Entrance into and Emergence from The Dark Ages:

The Decline and Revival of Mathematics

After the Golden Age of Greek Mathematics and before the Renaissance, mathematics (and scholarship in general, particularly in the sciences) went into a period of decline and stagnation with a few exceptions.  Some of the notable exceptions are the work of the Alexandrian Greeks Diophantus (200 -- 284 A.D.) and Pappus (290 -- 350 A.D.), Arabic Mathematics (especially  the work of Mohammed bin Musa al-Khowarizmi  (circa 780 -- 850 A.D. ), and much later, Fibonacci ( Leonardo of Pisa) (1170 -- 1240) .  Chinese mathematics (with the important Nine Chapters work and Liu Hui's commentary on it) developed separately during the period  200 A.D. forward).

The Decline of Greek Mathematics

The Christian Movement

The Rise of Islam and Mathematics in the Arabic World

Mohammed ibn Musa al-Khowarizmi  (circa 780 -- 850 )

The Decline and Revival of Learning --The Dark Ages

Fibonacci (Leonardo of Pisa)

The Decline of Greek Mathematics


During the past two weeks, we studied the works of several of the Greek Mathematicians

By the end of the third century B.C.,  the Golden Age of Greek mathematics was ending.  In 146 B.C. Ptolemy VII, over took Egypt and banished from scientists and scholars who were not loyal to him.  Many exiled Alexandrian scholars fled to more remote areas.   The last two pre-Christian centuries  saw the growth of Roman control.  Despite the military machines of Archimedes, Syracuse fell to the Romans in 212 B.C., Carthage in 202 B.C.   The  Romans conquered Greece in 146 B.C., and Mesopotamia by 64 B.C.  After Julius Caesar's assassination in 44 B.C.,  his grandnephew Augustus Caesar ruled the western Roman empire and also become ruler of the Eastern empire when Mark Antony was defeated.   Upon the suicides of Mark Antony and Cleopatra in 30 B.C.,  Augustus Caesar took over Egypt.   This began a period of time of prosperity and relative peace in Alexandria and Egypt which lasted until about 180 A.D.   Eventually exploitation by the Romans and the cultural mix of Greeks, Christians, Jews, and Egyptians led to unruly mobs with brawls and bloodshed in the city.   Diophantus ( 250 A.D. --   ) and Pappus  brought brought a brief return of Greek mathematical glory to Alexandria.

The Christian Movement


Christianity began as a sect within Palestinian Judaism, and then spread throughout the Roman world. Initially the movement was tolerated by the Roman state, but in the second and third centuries B.C. became the center of blame for internal catastrophes and invasions, and suffered periodic persecutions.  During the fourth century B.C.  the Roman emperor Constantine was converted to Christianity and under Emperor Theodosius's rule, it became the official religion of the entire empire.

The great days of Greek mathematical reasoning were over.  Scholars turned their energies to theological issues.  Faith, not scientific inquiry, directed the Church doctrine.  Physical science and mathematics were ridiculed, since the Bible was the source of all knowledge.  Greek learning became associated with paganism, and libraries and temples were looted and  holdings were destroyed.

The empire was frequently threatened with both internal civil wars and external threats. In 330 the empire was divided into an eastern and western half, and in the fifth century the western Roman half was overrun by invading Germanic peoples.

The Eastern (Byzantine) Empire remained independent and isolated for nearly one thousand more years, and here Greek learning was kept alive, although dormant.  They actively preserved and copied the ancient Greek works, thereby enabling the later Renaissance.
 

The Rise of Islam and Mathematics in the Arabic World


The new faith Islam based upon the teachings of Mohammed united the desert Arabian tribes, and their power spread quickly throughout the Mediterranean.  Damascus and Jerusalem fell to the Arabs in 635 and 637 respectively.  They advanced west as far as Spain and France and east through Syria, Persia, and northern India.  Only Christian Europe remained out of their control.

Originally ruling from Damascus, they built a new capital on the Tigris River, Baghdad with a population of 800,000 by 762.  Arab scholar set up the House of Wisdom which acquired and translated Greek manuscripts, placing them in a library for their use.  Thus what might have been lost forever was saved in Arabic translations and enhanced with their refinements.

A good article on the influence of Arabic mathematics especially on the development of algebra can be found at  Arabic mathematics at the Mac-Tutor History of Mathematics Site.

Mohammed ibn Musa al-Khowarizmi  (circa 780 -- 850 )

(from Al-Khwarizmi

The most well-known Arab mathematician of that period was Mohammed ibn Musa Al-Khowarizmi  who was associated with the House of Wisdom (it is presumed).  His major works consisted of a book on arithmetic and one on algebra.  His work " Book of Addition and Subtraction According to the Hindu calculation" contains the earliest Arabic use of the Hindu decimal system of numerals. (Only a Latin translation of the work survives today).  Its influence is the reason these base 10 numerals are misnamed Arabic instead of Hindu.    An excellent article on his life and works is found at the Mac-Tutor site:  Al-Khwarizmi.

In the above article you can an explanation of  Al-Khwarizmi solved quadratic equations using the example equation x + 10x2 = 39.

     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 method of proof he used was a geometric completing of the square.

Exercise:  Use the method indicated in the article at Mac-Tutor site:  Al-Khwarizmi.on the following:
x2 + 5x = 36.  Do it both algebraically and geometrically (provide the drawing).
 

The Decline into the Dark Ages and the Revival of Learning

From the barbarian invasions of Western Europe during the fifth century until the 11th century we have the period known as the Dark Ages.  It marks a low point in the development of mathematics. The seventh century was the darkest with virtual stagnation in mathematics, science and philosophy.
The Christian Church became the custodian of intellect in the few monasteries where learning still occurred. In order to provide literate clergy, the Church had to provide for their education in the monasteries.  Elements of reading and writing Latin and biblical study was the primary focus in the monasteries, and a suspicion of the ancient pagan Greek authors still remained.  Old Latin manuscripts however were preserved and copied preserving them from loss.
 

Fibonacci (Leonardo of Pisa)

from site:  Fibonacci .

No notable mathematicians in Latin civilization were produced from the decline until the 12th century.  The first glimmer of light was produced by Leonardo of Pisa ( circa 1170 to after 1240),
commonly known today  by the name Fibonacci (although he did not use this name).  His father's name was Bonacci and Fibonacci is the shortening of filio Bonacci.  Read the biographic article at the MacTutor History of Mathematics web site:   Fibonacci .

Exercise: After reading the above MacTutor History of Mathematics article on Fibonacci, write a short summary of his life and discuss one of his mathematical results (other than the Fibonacci numbers)  in some detail (within a web page).  (The result can be from this article or another that your find).  Place a link to your article on your history web page.