes Abu AbdAllah) Jabir ibn Haiyan al-Azdl (al-Tusl, al-Artusl, al-Harram, al-Sufi, also al-Kufi or al-Tartusi)[9] In 987 Ibn al-Nadim compiled the Kitab al-Fihrist which mentions Jabir as a spiritual leader and a companion to Jafar al-Sadiq (he is not listed among the students of Jafar but many of the writings of the Jabirian corpus are dedicated to Jafar). In an other reference al-Nadim reports that a group philosophers claimed Jabir was one of their own members. Another group, reported by al-Nadim, says only The Large Book of Mercy is genuine and that the rest are pseudographical. Their assertions are rejected by al-Nadim.[10] Joining al-Nadim in asserting a real Jabir; Ibn-Wahshiyya ("Jaber ibn Hayyn al-Sufi ...book on poison is a great work..") Rejecting a real Jabir; (the philosopher c.970) Abu Sulayman al-Mantiqi claims the real author is one al-Hasan ibn al-Nakad al-Mawili. 14th century critic of Arabic literature, Jamal al-Din ibn Nubata al-Misri declares all the writings attributed to Jabir doubtful.[9]
Life and background
Jabir was a Natural Philosopher who lived mostly in the 8th century, he was born in Tus (Iran), Khorasan, in Iran (Persia),[1] then ruled by the Umayyad Caliphate. In some sources, he is reported to have been the son of Hayyan al-Azdi, a pharmacist of the Arabian Azd tribe who emigrated from Yemen to Kufa (in present-day Iraq) during the Umayyad Caliphate.[11][12] Jābir became an alchemist at the court of Caliph Harun al-Rashid, for whom he wrote the Kitab al-Zuhra ("The Book of Venus", on "the noble art of alchemy").[citation needed] Hayyan had supported the Abbasid revolt against the Umayyads, and was sent by them to the province of Khorasan (present days Afghanistan, Iran, and part of North western Pakistan) to gather support for their cause. He was eventually caught by the Ummayads and executed. His family fled to Yemen,[11][13] where Jābir grew up and studied the Quran, mathematics and other subjects.[11] Jābir's father's profession may have contributed greatly to his interest in alchemy.
After the Abbasids took power, Jābir went back to Kufa. He began his career practicing medicine, under the patronage of a Vizir (from the noble Persian family Barmakids) of Caliph Harun al-Rashid.
Jābir may have been a student of the celebrated Islamic teacher and sixth Imam Ja'far al-Sadiq and Harbi al-Himyari.[14][8] His connections to the Barmakid cost him dearly in the end. When that family fell from grace in 803, Jābir was placed under house arrest in Kufa, where he remained until his death.
The Jabirian corpus
In total, nearly 3,000 treatises and articles are credited to Jabir ibn Hayyan.[15] Following the pioneering work of Paul Kraus, who demonstrated that a corpus of some several hundred works ascribed to Jābir were probably a medley from different hands,[9][16] mostly dating to the late ninth and early tenth centuries, many scholars believe that many of these works consist of commentaries and additions by his followers,[citation needed] particularly of an Ismaili persuasion.[17]
The scope of the corpus is vast: cosmology, music, medicine, magic, biology, chemical technology, geometry, grammar, metaphysics, logic, artificial generation of living beings, along with astrological predictions, and symbolic Imâmî myths.[9]
The 112 Books dedicated to the Barmakids, viziers of Caliph Harun al-Rashid. This group includes the Arabic version of the Emerald Tablet, an ancient work that proved a recurring foundation of and source for alchemical operations. In the Middle Ages it was translated into Latin (Tabula Smaragdina) and widely diffused among European alchemists.
The Seventy Books, most of which were translated into Latin during the Middle Ages. This group includes the Kitab al-Zuhra ("Book of Venus") and the Kitab Al-Ahjar ("Book of Stones").
The Ten Books on Rectification, containing descriptions of alchemists such as Pythagoras, Socrates, Plato and Aristotle.
The Books on Balance; this group includes his most famous 'Theory of the balance in Nature'.
Jābir states in his Book of Stones (4:12) that "The purpose is to baffle and lead into error everyone except those whom God loves and provides for". His works seem to have been deliberately written in highly esoteric code (see steganography), so that only those who had been initiated into his alchemical school could understand them. It is therefore difficult at best for the modern reader to discern which aspects of Jābir's work are to be read as symbols (and what those symbols mean), and what is to be taken literally. Because his works rarely made overt sense, the term gibberish is believed to have originally referred to his writings (Hauck, p. 19).
People
Jābir's interest in alchemy was probably inspired by his teacher Ja'far al-Sadiq. Ibn Hayyan was deeply religious, and repeatedly emphasizes in his works that alchemy is possible only by subjugating oneself completely to the will of Allah and becoming a literal instrument of Allah on Earth, since the manipulation of reality is possible only for Allah. The Book of Stones prescribes long and elaborate sequences of specific prayers that must be performed without error alone in the desert before one can even consider alchemical experimentation.
Jābir professes to draw his inspiration from earlier writers, Legendary and historic, on the subject.[18] In his writings, Jābir pays tribute to Egyptian and Greek alchemists Zosimos, Democritus, Hermes Trismegistus, Agathodaimon, but also Plato, Aristotle, Galen, Pythagoras, and Socratesas well as the commentators Alexander of Aphrodisias Simplicius, Porphyry and others.[9] A huge pseudo-epigraphic literature of alchemical books was composed in Arabic, among which the names of Persian authors also appear like Jāmāsb, Ostanes, Mani, testifying that alchemy-like operations on metals and other substances were also practiced in Persia. The great number of Persian technical names (zaybaq = mercury, nošāder = sal-ammoniac) also corroborates the idea of an important Iranian roots of medieval alchemy.[19] Ibn al-Nadim reports a dialogue between Aristotle and Ostanes, the Persian alchemist of Achaemenid era, which is in Jabirian corpus under the title of Kitab Musahhaha Aristutalis.[20] Ruska had suggested that the Sasanian medical schools played an important role in the spread of interest in alchemy.[19] He emphasizes the long history of alchemy, "whose origin is Arius ... the first man who applied the first experiment on the [philosopher's] stone... and he declares that man possesses the ability to imitate the workings of Nature" (Nasr, Seyyed Hussein, Science and Civilization of Islam).
Theories
Jābir's alchemical investigations ostensibly revolved around the ultimate goal of takwin — the artificial creation of life. The Book of Stones includes several recipes for creating creatures such as scorpions, snakes, and even humans in a laboratory environment, which are subject to the control of their creator. What Jābir meant by these recipes is unknown.
Jābir's alchemical investigations were theoretically grounded in an elaborate numerology related to Pythagorean and Neoplatonic systems. The nature and properties of elements was defined through numeric values assigned the Arabic consonants present in their name, ultimately culminating in the number 17.
By Jabirs' time Aristotelian physics, had become Neoplatonic. Each Aristotelian element was composed of these qualities: fire was both hot and dry, earth, cold and dry, water cold and moist, and air, hot and moist. This came from the elementary qualities which are theoretical in nature plus substance. In metals two of these qualities were interior and two were exterior. For example, lead was cold and dry and gold was hot and moist. Thus, Jābir theorized, by rearranging the qualities of one metal, a different metal would result. Like Zosimos, Jabir believed this would require a catalyst, an al-iksir, the elusive elixir that would make this transformation possible — which in European alchemy became known as the philosopher's stone.[9]
According to Jabir's mercury-sulfur theory, metals differ from each in so far as they contain different proportions of the sulfur and mercury. These are not the elements that we know by those names, but certain principles to which those elements are the closest approximation in nature.[21] Based on Aristotle's "exhalation" theory the dry and moist exhalations become sulfur and mercury (sometimes called "sophic" or "philosophic" mercury and sulfur). The sulfur-mercury theory is first recorded in a 7th century work Secret of Creation credited (falsely) to Balinus (Apollonius of Tyana). This view becomes wide spread.[22] In the Book of Explanation Jabir says
the metals are all, in essence, composed of mercury combined and coagulated with sulphur [that has risen to it in earthy, smoke-like vapors]. They differ from one another only because of the difference of their accidental qualities, and this difference is due to the difference of their sulphur, which again is caused by a variation in the soils and in their positions with respect to the heat of the sun
Holmyard says that Jabir proves by experiment that these are not ordinary sulfur and mercury.[11]
The seeds of the modern classification of elements into metals and non-metals could be seen in his chemical nomenclature. He proposed three categories:[23]
"Spirits" which vaporise on heating, like arsenic (realgar, orpiment), camphor, mercury, sulfur, sal ammoniac, and ammonium chloride.
"Metals", like gold, silver, lead, tin, copper, iron, and khar-sini
Non-malleable substances, that can be converted into powders, such as stones.
The origins of the idea of chemical equivalents might be traced back to Jabir, in whose time it was recognized that "a certain quantity of acid is necessary in order to neutralize a given amount of base."[24] Jābir also made important contributions to medicine, astronomy/astrology, and other sciences. Only a few of his books have been edited and published, and fewer still are available in translation.
Laboratory equipment and material
Ambix, cucurbit and retort of Zosimus, from Marcelin Berthelot, Collection of ancient greek alchemists (3 vol., Paris, 1887-1888).
Jabirian corpus is renowned for its contributions to alchemy. It shows a clear recognition of the importance of experimentation, "The first essential in chemistry is that thou shouldest perform practical work and conduct experiments, for he who performs not practical work nor makes experiments will never attain to the least degree of mastery."[25] He is credited with the use of over twenty types of now-basic chemical laboratory equipment,[26] such as the alembic[27] and retort, and with the description of many now-commonplace chemical processes – such as crystallisation, various forms of alchemical "distilation", and substances citric acid (the sour component of lemons and other unripe fruits), acetic acid (from vinegar) and tartaric acid (from wine-making residues), arsenic, antimony and bismuth, sulfur, and mercury[25][26] that have become the foundation of today's chemistry.[28]
Jabir applied his chemical knowledge to the improvement of many manufacturing processes, such as making steel and other metals, preventing rust, engraving gold, dyeing and waterproofing cloth, tanning leather, and the chemical analysis of pigments and other substances. He noted the use of manganese dioxide in glassmaking, to counteract the green tinge produced by iron — a process that is still used today. According to Ismail al-Faruqi and Lois Lamya al-Faruqi, "In response to Jafar al-Sadik's wishes, [Jabir ibn Hayyan] invented a kind of paper that resisted fire, and an ink that could be read at night. He invented an additive which, when applied to an iron surface, inhibited rust and when applied to a textile, would make it water repellent."[29]
Alcohol and the Mineral Acids
According to Forbes "no proof was ever found that the Arabs knew alcohol or any mineral acid in a period before they were discovered in Italy, whatever the opinion of some modern authors may be on this point."[30] Fractional distillation of alcohol first occurs about 1100 probably in Salerno. Magister Salernus (died 1167) provides one of the earliest direct recipes.[30] Directions to make sulfuric acid, nitric acid and aqua regis appear in Liber Fornacum, De inventione perfectionis, and the Summa.[30]
Legacy
The crater Geber on the Moon is named after him.
He paved the way for most of the later alchemists, including al-Kindi, al-Razi, al-Tughrai and al-Iraqi, who lived in the 9th-13th centuries. His books strongly influenced the medieval European alchemists[28] and justified their search for the philosopher's stone.[31][32]
In the Middle Ages, Jabir's treatises on alchemy were translated into Latin and became standard texts for European alchemists. These include the Kitab al-Kimya (titled Book of the Composition of Alchemy in Europe), translated by Robert of Chester (1144); and the Kitab al-Sab'een (Book of Seventy) by Gerard of Cremona (before 1187). Marcelin Berthelot translated some of his books under the fanciful titles Book of the Kingdom, Book of the Balances, and Book of Eastern Mercury. Several technical Arabic terms introduced by Jabir, such as alkali, have found their way into various European languages and have become part of scientific vocabulary.
Max Meyerhoff states the following on Jabir ibn Hayyan: "His influence may be traced throughout the whole historic course of European alchemy and chemistry."[28]
The historian of chemistry Erick John Holmyard gives credit to Jābir for developing alchemy into an experimental science and he writes that Jābir's importance to the history of chemistry is equal to that of Robert Boyle and Antoine Lavoisier. The historian Paul Kraus, who had studied most of Jābir's extant works in Arabic and Latin, summarized the importance of Jābir to the history of chemistry by comparing his experimental and systematic works in chemistry with that of the allegorical and unintelligible works of the ancient Greek alchemists.[33] The word gibberish is theorized to be derived from the Latinised version off Jābir's name,[34] in reference to the incomprehensible technical jargon often used by alchemists, the most famous of whom was Jābir.[35] Other sources such as the Oxford English Dictionary suggest the term stems from gibber; however, the first known recorded use of the term "gibberish" was before the first known recorded use of the word "gibber" (see Gibberish).
Quotation
"My wealth let sons and brethren part. Some things they cannot share: my work well done, my noble heart — these are mine own to wear."[36]
The Geber Problem
The identity of the author of works attributed to Jabir has long been discussed.[8] According to a famous controversy,[37] pseudo-Geber has been considered as the unknown author of several books in Alchemy.[38] This was first independently suggested, on textual and other grounds, by the nineteenth-century historians Hermann Kopp and Marcellin Berthelot.[39] Jabir, by reputation the greatest chemist of Islam, has long been familiar to western readers under the name of Geber, which is the medieval rendering of the Arabic Jabir, the Geber of the Middle Ages.[40] The works in Latin corpus were considered to be translations until the studies of Kopp, Hoefer, Berthelot, and Lippman. Although they reflect earlier Arabic alchemy the are not direct translations of "Jabir" but are the work of a 13th century Latin alchemist.[41] Eric Holmyard says in his book Makers of Chemistry Clarendon press.(1931) [1].)
There are, however, certain other Latin works, entitled The Sum of Perfection, The Investigation of Perfection, The Invention of Verity, The Book of Furnaces, and The Testament, which pass under his name but of which no Arabic original is known. A problem which historians of chemistry have not yet succeeded in solving is whether these works are genuine or not.
However by 1957 AD when he (Holmyard) wrote Alchemy. Courier Dover Publications. p. 134. ISBN 978-0-486-26298-7. Holmyard had abandoned the idea of an Arabic original. (although they are based on "Islamic" alchemical theories)
The question at once arises whether the Latin works are genuine translations from the Arabic, or written by a Latin author and, according to common practice, ascribed to Jabir in order to heighten their authority. That they are based on Muslim alchemical theory and practice is not questioned, but the same may be said of most Latin treatises on alchemy of that period; and from various turns of phrase it seems likely that their author could read Arabic. But the general style of the works is to clear and systematic to find a close parallel in any of the known writings of the Jabirian corpus, and we look in vain in them for any references to the characteristically Jabirian ideas of "balance" and the alphabetic numerology. Indeed for their age they have a remarkably matter of fact air about them, theory being stated with a minimum of prolixity and much precise practical detail being given. The general impression they convey is that they are the product of an occidental rather than an oriental mind, and a likely guess would be that they were written by a European scholar, possibly in Moorish Spain. Whatever their origin, they became the principal authorities in early Western alchemy and held that position for two or there centuries.
The question of Geber's identity, whether he is the original Jābir or a "pseudo-Geber" adopting his name, is still in dispute(1962).[42]
It is said that Geber, the Latinized form of "Jābir," was adopted presumably because of the great reputation of a supposed 8th-century alchemist by the name of Jābir ibn Hayyān.[43] About this historical figure, however, there is considerable uncertainty(1910).[44]
This is sometimes called the "Geber-Jābir problem".[45]
It is possible that some of the facts mentioned in the Latin works, ascribed to Geber and dating from the twelfth century and later, must also be placed to Jabir's credit. It is important to consider that it is impossible to reach definite conclusions until all the Arabic writings ascribed to Jābir have been properly edited and discussed.[40]
The Pseudo-Geber corpus
The Latin corpus consists of books with an author named "Geber" for which researchers have failed to find a text in Arabic. Although these books are heavily influenced by Arabic books written by Jābir, the "real" Geber, and by Al Razi and others, they were never written in Arabic. They are in Latin only, they date from about the year 1310, and their author is called Pseudo-Geber:
Summa perfectionis magisterii ("The Height of the Perfection of Mastery").[46]
Liber fornacum ("Book of Stills"),
De investigatione perfectionis ("On the Investigation of Perfection"), and
De inventione veritatis ("On the Discovery of Truth").
Testamentum gerberi
The 2nd, 3rd and 4th books listed above "are merely extracts from or summaries of the Summa Perfectionis Magisterii with later additions."[47]
English translations of Jābir and the pseudo-Geber
E. J. Holmyard (ed.) The Arabic Works of Jabir ibn Hayyan, translated by Richard Russel in 1678. New York, E. P. Dutton (1928); Also Paris, P. Geuther.
Syed Nomanul Haq, Names, Natures and Things: The Alchemists Jabir ibn Hayyan and his Kitab al-Ahjar (Book of Stones), [Boston Studies in the Philosophy of Science p. 158] (Dordrecht: Kluwer Academic Publishers, 1994), ISBN 0-7923-3254-7.
Donald Routledge Hill, 'The Literature of Arabic Alchemy' in Religion: Learning and Science in the Abbasid Period, ed. by M.J.L. Young, J.D. Latham and R.B. Serjeant (Cambridge University Press, 1990) pp. 328–341, esp. pp 333–5.
William Newman, New Light on the Identity of Geber, Sudhoffs Archiv, 1985, Vol.69, pp. 76–90.
Geber and William Newman The Summa Perfectionis of Pseudo-Geber: A Critical Edition, Translation and Study ISBN 9004094664
Popular culture
Geber is mentioned in Paulo Coelho's 1993 bestseller, The Alchemist.[48]
There is a villain in the Japanese manga and anime series Bio Booster Armor Guyver by the name of Jearvill bun Hiyern (translated in various ways), who is most likely named after ibn Hayyan.
Jabbir is said to be the creator of a (fictional) mystical chess set in Katherine Neville's novels The Eight and The Fire
In S.H.I.E.L.D, Jabir appears as the 8th century leader of the organization.
JABIR IBN HAYYAN
JABIR IBN HAYYAN
JABIR IBN HAYYAN
JABIR IBN HAYYAN
JABIR IBN HAYYAN
JABIR IBN HAYYAN
JABIR IBN HAYYAN
JABIR IBN HAYYAN
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JABIR IBN HAYYAN
Jabir Ibn Hayyan, Contributions to Chemistry
Jabir Ibn Hayyan
Abu Ali al-Husain ibn Abdullah ibn Sina (Avicenna)
SCIENTIST ABU AL-HUSAIN IBN ABDULLAH IBN SINA (Avicenna):
Ibn Sina is often known by his Latin name of Avicenna, although most references to him today have reverted to using the correct version of ibn Sina. We know many details of his life for he wrote an autobiography which has been supplemented with material from a biography written by one of his students. The autobiography is not simply an account of his life, but rather it is written to illustrate his ideas of reaching the ultimate truth, so it must be carefully interpreted. A useful critical edition of this autobiography appears in [7] while a new translation appears in [9].
The course of ibn Sina's life was dominated by the period of great political instability through which he lived. The Samanid dynasty, the first native dynasty to arise in Iran after the Muslim Arab conquest, controlled Transoxania and Khorasan from about 900. Bukhara was their capital and it, together with Samarkand, were the cultural centres of the empire. However, from the middle of the 10th century, the power of the Samanid's began to weaken. By the time ibn Sina was born, Nuh ibn Mansur was the Sultan in Bukhara but he was struggling to retain control of the empire.
Ibn Sina's father was the governor of a village in one of Nuh ibn Mansur's estates. He was educated by his father, whose home was a meeting place for men of learning in the area. Certainly ibn Sina was a remarkable child, with a memory and an ability to learn which amazed the scholars who met in his father's home. By the age of ten he had memorised the Qur'an and most of the Arabic poetry which he had read. When ibn Sina reached the age of thirteen he began to study medicine and he had mastered that subject by the age of sixteen when he began to treat patients. He also studied logic and metaphysics, receiving instruction from some of the best teachers of his day, but in all areas he continued his studies on his own. In his autobiography (see [7] or [9]) ibn Sina stresses that he was more or less self-taught but that at crucial times in his life he received help.
It was his skill in medicine that was to prove of great value to ibn Sina for it was through his reputation in that area that the Samanid ruler Nuh ibn Mansur came to hear of him. After ibn Sina had cured the Samanid ruler of an illness, as a reward, he was allowed to use the Royal Library of the Samanids which proved important for ibn Sina's development in the whole range of scholarship.
If the fortunes of the Samanid rulers had taken a turn for the better, ibn Sina's life would have been very different. Nuh ibn Mansur, in an attempt to keep in power, had put Sebüktigin, a former Turkish slave, as the ruler of Ghazna and appointed his son Mahmud as governor of Khorasan. However the Turkish Qarakhanids, already in control of most of Transoxania, joined with Mahmud and moved to depose the Samanids. After gaining Khorasan they took Bukhara in 999. There followed a period of five years in which the Samanids tried to regain control but their period of power was over. As recounted in [2]:-
Destiny had plunged [ibn Sina] into one of the tumultuous periods of Iranian history, when new Turkish elements were replacing Iranian domination in Central Asia and local Iranian dynasties were trying to gain political independence from the 'Abbasid caliphate in Baghdad (in modern Iraq).
The defeat of the Samanids and another traumatic event, the death of his father, changed ibn Sina's life completely. Without the support of a patron or his father, he began a life of wandering round different towns of Khorasan, acting as a physician and administrator by day while every evening he gathered students round him for philosophical and scientific discussion. He served as a jurist in Gurganj, was in Khwarazm, then was a teacher in Gurgan and next an administrator in Rayy. Perhaps most remarkable is the fact that he continued to produce top quality scholarship despite his chaotic life style. For [2]:-
... the power of concentration and the intellectual prowess of [ibn Sina] was such that he was able to continue his intellectual work with remarkable consistency and continuity and was not at all influenced by the outward disturbances.
After this period of wandering, ibn Sina went to Hamadan in west-central Iran. Here he settled for a while becoming court physician. The ruling Buyid prince, Shams ad-Dawlah, twice appointed him vizier. Politics was not easy at that time and ibn Sina was forced into hiding for a while by his political opponents and he also spent some time as a political prisoner in prison [26]
... but he escaped to Isafan, disguised as a Sufi, and joined Ala al-Dwla.
Ibn Sina's two most important works are The Book of Healing and The Canon of Medicine. The first is a scientific encyclopaedia covering logic, natural sciences, psychology, geometry, astronomy, arithmetic and music. The second is the most famous single book in the history of medicine. These works were begun while he was in Hamadan.
After being imprisoned, ibn Sina decided to leave Hamadan in 1022 on the death of the Buyid prince who he was serving, and he travelled to Isfahan. Here he entered the court of the local prince and spent the last years of his life in comparative peace. At Isfahan he completed his major works begun at Hamadan and also wrote many other works on philosophy, medicine and the Arabic language.
During military campaigns ibn Sina was expected to accompany his patron and many of his works were composed on such campaigns. It was on one such military campaign that he took ill and, despite attempting to apply his medical skills to himself, died [1]:-
... of a mysterious illness, apparently a colic that was badly treated; he may, however, have been poisoned by one of his servants.
Ibn Sina's wrote about 450 works, of which around 240 have survived. Of the surviving works, 150 are on philosophy while 40 are devoted to medicine, the two fields in which he contributed most. He also wrote on psychology, geology, mathematics, astronomy, and logic. His most important work as far as mathematics is concerned, however, is his immense encyclopaedic work, the Kitab al-Shifa' (The Book of Healing). One of the four parts of this work is devoted to mathematics and ibn Sina includes astronomy and music as branches of mathematics within the encyclopaedia. In fact he divided mathematics into four branches, geometry, astronomy, arithmetic, and music, and he then subdivided each of these topics. Geometry he subdivided into geodesy, statics, kinematics, hydrostatics, and optics; astronomy he subdivided into astronomical and geographical tables, and the calendar; arithmetic he subdivided into algebra, and Indian addition and subtraction; music he subdivided into musical instruments.
The geometric section of the encyclopaedia is, not surprisingly, based on Euclid's Elements. Ibn Sina gives proofs but the presentation lacks the rigour adopted by Euclid. In fact ibn Sina does not present geometry as a deductive system from axioms in this work. We should note, however, that this was the way that ibn Sina chose to present the topic in the encyclopaedia. In other writings on geometry he, like many Muslim scientists, attempted to give a proof of Euclid's fifth postulate. The topics dealt with in the geometry section of the encyclopaedia are: lines, angles, and planes; parallels; triangles; constructions with ruler and compass; areas of parallelograms and triangles; geometric algebra; properties of circles; proportions without mentioning irrational numbers; proportions relating to areas of polygons; areas of circles; regular polygons; and volumes of polyhedra and the sphere. Full details are given in [17].
Ibn Sina made astronomical observations and we know that some were made at Isfahan and some at Hamadan. He made several correct deductions from his observations. For example he observed Venus as a spot against the surface of the Sun and correctly deduced that Venus must be closer to the Earth than the Sun. This observation, and other related work by ibn Sina, is discussed in [53]. Ibn Sina invented an instrument for observing the coordinates of a star. The instrument had two legs pivoted at one end; the lower leg rotated about a horizontal protractor, thus showing the azimuth, while the upper leg marked with a scale and having observing sights, was raised in the plane vertical to the lower leg to give the star's altitude. Another of ibn Sina's contributions to astronomy was his attempt to calculate the difference in longitude between Baghdad and Gurgan by observing a meridian transit of the moon at Gurgan. He also correctly stated, with what justification it is hard to see, that the velocity of light is finite.
As ibn Sina considered music as one of the branches of mathematics it is fitting to give a brief indication of his work on this topic which was mainly on tonic intervals, rhythmic patterns, and musical instruments. Some experts claim that ibn Sina's promotion of the consonance of the major third led to the use of just intonation rather than the intonation associated with Pythagoras. More information is contained in T S Vyzgo's paper "On Ibn Sina's contribution to musicology" in [5].
Mechanics was a topic which ibn Sina classified under mathematics. In his work Mi'yar al-'aqul ibn Sina defines simple machines and combinations of them which involve rollers, levers, windlasses, pulleys, and many others. Although the material was well-known and certainly not original, nevertheless ibn Sina's classification of mechanisms, which goes beyond that of Heron, is highly original.
Since ibn Sina's major contributions are in philosophy, we should at least mention his work in this area, although we shall certainly not devote the space to it that this work deserves. He discussed reason and reality, claiming that God is pure intellect and that knowledge consists of the mind grasping the intelligible. To grasp the intelligible both reason and logic are required. But, claims ibn Sina [26]:-
... it is important to gain knowledge. Grasp of the intelligibles determines the fate of the rational soul in the hereafter, and therefore is crucial to human activity.
Ibn Sina gives a theory of knowledge, describing the abstraction in perceiving an object rather than the concrete form of the object itself. In metaphysics ibn Sina examined existence. He considers the scientific and mathematical theory of the world and ultimate causation by God. His aims are described in [1] as follows:-
Ibn Sina sought to integrate all aspects of science and religion in a grand metaphysical vision. With this vision he attempted to explain the formation of the universe as well as to elucidate the problems of evil, prayer, providence, prophecies, miracles, and marvels. also within its scope fall problems relating to the organisation of the state in accord with religious law and the question of the ultimate destiny of man.
Ibn Sina is known to have corresponded with al-Biruni. In [10], eighteen letters which ibn Sina sent to al-Biruni in answer to questions that he had posed are given. These letters cover topics such as philosophy, astronomy and physics. There is other correspondence from ibn Sina which has been preserved which has been surveyed in the article [31]. The topics of these letters include arguments against theologians and those professing magical powers, and refutation of the opinions those who having a superficial interest in a branch of knowledge. Ibn Sina writes on certain topics in philosophy, and writes letters to students who must have asked him to explain difficulties they have encountered in some classic text. The authors of [31] see ibn Sina as promoting natural science and arguing against religious men who attempt to obscure the truth.
ABU AL-HUSAIN IBN ABDULLAH IBN SINA
ABU AL-HUSAIN IBN ABDULLAH IBN SINA
ABU AL-HUSAIN IBN ABDULLAH IBN SINA
ABU AL-HUSAIN IBN ABDULLAH IBN SINA
ABU AL-HUSAIN IBN ABDULLAH IBN SINA
ABU AL-HUSAIN IBN ABDULLAH IBN SINA
ABU AL-HUSAIN IBN ABDULLAH IBN SINA
ABU AL-HUSAIN IBN ABDULLAH IBN SINA
ABU AL-HUSAIN IBN ABDULLAH IBN SINA
ABU AL-HUSAIN IBN ABDULLAH IBN SINA
Avicenna (Ibn Sina)
Avicenna - Impostor, Philosopher, Healer
Abu Ja'far Muhammad ibn Musa Al-Khwarizmi
SCIENTEST ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
We know few details of Abu Ja'far Muhammad ibn Musa al-Khwarizmi's life. One unfortunate effect of this lack of knowledge seems to be the temptation to make guesses based on very little evidence. In [1] Toomer suggests that the name al-Khwarizmi may indicate that he came from Khwarizm south of the Aral Sea in central Asia. He then writes:-
But the historian al-Tabari gives him the additional epithet "al-Qutrubbulli", indicating that he came from Qutrubbull, a district between the Tigris and Euphrates not far from Baghdad, so perhaps his ancestors, rather than he himself, came from Khwarizm ... Another epithet given to him by al-Tabari, "al-Majusi", would seem to indicate that he was an adherent of the old Zoroastrian religion. ... the pious preface to al-Khwarizmi's "Algebra" shows that he was an orthodox Muslim, so Al-Tabari's epithet could mean no more than that his forebears, and perhaps he in his youth, had been Zoroastrians.
However, Rashed [7], put a rather different interpretation on the same words by Al-Tabari:-
... Al-Tabari's words should read: "Muhammad ibn Musa al-Khwarizmi and al-Majusi al-Qutrubbulli ...", (and that there are two people al-Khwarizmi and al-Majusi al-Qutrubbulli): the letter "wa" was omitted in the early copy. This would not be worth mentioning if a series of conclusions about al-Khwarizmi's personality, occasionally even the origins of his knowledge, had not been drawn. In his article ([1]) G J Toomer, with naive confidence, constructed an entire fantasy on the error which cannot be denied the merit of making amusing reading.
This is not the last disagreement that we shall meet in describing the life and work of al-Khwarizmi. However before we look at the few facts about his life that are known for certain, we should take a moment to set the scene for the cultural and scientific background in which al-Khwarizmi worked.
Harun al-Rashid became the fifth Caliph of the Abbasid dynasty on 14 September 786, about the time that al-Khwarizmi was born. Harun ruled, from his court in the capital city of Baghdad, over the Islam empire which stretched from the Mediterranean to India. He brought culture to his court and tried to establish the intellectual disciplines which at that time were not flourishing in the Arabic world. He had two sons, the eldest was al-Amin while the younger was al-Mamun. Harun died in 809 and there was an armed conflict between the brothers.
Al-Mamun won the armed struggle and al-Amin was defeated and killed in 813. Following this, al-Mamun became Caliph and ruled the empire from Baghdad. He continued the patronage of learning started by his father and founded an academy called the House of Wisdom where Greek philosophical and scientific works were translated. He also built up a library of manuscripts, the first major library to be set up since that at Alexandria, collecting important works from Byzantium. In addition to the House of Wisdom, al-Mamun set up observatories in which Muslim astronomers could build on the knowledge acquired by earlier peoples.
Al-Khwarizmi and his colleagues the Banu Musa were scholars at the House of Wisdom in Baghdad. Their tasks there involved the translation of Greek scientific manuscripts and they also studied, and wrote on, algebra, geometry and astronomy. Certainly al-Khwarizmi worked under the patronage of Al-Mamun and he dedicated two of his texts to the Caliph. These were his treatise on algebra and his treatise on astronomy. The algebra treatise Hisab al-jabr w'al-muqabala was the most famous and important of all of al-Khwarizmi's works. It is the title of this text that gives us the word "algebra" and, in a sense that we shall investigate more fully below, it is the first book to be written on algebra.
Rosen's translation of al-Khwarizmi's own words describing the purpose of the book tells us that al-Khwarizmi intended to teach [11] (see also [1]):-
... what is easiest and most useful in arithmetic, such as men constantly require in cases of inheritance, legacies, partition, lawsuits, and trade, and in all their dealings with one another, or where the measuring of lands, the digging of canals, geometrical computations, and other objects of various sorts and kinds are concerned.
This does not sound like the contents of an algebra text and indeed only the first part of the book is a discussion of what we would today recognise as algebra. However it is important to realise that the book was intended to be highly practical and that algebra was introduced to solve real life problems that were part of everyday life in the Islam empire at that time. Early in the book al-Khwarizmi describes the natural numbers in terms that are almost funny to us who are so familiar with the system, but it is important to understand the new depth of abstraction and understanding here [11]:-
When I consider what people generally want in calculating, I found that it always is a number. I also observed that every number is composed of units, and that any number may be divided into units. Moreover, I found that every number which may be expressed from one to ten, surpasses the preceding by one unit: afterwards the ten is doubled or tripled just as before the units were: thus arise twenty, thirty, etc. until a hundred: then the hundred is doubled and tripled in the same manner as the units and the tens, up to a thousand; ... so forth to the utmost limit of numeration.
Having introduced the natural numbers, al-Khwarizmi introduces the main topic of this first section of his book, namely the solution of equations. His equations are linear or quadratic and are composed of units, roots and squares. For example, to al-Khwarizmi a unit was a number, a root was x, and a square was x2. However, although we shall use the now familiar algebraic notation in this article to help the reader understand the notions, Al-Khwarizmi's mathematics is done entirely in words with no symbols being used.
He first reduces an equation (linear or quadratic) to one of six standard forms:
1. Squares equal to roots.
2. Squares equal to numbers.
3. Roots equal to numbers.
4. Squares and roots equal to numbers; e.g. x2 + 10 x = 39.
5. Squares and numbers equal to roots; e.g. x2 + 21 = 10 x.
6. Roots and numbers equal to squares; e.g. 3 x + 4 = x2.
The reduction is carried out using the two operations of al-jabr and al-muqabala. Here "al-jabr" means "completion" and is the process of removing negative terms from an equation. For example, using one of al-Khwarizmi's own examples, "al-jabr" transforms x2 = 40 x - 4 x2 into 5 x2 = 40 x. The term "al-muqabala" means "balancing" and is the process of reducing positive terms of the same power when they occur on both sides of an equation. For example, two applications of "al-muqabala" reduces 50 + 3 x + x2 = 29 + 10 x to 21 + x2 = 7 x (one application to deal with the numbers and a second to deal with the roots).
Al-Khwarizmi then shows how to solve the six standard types of equations. He uses both algebraic methods of solution and geometric methods. For example to solve the equation x2 + 10 x = 39 he writes [11]:-
... a square and 10 roots are equal to 39 units. The question therefore in this type of equation is about as follows: what is the square which combined with ten of its roots will give a sum total of 39? The manner of solving this type of equation is to take one-half of the roots just mentioned. Now the roots in the problem before us are 10. Therefore take 5, which multiplied by itself gives 25, an amount which you add to 39 giving 64. Having taken then the square root of this which is 8, subtract from it half the roots, 5 leaving 3. The number three therefore represents one root of this square, which itself, of course is 9. Nine therefore gives the square.
The geometric proof by completing the square follows. Al-Khwarizmi starts with a square of side x, which therefore represents x2 (Figure 1). To the square we must add 10x and this is done by adding four rectangles each of breadth 10/4 and length x to the square (Figure 2). Figure 2 has area x2 + 10 x which is equal to 39. We now complete the square by adding the four little squares each of area 5/2 × 5/2 = 25/4. Hence the outside square in Fig 3 has area 4 × 25/4 + 39 = 25 + 39 = 64. The side of the square is therefore 8. But the side is of length 5/2 + x + 5/2 so x + 5 = 8, giving x = 3.
These geometrical proofs are a matter of disagreement between experts. The question, which seems not to have an easy answer, is whether al-Khwarizmi was familiar with Euclid's Elements. We know that he could have been, perhaps it is even fair to say "should have been", familiar with Euclid's work. In al-Rashid's reign, while al-Khwarizmi was still young, al-Hajjaj had translated Euclid's Elements into Arabic and al-Hajjaj was one of al-Khwarizmi's colleagues in the House of Wisdom. This would support Toomer's comments in [1]:-
... in his introductory section al-Khwarizmi uses geometrical figures to explain equations, which surely argues for a familiarity with Book II of Euclid's "Elements".
Rashed [9] writes that al-Khwarizmi's:-
... treatment was very probably inspired by recent knowledge of the "Elements".
However, Gandz in [6] (see also [23]), argues for a very different view:-
Euclid's "Elements" in their spirit and letter are entirely unknown to [al-Khwarizmi]. Al-Khwarizmi has neither definitions, nor axioms, nor postulates, nor any demonstration of the Euclidean kind.
I [EFR] think that it is clear that whether or not al-Khwarizmi had studied Euclid's Elements, he was influenced by other geometrical works. As Parshall writes in [35]:-
... because his treatment of practical geometry so closely followed that of the Hebrew text, Mishnat ha Middot, which dated from around 150 AD, the evidence of Semitic ancestry exists.
Al-Khwarizmi continues his study of algebra in Hisab al-jabr w'al-muqabala by examining how the laws of arithmetic extend to an arithmetic for his algebraic objects. For example he shows how to multiply out expressions such as
(a + b x) (c + d x)
although again we should emphasise that al-Khwarizmi uses only words to describe his expressions, and no symbols are used. Rashed [9] sees a remarkable depth and novelty in these calculations by al-Khwarizmi which appear to us, when examined from a modern perspective, as relatively elementary. He writes [9]:-
Al-Khwarizmi's concept of algebra can now be grasped with greater precision: it concerns the theory of linear and quadratic equations with a single unknown, and the elementary arithmetic of relative binomials and trinomials. ... The solution had to be general and calculable at the same time and in a mathematical fashion, that is, geometrically founded. ... The restriction of degree, as well as that of the number of unsophisticated terms, is instantly explained. From its true emergence, algebra can be seen as a theory of equations solved by means of radicals, and of algebraic calculations on related expressions...
If this interpretation is correct, then al-Khwarizmi was as Sarton writes:-
... the greatest mathematician of the time, and if one takes all the circumstances into account, one of the greatest of all time....
In a similar vein Rashed writes [9]:-
It is impossible to overstress the originality of the conception and style of al-Khwarizmi's algebra...
but a different view is taken by Crossley who writes [4]:-
[Al-Khwarizmi] may not have been very original...
and Toomer who writes in [1]:-
... Al-Khwarizmi's scientific achievements were at best mediocre.
In [23] Gandz gives this opinion of al-Khwarizmi's algebra:-
Al-Khwarizmi's algebra is regarded as the foundation and cornerstone of the sciences. In a sense, al-Khwarizmi is more entitled to be called "the father of algebra" than Diophantus because al-Khwarizmi is the first to teach algebra in an elementary form and for its own sake, Diophantus is primarily concerned with the theory of numbers.
The next part of al-Khwarizmi's Algebra consists of applications and worked examples. He then goes on to look at rules for finding the area of figures such as the circle and also finding the volume of solids such as the sphere, cone, and pyramid. This section on mensuration certainly has more in common with Hindu and Hebrew texts than it does with any Greek work. The final part of the book deals with the complicated Islamic rules for inheritance but require little from the earlier algebra beyond solving linear equations.
Al-Khwarizmi also wrote a treatise on Hindu-Arabic numerals. The Arabic text is lost but a Latin translation, Algoritmi de numero Indorum in English Al-Khwarizmi on the Hindu Art of Reckoning gave rise to the word algorithm deriving from his name in the title. Unfortunately the Latin translation (translated into English in [19]) is known to be much changed from al-Khwarizmi's original text (of which even the title is unknown). The work describes the Hindu place-value system of numerals based on 1, 2, 3, 4, 5, 6, 7, 8, 9, and 0. The first use of zero as a place holder in positional base notation was probably due to al-Khwarizmi in this work. Methods for arithmetical calculation are given, and a method to find square roots is known to have been in the Arabic original although it is missing from the Latin version. Toomer writes [1]:-
... the decimal place-value system was a fairly recent arrival from India and ... al-Khwarizmi's work was the first to expound it systematically. Thus, although elementary, it was of seminal importance.
Seven twelfth century Latin treatises based on this lost Arabic treatise by al-Khwarizmi on arithmetic are discussed in [17].
Another important work by al-Khwarizmi was his work Sindhind zij on astronomy. The work, described in detail in [48], is based in Indian astronomical works [47]:-
... as opposed to most later Islamic astronomical handbooks, which utilised the Greek planetary models laid out in Ptolemy's "Almagest"...
The Indian text on which al-Khwarizmi based his treatise was one which had been given to the court in Baghdad around 770 as a gift from an Indian political mission. There are two versions of al-Khwarizmi's work which he wrote in Arabic but both are lost. In the tenth century al-Majriti made a critical revision of the shorter version and this was translated into Latin by Adelard of Bath. There is also a Latin version of the longer version and both these Latin works have survived. The main topics covered by al-Khwarizmi in the Sindhind zij are calendars; calculating true positions of the sun, moon and planets, tables of sines and tangents; spherical astronomy; astrological tables; parallax and eclipse calculations; and visibility of the moon. A related manuscript, attributed to al-Khwarizmi, on spherical trigonometry is discussed in [39].
Although his astronomical work is based on that of the Indians, and most of the values from which he constructed his tables came from Hindu astronomers, al-Khwarizmi must have been influenced by Ptolemy's work too [1]:-
It is certain that Ptolemy's tables, in their revision by Theon of Alexandria, were already known to some Islamic astronomers; and it is highly likely that they influenced, directly or through intermediaries, the form in which Al-Khwarizmi's tables were cast.
Al-Khwarizmi wrote a major work on geography which give latitudes and longitudes for 2402 localities as a basis for a world map. The book, which is based on Ptolemy's Geography, lists with latitudes and longitudes, cities, mountains, seas, islands, geographical regions, and rivers. The manuscript does include maps which on the whole are more accurate than those of Ptolemy. In particular it is clear that where more local knowledge was available to al-Khwarizmi such as the regions of Islam, Africa and the Far East then his work is considerably more accurate than that of Ptolemy, but for Europe al-Khwarizmi seems to have used Ptolemy's data.
A number of minor works were written by al-Khwarizmi on topics such as the astrolabe, on which he wrote two works, on the sundial, and on the Jewish calendar. He also wrote a political history containing horoscopes of prominent persons.
We have already discussed the varying views of the importance of al-Khwarizmi's algebra which was his most important contribution to mathematics. Let us end this article with a quote by Mohammad Kahn, given in [3]:-
In the foremost rank of mathematicians of all time stands Al-Khwarizmi. He composed the oldest works on arithmetic and algebra. They were the principal source of mathematical knowledge for centuries to come in the East and the West. The work on arithmetic first introduced the Hindu numbers to Europe, as the very name algorism signifies; and the work on algebra ... gave the name to this important branch of mathematics in the European world.
We know few details of Abu Ja'far Muhammad ibn Musa al-Khwarizmi's life. One unfortunate effect of this lack of knowledge seems to be the temptation to make guesses based on very little evidence. In [1] Toomer suggests that the name al-Khwarizmi may indicate that he came from Khwarizm south of the Aral Sea in central Asia. He then writes:-
But the historian al-Tabari gives him the additional epithet "al-Qutrubbulli", indicating that he came from Qutrubbull, a district between the Tigris and Euphrates not far from Baghdad, so perhaps his ancestors, rather than he himself, came from Khwarizm ... Another epithet given to him by al-Tabari, "al-Majusi", would seem to indicate that he was an adherent of the old Zoroastrian religion. ... the pious preface to al-Khwarizmi's "Algebra" shows that he was an orthodox Muslim, so Al-Tabari's epithet could mean no more than that his forebears, and perhaps he in his youth, had been Zoroastrians.
However, Rashed [7], put a rather different interpretation on the same words by Al-Tabari:-
... Al-Tabari's words should read: "Muhammad ibn Musa al-Khwarizmi and al-Majusi al-Qutrubbulli ...", (and that there are two people al-Khwarizmi and al-Majusi al-Qutrubbulli): the letter "wa" was omitted in the early copy. This would not be worth mentioning if a series of conclusions about al-Khwarizmi's personality, occasionally even the origins of his knowledge, had not been drawn. In his article ([1]) G J Toomer, with naive confidence, constructed an entire fantasy on the error which cannot be denied the merit of making amusing reading.
This is not the last disagreement that we shall meet in describing the life and work of al-Khwarizmi. However before we look at the few facts about his life that are known for certain, we should take a moment to set the scene for the cultural and scientific background in which al-Khwarizmi worked.
Harun al-Rashid became the fifth Caliph of the Abbasid dynasty on 14 September 786, about the time that al-Khwarizmi was born. Harun ruled, from his court in the capital city of Baghdad, over the Islam empire which stretched from the Mediterranean to India. He brought culture to his court and tried to establish the intellectual disciplines which at that time were not flourishing in the Arabic world. He had two sons, the eldest was al-Amin while the younger was al-Mamun. Harun died in 809 and there was an armed conflict between the brothers.
Al-Mamun won the armed struggle and al-Amin was defeated and killed in 813. Following this, al-Mamun became Caliph and ruled the empire from Baghdad. He continued the patronage of learning started by his father and founded an academy called the House of Wisdom where Greek philosophical and scientific works were translated. He also built up a library of manuscripts, the first major library to be set up since that at Alexandria, collecting important works from Byzantium. In addition to the House of Wisdom, al-Mamun set up observatories in which Muslim astronomers could build on the knowledge acquired by earlier peoples.
Al-Khwarizmi and his colleagues the Banu Musa were scholars at the House of Wisdom in Baghdad. Their tasks there involved the translation of Greek scientific manuscripts and they also studied, and wrote on, algebra, geometry and astronomy. Certainly al-Khwarizmi worked under the patronage of Al-Mamun and he dedicated two of his texts to the Caliph. These were his treatise on algebra and his treatise on astronomy. The algebra treatise Hisab al-jabr w'al-muqabala was the most famous and important of all of al-Khwarizmi's works. It is the title of this text that gives us the word "algebra" and, in a sense that we shall investigate more fully below, it is the first book to be written on algebra.
Rosen's translation of al-Khwarizmi's own words describing the purpose of the book tells us that al-Khwarizmi intended to teach [11] (see also [1]):-
... what is easiest and most useful in arithmetic, such as men constantly require in cases of inheritance, legacies, partition, lawsuits, and trade, and in all their dealings with one another, or where the measuring of lands, the digging of canals, geometrical computations, and other objects of various sorts and kinds are concerned.
This does not sound like the contents of an algebra text and indeed only the first part of the book is a discussion of what we would today recognise as algebra. However it is important to realise that the book was intended to be highly practical and that algebra was introduced to solve real life problems that were part of everyday life in the Islam empire at that time. Early in the book al-Khwarizmi describes the natural numbers in terms that are almost funny to us who are so familiar with the system, but it is important to understand the new depth of abstraction and understanding here [11]:-
When I consider what people generally want in calculating, I found that it always is a number. I also observed that every number is composed of units, and that any number may be divided into units. Moreover, I found that every number which may be expressed from one to ten, surpasses the preceding by one unit: afterwards the ten is doubled or tripled just as before the units were: thus arise twenty, thirty, etc. until a hundred: then the hundred is doubled and tripled in the same manner as the units and the tens, up to a thousand; ... so forth to the utmost limit of numeration.
Having introduced the natural numbers, al-Khwarizmi introduces the main topic of this first section of his book, namely the solution of equations. His equations are linear or quadratic and are composed of units, roots and squares. For example, to al-Khwarizmi a unit was a number, a root was x, and a square was x2. However, although we shall use the now familiar algebraic notation in this article to help the reader understand the notions, Al-Khwarizmi's mathematics is done entirely in words with no symbols being used.
He first reduces an equation (linear or quadratic) to one of six standard forms:
1. Squares equal to roots.
2. Squares equal to numbers.
3. Roots equal to numbers.
4. Squares and roots equal to numbers; e.g. x2 + 10 x = 39.
5. Squares and numbers equal to roots; e.g. x2 + 21 = 10 x.
6. Roots and numbers equal to squares; e.g. 3 x + 4 = x2.
The reduction is carried out using the two operations of al-jabr and al-muqabala. Here "al-jabr" means "completion" and is the process of removing negative terms from an equation. For example, using one of al-Khwarizmi's own examples, "al-jabr" transforms x2 = 40 x - 4 x2 into 5 x2 = 40 x. The term "al-muqabala" means "balancing" and is the process of reducing positive terms of the same power when they occur on both sides of an equation. For example, two applications of "al-muqabala" reduces 50 + 3 x + x2 = 29 + 10 x to 21 + x2 = 7 x (one application to deal with the numbers and a second to deal with the roots).
Al-Khwarizmi then shows how to solve the six standard types of equations. He uses both algebraic methods of solution and geometric methods. For example to solve the equation x2 + 10 x = 39 he writes [11]:-
... a square and 10 roots are equal to 39 units. The question therefore in this type of equation is about as follows: what is the square which combined with ten of its roots will give a sum total of 39? The manner of solving this type of equation is to take one-half of the roots just mentioned. Now the roots in the problem before us are 10. Therefore take 5, which multiplied by itself gives 25, an amount which you add to 39 giving 64. Having taken then the square root of this which is 8, subtract from it half the roots, 5 leaving 3. The number three therefore represents one root of this square, which itself, of course is 9. Nine therefore gives the square.
The geometric proof by completing the square follows. Al-Khwarizmi starts with a square of side x, which therefore represents x2 (Figure 1). To the square we must add 10x and this is done by adding four rectangles each of breadth 10/4 and length x to the square (Figure 2). Figure 2 has area x2 + 10 x which is equal to 39. We now complete the square by adding the four little squares each of area 5/2 × 5/2 = 25/4. Hence the outside square in Fig 3 has area 4 × 25/4 + 39 = 25 + 39 = 64. The side of the square is therefore 8. But the side is of length 5/2 + x + 5/2 so x + 5 = 8, giving x = 3.
These geometrical proofs are a matter of disagreement between experts. The question, which seems not to have an easy answer, is whether al-Khwarizmi was familiar with Euclid's Elements. We know that he could have been, perhaps it is even fair to say "should have been", familiar with Euclid's work. In al-Rashid's reign, while al-Khwarizmi was still young, al-Hajjaj had translated Euclid's Elements into Arabic and al-Hajjaj was one of al-Khwarizmi's colleagues in the House of Wisdom. This would support Toomer's comments in [1]:-
... in his introductory section al-Khwarizmi uses geometrical figures to explain equations, which surely argues for a familiarity with Book II of Euclid's "Elements".
Rashed [9] writes that al-Khwarizmi's:-
... treatment was very probably inspired by recent knowledge of the "Elements".
However, Gandz in [6] (see also [23]), argues for a very different view:-
Euclid's "Elements" in their spirit and letter are entirely unknown to [al-Khwarizmi]. Al-Khwarizmi has neither definitions, nor axioms, nor postulates, nor any demonstration of the Euclidean kind.
I [EFR] think that it is clear that whether or not al-Khwarizmi had studied Euclid's Elements, he was influenced by other geometrical works. As Parshall writes in [35]:-
... because his treatment of practical geometry so closely followed that of the Hebrew text, Mishnat ha Middot, which dated from around 150 AD, the evidence of Semitic ancestry exists.
Al-Khwarizmi continues his study of algebra in Hisab al-jabr w'al-muqabala by examining how the laws of arithmetic extend to an arithmetic for his algebraic objects. For example he shows how to multiply out expressions such as
(a + b x) (c + d x)
although again we should emphasise that al-Khwarizmi uses only words to describe his expressions, and no symbols are used. Rashed [9] sees a remarkable depth and novelty in these calculations by al-Khwarizmi which appear to us, when examined from a modern perspective, as relatively elementary. He writes [9]:-
Al-Khwarizmi's concept of algebra can now be grasped with greater precision: it concerns the theory of linear and quadratic equations with a single unknown, and the elementary arithmetic of relative binomials and trinomials. ... The solution had to be general and calculable at the same time and in a mathematical fashion, that is, geometrically founded. ... The restriction of degree, as well as that of the number of unsophisticated terms, is instantly explained. From its true emergence, algebra can be seen as a theory of equations solved by means of radicals, and of algebraic calculations on related expressions...
If this interpretation is correct, then al-Khwarizmi was as Sarton writes:-
... the greatest mathematician of the time, and if one takes all the circumstances into account, one of the greatest of all time....
In a similar vein Rashed writes [9]:-
It is impossible to overstress the originality of the conception and style of al-Khwarizmi's algebra...
but a different view is taken by Crossley who writes [4]:-
[Al-Khwarizmi] may not have been very original...
and Toomer who writes in [1]:-
... Al-Khwarizmi's scientific achievements were at best mediocre.
In [23] Gandz gives this opinion of al-Khwarizmi's algebra:-
Al-Khwarizmi's algebra is regarded as the foundation and cornerstone of the sciences. In a sense, al-Khwarizmi is more entitled to be called "the father of algebra" than Diophantus because al-Khwarizmi is the first to teach algebra in an elementary form and for its own sake, Diophantus is primarily concerned with the theory of numbers.
The next part of al-Khwarizmi's Algebra consists of applications and worked examples. He then goes on to look at rules for finding the area of figures such as the circle and also finding the volume of solids such as the sphere, cone, and pyramid. This section on mensuration certainly has more in common with Hindu and Hebrew texts than it does with any Greek work. The final part of the book deals with the complicated Islamic rules for inheritance but require little from the earlier algebra beyond solving linear equations.
Al-Khwarizmi also wrote a treatise on Hindu-Arabic numerals. The Arabic text is lost but a Latin translation, Algoritmi de numero Indorum in English Al-Khwarizmi on the Hindu Art of Reckoning gave rise to the word algorithm deriving from his name in the title. Unfortunately the Latin translation (translated into English in [19]) is known to be much changed from al-Khwarizmi's original text (of which even the title is unknown). The work describes the Hindu place-value system of numerals based on 1, 2, 3, 4, 5, 6, 7, 8, 9, and 0. The first use of zero as a place holder in positional base notation was probably due to al-Khwarizmi in this work. Methods for arithmetical calculation are given, and a method to find square roots is known to have been in the Arabic original although it is missing from the Latin version. Toomer writes [1]:-
... the decimal place-value system was a fairly recent arrival from India and ... al-Khwarizmi's work was the first to expound it systematically. Thus, although elementary, it was of seminal importance.
Seven twelfth century Latin treatises based on this lost Arabic treatise by al-Khwarizmi on arithmetic are discussed in [17].
Another important work by al-Khwarizmi was his work Sindhind zij on astronomy. The work, described in detail in [48], is based in Indian astronomical works [47]:-
... as opposed to most later Islamic astronomical handbooks, which utilised the Greek planetary models laid out in Ptolemy's "Almagest"...
The Indian text on which al-Khwarizmi based his treatise was one which had been given to the court in Baghdad around 770 as a gift from an Indian political mission. There are two versions of al-Khwarizmi's work which he wrote in Arabic but both are lost. In the tenth century al-Majriti made a critical revision of the shorter version and this was translated into Latin by Adelard of Bath. There is also a Latin version of the longer version and both these Latin works have survived. The main topics covered by al-Khwarizmi in the Sindhind zij are calendars; calculating true positions of the sun, moon and planets, tables of sines and tangents; spherical astronomy; astrological tables; parallax and eclipse calculations; and visibility of the moon. A related manuscript, attributed to al-Khwarizmi, on spherical trigonometry is discussed in [39].
Although his astronomical work is based on that of the Indians, and most of the values from which he constructed his tables came from Hindu astronomers, al-Khwarizmi must have been influenced by Ptolemy's work too [1]:-
It is certain that Ptolemy's tables, in their revision by Theon of Alexandria, were already known to some Islamic astronomers; and it is highly likely that they influenced, directly or through intermediaries, the form in which Al-Khwarizmi's tables were cast.
Al-Khwarizmi wrote a major work on geography which give latitudes and longitudes for 2402 localities as a basis for a world map. The book, which is based on Ptolemy's Geography, lists with latitudes and longitudes, cities, mountains, seas, islands, geographical regions, and rivers. The manuscript does include maps which on the whole are more accurate than those of Ptolemy. In particular it is clear that where more local knowledge was available to al-Khwarizmi such as the regions of Islam, Africa and the Far East then his work is considerably more accurate than that of Ptolemy, but for Europe al-Khwarizmi seems to have used Ptolemy's data.
A number of minor works were written by al-Khwarizmi on topics such as the astrolabe, on which he wrote two works, on the sundial, and on the Jewish calendar. He also wrote a political history containing horoscopes of prominent persons.
We have already discussed the varying views of the importance of al-Khwarizmi's algebra which was his most important contribution to mathematics. Let us end this article with a quote by Mohammad Kahn, given in [3]:-
In the foremost rank of mathematicians of all time stands Al-Khwarizmi. He composed the oldest works on arithmetic and algebra. They were the principal source of mathematical knowledge for centuries to come in the East and the West. The work on arithmetic first introduced the Hindu numbers to Europe, as the very name algorism signifies; and the work on algebra ... gave the name to this important branch of mathematics in the European world.
ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
ABU JA'FAR MUHAMMAD IBN MUSA AL-KHWARIZIMI
al khwarizmi
father of mathematics
Isaac Newton Anglican
SIR ISAAC NEWTON ANGLICAN
In 1642, the year Galileo died, Isaac Newton was born in Woolsthorpe, Lincolnshire, England on Christmas Day. His father had died three months earlier, and baby Isaac, very premature, was also not expected to survive. It was said he could be fitted into a quart pot. When Isaac was three, his mother married a wealthy elderly clergyman from the next village, and went to live there, leaving Isaac behind with his grandmother. The clergyman died, and Isaac’s mother came back, after eight years, bringing with her three small children. Two years later, Newton went away to the Grammar School in Grantham, where he lodged with the local apothecary, and was fascinated by the chemicals. The plan was that at age seventeen he would come home and look after the farm. He turned out to be a total failure as a farmer.
His mother’s brother, a clergyman who had been an undergraduate at Cambridge, persuaded his mother that it would be better for Isaac to go to university, so in 1661 he went up to Trinity College, Cambridge. Isaac paid his way through college for the first three years by waiting tables and cleaning rooms for the fellows (faculty) and the wealthier students. In 1664, he was elected a scholar, guaranteeing four years of financial support. Unfortunately, at that time the plague was spreading across Europe, and reached Cambridge in the summer of 1665. The university closed, and Newton returned home, where he spent two years concentrating on problems in mathematics and physics. He wrote later that during this time he first understood the theory of gravitation, which we shall discuss below, and the theory of optics (he was the first to realize that white light is made up of the colors of the rainbow), and much mathematics, both integral and differential calculus and infinite series. However, he was always reluctant to publish anything, at least until it appeared someone else might get credit for what he had found earlier.
On returning to Cambridge in 1667, he began to work on alchemy, but then in 1668 Nicolas Mercator published a book containing some methods for dealing with infinite series. Newton immediately wrote a treatise, De Analysi, expounding his own wider ranging results. His friend and mentor Isaac Barrow communicated these discoveries to a London mathematician, but only after some weeks would Newton allow his name to be given. This brought his work to the attention of the mathematics community for the first time. Shortly afterwards, Barrow resigned his Lucasian Professorship (which had been established only in 1663, with Barrow the first incumbent) at Cambridge so that Newton could have the Chair.
Newton’s first major public scientific achievement was the invention, design and construction of a reflecting telescope. He ground the mirror, built the tube, and even made his own tools for the job. This was a real advance in telescope technology, and ensured his election to membership in the Royal Society. The mirror gave a sharper image than was possible with a large lens because a lens focusses different colors at slightly different distances, an effect called chromatic aberration. This problem is minimized nowadays by using compound lenses, two lenses of different kinds of glass stuck together, that err in opposite directions, and thus tend to cancel each other’s shortcomings, but mirrors are still used in large telescopes.
Later in the 1670’s, Newton became very interested in theology. He studied Hebrew scholarship and ancient and modern theologians at great length, and became convinced that Christianity had departed from the original teachings of Christ. He felt unable to accept the current beliefs of the Church of England, which was unfortunate because he was required as a Fellow of Trinity College to take holy orders. Happily, the Church of England was more flexible than Galileo had found the Catholic Church in these matters, and King Charles II issued a royal decree excusing Newton from the necessity of taking holy orders! Actually, to prevent this being a wide precedent, the decree specified that, in perpetuity, the Lucasian professor need not take holy orders. (The current Lucasian professor is Stephen Hawking.)
In 1684, three members of the Royal Society, Sir Christopher Wren, Robert Hooke and Edmond Halley, argued as to whether the elliptical orbits of the planets could result from a gravitational force towards the sun proportional to the inverse square of the distance. Halley writes:
Mr. Hook said he had had it, but that he would conceal it for some time so that others, triing and failing might know how to value it, when he should make it publick.
Halley went up to Cambridge, and put the problem to Newton, who said he had solved it four years earlier, but couldn’t find the proof among his papers. Three months later, he sent an improved version of the proof to Halley, and devoted himself full time to developing these ideas, culminating in the publication of the Principia in 1686. This was the book that really did change man’s view of the universe, as we shall shortly discuss, and its importance was fully appreciated very quickly. Newton became a public figure. He left Cambridge for London, where he was appointed Master of the Mint, a role he pursued energetically, as always, including prosecuting counterfeiters. He was knighted by Queen Anne. He argued with Hooke about who deserved credit for discovering the connection between elliptical orbits and the inverse square law until Hooke died in 1703, and he argued with a German mathematician and philosopher, Leibniz, about which of them invented calculus. Newton died in 1727, and was buried with much pomp and circumstance in Westminster Abbey—despite his well-known reservations about the Anglican faith.
An excellent, readable book is The Life of Isaac Newton, by Richard Westfall, Cambridge 1993, which I used in writing the above summary of Newton’s life.
A fascinating collection of articles, profusely illustrated, on Newton’s life, work and impact on the general culture is Let Newton Be!, edited by John Fauvel and others, Oxford 1988, which I also consulted.
Projectiles and Planets
Let us now turn to the central topic of the Principia, the universality of the gravitational force. The legend is that Newton saw an apple fall in his garden in Lincolnshire, thought of it in terms of an attractive gravitational force towards the earth, and realized the same force might extend as far as the moon. He was familiar with Galileo’s work on projectiles, and suggested that the moon’s motion in orbit could be understood as a natural extension of that theory. To see what is meant by this, consider a gun shooting a projectile horizontally from a very high mountain, and imagine using more and more powder in successive shots to drive the projectile faster and faster.
The parabolic paths would become flatter and flatter, and, if we imagine that the mountain is so high that air resistance can be ignored, and the gun is sufficiently powerful, eventually the point of landing is so far away that we must consider the curvature of the earth in finding where it lands.
In fact, the real situation is more dramatic—the earth’s curvature may mean the projectile never lands at all. This was envisioned by Newton in the Principia. The following diagram is from his later popularization, A Treatise of the System of the World, written in the 1680’s:
The mountaintop at V is supposed to be above the earth’s atmosphere, and for a suitable initial speed, the projectile orbits the earth in a circular path. In fact, the earth’s curvature is such that the surface falls away below a truly flat horizontal line by about five meters in 8,000 meters (five miles). Recall that five meters is just the vertical distance an initially horizontally moving projectile will fall in the first second of motion. But this implies that if the (horizontal) muzzle velocity were 8,000 meters per second, the downward fall of the cannonball would be just matched by the earth’s surface falling away, and it would never hit the ground! This is just the motion, familiar to us now, of a satellite in a low orbit, which travels at about 8,000 meters (five miles) a second, or 18,000 miles per hour. (Actually, Newton drew this mountain impossibly high, no doubt for clarity of illustration. A satellite launched horizontally from the top would be far above the usual shuttle orbit, and go considerably more slowly than 18,000 miles per hour.)
For an animated version of Newton’s cannon on a mountain, click here!
The Moon is Falling
Newton realized that the moon’s circular path around the earth could be caused in this way by the same gravitational force that would hold such a cannonball in low orbit, in other words, the same force that causes bodies to fall.
To think about this idea, let us consider the moon’s motion, beginning at some particular instant, as deviating downwards—falling—from some initial “horizontal” line, just as for the cannonball shot horizontally from a high mountain. The first obvious question is: does the moon fall five meters below the horizontal line, that is, towards the earth, in the first second? This was not difficult for Newton to check, because the path of the moon was precisely known by this time. The moon’s orbit is approximately a circle of radius about 384,000 kilometers (240,000 miles), which it goes around in a month (to be precise, in 27.3 days), so the distance covered in one second is, conveniently, very close to one kilometer. It is then a matter of geometry to figure out how far the curved path falls below a “horizontal” line in one second of flight, and the answer turns out to be not five meters, but only a little over one millimeter! (Actually around 1.37 millimeters.)
It’s completely impossible to draw a diagram showing how far it falls in one second, but the geometry is the same if we look how far it falls in one day, so here it is:
For one second, AB would be only one kilometer, so since AC is 384,000 km., the triangle ABC is really thin, but we can still use Pythagoras’ theorem!
Thus the “natural acceleration” of the moon towards the earth, measured by how far it falls below straight line motion in one second, is less than that of an apple here on earth by the ratio of five meters to 1.37 millimeters, which works out to be about 3,600.
What can be the significance of this much smaller rate of fall? Newton’s answer was that the natural acceleration of the moon was much smaller than that of the cannonball because they were both caused by a force—a gravitational attraction towards the earth, and that the gravitational force became weaker on going away from the earth.
In fact, the figures we have given about the moon’s orbit enable us to compute how fast the gravitational attraction dies away with distance. The distance from the center of the earth to the earth’s surface is about 6,350 kilometers (4,000 miles), so the moon is about 60 times further from the center of the earth than we and the cannonball are.
From our discussion of how fast the moon falls below a straight line in one second in its orbit, we found that the gravitational acceleration for the moon is down by a factor of 3,600 from the cannonball’s (or the apple’s).
Putting these two facts together, and noting that 3,600 = 60 x 60, led Newton to his famous inverse square law: the force of gravitational attraction between two bodies decreases with increasing distance between them as the inverse of the square of that distance, so if the distance is doubled, the force is down by a factor of four.
ISAAC NEWTON ANGLICAN
ISAAC NEWTON ANGLICAN
ISAAC NEWTON ANGLICAN
ISAAC NEWTON ANGLICAN
ISAAC NEWTON ANGLICAN
ISAAC NEWTON ANGLICAN
ISAAC NEWTON ANGLICAN
ISAAC NEWTON ANGLICAN
ISAAC NEWTON ANGLICAN
ISAAC NEWTON ANGLICAN
The Life of Sir Isaac Newton
Isaac Newton
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