Science & Islam (Full) | by Jim Al-Khalili | BBC Documentary (EN)

0:00[Music]

0:09my name is Jim alkal and I'm a professor

0:13of physics at the University of

0:17su studying the innermost secrets of

0:20atoms and their nuclei has been at the

0:22heart of my working

0:26life but there's another side to me

0:32[Music]

0:40I was born and grew up in Baghdad to an

0:43English mother and Iraqi father but left

0:46Iraq with my family in the late '70s

0:48when Saddam Hussein came to

0:52Power by then science was already my

0:55great passion in life and as I studied

0:57it further I saw myself fully par of the

1:00western tradition inspired by names like

1:03Newton and

1:08Einstein but buried away was this

1:10nagging feeling that I was ignoring part

1:12of my own scientific

1:17Heritage I still remembered my school

1:20days in Iraq and being taught of a

1:23golden age of Islamic scholarship there

1:26between the 9th and 12th centuries a

1:28great leap in scient scientific

1:30knowledge took place in Baghdad Damascus

1:33Cairo and Cordo so I want to unearth

1:37this buried history to discover its

1:40great figures and to assess exactly what

1:42their contribution to science really was

1:45are there medieval Muslim scientists who

1:48should be spoken of in the same breath

1:50as Galileo or Newton or Einstein and

1:53crucially what is the relationship

1:56between science and Islam

1:59[Music]

2:07[Applause]

2:08[Music]

2:22my journey into the science of the

2:24medieval Islamic world will take me

2:27through Syria Iran and North Africa

2:35I started in the back streets of the

2:37Egyptian Capital Cairo with the

2:40realization that the language of modern

2:42science still has many references to its

2:45Arabic

2:48Roots take scientific terms like algebra

2:52algorithm alali I instantly recognize

2:56these words as

2:58Arabic and and these are at the very

3:00heart of what science

3:03does there will be no modern mathematics

3:06or physics without algebra no computers

3:09without algorithms and no chemistry

3:12without

3:19alkalis surprisingly few people in the

3:22west today even scientists are aware of

3:25this medieval Islamic Legacy but it

3:28wasn't always

3:31so from the 12th to the 17th century

3:35European scholars regularly refer to

3:37earlier Islamic

3:39texts I have here copies of some pages

3:44uh of the book liberachi by the great

3:47Italian mathematician Leonardo Pizano

3:49otherwise known as

3:51Fibonacci what's fascinating is that on

3:53page

3:5446 is a reference to an older text

3:58called modem algebra El mukabala and in

4:01the margin is the name Ma which is the

4:05latinized version of the Arabic name

4:07Muhammad the person he's referring to is

4:11Muhammad IB mus

4:16alari in fact Arabic names crop up in

4:20many medieval European texts on subjects

4:23as varied as mapmaking Optics and

4:26Medicine

4:31but I want to start with elawar ismi

4:34because his work touches on a crucial

4:36aspect of all our lives

4:40today it's thanks to elisi that the

4:44European World realized that their way

4:46of doing arithmetic which was still

4:49essentially based on Roman numerals was

4:52hopelessly inefficient and downright

4:56clunky if I ask you to multiply 100 23

5:01by 11 you may even be able to do it in

5:03your head the answer is

5:071353 but try doing it with Roman

5:10numerals you'd have to multiply cxx I I

5:14I by XI it can be done but trust me it's

5:18not

5:22fun ismi showed Europeans that there's a

5:26better way of doing arithmetic in his

5:29book entitled it the Hindu art of

5:31Reckoning he describes a revolutionary

5:34idea you can represent any number you

5:38like with just 10 simple

5:43symbols the idea of using just 10

5:47symbols the digits from 1 to 9 plus a

5:49symbol for zero to represent all numbers

5:52from one to Infinity was first developed

5:55by Indian mathematicians around the 6th

5:58Century ad and I can't overstate its

6:02importance let me show you here are the

6:04numbers in Indian Arabic

6:14numerals and here are the numbers we're

6:16more familiar with in the west 1 2 3 4 5

6:226 7 eight nine and you can see the

6:26similarity between these numbers in

6:28particular for instance the digits two

6:31and three if I tip this sideways you can

6:34see now how they look like numbers two

6:36and three and what's powerful about

6:40these digits this numerical system is

6:42how it simplified arithmetic

6:46calculations but elisi and his

6:49colleagues went further than just

6:50translating the Indian system into

6:53Arabic they created the decimal

6:57point this text written a century afteri

7:01is by a man we know only as

7:04Al here he shows it this same decimal

7:07system can be extended to describe not

7:10just whole numbers but fractions as well

7:13the Infinity of possibilities that lie

7:16in between the integers here's a copy of

7:19El's manuscript where he showed how the

7:22decimal point is used for the very first

7:24time he describes it by using a dash

7:28here are the digits 1 7 7 968 and you

7:31can see there's a small Dash over the

7:33nine indicating the decimal

7:36place the idea of the decimal point is

7:39so familiar to us that it's hard to

7:42understand how people managed without it

7:44but like all great science it's

7:46blindingly obvious after it's been

7:49discovered

7:53[Music]

7:59story of numbers and the decimal point

8:02hints that even over a thousand years

8:04ago science was becoming much more

8:08Global ideas were spreading emerging out

8:11of India Greece even China and cross

8:16fertilizing and looking on a map that

8:19shows where people lived a thousand

8:21years ago gave me my first insight into

8:24why medieval Islam would play such an

8:27important role in the development of

8:29science

8:32now look at which city lies at the

8:34center of the Known World a place where

8:37the widest range of peoples and ideas

8:39were bound to

8:41collide it's the city where I was born

8:45the capital of the Islamic empire

8:54Baghdad recent events mean I can no

8:57longer visit the city but these are the

8:59home movies of my cousin Faris filmed in

9:02the

9:031960s the Baghdad we knew then looked

9:06nothing like the bomb wrecked City it is

9:10now I certainly grew up proud to be

9:13associated with one of the world's

9:15greatest

9:19cities Baghdad was founded in 762 ad by

9:23the caleff El

9:25Mansour his aim was to make it the

9:28Glorious capital of a brand new Empire

9:31United by Islam the rising religion of

9:34the

9:36time the Abbasid cffs had claimed their

9:40right to rule by declaring that they

9:42were directly related to The Prophet

9:44Muhammad who had founded the new

9:46religion over a hundred years

9:49earlier but in that short time the

9:52armies of Islam had conquered a vast

9:57territory St in a small area around

10:01Medina they moved rapidly out of the

10:03Arabian Peninsula and within a few

10:06decades had taken control of the Levant

10:09North Africa Spain and

10:12Persia I think one must bear in mind

10:14that this is an era in which people

10:16actually believed in God and the

10:18dramatic successes of the Arabs as they

10:20poured out of Arabia uh was such that a

10:23lot of people did sort of observe and

10:25say they must have God on their side

10:28this must be the truth true God some

10:30people did convert or if they didn't

10:32convert they did submit to Arab Muslim

10:35political control for that

10:39reason by the early 8th Century Islamic

10:43cffs ruled a vast

10:46territory and like most successful

10:48Emperors from Caesar to Napoleon they

10:51understood that political power and

10:54scientific knowhow go hand in hand

11:03there were many reasons for this some

11:05were practical medical knowledge could

11:07save lives military technology could win

11:10Wars mathematics could help deal with

11:13the increasing complexities of the

11:14finances of state and Islam as a

11:18religion also played a pivotal role the

11:20prophet himself had told Believers to

11:22seek knowledge wherever they could find

11:24it even if they had to go as far as

11:26China and many Muslims I'm sure felt

11:29that to study and better understand

11:32God's creation was in itself a religious

11:35duty but there were also other less

11:37edifying motives at play to many in the

11:40ruling Elite of the Islamic empire

11:43knowledge itself had a self-serving

11:46purpose because possessing it was seen

11:48as proof of the new Empire's superiority

11:52over the rest of the

11:57world but with military EMP political

11:59success the Islamic cffs faced an

12:03inevitable

12:05problem how do you sensibly govern a

12:08hugely diverse

12:10population although some of the Empire

12:13had converted to Islam they were still

12:16separated by huge distances and adhered

12:19to many different traditions and

12:23languages in the 8th Century ad the

12:26Empire's leader the caleff Abdul mik had

12:29to find a way of administering this mish

12:32mash of

12:33languages like all the great figures of

12:36the Islamic empire Abdul mik lived in a

12:39culture without portraiture all we have

12:42are later impressions of what he might

12:44have looked like his solution was

12:47Sweeping in scale and inadvertently laid

12:50the foundations of a scientific

12:53Renaissance it was this Abdul Malik

12:56Maran who said this bureaucratic chaos

12:58has to stop we cannot continue to run a

13:01government and govern all of this span

13:04of land with this uh uh Tower of Babel

13:09languages so he wanted to govern it with

13:12a uniform language that uniform language

13:15of course he wanted to be able to

13:16understand it so he demanded that it be

13:18in

13:24Arabic but the choice of Arabic as the

13:27common language of the empire went

13:29beyond administrative

13:32convenience the decision had extra force

13:35and persuasiveness because Islam's holy

13:38book the Quran is in Arabic and Muslims

13:42therefore consider Arabic to be the

13:44language of

13:53[Music]

13:56God the words of the Quran are so sacred

13:59that its text hasn't changed in over

14:021,400

14:04years by comparison English has changed

14:07dramatically in just 700 years to our

14:10ears cha is almost

14:13unintelligible whereas any Quran can be

14:16understood by Anyone who reads

14:22Arabic making copies of the Quran has

14:26always been a specialized and highly

14:28respected job since the foundation of

14:32Islam calligraphy expert naif scaf who

14:36lives in the Syrian Capital Damascus

14:38writes for mosques and IM medras all

14:41over the

14:43country these are words he's found

14:45himself writing over and over again

14:48words of great significance for Muslims

14:51they're the opening line to each chapter

14:53in the

14:54Quran so it what it says is

15:01which means in the name of God the most

15:03gracious and the most

15:12merciful so he saying the complexity

15:16of Arabic calligraphy was enforced on

15:20them because of the spread of Islam

15:22because they were worried that the

15:24meaning of the words in the Quran will

15:26be lost uh if it was read by people who

15:29don't speak Arabic then they wouldn't

15:30Not only would they misinterpret it they

15:32just wouldn't be able to distinguish

15:33between different letters so not only

15:34did they add dots on certain letters

15:37they also added other little squiggly

15:39lines which changed the sound of vowels

15:42and it was something that they put in

15:44place just to ensure that people were

15:46able to have the right pronunciation

15:48when they read the

15:53Quran the consequences for science were

15:56immediate Scholars from different lands

15:59who previously had no way of

16:01communicating now had a Common

16:05Language and it was a language that was

16:07specially developed to be precise and

16:11unambiguous which made it ideal for

16:13scientific and Technical

16:15terms what this meant was the summoning

16:18into existence of a vast intellectual

16:22Community where Scholars from very

16:24different parts of the world could

16:26engage in dialogue comparison debate

16:29argument often very Fierce argument with

16:31each other it was possible for Scholars

16:33based in Corda in southern Spain to

16:37engage in literary and scientific debate

16:40with Scholars from Baghdad or from uh

16:50sarand but I can tell you that Scholars

16:53aren't motivated by the love of

16:54knowledge alone there's nothing like a

16:57large hunk of cash to focus the

17:01Mind by the early 800s the ruling Elite

17:04of the Islamic empire were pouring money

17:07into a truly ambitious project which was

17:10Global in scale and which was to have a

17:13profound impact on

17:16science it was to scour the libraries of

17:19the world for scientific and

17:21philosophical manuscripts in any

17:23language Greek syak Persian and Sanskrit

17:28bring them to the Empire and translate

17:30them into

17:31Arabic this became known as the

17:34translation

17:38[Music]

17:49movement the effort Scholars put into

17:52finding ancient texts was

17:54astonishing and one key reason for this

17:57is that bringing a book to the cff which

17:59you could add to his Library could be

18:02extremely

18:03lucrative The Story Goes that the khif

18:06aloon was was so obsessed that he would

18:09send his Messengers out of Baghdad far

18:12and wide to distant lands just to get

18:14hold of books that he didn't possess for

18:16the translation movement and anyone who

18:18brought him back a book that he didn't

18:20have he'd repay him its weight in

18:23gold to give some sense of the extent of

18:26this activity sort of between seven 50

18:29and 950 um somebody called aadim who

18:32wrote a list of sort of the

18:34intelligencia of the aasted era lists 70

18:38translators so it was quite a large

18:41cohort of people involved in translation

18:43and obviously he only named the

18:46well-known they could get up to 500 gold

18:49dinar a month which is probably around

18:52$24,000 which is a huge sum of money for

18:55what they were doing it was a very very

18:57prestigious well-paid well patronized

19:03activity and motivating This Global

19:06acquisition of knowledge was a pressing

19:09practical concern one that rarely

19:11crosses our minds

19:13today this is the new library at

19:16Alexandria in

19:18Egypt but fresh in the memory of many in

19:21the empire was the story of the

19:23destruction of the original library at

19:25Alexandria centuries earlier and the

19:27shocking loss of thousands of years of

19:30accumulated

19:32knowledge one of the things that we tend

19:34to forget because we live in an age of

19:38massive information storage and perfect

19:40communication more or less um is the

19:44everpresent possibility of total

19:48loss that was very very important for

19:51medieval Islamic scholars they knew

19:54extremely well that writings could be

19:57forgotten or buried or burnt or

20:00destroyed that cities could pass away

20:03and what we see in Baghdad or Cairo or

20:06sarand is exactly the Gathering Together

20:10translation analysis accumulation

20:13storage and preservation of material

20:17that they were well aware could be

20:18entirely lost forever

20:24[Applause]

20:25[Music]

20:26[Applause]

20:33and if there was one branch of knowledge

20:35that everyone from the Mighty kff To The

20:37Humble Trader wanted to preserve and

20:40enhance it was

20:45medicine these were after all times when

20:48few lived to old age writings from the

20:51time remind us that what we might

20:53consider a relatively minor infection

20:56today could be a death sentence

21:00religious teachings then were not just a

21:02source of comfort there were a constant

21:05reminder that we should never give

21:08up in the Hadith which is the collected

21:11sayings of the Prophet Muhammad it

21:17says which means that God did not send

21:20down a disease without also sending down

21:23its

21:26cure it statements like this that lead

21:29Muslims even today to believe that cures

21:33for all diseases are out there somewhere

21:35and that we need to search to find

21:39them to assess how this optimism

21:42actually affected Islamic

21:44medicine I met up with Dr Peter pman in

21:48the Syrian Capital

21:50Damascus he's a leading expert on

21:52Islamic medicine who spends much of his

21:55time researching here in the Middle East

21:58what people don't realize is that uh the

22:00history of Islamic medicine is really

22:02the history of our medicine because our

22:05medicine the university medicine be used

22:06until the 19th century it was based to a

22:09large extent on all these work of these

22:11Islamic

22:15Physicians Islamic medicine built

22:18extensively on the foundations laid by

22:20the ancient

22:23Greeks the most highly prized and among

22:26the first to be translated into Arabic

22:28with the medical manuscripts of the 3

22:31Century Greek physician

22:34galin galin believed that a healthy body

22:37was one in balance a balance of four

22:41types of fluids called humors which

22:44circulate through the body and any one

22:46of which if out of balance would cause

22:48illness and a change of

22:50temperament the four humors were yellow

22:54bile which if in excess would cause the

22:59patient to become bilious or bad

23:01tempered and

23:04nauseous blood too much of which would

23:08cause the patient to become sanguin or

23:12cheerful and

23:16flushed black bile which nxs would cause

23:20the patient to become lethargic

23:23melancholic even

23:25depressed and FL M which in excess would

23:31cause the patient to become fmatic or

23:34apathetic and emotionally

23:38detached Galen argued that illnesses are

23:42caused by an imbalance in one of the

23:44humors and so the Cure lies in draining

23:47the body of some of that humor and so he

23:49recommended techniques like cutting to

23:52induce bleeding or using emetics to

23:55induce vomiting

23:59but Islamic doctors were acutely aware

24:01that galin and Greek medicine were only

24:04one source of medical

24:06[Music]

24:08knowledge there were other traditions of

24:11medicine that they were equally Keen to

24:13incorporate into their understanding of

24:15how the body

24:18functioned medieval Arabic texts refer

24:21to Wise Women folk healers Who provided

24:25medical

24:26drugs this tradition continues today as

24:30I found when I came across one for

24:32myself in the back streets of hamamat in

24:36Tunisia this is Arafat

24:39nail she's been running her shop selling

24:41medicinal herbs and spices for over 20

24:44years she believes that her remedies can

24:47cure a wide range of medical ailments

25:11ah

25:26okay well

25:34in the back streets of Tunisia this

25:37knowledge is still being

25:39used but medieval Islamic doctors were

25:42also aware of other traditions of

25:43medicine from China and

25:52India and yet another tradition of

25:54medical guidance Came From Within Islam

25:57itself

25:59and takes some of its ideas from the

26:00Quran and some from the collected

26:02sayings of the Prophet the

26:06Hadith in a book shop in monasa in

26:09Tunisia I found a copy of a very popular

26:12book available right across the Islamic

26:17world this book is called The Prophet's

26:20medicine and uh it see how old it is the

26:23author was born between 691 and 751 H

26:27which places him in the 14th

26:30century here's an interesting bit uh

26:32where it deals with the

26:43plague it says if you come across a land

26:46where the plague has come down then do

26:48not enter that land and if the plague

26:51comes down onto your land and you're you

26:53are there then do not leave your homes

26:56in the hope of escaping it so sort of

26:58makes a lot of

26:59sense but here's quite an amusing part

27:02um it deals with

27:04epilepsy uh and it says that the Greeks

27:07or or galin believed that epilepsy

27:10originated in the brain so however they

27:13were ignorant they didn't realize the

27:15true cause of epilepsy which is the the

27:17possession of the body by evil spirits

27:20and it talks about the cure for epilepsy

27:23being

27:25exorcism hardly scientific

27:28but Islam's most tangible contribution

27:30to medicine is less in its specific

27:33remedies and More in its overarching

27:40[Music]

27:42philosophy it is after all a religion

27:45whose central idea is that we should

27:47feel compassion for our fellow

27:53humans and accompanied by Dr Peter pman

27:57I'm going to see a physical bricks and

27:59mortar manifestation of medieval Islamic

28:04compassion this is the naline hospital

28:08the leading Hospital of the Islamic

28:10empire built here in Damascus and now a

28:16museum this was built in the 1150s 1154

28:19I believe one of the ideas which are

28:22stipulated in uh in Islam is the idea to

28:25be charitable and charity yes exactly

28:28and it's an obligation to to give arms

28:31and stuff like that and so if you're a

28:33ruler or if you have a lot of money what

28:34you could do is obviously you could

28:36really be charitable charitable and set

28:38up like a nice Hospital like this

28:40one and within the hospital Islam

28:43actively encouraged a high degree of

28:46religious tolerance something we take

28:48for granted in modern secular society

28:51the hospital was open to all communities

28:54so you would have Christians you would

28:56have Jews Muslims obviously Maybe other

28:58denominations both as patients and also

29:01as practitioners like a Christian

29:03Studies with the Muslim Muslim says my

29:05best student was a Jew and so the

29:07medicine which was practiced here

29:09transcended religion I mean typically

29:11how many Physicians would there be well

29:13it depends well like for certain

29:14hospitals we hear figures of like 24 or

29:1828 Physicians yes the Physicians would

29:21do the rounds in the morning to sit do

29:23their prescriptions and stuff like that

29:25hasn't changed over the ages yeah

29:30as a result of the translation movement

29:33those Physicians now became aware of the

29:36latest remedies from as far away as

29:38India and

29:41China and as the new drugs filtered in

29:44from the rest of the world hospitals

29:46started to set up a new kind of facility

29:49within their

29:50walls the

29:52pharmacy so this notion of a pharmacy in

29:55a hospital is that a new innovation the

29:58whole package certainly that's uh that's

30:00new and what is interesting if you look

30:01for Innovation you like on the level of

30:03Pharmacy if you look at Baghdad or even

30:05Damascus it's at this Crossroad of

30:08cultures so Nots of new things come in

30:10like mask for instance my robal and you

30:13have like Indian drugs there's like an

30:14Indian pill for instance which is good

30:16against headaches and you like a bad

30:19breath but also you know gives you

30:20sexual appetite and stuff like that so

30:22you know kills a headache gives you um

30:26fresh breath fresh breath and and gives

30:28you increase and so so it's like

30:30toothpaste Viagra and aspirin that's

30:33right all in one fantastic so well let's

30:36uh walk in here Peter wants to show me

30:39perhaps the most ghoulish aspect of

30:41Islamic medicine

30:44surgery here you have like a wonderful

30:46illustration this it appears that this

30:49is the the first anatomical illustration

30:51in history you like you see it says

30:53adala which is which means muscle and so

30:56these are like the different muscles

30:58which move the eyelids so it was

31:00understood then that the muscles

31:02controlled the oh absolutely the lens in

31:04your eye yeah and move the eyelid and

31:07stuff like that so the other thing which

31:10which we have here which is really nice

31:11is I think we have some uh you know like

31:14opthalmological instruments for instance

31:15it's a hook could be used for instance

31:17you like to kind of pull back your

31:20eyelid that sort of thing you know I

31:22mean these instruments were very useful

31:23to the

31:24doctor although these tools might look

31:27crude eye surgery was one of Islamic

31:29medicine's great

31:31successes one Innovation was to improve

31:34an older technique for curing cataracts

31:38called couching which in their hands had

31:41a success rate of over

31:4360% in a living subject the corne would

31:46be clear and you'd be able to see the

31:48pupil clearly with the catara sitting

31:50behind the pupil the the wiac to see how

31:52couching stands the test of time I'm

31:55meeting up with eye surgeon Mr Vic sh

31:58right cataract is the lens inside the

32:00eye which sits behind the pupil um as

32:05with time with age the Cataract the lens

32:07gets cloudier and cloudier and that's

32:09what it's referred to as a cataract um

32:12I've brought along a replica of a

32:13medieval couching knife and a

32:16description of the treatment by

32:18alassis which is the Latin name for the

32:20great 10th Century Islamic surgeon El

32:24zahi uh he says you take the couching

32:27needle in your right hand if it be the

32:29left eye and so on and then thrust the

32:31needle firmly in at the same time

32:33rotating it with your hand until it

32:35penetrates the white of the eye and you

32:36feel the needle has reached something

32:38empty uh so he's talking about how to

32:40dislodge exactly so I mean maybe you can

32:42show me we've got some eyes here y I'll

32:45certainly give it a shot and what they

32:47would have done would have attempted to

32:50go in just by the white of the eye just

32:53at the edge where the corer is and then

32:55what they are attempting to do is to

32:57sweep around

32:58trying to break all those ligaments of

33:00that lens and trying to get the lens to

33:02drop away from the pupil to allow more

33:04light to enter in through the people and

33:06to brighten the subject's vision but of

33:09course you haven't got the capacity to

33:10focus oh yeah you haven't got a lens

33:12nowly so that was a big problem until

33:14people started compensating that with

33:16specs later on right right what is your

33:20feeling about how advanced and

33:22successful well they were on the you

33:24know the general ballpark they were at

33:27the right place they were they were

33:28trying to remove the Cataract away from

33:30the visual axis they understood the

33:32anatomy of the eye they had some

33:34understanding of the anatomy of the eye

33:35and you know that the lens was behind

33:37the pupil and that's what was causing

33:39the um visual loss and so removing that

33:42um you know and that General principle

33:44is still the same right and you know

33:46there are still accounts of it being

33:47used in certain parts of the world

33:50[Music]

33:54presently looking back at Medieval

33:57Islamic

33:58with modern scientific eyes is

34:01frustrating they take us true many

34:04things we know to be nonsense but on the

34:06other hand their desire to deal with

34:09this vast subject logically and

34:11systematically is admirable and truly

34:14marks a break with the

34:16past one Islamic scholar more than any

34:19other embodies the synthesis of religion

34:22faith and

34:24reason his name was ibben Cena or avyna

34:29as he's known in the west he was a

34:31polymath who clearly thrived in

34:33intellectual and courtly

34:36circles in 1025 he completed this

34:41Al or the cannon of

34:44medicine in it ibben Cena collated and

34:47expanded on all that had gone before him

34:50medical ideas from Greece to India and

34:53turn them into a single

34:55work so how would you place this SP book

34:58in a historical context oh it's hugely

35:01important I mean it's uh I mean there

35:03are a few books which are as important

35:04as the Canon because what this

35:06encyclopedia does it kind of you know

35:09sweeps away everything else it becomes a

35:11text book it be it supersedes a lot of

35:14other texts and people even complain

35:16that like it's so good it's so tightly

35:19organized it's so easily accessible that

35:22uh you know like people forget to read

35:24the the Greek sources in Arabic

35:26translation this whole first book this

35:28is the first book contains what we call

35:30the Kad the general principles so it's

35:32all about how the human body works you

35:34know how disas work in general the

35:37second book contains the diseases what

35:40we sometimes call from tip to toe like

35:42from tip to toe so he starts with the

35:44diseases of the head and then he moves

35:47moves down like the eyes the ears the

35:49nose the mouth and he he normally they

35:52end up at the sexual organs you

35:55see at First Sight the sheer ambition of

35:58the three volumes is hugely

36:01impressive here's an attempt at

36:03diagnosis and cure for diseases as

36:06diverse as depression meningitis and

36:08small poox and there's even detailed

36:11chapters on more common problems so um

36:15like for instance here you have like

36:16headaches so different kinds of

36:23headach so headaches caused by Pleasant

36:27fragrant smells or and then he's also

36:29got

36:30um so um hangovers different kind you

36:35can get headache from sex is that right

36:38well I mean I hasn't happened to me yet

36:40but I mean you know let's see so the

36:44treatment of headache caused by

36:55sex so if somebody uh has or is befallen

37:00by suffers from a headache after sex and

37:03he also has a repletion so he like he

37:06has too many superfluities or something

37:07like that um

37:11so one has to First Resort to Venice

37:14section or blood

37:16letting and then you should use purging

37:21in for each both of them I mean like

37:24blood letting and purging are necessary

37:27a lot of the the stuff in here sounds

37:29like nonsense of course because this is

37:30not modern medicine no it's not um so

37:34how long was was this taken seriously

37:37well the fundamental ideas contained

37:40here about how the body works I

37:42mean they hadn't changed until the early

37:4519th century I mean there was there were

37:47there was progress obviously on certain

37:49levels but the feel like the essence was

37:52the same and then came the big break

37:53with the discovery of bacteria and and

37:56viruses and things like that and from

37:59the second half of the 19th century

38:01onward you know medicine was totally

38:03revolutionized that's right IB Cena's

38:05Cannon of medicine is a landmark in the

38:08history of the

38:09subject although much of the Medical

38:11Science it espouses we know now to be

38:14terribly misguided its value lies in

38:17accumulating the best knowledge in the

38:19world at the time into one accessible

38:22organized

38:24text the cannon would give future

38:26Generations something to

38:32[Music]

38:45rewrite cataloging the world's medical

38:48knowledge has clear and obvious benefits

38:51but the Islamic Empire's Obsession to

38:54uncover the knowledge of the Ancients

38:56went beyond practical matters like

38:58medicine many like the cff elmon

39:02believed that the people of antiquity

39:04possessed dark even magical

39:07powers and what's more new evidence is

39:10coming to light to show just how hard

39:13Islamic scientists worked to ReDiscover

39:17[Music]

39:25them to find out about that story I have

39:29to visit the harsh burnt yellow of the

39:31Sahara desert in

39:34Egypt there I am to meet an academic who

39:37wants to show me how the translation

39:39movement took the Arabs to Egypt on a

39:41quest to break a code which they thought

39:45hid the secret of the Dark Art of

39:48alchemy

39:50[Music]

39:57this is Sakara a necropolis or graveyard

40:00of the ancient

40:02pharaohs over a 10 Acre Site it's a

40:05collection of burial Chambers and step

40:07pyramids that were built in the third

40:10millennium before

40:12Christ these are said to be among the

40:15oldest Stone buildings in the

40:18world mind the step here archaeologist

40:21Dr okasha alali is my guide he was about

40:25to reveal the most astonishing story of

40:27my journey so

40:32far look at

40:36that like most people I believe that

40:39Egyptian hieroglyphs had remained

40:41completely undeciphered until the 19th

40:44century then came the chance discovery

40:47of the famous Rosetta Stone this Stone

40:50had the same inscription written in both

40:53hieroglyphs and Greek it provided the

40:56crucial Clues which British and French

40:58Scholars used to decipher the writings

41:01of ancient

41:03Egypt that's the usual Story one hears

41:07but Dr alali has made a discovery that

41:10dramatically Alters it he has recently

41:13Unearthed a number of rare works by the

41:16Islamic scholar ibben

41:19wah what he did was figure out a

41:21correspondence between hieroglyphs like

41:24these and letters in the Arabic alphabet

41:27if look here for example at's manuscript

41:30you see he's giving us the Egyptian

41:32hieroglyphic signs that have underneath

41:36yes and they have the fanatic value in

41:38Arabic underneath so look very carefully

41:40at this one he says seen underneath that

41:43seat yes now look at this seat here that

41:46is s that seat in Egyptian hieroglyphic

41:48is used for the sign s scene which is

41:50what you see here

41:52SE that is the name of the god Osiris

41:55Osiris oh with an S that's a scene

41:58yeah this is the letter

42:00H this one here this is the H the water

42:05wave right is a letter N or n in Arabic

42:10T and the letter F these are all letters

42:13these are all letters but then he

42:15realized but how did he decipher the

42:17hieroglyphs the one good thing about the

42:19early Arabic Scholars was their ability

42:21to link ancient Egyptian language we

42:24call heroglyph to link it with their own

42:26contemporary Coptic they realized that

42:28Coptic is nothing but the later stage of

42:32ancient Egyptian

42:34language and they realized this because

42:36the translation movement had literally

42:39placed hundreds of Coptic texts into

42:41their hands the scholars could now see a

42:45direct link between hieroglyphs and

42:49Arabic what fraction of these symbols

42:52would have been correctly deciphered

42:56they got about 14 letters they CRA more

42:58than half of the Egyptian hieroglyphic

42:59correctly so that was a remarkable

43:01achievement for people were on the 9th

43:02century 10th

43:09Century well that's probably the biggest

43:12Revelation for me so far on on my

43:14travels that uh egyptology didn't begin

43:18in the 19th century yet again it seems

43:21that Islamic scholars actually cracked

43:24hieroglyphics and they cracked it for

43:26for strange reasons they cracked it

43:28because they were interested in in

43:30astrology and and Alchemy but here is

43:33another example of this amazing

43:36translation movement they weren't just

43:37translating Greek and and and Indian and

43:40Persian text they were translating

43:43Egyptian hieroglyphics as well

43:45absolutely

43:50incredible unfortunately for the cff El

43:52mmon the hieroglyphs contained no

43:55alchemical secrets

43:58but what this story reveals to me is the

44:01insatiable curiosity Islamic scholars

44:04had about the

44:06world they were desperate to absorb

44:08Knowledge from all cultures purely on

44:11merit with no quals about the places or

44:13religions from which it

44:15came most intellectual Traditions

44:18including if I may say so our own tend

44:21to work very hard to keep everybody else

44:24out whereas here we have an example of

44:28an Enterprise which is desperate curious

44:32to turn itself into a net importer of

44:35intellectual product that's a very

44:38important lesson for the history of the

44:42Sciences I was soon to see just how

44:45dramatically this fueled scientific

44:49innovation but it's worth remembering

44:51that the translation movement wasn't

44:53just about science and

44:56medicine as the capital Baghdad sat in

44:58the center of a vast successful Empire

45:01it became home to an extraordinary

45:04flourishing of all kinds of

45:12[Music]

45:15culture for this is the time described

45:18by 101

45:21Knights of great and generous cffs magic

45:24carpets great Journeys

45:27but also ambitious buildings music dance

45:31storytellers and the

45:37[Applause]

45:42Arts Baghdad was such a cultured and

45:46vibrant City that one traveler of the

45:48time wrote there is none more learned

45:51than their Scholars more cogent than

45:54their theologians more poetic than their

45:57poets or more Reckless than their

46:01[Music]

46:06rakes it really must have felt like

46:09Baghdad and the Arabic empire were the

46:11world leaders in Civilization and

46:14culture to be part of that City's

46:17growing intellectual Elite must have

46:19been as exciting as it

46:23gets it was a new Muslim City it only

46:26started to be built in

46:28756 so it has that sort of sense of

46:30almost being on on a frontier of being

46:33something new of being something

46:34different um it was full of coures it

46:37was full of um sort of nvo individuals

46:40who were trying to make their way at the

46:42aasted court and it is the sort of a

46:46place if you like where Innovation is

46:48valued and

46:52appreciated at the heart of the city's

46:55intellectual life was a system called

46:58the Magus now the word Magus could

47:00probably best be translated as Salon or

47:02talking

47:06house in 9th century Baghdad what this

47:09meant was that the city's Elite the

47:11califf his courters generals and the

47:14aristocracy would hold regular meetings

47:17you might call them seminars or

47:19discussions during which the city's

47:21cleverest men the philosophers

47:23theologians astronomers and logicians

47:26would gather to discuss and debate their

47:29ideas it was not the case that people

47:31were expected to adhere to a particular

47:34line or adopt a particular religion they

47:37were allowed to express their own

47:38sentiments and their own views very

47:40freely the point was that they should do

47:42so in elegant Arabic and a good logical

47:47reasoning the effect of the Magus was to

47:50create a hey mix of money and brains

47:54with the best Minds in the Empire

47:55swapping ideas while simultaneously

47:58engaged in Fierce competition for

48:01patronage it's at this point my

48:03investigation into the first wave of

48:06Islamic science returns me to the man we

48:09first met at the beginning of this story

48:11in the back streets of Cairo the great

48:13mathematician who brought the West the

48:15decimal system out of the very heart of

48:19this intellectual Whirlwind came

48:22alisi mathematician astronomer courtier

48:25and favorite of the kff El mmon he was a

48:28product of his age an immigrate from

48:31Eastern Persia into Baghdad surrounded

48:34by books well-versed in learning from

48:36Greece Persia India and China and

48:39fearless in his

48:43thinking alisi brought together two very

48:46different mathematical traditions and

48:49synthesized them into something

48:52new the capacity to have on your desk

48:56simil

48:57aneous two very different kinds of

49:01mathematics presses on models of what

49:05counts as calculation what counts his

49:08measurement and I think accelerates the

49:10process of intellectual

49:14change the first of these Traditions

49:17came from the greeke speaking

49:20World Greek mathematics dealt mainly

49:23with geometry the science of shapes like

49:26triangle angles circles and polygons and

49:29how to calculate area and

49:32volume the other great mathematical

49:34tradition alisi inherited came from

49:38India they' invented the 10 symbol

49:41decimal system which made calculating

49:43much

49:45simpler thanks to the translation

49:47movement alar ismi was in the

49:49astonishingly lucky position of having

49:52access to both Greek and Indian

49:55mathematical traditions he was able to

49:57combine geometrical intuition with

50:00arithmetic Precision Greek pictures and

50:04Indian symbols inspiring a new form of

50:07mathematical thinking that today we call

50:15algebra as a physicist I've spent much

50:18of my life doing algebra and I can't

50:20overstate its importance in

50:23science but it is a strange idea I

50:27remember being perplexed when my math

50:29teacher first started talking about

50:31mathematics not using numbers but with

50:33symbols like X and

50:38Y it's an incredibly liberating idea

50:41because it allows you to solve problems

50:43without getting bogged down in messy

50:45numerical

50:47calculations so we have here this

50:50Priceless manuscript kab Alaris alar

50:54ism's book and professor Ian Stewart has

50:57studied algebra for much of his working

51:00life together we looked at an early copy

51:03of the book in which the idea really

51:05took form published I see here although

51:08it's written sort of in the margin the

51:10title of the book uh Al jabber M so

51:13that's the first time the word

51:16algebra appears algebra algebra that's

51:19where our word algebra comes from now

51:21what I found very early on is that he

51:23said I I I discovered that people

51:26require three kinds of numbers

51:30umud so Roots squares and numbers so

51:34what is it trying to do here this is

51:36what we would Now call x and x squ this

51:38is quadratic equations this really is

51:40algebra so he's setting you up for a

51:42book about how to solve equations by

51:45algebraic methods okay now quadratic

51:48equations I thought were around and

51:50being solved long before Caris me back

51:53to Babylonian time so you know what's

51:55the big deal about this book

51:57it's the point of view he treats root

52:00and square as if they're objects in

52:02their own right they're not just

52:05something some number that we're trying

52:07to find out they're a process you apply

52:11what Al charism is thinking of is square

52:14means take the root and multiply by

52:16itself and that recipe is true whatever

52:19the root might be if it's five it's 5

52:21Time 5 it's 25 if it's three it's 3 *

52:24three um he's giving you a general

52:26recipe now called an algorithm after

52:30him right the algorithm comes from it

52:32comes from it's another word that comes

52:34from Alaris yes now he talks about this

52:37procedure here on the next page um you

52:40you take the number multiplying the root

52:42and then you Harve it and then you

52:43multiply it by itself then you add add

52:46it to the other number and take the

52:47square root that's that's the algorithm

52:49is it that's right and this is where you

52:51see the difference because previous

52:55writers on the subject would have said

52:57things like take half of 10 which is

52:59five square that which is

53:0225 and then they do another problem take

53:05half of 12 which is six square that

53:07which is 36 and they'd run you through

53:09this same process over and over again

53:11with different numbers and it would be

53:13up to you to infer how to do it on the

53:16next problem but he doesn't do that he

53:18doesn't do that he says take half the

53:20root whatever the root is take half the

53:22root so half the root is actually an

53:24object if the root is an object half the

53:26roote is an object so you don't have to

53:28have in your mind what that route stands

53:30for you you can forget about what it

53:31stands for when you come to square it

53:33you just know okay I should Square this

53:35thing I don't care what the thing is so

53:38you abandon temporarily this link with

53:41specific

53:42numbers manipulate the new objects

53:45according to the rules that his book is

53:48explaining and then the numbers that

53:51these objects represent in your

53:52particular problem will miraculously

53:55appear at the end and you'll end up with

53:57x equals 3 or whatever it is how

54:00revolutionary do you regard Alaris his

54:03work

54:04he made it possible for algebra to exist

54:08as a subject in its own right rather

54:10than as a technique for finding numbers

54:13the least interesting bit of an

54:14algebraic calculation is when you get to

54:16the end and discover that x equals 3

54:19it's the route you take to get there but

54:21if it was a special route for each

54:23problem and a different route for each

54:24problem that wouldn't be interesting

54:26either it would just be a big mess

54:28there's this beautiful General series of

54:30principles and if you understand those

54:33then you really understand algebra

54:40[Music]

54:51[Applause]

54:57what is the true Global importance of

55:00algebra it's been used throughout the

55:02ages to solve all sorts of problems let

55:05the mass of the Cannonball be M let the

55:08distance it has to travel be D use

55:11algebra to work out the optimum angle

55:13you have to point your cannon that sort

55:16of knowledge wins

55:18Wars or let's call the speed of light C

55:22the change in mass of an atomic nucleus

55:24M and then calculate the energy released

55:27with the following algebraic Formula E =

55:31M

55:33c² Mastery of that information truly is

55:49power algebra has helped create the

55:52modern world our science is unimaginable

55:55without it

55:56it it sums up so much that was

55:59remarkable about medieval Islamic

56:02science taking ideas from Greece and

56:04India combining and enhancing them

56:08similarly modern medicine owes a

56:10considerable debt to the work of the

56:12Islamic

56:14Physicians but I think the real story of

56:16what happened to science in the Islamic

56:18world in the eth and 9th centuries tells

56:21us more than any single Discovery what

56:24it really tells us is is about the

56:26universal truth of science

56:33itself I believe that the first great

56:36achievement of the medieval Islamic

56:37scientists was to prove that science

56:40isn't Islamic or Hindu or helenistic or

56:43Jewish Buddhist or Christian it cannot

56:46be claimed by any one

56:48culture before Islam science was spread

56:51across the world but the scholars of

56:54medieval Islam pieced together this

56:56giant scientific jigsaw by absorbing

56:58knowledge that had originated from far

57:00beyond their own Empire's

57:02borders this great synthesis produced

57:05not just new science but showed for the

57:08first time that science as an Enterprise

57:11transcends political borders and

57:13religious affiliations it's a body of

57:16knowledge that benefits All Humans now

57:19that's an idea that's as relevant and as

57:22inspiring as ever

57:24[Music]

57:37in the next episode I investigate how

57:39one of the most important ideas in the

57:42world arose in the Islamic

57:45empire I discover how mathematics and

57:48experimentation Fus together as the

57:51Empire embraced a medieval Industrial

57:54Revolution and incar

57:56I find out how these ideas led directly

58:00to today's world of science and

58:08[Music]

58:11technology science and Islam continues

58:14next Monday night at 11:25 tonight we're

58:17heading for broadcasting house and a day

58:18out with you too

58:20[Applause]

58:21[Music]

58:42[Music]

58:50every now and then an idea takes form

58:53that changes everything it's

58:56revolutionizes the way we see and

58:58understand the world around us I believe

59:00that just such an idea took form in the

59:03medieval Islamic world it's the idea

59:06that everything from the stars above to

59:09the workings of our own bodies is not

59:11arbitrary or whimsical but subject to

59:14certain systematic rules and what's more

59:17that we humans can work out what those

59:19rules might be and then we can refine

59:22and test our theories through

59:23observation and experiment in other

59:26words it's the idea we now call the

59:30scientific method

59:33[Music]

59:56for me the story of the scientific

59:58Renaissance that took place in the

1:00:00medieval Islamic world is a personal

1:00:06one this is my cousin samir's house in

1:00:09the Iranian Capital

1:00:11tan I haven't seen some of the relatives

1:00:14on my father's side of the family in

1:00:16over 30

1:00:18years this is my not so tall but very

1:00:22beautiful Auntie Ana

1:00:26the alkal family is originally from the

1:00:28city of nef in Iraq south of

1:00:31Baghdad in fact I grew up in

1:00:35Iraq but when Saddam Hussein came to

1:00:37power the family split many of the

1:00:40alkalis fled here to

1:00:43Iran as my mother's English I came to

1:00:46Britain with my

1:00:49parents there I pursued my passion for

1:00:52Science and am now a professor of

1:00:54physics at the University of

1:00:57Sor but now I find that my own

1:01:00scientific work and my Arabic and

1:01:02Islamic Heritage are

1:01:07intertwined on my journey through the

1:01:09Middle East I discovered that an

1:01:11astonishing leap in scientific knowledge

1:01:13took place here a thousand years ago

1:01:16under a powerful and flourishing Islamic

1:01:21empire wealthy powerful successful

1:01:25cultures will produce enormous advances

1:01:29in understanding and in technique and

1:01:33that's just what we find in Islam in

1:01:37Baghdad under a series of successful

1:01:41powerful wealthy and self-confident

1:01:45Islamic

1:01:46regimes over a thousand years ago the

1:01:49Islamic empire was the largest in the

1:01:52world it governed and estimated 60

1:01:55million people

1:01:56that was over 30% of the world's

1:02:02population I found an archaeological

1:02:04fragment of this glorious past in a

1:02:07suburb of tran not far from my cousin's

1:02:13house these ancient walls tucked behind

1:02:16a back street on the outskirts of

1:02:17Southern Teran are literally all that

1:02:20remain of the ancient city of Ray the

1:02:24city that the great Persian geog al mad

1:02:27described as one of the glories of

1:02:32Islam of course Ray was just one of a

1:02:35number of cities that flourished under

1:02:37early Islamic rule from Baghdad its

1:02:40capital the empire spread across

1:02:42thousands of miles from North Africa

1:02:45through to central Asia cities like

1:02:48alasar Basra MV Gan bhara each powerful

1:02:53and thriving cities each would have been

1:02:55rich in trade alive with culture each

1:02:58would have had its own libraries its

1:03:00ownmy these were powerhouses of the new

1:03:03science this really was a golden age

1:03:08think of that span of land this is

1:03:10larger than any Empire human

1:03:13civilization had ever known within that

1:03:16span of land you can plug in the Roman

1:03:19Empire and it will fill just maybe what

1:03:21one third of it one half of it or

1:03:23something like that

1:03:26[Applause]

1:03:28[Music]

1:03:34reminders of this great Islamic empire

1:03:36are everywhere in the Arab world

1:03:39today this football match in the Syrian

1:03:41Capital Damascus is being played at the

1:03:44Abbasid Stadium that's the name of the

1:03:47family who ruled the Islamic empire from

1:03:49750 to 1258 ad

1:03:53[Applause]

1:04:02this large territory allowed them to

1:04:04raise enormous tax revenues to fund a

1:04:07search for knowledge and scholarship

1:04:09which became known as the translation

1:04:13movement they sent Scholars around the

1:04:15known world to gather up great books and

1:04:18have them translated into

1:04:20Arabic it's a legacy that's still alive

1:04:23in the minds of most modern Arabs

1:04:30[Music]

1:04:31[Applause]

1:04:34[Music]

1:04:42[Applause]

1:04:44for medieval Islamic leaders scientific

1:04:47knowledge was crucial to successfully

1:04:49running a vast

1:04:52Empire they did have a big and

1:04:55sophisticated governmental

1:04:56Administration and obviously that needed

1:04:59knowledge if you wanted to be an

1:05:00administrator and you had to assess

1:05:02taxes you needed to know about

1:05:05mathematics it also wants to be able to

1:05:07build Monumental buildings that requires

1:05:09the knowledge of architecture and again

1:05:11mathematical skills to construct fine

1:05:13buildings

1:05:15safely medicine just to keep the elite

1:05:18happy and healthy and those are the

1:05:21areas of knowledge which are first

1:05:22translated from other languages into

1:05:31Arabic the legacy of the medieval

1:05:34Islamic empire is scattered across a

1:05:36vast

1:05:38region there's architectural

1:05:41masterpieces like the omad mosque in

1:05:44Damascus the jam mosque in

1:05:47Isfahan and Al ashar University of

1:05:49mosque in

1:05:52Cairo and then there are many ruins that

1:05:54still hint at past glories like this a

1:05:58crumbling 8th Century Palace deep in the

1:06:00Syrian

1:06:02desert and this a huge Muslim palace

1:06:06called Medina Zahra currently being

1:06:08excavated in southern

1:06:12Spain these are the impressive ruins of

1:06:16Medina to Zahra the Fantastic Palace

1:06:19City built outside Corda in the 9th

1:06:22century by abdur Rahman III who was the

1:06:26greatest of all the Andalusian

1:06:28cffs at the time that it was ruined

1:06:31Cordoba was in fact the largest and most

1:06:35important city in Europe arrival to

1:06:38Baghdad in the East for a center for

1:06:41Islamic scholarship and

1:06:47Science and as I traveled I saw how

1:06:50science especially numerical

1:06:53recordkeeping and measurement was

1:06:55crucial to dealing with the challenges

1:06:57of running a vast

1:07:03Empire this is the mighty River Nile as

1:07:07it flows through the Egyptian Capital

1:07:10Cairo since Antiquity its unpredictable

1:07:13floods have determined the fate of

1:07:16Egypt's people bringing years of lean

1:07:18and

1:07:19plenty by the 8th Century Cairo was part

1:07:23of the Islamic empire and the new rulers

1:07:25took the first step to understanding

1:07:28this Mighty River in a scientific

1:07:31way they built a device to measure

1:07:41it amazing

1:07:44structure Dr Nardo Al bizer of The

1:07:47Institute of ismi studies is showing me

1:07:50the

1:07:51nilometer it's basically a huge colonade

1:07:54that was built in a chamber connected by

1:07:56tunnels to the river as the water Rose

1:07:59or fell its height could be read from

1:08:02the central

1:08:03column the central colonade here is

1:08:07ultimately a measuring uh instrument it

1:08:10is very precise it's almost one inch

1:08:12between a marking and another presumably

1:08:15they need to know seasonal variations in

1:08:17the Heights and to the mark try to have

1:08:20some sort of record so that they could

1:08:22measure against certain years where a

1:08:24year was known for a high level of Flood

1:08:27versus another year known for its

1:08:29drought then they might perhaps take

1:08:32some precautions

1:08:34yes the data collected from the

1:08:37nilometer did have one practical use by

1:08:40creating an objective record of the

1:08:42river's Behavior it allowed the rulers

1:08:45of the time to calculate how much tax to

1:08:48levy on Egypt's

1:08:50Farmers but whatever its use is what I

1:08:53love about the nomer is how it shows

1:08:56that to understand the world you have to

1:08:59build devices to measure it if you think

1:09:03very hard it's never

1:09:06obvious that measurement can make sense

1:09:10of the world around us the world appears

1:09:14as a western philosopher once put it

1:09:17like a buzzing blooming

1:09:19confusion and the idea that we as a

1:09:22group have tools which are reliable

1:09:26which have sufficient Integrity which

1:09:29have an intellectual grip that can make

1:09:33sense of the basic phenomena we see

1:09:35around us that's an astonishing

1:09:46idea and one medieval Islamic ruler made

1:09:49measurement a personal Obsession giving

1:09:52it a scale and ambition that was truly

1:09:54unprecedented

1:09:57his name was el- mmon and he became the

1:10:00cff or ruler of the Islamic empire in 83

1:10:04ad El mmon lived in a culture without

1:10:07portraiture so all we have are later

1:10:09impressions of what he might have looked

1:10:13like elmm Moon funded a range of

1:10:16scientific research but one particular

1:10:19project was a personal favorite of

1:10:22his and given that he ruled over such

1:10:25such a large territory it's hardly

1:10:27surprising what it was

1:10:31mapmaking in the second decade of the

1:10:349th century ad El mmon commissioned a

1:10:38new map of the world and his scientists

1:10:41did a pretty impressive job it was a

1:10:44vast Improvement on all maps that had

1:10:46come before what we see here is that

1:10:49they've really got the the Mediterranean

1:10:51uh it shape and how it links in with the

1:10:53Black Sea the middle e

1:10:55even the whole of Asia as far as China

1:10:58and Japan they've even got the the

1:11:00Indian Ocean and the east coast of

1:11:02Africa it all looks pretty impressive

1:11:04for the known world at the

1:11:07time of course what Al mmon ultimately

1:11:10wanted to know was how much of the Earth

1:11:14as a whole did he possess and this beged

1:11:17the question just how big is the

1:11:24Earth it's a sign of amazing ambition

1:11:27that groups of Scholars and Craftsmen

1:11:31together can as it were capture the

1:11:34world where does that ambition and that

1:11:37confidence come from part of it comes

1:11:40from uh religious

1:11:43Faith because the world was made by

1:11:47someone a bit like us but much

1:11:50smarter if we're smart enough the

1:11:54thought was we could probably make sense

1:11:57of a bit of what he

1:11:59did and that's very clear as a

1:12:02motivation in a lot of Islamic as in a

1:12:05lot of Christian

1:12:07Science and more specifically the

1:12:10practice of Islam demanded that its

1:12:12followers have a very clear idea of the

1:12:16size and shape of the

1:12:18world now this is crucial information

1:12:20for Muslims because wherever they are in

1:12:22the world they need to know the

1:12:24direction to mecca for their prayer this

1:12:27is known as Al now over such a large

1:12:30territory finding the direction to Mecca

1:12:32is not a trivial

1:12:36problem this problem was wonderfully

1:12:38Illustrated when a mosque was built

1:12:40recently in Washington

1:12:42DC some worshippers were confused

1:12:45because the direction they were told to

1:12:47face when praying was slightly North and

1:12:50not Southeast as they expected after all

1:12:53Mecca is southeast of Washington and on

1:12:56a flat map it does appear to lie in that

1:12:59direction but on a curved sphere the

1:13:03shortest distance between any two points

1:13:06follows what's called a great circle so

1:13:09for example this great circle line

1:13:12between Washington and Mecca is quite

1:13:15different to what you might expect so

1:13:17the direction to Mecca from Washington

1:13:19actually points slightly Northeast

1:13:22rather than

1:13:24Southeast of course this is complicated

1:13:26stuff but the key point for Islamic

1:13:28scholars is that knowing the direction

1:13:30to Mecca requires a knowledge of how

1:13:33steeply the Earth curves and that means

1:13:36knowing how big it

1:13:39is so Elma Moon commissioned his very

1:13:42best scientists to measure

1:13:45it hello

1:13:47hello I'm jar nice to meet you to

1:13:52understand how they did it I'm meeting

1:13:53up with Professor Sami Ubi from Aleppo

1:13:56University in Syria who's an expert in

1:13:59early Islamic science join

1:14:06me Professor chalbi began by explaining

1:14:09the measuring technique which elmon

1:14:12scientists first used and which they had

1:14:14inherited from the Greeks we're now

1:14:17talking about this the earlier

1:14:20Aristophanes um technique of measuring

1:14:22the circumference it was repeated again

1:14:25by the the abased astronomers was to

1:14:29measure the distance between two points

1:14:31and then look at the angle of

1:14:32inclination of the Sun so in Egypt in

1:14:35Aswan down in the South they regard the

1:14:38Sun as being vertical this is you know

1:14:40near to the equator and they worked out

1:14:43how far away from the vertical the sun

1:14:45was if they measured it from the north

1:14:48of Egypt in Alexandria which is on the

1:14:50Mediterranean Coast Elm Moon's

1:14:53astronomers repeated the Greek

1:14:55experiment in Syria and Iraq by

1:14:57measuring the angle of the Sun in the

1:14:59sky at noon at one known

1:15:03location they then walked due north to a

1:15:06second location carefully measuring the

1:15:08distance they

1:15:10traveled at the second location they

1:15:12once again measured the angle of the Sun

1:15:15at noon this angle would have been

1:15:17slightly smaller than the first

1:15:21one with these figures elmm Moon's

1:15:23astronomers were able to estimate the

1:15:26Earth's

1:15:27circumference they got a value of 24,000

1:15:31M within 4% of the correct value not bad

1:15:35you might think but this method was

1:15:37flawed and ultimately unreliable the

1:15:40main problem with it was that measuring

1:15:42the distance between two locations was

1:15:45incredibly difficult it could only be

1:15:47done by the unreliable method of

1:15:49counting Paces as you walked through the

1:15:51burning

1:15:53desert a more reliable and sophisticated

1:15:57method for estimating the Earth's size

1:15:59was needed and two centuries after elmm

1:16:01Moon died it

1:16:03came what made it possible was a great

1:16:06leap of imagination and the fact that by

1:16:09900 ad much of the world's mathematical

1:16:12knowledge had been translated into

1:16:14Arabic so Scholars could scrutinize and

1:16:17improve on

1:16:19it out of this obsession with scholarly

1:16:22learning came a true mathematical

1:16:24visionary

1:16:25Abu ran Muhammad IB Ahmed

1:16:29Ali and like all Islamic scholars of the

1:16:32time alboni was obsessed with the

1:16:34Science and Mathematics of the ancient

1:16:36Greeks Babylonians and

1:16:39Indians and because of the success of

1:16:41the translation movement he had

1:16:43literally on his desk the great work on

1:16:46Geometry by euklid toames alest the

1:16:49Indian text the sind and the famous work

1:16:52on algebra by Al karisi

1:16:59Professor chelbi has brought along the

1:17:01book in which elb Rooney describes how

1:17:04he combined algebra and geometry with

1:17:07some very simple and practical

1:17:09measurements to solve the Epic Problem

1:17:11of how to calculate the size of the

1:17:16Earth this is this is

1:17:19hisi the masi cannon yes this is Boon's

1:17:22Cannon which I've been trying to get

1:17:24hold of

1:17:25um where he describes this this

1:17:27fantastic experiment and oh and you

1:17:30found the page

1:17:34yes having read elon's description of

1:17:37how to estimate the size of the world I

1:17:39wanted to try it for

1:17:44myself first he had to find a fairly

1:17:48high mountain from the top of which he

1:17:50could see a flat Horizon in this case

1:17:53the sea

1:17:56what I love about this story is that

1:17:58with a few simple measurements around

1:18:00this small mountain peak you can work

1:18:02out the size of the whole

1:18:05world ALB Ro's First Step was to work

1:18:09out the height of the mountain he did

1:18:11this by going to two points at sea level

1:18:14a known distance apart and then

1:18:16measuring the angles from these points

1:18:19to the

1:18:22Mountaintop so to measure the angle to

1:18:25the Mountaintop Boon had to use a device

1:18:29like this called an astrola it's

1:18:31basically a giant protractor it has the

1:18:34Angles and degrees marked around the

1:18:36outside and a pointer to help him

1:18:38determine his line of sight so if we try

1:18:41now and determine the the angle to the

1:18:44top it has to hang freely and then okay

1:18:48so you let it

1:18:49hang I'd like to stress if you haven't

1:18:52noticed already that Alber rooni would

1:18:54have made his measurements more

1:18:56meticulously than I am he did them again

1:18:59and again to get consistently reliable

1:19:02results okay that's about

1:19:05it and that is

1:19:08242° okay so now we've determined one

1:19:11angle we now have to go and pick our

1:19:13second spot along the

1:19:19beach the distance from the first to the

1:19:21second points must be measured

1:19:23accurately in this case case is 100 m

1:19:26and the two points must be in a straight

1:19:28line with the

1:19:35mountain I measured the second angle to

1:19:38be about

1:19:40262° and now had enough information to

1:19:43calculate the height of the

1:19:46mountain using trigonometry and algebra

1:19:49elb Rooney used a formula that relates

1:19:52the height of the mountain to what are

1:19:54known as the tangents of the angles he

1:19:57measured using my measurements I get a

1:20:00figure for this mountain of about 530

1:20:05m i now need only one more measurement

1:20:08to get the size of the

1:20:10Earth and to get that I have to climb to

1:20:13the top of the

1:20:15mountain what beon did next was measure

1:20:19the angle of the line of sight to the

1:20:21Horizon as it dips below the horizontal

1:20:25so we're going to try and reproduce that

1:20:27so if you can lift it up so that it's

1:20:31hanging and if I locate The

1:20:36Horizon okay which is about half a

1:20:41degree which is about the value that

1:20:42beon

1:20:46got now here's the really ingenious part

1:20:49beoni had measured four quantities three

1:20:53angles and a distance he used two of the

1:20:55angles and the distance to work out the

1:20:57height of the mountain ALB roon now had

1:21:01everything he needed in essence ALB roon

1:21:04imagined a huge right angled triangle

1:21:06which has as its three corners The

1:21:09Mountaintop The Horizon and the center

1:21:11of the

1:21:12earth trigonometry told him that the

1:21:15angle he had measured and the height of

1:21:17the mountain are related to the radius

1:21:19of the Earth and algebra allowed him to

1:21:22calculate it with this formula beon is

1:21:26able to arrive at a value for the

1:21:28circumference of the earth that's within

1:21:31200 miles of the exact value we know it

1:21:33to be today about 25,000 mil that's to

1:21:37within an accuracy of less than 1% a

1:21:40remarkable achievement for someone a

1:21:43thousand years ago

1:21:50[Music]

1:21:56for me Boon's experiment is an early

1:21:59dramatic example of a scientist using

1:22:02mathematical reasoning to extend

1:22:05Humanity's reach he really pushes the

1:22:08idea that abstract geometrical rules

1:22:11governing idealized shapes like perfect

1:22:13circles and triangles can help us to

1:22:16comprehend the real world Einstein used

1:22:20precisely the same approach admittedly

1:22:23with much more advanced mathematics ICS

1:22:25when he developed his general theory of

1:22:27relativity almost a thousand years after

1:22:30beoni but both Einstein and beon were

1:22:34United by a single common idea with

1:22:38mathematics Humanity can embrace the

1:22:50universe in this story of the birth of

1:22:53the scientific method the Islamic

1:22:56Scholar's ability to master

1:22:57sophisticated mathematics is the first

1:23:01crucial

1:23:03[Music]

1:23:09ingredient the second crucial ingredient

1:23:12is the use of experiments in science

1:23:15without experiments Theory remains

1:23:18meaningless and sterile it's

1:23:20experimentation that allows Theory to be

1:23:22held up against the real world

1:23:25it gives it physical meaning but whereas

1:23:28sophisticated mathematics grew out of

1:23:30the Empire's obsession with the world's

1:23:32learning through the translation

1:23:33movement practical experiments came from

1:23:37the daily needs of a powerful and

1:23:39expanding

1:23:46civilization the driving force of the

1:23:49expanding medieval Islamic empire was

1:23:52trade it boomed from around 700 AD

1:23:55onwards creating a massive demand for

1:23:58metal workers glass blowers tile makers

1:24:03Craftsmen of every possible

1:24:06kind when this collided with scholarly

1:24:09tradition symbolized by the translation

1:24:12movement it had seismic consequences for

1:24:16science the scienes absolutely depend

1:24:21astronomy is a wonderful example

1:24:23chemistry is other on really intense

1:24:26relationships between craft traditions

1:24:30of instrument making of working with

1:24:33metal and fire of working with medicines

1:24:37drugs plants and

1:24:40scholarship highly sophisticated

1:24:42literary and mathematical

1:24:44analysis and the Islamic world is just

1:24:48such a

1:24:51place by around 800 ad the great cities

1:24:54of the Islamic empire dominated the

1:24:57World's

1:24:58Trade to its markets came silks spices

1:25:03drugs fruit perfumes and gold from as

1:25:07far a field as India and China in the

1:25:09East and Spain in the west anything that

1:25:12could be traded was

1:25:15[Music]

1:25:27a wonderful relic of this medieval trade

1:25:29boom are the great Caravan s like this

1:25:33one in the Syrian Capital

1:25:35Damascus this huge vaulted building was

1:25:38designed as a resting place for all the

1:25:40Traders and their animals who visited

1:25:43the

1:25:45[Music]

1:25:49city on their ground floors were wide

1:25:52spaces for animals and goods

1:25:55and above there were rooms for the rich

1:25:57Merchants to refresh themselves before

1:25:59another day of

1:26:01[Music]

1:26:03haggling one 10th Century traveler talks

1:26:07of the riches and beauties of the

1:26:09bazaars and that the income of the

1:26:11provinces and localities was between 700

1:26:14and 800 million din

1:26:25markets like this in the Egyptian

1:26:27Capital Cairo still capture the

1:26:29intensity of medieval

1:26:32trade and still surviving in the modern

1:26:34world of the internet and the mobile

1:26:36phone is a fantastic example of how

1:26:39Traders a thousand years ago

1:26:41communicated across a vast

1:26:47Empire so so this is a carrier pigeon it

1:26:50Bas is here so wherever you took this

1:26:52pigeon all over Egypt it will make its

1:26:54way back to this

1:26:59guy there's a famous story that a rich

1:27:03Cairo Merchant by the name of Anor

1:27:05wanted to grow cherry trees so he sent a

1:27:07message with a carrier pigeon took

1:27:09contact of his in Damascus asking for

1:27:11some seeds his contact sent back 500

1:27:15Birds each one carrying a small bag with

1:27:17seeds in it the whole process took just

1:27:19three days sort of a medieval FedEx

1:27:23really

1:27:24[Music]

1:27:25by 700 AD the Islamic empire was taking

1:27:29the first steps towards mass

1:27:35production and in this world where

1:27:38knowledge of materials metals and how

1:27:40they worked became increasingly

1:27:43important one practice

1:27:47flourished it's the practice that was

1:27:50inextricably linked with

1:27:52magic specific speically the dream to

1:27:55turn base Metals into

1:27:59gold the mysterious practice of

1:28:03alemy the Ancient Art of alchemy was a

1:28:06mystical system of belief based on

1:28:09spells symbols and Magic but I believe

1:28:11it took Islamic scholars to turn this

1:28:14quasi religion into something much more

1:28:17scientific

1:28:22chemistry increasingly the knowledge of

1:28:24the Alchemists found more and more

1:28:27practical

1:28:28applications for instance when during

1:28:31the last decade of the 7th Century the

1:28:34ruler of the Islamic empire Abdul mik

1:28:37made the Bold decision to create a

1:28:39common currency for all his dominions he

1:28:42turned to Alchemists for

1:28:45help the proportion of gold to other

1:28:49alloyed metals that you have to put into

1:28:51the din to make the din usable otherwise

1:28:54pure gold will become uh very soft and

1:28:56you can't use it so that proportion is

1:28:59adjusted by believe it or not in this

1:29:02period the Alchemists it is the

1:29:05Alchemists who knew how to combine

1:29:07Metals together and how to get the

1:29:09proportions of this gold to Silver and

1:29:11Gold to bronze and so on

1:29:28I hunted down tangible evidence of the

1:29:30skill of medieval Islamic Alchemists in

1:29:33the old markets in the Syrian Capital

1:29:36Damascus this is an Islamic din the date

1:29:39of this 128 after hij so the middle of

1:29:44the 8th Century 7 almost

1:29:487 this 1300 year old coin made of an

1:29:52alloy of different metals isn't just

1:29:54durable it's also malleable enough to be

1:29:57inscribed with intricate Arabic writing

1:30:00no God and of Allah and coin making is

1:30:05one of the many examples of how the

1:30:07Practical needs of a booming economy

1:30:10began to turn the magical practice of

1:30:12alchemy into modern

1:30:16chemistry what striking about chemistry

1:30:19in the medieval Islamic world is the

1:30:22sheer quantity of manuscripts that deal

1:30:24with the subject there are literally

1:30:26thousands that survive dealing with

1:30:28subjects as varied as metalogy glass

1:30:32making tile making dying perfumery

1:30:36Weaponry there's even a description on

1:30:38how to distill alcohol all this activity

1:30:41clearly points to a bustling economy

1:30:44with consumers soldiers Engineers

1:30:47Architects all demanding Innovation and

1:30:50all demanding new technology

1:30:55a great example of applied chemistry in

1:30:58the medieval Islamic world was the

1:31:00manufacturer of

1:31:02soap this stuff solid soap that you can

1:31:05really clean yourself with was virtually

1:31:07unknown in northern Europe until the

1:31:0913th century when it started being

1:31:11imported from Islamic Spain and North

1:31:14Africa by that time the manufacturer

1:31:16soap in the Islamic world had become

1:31:18virtually

1:31:19industrialized the town of Fez boasted

1:31:22some 27 different soap makers and cities

1:31:26like Nabis Damascus and of course Aleppo

1:31:29became world renowned for the quality of

1:31:31their

1:31:33soaps a 12th century document has the

1:31:36world's first detailed description of

1:31:39how to make soap it mentions a key

1:31:42ingredient and it's a substance that

1:31:44became crucial to Modern Chemistry an

1:31:48alkaline now alkaline substances are

1:31:50crucial to soap making but what's

1:31:53interesting is that our word Alkali

1:31:56derives from the Arabic alali which

1:31:59means ashes that's because back then

1:32:01alkalis were manufactured From the Ashes

1:32:04of the roots of certain plants like salt

1:32:10warts Islamic chemists new understanding

1:32:13of alkalis and other new chemicals gave

1:32:16another industry a lift to Glass making

1:32:27the Islamic chemists discovered that

1:32:29they could change the color of glass

1:32:31using newly discovered chemicals like

1:32:33manganese

1:32:36salts and they built industrial furnaces

1:32:39some several stories high to manufacture

1:32:42glass in huge

1:32:45quantities the legacy of their skills

1:32:48can still be seen in beautiful stained

1:32:50glass windows

1:32:56Islamic chemists also developed many

1:32:58other colors pigments and dyes using

1:33:01their new alkalizes and metals like lead

1:33:04and

1:33:05Tin these helped Architects to decorate

1:33:08mosques like this one in the Iranian

1:33:10city of Isfahan in a glorious range of

1:33:13colors and designs

1:33:25chemistry was also driven by the booming

1:33:28markets in

1:33:32perfumes in the main Market in Damascus

1:33:35Traders still make up your favorite

1:33:38scent as they would have a thousand

1:33:40years ago so it's basically has a base

1:33:42of alcohol and then he adds to it the uh

1:33:45the oils from the plants that you want

1:33:48Jasmine and and and Rose Water and mint

1:33:52but these days they'll they'll use um

1:33:55very

1:33:57nice yeah I think I'll buy some of

1:34:00that perfumers pushed chemists to come

1:34:03up with ever more ingenious techniques

1:34:06for extracting subtle and fragile

1:34:08fragrances from flowers and

1:34:13plants they responded by refining and

1:34:16really establishing a technique that all

1:34:19chemists would instantly recognize today

1:34:22distillation

1:34:24many of the techniques originate with

1:34:25Islamic scholars or even earlier Dr

1:34:28Andrea c a chemist from University

1:34:30College London shows me how distillation

1:34:33was used distillations would have been

1:34:35done in devices sort of related to these

1:34:39this is what's now called a retort and

1:34:42we don't really use them anymore but

1:34:44retort comes from from the word to bend

1:34:46in other words a flask which has been

1:34:48bent over and that's crucial well many

1:34:51of the Techni the shape means that a gas

1:34:53produced in the flask is forced to

1:34:55condense in the spout and it's the main

1:34:58way of extracting scents from flowers

1:35:00and plants now the idea here is that you

1:35:03heat at this end and you collect at the

1:35:06other and so we should actually take a

1:35:07look and see if we can do a quick

1:35:10distillation with rose petals first we

1:35:12need to just put in a little bit of

1:35:14water the water and steam will

1:35:16essentially control the temperature what

1:35:19we don't want is for this to get too hot

1:35:22um because the trick with this kind of

1:35:23distillation is to use heat to release

1:35:26the scent molecules but at the same time

1:35:29making sure that these delicate

1:35:31substances aren't destroyed in the

1:35:34process you actually use the steam to

1:35:37control the temperature and the steam

1:35:40will carry the those smells over you can

1:35:43see the liquid coming up condensing in

1:35:46the long tube and there is already

1:35:49liquid coming coming over and that

1:35:52should be carrying with with it some of

1:35:55the sort of rose water

1:35:59smell yes you can really spell

1:36:03it this picture shows a 14th century

1:36:06perfume Distillery Middle Eastern

1:36:09perfumes were known to have been sold as

1:36:11far away as India and

1:36:16China the Islamic chemists also played a

1:36:19pivotal role in another more gruesome

1:36:22industry

1:36:27Weaponry historical records during the

1:36:30Crusades talk in terrified tones of how

1:36:33the Muslims would attack the Christians

1:36:35with burning missiles and grenades

1:36:37striking fear into the hearts of the

1:36:39Defenders many of these use a substance

1:36:43known as Greek

1:36:45Fire Islamic chemists improved on Greek

1:36:49Fire by using and refining a naturally

1:36:52occurring resource

1:36:55petroleum they developed the idea of

1:36:58distilling petroleum or nft to create a

1:37:01lighter extremely flammable oil which

1:37:04they mixed with other volatile chemicals

1:37:06to make them burn

1:37:08furiously and the result was clearly

1:37:15terrifying what all these medieval

1:37:17Islamic texts on chemistry have in

1:37:19common is their great attention to

1:37:21detail which is clearly based on careful

1:37:25experimentation in fact the whole idea

1:37:27of a laboratory where chemical and

1:37:30Industrial processes can be tried out

1:37:32really takes hold at this

1:37:37time the Ingenuity of medieval Islamic

1:37:40chemists is

1:37:41impressive but I wanted to know

1:37:43something deeper what contribution did

1:37:46they make to our modern understanding of

1:37:48the principles behind

1:37:51chemistry this is the center piece of

1:37:53modern chemistry the periodic table it

1:37:57lists all the known elements its key

1:38:00idea is to group substances with similar

1:38:03properties together on the far right for

1:38:06instance are the inert gases on the far

1:38:09left are the volatile Metals the

1:38:12periodic table is a Triumph of

1:38:15classification giving scientists a way

1:38:17of organizing their knowledge of the

1:38:19material world classification is is

1:38:22simply a way to to think clearly I mean

1:38:25what you need when when you when you

1:38:27have some ideas about how the world

1:38:28works is that gives you a kind of schema

1:38:30and you chop the world up into

1:38:32categories and that actually helps you

1:38:34to understand to to to to make sense of

1:38:37what's around you people had been trying

1:38:40to classify the material world since

1:38:42ancient times the Greeks for instance

1:38:45thought there were just four worldly

1:38:47elements air Earth fire and water but

1:38:52this idea was was a philosophical one

1:38:54and had little practical

1:38:57value and that's what medieval Islamic

1:38:59chemists really changed they used

1:39:02experimental observations to classify

1:39:05the stuff the world is made of at the

1:39:08Forefront of this was a medieval Islamic

1:39:11doctor and chemist called iban Zakaria

1:39:14al- razi who was born here in the city

1:39:16of Ray just outside the Iranian Capital

1:39:18Teran in 865

1:39:22ad elzi's classification was very

1:39:25different from the Greek one he argued

1:39:28for instance that minerals roughly stuff

1:39:31we dig out of the ground should be

1:39:33classified into six groups depending on

1:39:36their observed chemical properties the

1:39:39same guiding principle that lies behind

1:39:42the modern periodic

1:39:44table now what I've done is I've brought

1:39:46materials from his classification scheme

1:39:49and we have here what we would what he

1:39:51called the spirits we have the alic

1:39:53bodies we have the stones then we have

1:39:56the atrament the salts and finally The

1:40:01Borax each of elzi's groups had a

1:40:04profoundly different experimental

1:40:07behavior for instance Spirits were

1:40:11flammable the metals were shiny and

1:40:14malleable salts dissolved in

1:40:18water of course these classifications

1:40:20are not the way we do it today but the

1:40:23point is that for the first time elrazi

1:40:26was grouping substances on the basis of

1:40:28experimental

1:40:30observations not philosophical

1:40:33musings we've come over a thousand years

1:40:36since the work of

1:40:38arazi what sort of debt does Modern

1:40:41Chemistry owe to him for his

1:40:44classification well I think with razi we

1:40:46start to see the the the first

1:40:48classification which really leads on to

1:40:51further experiments the first schema

1:40:53which allows people to start doing

1:40:55rational work and so really he lies at

1:40:58the start of of almost formal chemistry

1:41:01which ultimately leads to our periodic

1:41:06[Music]

1:41:09table I believe that what we see in the

1:41:12work of the Islamic chemists and

1:41:14Alchemists is the first tentative steps

1:41:17to a new

1:41:18science yes by our standards it

1:41:21contained a lot of magic and Mumbo jumbo

1:41:24but it placed an emphasis on

1:41:26experimentation that was truly

1:41:30revolutionary but bigger and better was

1:41:33to come because Islamic mathematics and

1:41:36the experimental techniques of Jabar and

1:41:39hayan and arazi were about to be welded

1:41:42together in a completely Innovative way

1:41:44that would revolutionize their work and

1:41:47create the modern scientific age

1:41:54until the 9th or 10th centuries ideas

1:41:57about science and how the natural world

1:41:59worked were dominated by the Greek

1:42:02philosopher Aristotle and they were very

1:42:04different from ours

1:42:06today he believed that mathematics was

1:42:09concerned only with an abstract world of

1:42:11perfect forms of idealized shapes like

1:42:15circles squares and triangles it had no

1:42:18power to explain what we observe in the

1:42:20world around us a world character ized

1:42:23by irregular wonky shapes and constant

1:42:28change physics is a Greek word meaning

1:42:33the science of

1:42:34change and for the classical Greek

1:42:38tradition there was a strong sense in

1:42:41which the science of change was in

1:42:44contradiction with

1:42:46mathematics mathematics dealt with

1:42:50perfect knowledge with the unch changing

1:42:53world of mathematical

1:42:55forms and it seemed in principle

1:42:58extremely unlikely that processes of

1:43:01coming into being and passing away of

1:43:04growth and of decay of qualitative

1:43:08change could be captured with the

1:43:13beauties of geometry and

1:43:19Mathematics the story of how Humanity

1:43:22shook off this idea and began to see

1:43:25that mathematics is actually an

1:43:26incredibly powerful way of describing

1:43:29the world around us is long and

1:43:34complicated but for me Islamic

1:43:36scientists played a crucial role and I

1:43:39believe one man really LED this movement

1:43:42to turn mathematics from a language of

1:43:45abstract thought into a truly practical

1:43:49science he was like me from Iraq and his

1:43:52name name

1:43:54wasam what alham and his contemporaries

1:43:58argued for was the possibility in a way

1:44:01of a single

1:44:03science which would be both mathematical

1:44:07and philosophical which would link

1:44:10together a physics a science of change

1:44:13with a mathematics a science of quantity

1:44:17and that seems to me to be radical and

1:44:20crucial for the construction of new

1:44:22forms of Rel reliable

1:44:24knowledge iel haam was born in 965 ad in

1:44:28the southern Iraqi town of Basra and

1:44:31other Scholars regarded him as a prodigy

1:44:34he shot to Scientific Fame just after

1:44:36the turn of the first Millennium and was

1:44:38an incredibly Innovative and Brilliant

1:44:41scholar his reputation as an intellect

1:44:43spread throughout the Empire but it was

1:44:46this reputation that would almost cause

1:44:48him to lose everything when he took up

1:44:50the poison Chalice of trying to tame one

1:44:53of the world's greatest

1:45:04Rivers there's a wonderful if

1:45:06suspiciously apocryphal story about how

1:45:09iel Ham's career as a scientist was

1:45:13transformed it concerns the Nile and how

1:45:16just after the turn of the Millennium

1:45:18nnel haam was asked by the ruler of

1:45:21Egypt to find a way of controlling it

1:45:24could he prevent its unpredictable and

1:45:26potentially devastating floods and

1:45:30droughts but it didn't take imel haam

1:45:32long to realize that the Nile was way

1:45:35too large to

1:45:37control on hearing this the califf flew

1:45:40into a terrible rage and ordered iel

1:45:43Ham's

1:45:45execution iel haam responded by feigning

1:45:49Madness the execution was called off and

1:45:52he was placed under under house

1:45:54arrest there with time on his hands to

1:45:57contemplate The Story Goes iel haam

1:46:00considered deep and fundamental

1:46:02questions in

1:46:04physics and he began with a truly

1:46:07enigmatic and Universal problem he asked

1:46:10if the wonderful and entirely mysterious

1:46:13nature of light and vision could be

1:46:15explained by mathematics and

1:46:19geometry under house arrest or perhaps

1:46:22here in the rooms of Al ashar University

1:46:25in Cairo IAM carried out a series of

1:46:28experiments that created the modern

1:46:31science of

1:46:34Optics I'm with Dr Al bizri who has

1:46:37carefully studied imam's work he

1:46:40explained that I haam first considered

1:46:43the Aristotelian explanation for how we

1:46:45see an explanation that was completely

1:46:52could say a tree its essence or form

1:46:56emanates from it and then mysteriously

1:46:59flows into our eyes so if I'm uh for

1:47:03instance now looking at the buildings

1:47:06and the trees on the banks of the Nile

1:47:09uh I'm receiving the forms of these

1:47:12buildings and these trees uh in the eye

1:47:17abstracted from their

1:47:19matter according to Dr albis

1:47:23found this idea deeply

1:47:25unsatisfactory he wanted a mathematical

1:47:30explanation and looking back at existing

1:47:32Greek writings he found one although it

1:47:35was obscure and

1:47:38bizarre this idea claimed that we see

1:47:42because light rays come out of the eye

1:47:46ultimately it says that Vision occurs by

1:47:48way of the emission uh from the eye of

1:47:52light that is shaped in the form of a

1:47:54pyramid or a

1:47:56core this cone shaped beam illuminates

1:47:59what we're looking at and is defined by

1:48:02nice geometric straight

1:48:06lines it seems haam liked this

1:48:09mathematical approach but immediately

1:48:11spotted its

1:48:12flaws if we see he asked because light

1:48:16comes out of the eye why does it hurt

1:48:19when you look at a bright object like

1:48:20the Sun but not hurt when you look at

1:48:23something

1:48:24dim or at night can light from our eyes

1:48:28really be lighting up distant objects in

1:48:31the

1:48:32sky so in an inspired piece of thinking

1:48:36IAM combined the two Greek ideas and

1:48:40defined our modern understanding of

1:48:43light and vision light he said does

1:48:46travel in straight lines that obey

1:48:48geometric laws but instead of them

1:48:50coming out of the eye these

1:48:53travel into

1:48:54it it is the development of an entirely

1:48:57new Theory and also

1:49:00methodologically it is the beginnings of

1:49:02mathematizing

1:49:06physics whatam did was take the

1:49:09principles of geometry with its rules

1:49:11governing straight lines and apply them

1:49:14to the real world he then designed

1:49:17experiments which would test whether the

1:49:19real world measured up to his

1:49:20mathematics

1:49:23in about 1020 iel haam published his

1:49:27groundbreaking geometric explanation of

1:49:29light in hisab manad or book of

1:49:34Optics and what really marks this book

1:49:36out as science is that iel haam

1:49:39carefully justifies his theories with

1:49:42detailed experiments that others can

1:49:44repeat and

1:49:45verify he starts from first principles

1:49:49to find out how light travels

1:49:57for his first experiment iel haam wanted

1:50:00to test the idea that light travels in

1:50:03straight lines now to do this he took a

1:50:06straight tube on which he drawn a

1:50:09straight line down the side and a ruler

1:50:12again with a straight line down the

1:50:14length of it and by matching the two

1:50:16together he was convinced then that the

1:50:18tube was straight now if he uses it to

1:50:21look at an object in this case a candle

1:50:24he can see the candle through the tube

1:50:27which is good evidence that the light is

1:50:28traveling up in a straight line but just

1:50:31to be sure he then blocked the end of

1:50:34the

1:50:35tube and then by looking at the candle

1:50:38again of course he can't see it because

1:50:40what this does is confirm that the light

1:50:43doesn't travel to his eye via any other

1:50:45route in a curved path outside the tube

1:50:48proof that light only travels in a

1:50:50straight line now this might sound quite

1:50:53trivial and obvious to us but IAM was

1:50:56starting from first

1:50:59principles then through experiment he

1:51:02extends his light travels in straight

1:51:04lines idea to many other phenomena he

1:51:07explains how mirrors work by arguing

1:51:10that the angle the ray comes in at is

1:51:13the same as the angle it bounces off at

1:51:16he explains what we now call refraction

1:51:19why objects look kinked in a glass of

1:51:21water are arguing that light rays Bend

1:51:24when they move from one medium to

1:51:27another and then he tackles the nature

1:51:30of vision IAM wanted to understand how

1:51:34an object makes an image on the retina

1:51:36of the eye so he built what he believed

1:51:40was a stripped down version of the eye

1:51:42which is basically a black box with a

1:51:44tiny hole in it this is what we call

1:51:46today the camera

1:51:48obscurer he next took his subject in

1:51:51this case Anna is very brightly lit and

1:51:54we now go inside the box to see what the

1:51:56image looks

1:52:00like now that I'm inside the camera

1:52:02obscurer and I've allowed my eyes to get

1:52:04used to the dark we can open the

1:52:07hole and there we clearly see the image

1:52:10of Anna waving on the screen but the

1:52:13image is inverted because light travels

1:52:15in straight lines and so the light from

1:52:17her head has to move diagonally

1:52:19downwards to hit the bottom of the

1:52:21screen and light from from her feet

1:52:23travels diagonally upwards to hit the

1:52:25top but more importantly what this

1:52:28proved to inel hm is that there's a

1:52:30onetoone correspondence between every

1:52:33point on the object on Anna and every

1:52:35point on her image on the

1:52:38screen just like a modern scientific

1:52:41paper the attention to detail in theab

1:52:44manad is

1:52:46incredible his book isn't just a dry

1:52:49scientific Treatise it's a manual for f

1:52:52future

1:52:53Generations in his work he constantly

1:52:56justifies his theories about light with

1:52:58experimental observation and he

1:53:01describes his experiments in great

1:53:03detail so that other people can repeat

1:53:05them and confirm his ideas his messages

1:53:08don't take my word for it see for

1:53:11yourself I believe that I haam was one

1:53:13of the very first people to ever work

1:53:16like this this for me is the moment that

1:53:19science itself is summoned into

1:53:21existence and becomes a discipline in

1:53:24its own

1:53:33right what I find so impressive about

1:53:36iel haam is how once he arrives at his

1:53:39mathematical theories he then uses them

1:53:42to extend our knowledge of the real

1:53:45world so for instance he used his new

1:53:48ideas about light to deduce that the

1:53:50Earth's atmosphere is of a finite

1:53:54thickness and he even estimated what

1:53:56that thickness

1:53:58is he did it basically by measuring how

1:54:01long Twilight

1:54:03lasts he rightly assumed that the reason

1:54:06it continues to be light after the sun

1:54:09has dropped below the Horizon must be

1:54:12because its Rays Bend as they enter the

1:54:14Earth's

1:54:16atmosphere the length of Twilight and an

1:54:19educated guess for what we today call

1:54:21the Air's refractive index gave iel haam

1:54:25a way of estimating the thickness of the

1:54:27Earth's

1:54:28atmosphere he came up with a figure of

1:54:31around 40 kilm about half of the modern

1:54:34value that's pretty impressive it really

1:54:38shows how mathematics extends the power

1:54:41of science to

1:54:49explain on my journey so far I've been

1:54:52overwhelmed by the sheer intellectual

1:54:55ambition of medieval Islamic

1:54:58scientists when their leaders asked them

1:55:00to find out the size of the World

1:55:02Scholars like ALB roon used mathematics

1:55:05in startling new ways to reach out and

1:55:08describe the

1:55:13universe and as trade and commerce

1:55:15boomed scientists like Al Razzi

1:55:18responded by developing a new kind of

1:55:20experimental science

1:55:25chemistry but if there's one Islamic

1:55:27scientist we should remember above all

1:55:29others it is in my view IAM for doing so

1:55:34much to create what we now call the

1:55:37scientific

1:55:41method the scientific method is I

1:55:44believe the single most important idea

1:55:47the human race has ever come up with

1:55:50there is no other strategy that tells us

1:55:53how to find out how the universe works

1:55:55and what our place in it is of course

1:55:58it's also delivered technologies that

1:55:59have transformed our lives so the next

1:56:01time you jet off on holiday or use a

1:56:03mobile phone or get vaccinated against a

1:56:06deadly disease remember I haam IB Cena

1:56:10El Boni and countless other Islamic

1:56:13scholars a thousand years ago who

1:56:15struggled to make sense of the universe

1:56:18using crude mirrors and astrolabes they

1:56:21didn't get all the right answers but

1:56:23they did teach us how to ask the right

1:56:29[Music]

1:56:38[Music]

1:56:39questions in the next episode I travel

1:56:41to Syria and Northern Iran to find out

1:56:44about the great Islamic scientists who

1:56:46revolutionized astronomy making it a

1:56:49truly modern science

1:56:53and I'll also discover how the man many

1:56:55consider to be the father of the

1:56:57European scientific Renaissance cernus

1:57:00borrowed from Islamic astronomical

1:57:03theories and I'll unravel the mystery of

1:57:07how the Golden Age of Islamic science

1:57:09came to an

1:57:11[Music]

1:57:13end and there's more from science and

1:57:16Islam next week next night plunging

1:57:19right into the thick of it with more

1:57:21biting comedy

1:57:23[Music]

1:57:23[Applause]

1:57:25[Music]

1:57:46the Sun the moon the planets and stars

1:57:49have always fired our imaginations and

1:57:52fueled our mythologies and studying the

1:57:55heavens astronomy is surely the oldest

1:57:59scientific discipline there

1:58:03is what's really unexpected I guess is

1:58:06that astronomy has repaid our interest

1:58:09in it over the centuries time after time

1:58:12it's been the place where new ideas have

1:58:14emerged and it's often led the rest of

1:58:17the Sciences

1:58:22I'm a professor of physics at the

1:58:24University of su and the ideas and

1:58:27theories of the great European

1:58:29scientists like Galileo muttin and

1:58:32Einstein lie at the heart of my

1:58:35work but there's another side to me I'm

1:58:38half Iraqi and I'm Keen to investigate

1:58:41stories I'd heard as a school boy in

1:58:43Baghdad of great astronomers from the

1:58:46medieval Islamic World whose work shapes

1:58:49the discoveries of these later Western

1:58:51SCI

1:58:54scientists so I'm going on a journey

1:58:56through Syria and Egypt to the remote

1:58:59mountains in Northern Iran to discover

1:59:02how the work of these Islamic

1:59:04astronomers had dramatic and

1:59:06far-reaching

1:59:08consequences there I'll discover how

1:59:10they were the first to attack seemingly

1:59:13unshakable Greek ideas about how the

1:59:16heavenly bodies move around the

1:59:19earth it was Islam that paved the way

1:59:23for one of the greatest upheavals in the

1:59:25history of science

1:59:28[Music]

1:59:49[Music]

1:59:55this is the University of Padua in

1:59:57Northern

2:00:00Italy I'm here to see incontrovertible

2:00:03evidence that one of the greatest

2:00:05breakthroughs in European science links

2:00:08back to the earlier work by Islamic

2:00:11scholars because it was a news one that

2:00:15that time astronomer Dr Louisa piotti

2:00:18and I are climbing up to the 18th

2:00:21century observ

2:00:24at the top she promises to show me one

2:00:26of the most important books in

2:00:28scientific

2:00:31history so what do we have

2:00:33here okay this is the second edition

2:00:39of

2:00:41ricus yes this is the revolutionibus

2:00:45orium celestium which was published in

2:00:481543 by the Polish astronomer Nicholas

2:00:52cernus I'll be

2:00:54careful the significance of this book is

2:00:56enormous in it cernus argues for the

2:00:59first time since Greek Antiquity that

2:01:02all the planets including the Earth go

2:01:04around the

2:01:09Sun for thousands of years everyone had

2:01:12believed a very different view that the

2:01:14Earth is static and everything including

2:01:17the Stars sun and planets move around it

2:01:22and here the all his system okay oh here

2:01:28we go system the sun in the middle it's

2:01:31a famous drawing this

2:01:34one oh yes and there's yes there's

2:01:37teror with the moon going around it okay

2:01:40yes this is an astonishing book and many

2:01:43historians credit it with starting the

2:01:45European Scientific

2:01:49Revolution the first crucial step in a

2:01:52journey that led to Modern

2:01:56physics well I agree but it does seem a

2:01:59bit odd that one doesn't hear much about

2:02:01where cernus got his ideas and

2:02:04information the impression is that they

2:02:06came out of

2:02:09nowhere the beginning the beginning is

2:02:12all in in

2:02:13Arabic it certainly is a real Revelation

2:02:16to me that he explicitly mentions a 9th

2:02:19century Muslim for providing him with a

2:02:21great deal of observational data an

2:02:24astronomer who lived in Damascus called

2:02:29elbani like all the great scientists of

2:02:31the Islamic empire elbani lived in a

2:02:34culture without portraiture all we have

2:02:37are later impressions of what he might

2:02:39have looked

2:02:41like and here he

2:02:44mention parus calipo me and so on and he

2:02:49started to mention what he call

2:02:53MAK means Alat okay and then this second

2:02:58book here the second book is oh we can

2:03:01look at the beginning in Latin I see we

2:03:04can open cernus in fact made extensive

2:03:07use of elani's observations of the

2:03:09positions of planets the Sun the moon

2:03:11and stars he worked with Latin

2:03:14translations similar to this one of the

2:03:16Syrian astronomer's data

2:03:22so this is Ban's Z is his his book of

2:03:26Star

2:03:27Charts so it has the Arabic yes all the

2:03:31Arabic PR yes and then the Latin version

2:03:35that's convenient ah but he certainly he

2:03:38had the data the observational data by

2:03:42Al batani and you know he and

2:03:45copernicus's book is full of clues that

2:03:47hints at other past sources

2:03:52and though alberani is the only Islamic

2:03:54astronomer cernus actually names recent

2:03:58detective work has uncovered clues that

2:04:00cernus based many of his ideas on the

2:04:03work of other Islamic

2:04:06scholars the clearest example is cernus

2:04:09is use of a mathematical idea devised by

2:04:12the 13th century Islamic astronomer El

2:04:15tusi called the tusi couple

2:04:22back in England I compared a copy of

2:04:27Al's with another edition of Cernic's

2:04:30revolutionary

2:04:32bus in it there's a diagram of the tusi

2:04:35couple and there's an almost identical

2:04:38diagram in Cernic's book even down to

2:04:42the letters that Mark the points on the

2:04:44circles so in elzi there's the Arabic Al

2:04:47if which is a there's the ba which is B

2:04:51G over here is the G and the Dal at the

2:04:55center D it's a remarkable

2:04:59similarity now this might just be

2:05:01coincidence but it's pretty compelling

2:05:04evidence in fact I truly believe that

2:05:07cernus must have been aware of alu's

2:05:10work and other Islamic

2:05:15[Music]

2:05:16astronomers further detective work also

2:05:19shows that cernus used mathema iCal

2:05:22ideas for planetary motion that are

2:05:24remarkably similar to ones developed by

2:05:27another Islamic astronomer a 14th

2:05:30century Syrian called

2:05:32IAT for some historians this cannot be

2:05:36coincidence Copernicus to me I have no

2:05:39proof I don't have a Smoking Gun but to

2:05:42me it looked like and again by analyzing

2:05:45his own works it looks like he was

2:05:48working from diagrams somebody gave him

2:05:51a a geometric diagram of what was done

2:05:54by I shat to solve the problem of the

2:05:56moon for example to solve the problem of

2:05:58the upper planets to solve the problem

2:06:00of the movement of mercury he had

2:06:02diagrams and he was genius enough to be

2:06:05able to figure out from the diagrams

2:06:08what was the underlying theory behind

2:06:10those

2:06:14diagrams so far from emerging from

2:06:17nowhere it seems cernus is work will be

2:06:20better described as the culmination of

2:06:22the preceding 500 years of Islamic

2:06:26astronomy I wanted to investigate this

2:06:28story find out more about those

2:06:31astronomers and their

2:06:33ideas but before that I wanted to

2:06:36investigate an even deeper

2:06:39question what actually motivated

2:06:41medieval Islamic scholars interest in

2:06:43astronomy

2:06:45[Music]

2:06:54[Music]

2:06:59this is the umed mosque in the heart of

2:07:01the Syrian Capital Damascus and is one

2:07:04of the oldest in the

2:07:07[Music]

2:07:09world and I'm here on a kind of treasure

2:07:13hunt well it it says in the books that

2:07:16there is a sun dial on the top of the

2:07:18arus minate the bride minate over there

2:07:21so we'll see whether it is there or not

2:07:24so this is Dr re turkmani an

2:07:27astrophysicist and medieval astronomy

2:07:30expert from Imperial College London and

2:07:33we're looking for one of the most

2:07:34accurate Sund dials made in the medieval

2:07:37world and equally exciting for me is the

2:07:40fact that it was made by one of the

2:07:42Islamic astronomers who had so heavily

2:07:44influenced cernus I

2:07:48Shad let's see

2:07:54officials in the mosque claim that the

2:07:56Sundial was removed in the 19th century

2:07:59but Ream's research suggests that an

2:08:01exact replica might still exist high in

2:08:05one of the minettes Hidden from

2:08:07view it's not quite the Lost Arc of the

2:08:10Covenant but the idea of discovering a

2:08:12150y old artifact is still quite

2:08:16something would would you recognize

2:08:18anything if you had I need to look that

2:08:20off the other window

2:08:23sorry no no it it is further up

2:08:28yeah marking time accurately is

2:08:31essential to

2:08:34Islam the Quran requires the faithful to

2:08:37pray five times a day at five very

2:08:40precise

2:08:44times at the exact moment of Dawn when

2:08:48the sun is overhead in the afternoon

2:08:51moon at Sunset and then again at the

2:08:55moment of

2:08:56Nightfall so for early Islam an accurate

2:08:59Sundi was an extremely important fixture

2:09:02in many

2:09:08mosques that's it that's it I found it I

2:09:12found

2:09:14it here is that's it look just as descri

2:09:18in the it's hidden by the hill yeah no

2:09:21wonder they didn't know that it exists

2:09:23here it's all covered with the pigeons F

2:09:27pigeon crap yeah oh oh great thank you

2:09:31try that so let's

2:09:36see now this consist of three candiles

2:09:40you know the main big one and there's

2:09:43the northern one and the southern one

2:09:45there is a line here for Salat the the

2:09:49midday prayer and there is one for the

2:09:50afternoon

2:09:52prer innat had calculated the

2:09:55arrangement of these lines so that the

2:09:57Su dial remains accurate all through the

2:10:00year even though the length of the days

2:10:03change they will have the eke keeper you

2:10:06know it's a very important job so he

2:10:08would sit here watching the shadow

2:10:11exactly and exactly the precise moment

2:10:13for prayer he'd signal to them then to

2:10:16start to the call for prayer exactly

2:10:18okay

2:10:19[Music]

2:10:32accurate to within minutes really showed

2:10:35me how Islam required its Scholars to

2:10:38make meticulously accurate observations

2:10:40of heavenly bodies

2:10:51and I began to understand why kernus was

2:10:54so impressed by the work of his Islamic

2:10:59predecessors they really brought

2:11:01standards of accuracy and precision to

2:11:03astronomy that were unheard of

2:11:06before they' calculated the size of the

2:11:08Earth to within

2:11:101% and created trigonometric tables

2:11:14accurate to three decimal

2:11:18places and when I met up with re

2:11:21turkmani again on Mount kasun outside

2:11:24Damascus I was to hear about the Islamic

2:11:27astronomer who personified accurate

2:11:30observation the man whose astronomical

2:11:32tables and measurements cernus

2:11:34explicitly makes reference

2:11:37to

2:11:38alberani born in 858 in southern turkey

2:11:42alberani made accurate astronomical

2:11:45measurements a personal

2:11:47Obsession and the story goes is that

2:11:50alatan used to observe on this mountain

2:11:53here in that in this

2:11:55Observatory over 40 years from

2:11:59877 both here and in the town of raka

2:12:02Alban's great project was to work out as

2:12:05accurately as possible the length of the

2:12:08Year this is a copy of the original

2:12:11manuscript okay so I'll show you the