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00:01From the deserts of the East, a thousand years ago, arose a mighty empire.
00:06Within a hundred years, it had become a medieval superpower.
00:10Its unifying language was Arabic, and its religion, Islam, lay at the heart of its power.
00:17Much of the knowledge and many of the inventions produced by the Islamic world are still with us.
00:22For example, what has this piece of ancient technology got to do with this? My bicycle!
00:28Master carpenter Marty Jopson and I will recreate and test some of the early Islamic world's most amazing inventions.
00:41Roving reporter Amani Zain is going to travel to where it all took place.
00:46She'll be exploring the stories behind the golden age of Islamic discovery.
01:14At its height in the 10th century, the Islamic empire was so vast that it stretched from Spain all the
01:22way east to what is now Pakistan.
01:25The ideas and the inventions of the Muslim world have had an enormous and lasting effect on the world we
01:32live in today.
01:38Islam was born in the searing heat of the Arabian desert.
01:42Most of it is a vast featureless ocean of sand, scrub and rock.
01:47The early peoples of Arabia were nomads who travelled the sands on camels.
01:51With little or no landmarks, it was vital to know where you were going.
01:55It was too hot to travel during the day, so journeys were undertaken in the cool of the night.
02:11In the cool of the night, the only things to see were the stars.
02:14And as they remained constant, it was a short step to learn to navigate by them.
02:23Astronomy was virtually abandoned in the Europe of the Middle Ages.
02:27But in the Islamic empire, the science flourished.
02:30Across the Islamic world, from the deserts of Arabia to here, al-Hamra in Spain,
02:35these early astronomers probably worked from minarets in mosques just like this one.
02:41Their understanding derived from the direct observation of the stars.
02:46So they began to understand exactly where the Earth sat within the universe.
02:52One of the greatest of these men was al-Sufi, who in the 10th century named all the visible stars.
02:58The Arabic names, like Aldebran, Altair and Algol, are still in use today.
03:06But probably the greatest feat of Islamic astronomy was achieved by Al-Khujjandi.
03:12He was able to complete the most staggering of calculations,
03:15which helped close the book on an age-old question.
03:19The seasons changed because the Earth's axis is tilted.
03:23But by what amount had been one of the great astronomical questions of the day?
03:29We get seasons because the Earth is tilted in space.
03:33Here we are in space, here's the Earth, the big red ball is the Sun,
03:37and this is what's called the plane of the ecliptic.
03:40Now suppose the equator was in the plane of the ecliptic like that,
03:44then we would have no seasons.
03:46But it isn't, the point is the Earth is tilted like that.
03:49Here we're tilted away from the Sun.
03:52If we were like that, the Sun's rays would be coming much more directly than they actually do in winter.
03:57Anyway, here we are going through the seasons now.
04:00We're getting to sort of February, March, April, May, and then finally June.
04:07And we've now got to midsummer, and we've still got the same tilt, but now we're tilted towards the Sun.
04:13So the Sun's rays are now coming much more directly, longer days, hotter Sun, that summer.
04:19The first chap who realised that the Earth is tilted was Eratosthenes,
04:23the brilliant Greek mathematician who lived in Alexandria and worked out the circumference of the Earth more than 2,000
04:29years ago.
04:31But he didn't know what angle we were tilted at, and astronomers worked on that for ages.
04:36It turns out that what you have to do is to measure the highest elevation of the Sun in midsummer,
04:41and then the lowest in midwinter, take the angle between the two and divide it by 2,
04:45and that gives you this angle of tilt, and it's about 23 degrees.
04:49But more than a thousand years ago, a Muslim mathematician and astronomer called Al-Qujandi worked this angle out with
04:58incredible precision.
05:01Advances in understanding the movements of the heavens enabled men like Al-Qujandi to create the most accurate calendars and
05:08almanacs of the age.
05:09These were vital for the precise timing of religious rites.
05:16The prophet of Islam is Muhammad, and the religious spiritual home is Mecca in Saudi Arabia.
05:23But its heart is the Kaaba, or black stone, in the centre of the mosque.
05:30Islam means to surrender, surrender oneself to God.
05:34It marked the beginning of a new religion, a new civilisation, and a new empire.
05:42Then, just as now, the ma'azzin calls the faithful to prayer.
05:46There are prayers five times a day, at dawn, midday, afternoon, sunset and evening.
05:56Islamic prayer times are astronomically determined, and change from day to day.
06:01It's vital to know exactly when they are, so the Arabs developed an extraordinarily accurate machine.
06:06In the early days, the Arabs got their prayer times from, well, probably sundials or maybe water clocks.
06:13But then along came the high-tech astrolabe.
06:16And this is it. Well, this is one. There were many, many of them.
06:19Very beautiful brass things with dials on both sides.
06:22And they work by stereographic projection.
06:25That's bringing the heavens down onto the brass plate.
06:28And I don't understand how it works, and fortunately, Emily Winterburn does.
06:32She's curator of astronomical instruments at the National Maritime Museum.
06:36Tell me about the astrolabe.
06:38Well, it's name comes from Arabic to mean star taker.
06:41Right, so it literally takes the stars down.
06:43Exactly, yeah.
06:44This bit is basically the stars flat.
06:48Right.
06:48So what are all these little pointy bits sticking off?
06:51Each one is a bright star that you should be able to see easily with the naked eye.
06:57Okay.
06:57So you've got Aldebrun.
06:58Oh, right.
07:00And Altair.
07:01Yeah, exactly.
07:01And so it's the very point, the point of them.
07:03Exactly, the very, very tip.
07:04That's where the star is in relation to the other stars.
07:07Okay.
07:08And then this bit here is where the sun is over a year.
07:13Okay, so suppose we want to tell the time, what do we do first?
07:17Okay, first of all, you find, so if you're doing it in the day, you find the height of the
07:21sun.
07:21Well, we don't have any sun with typical, you know, cloud, but let us imagine that the sun is just
07:26coming through that window over there.
07:28Okay.
07:28What do we do?
07:29You would hold it up by the ring.
07:31Okay, like this.
07:32Yeah.
07:32Right.
07:33Okay, and because it's the sun, you wouldn't look through it.
07:35You would get the sun to shine through.
07:37Through the holes.
07:38Exactly.
07:39Okay, so I'm imagining, I'm not knocking at the sun, I promise you, and you hang it from your fingers
07:43so gravity is keeping it vertical, yes?
07:45Exactly, yeah.
07:46Okay, so that's nicely lined up now.
07:48Okay.
07:48There you are.
07:48I hand it over to your tender markers.
07:50Okay, so from that, you can read the degree scale.
07:55So that tells you the height above the horizon that the sun is.
07:59Once the height of the sun relative to the horizon has been set against the day of the month, the
08:05exact time can be read off from the hour markings around the edge.
08:08In our case, it's 8am.
08:12Can you use this to predict things?
08:14Yeah, you can work out when the sun is going to rise and set, so important for Ramadan, knowing when
08:19you can eat.
08:20Fantastic.
08:21You can also work out when stars are going to rise and set.
08:24I'm very impressed.
08:25The astrolabe had many other uses, navigating across sand or oceans and measuring the height of buildings.
08:31It was even used to determine the alignment of planets for horoscopes.
08:35And for Muslims travelling away from home, it was vital.
08:39From the angles of the sun and the stars, they could work out the direction of Mecca and therefore which
08:45way to pray.
08:47With the development of instruments like the astrolabe came enormous leaps in all forms of scientific knowledge.
08:55At the heart of these new ideas was the principle of direct observation.
09:00In order to understand something fully, you needed to see it with your own eyes.
09:05One man, Al-Haytham, revolutionised the way we see the world by doing experiments in complete darkness.
09:15Al-Haytham's story starts more than a thousand years ago on the banks of the river Nile in Egypt.
09:20A renowned Iraqi scientist, he had been asked by the caliph to regulate the flow of the water.
09:27He quickly realised that if the ancient Egyptians weren't able to do it, he wouldn't either.
09:43Sure enough, his calculations were wrong.
09:46Terrified of what had happened to him, Al-Haytham pretended to be mad so that Al-Hakim, nicknamed the Mad
09:51Caliph, wouldn't execute him.
09:53Instead, he was put under house arrest.
10:10It wasn't all bad. In fact, it suited Al-Haytham, because it meant that he could devote more time to
10:16his experiments.
10:17And when he did start his experiments, it merely confirmed what everyone thought, that he was indeed mad.
10:25Legend has it that he stayed up all night making holes in the walls, and spent his days staring at
10:30shafts of light.
10:38But Al-Haytham's main interest lay in optical science.
10:41And his experiments under house arrest led him to an extraordinary discovery.
10:46He was the first one to work out how we actually see.
10:51Before about the 10th century, people thought that if you wanted to see something, you'd open your eyes and send
10:56out a sort of beam, a beam of light, a bit like radar, and it would bounce back and that
11:01would give you an image of the object.
11:03But Al-Haytham realised that that was complete nonsense, that the light's there anyway, it comes from the sun, it
11:07doesn't matter if you've got your eyes shut, it's still there.
11:09What happens is that when you open your eyes, light streams in, it's like pulling out the plug in the
11:14bath and all the water streaming down the hole.
11:16The light streams in and you see the trees and everything around you.
11:20He was one of the first people to do experiments to test his theories, and so he started off the
11:26scientific method.
11:27Now, Marty is across there. Marty, can you hear me?
11:30Yes, Adam. Woo!
11:31Good. Al-Haytham actually took round with him a sort of portable laboratory, a bit like this garden shed really,
11:36although he probably used a tent.
11:38It was called a camera obscura. The Arab word camera means a private room, and the Latin camera obscura means
11:45dark room.
11:45And if you look inside, it's completely dark, but there's magic in the air.
11:53Now, here we are inside the camera obscura. It's very dark in here, but we've got a hole in the
11:58wall.
11:58It should be a pinhole, but we've made a bigger hole to let more light in and put a lens
12:02in it.
12:03And over there is the castle, and over here, there's a screen. And if you see, there's an image of
12:08the castle.
12:09Look, here's the moat, and here's the castle, and here's the battlements, and you will have noticed by now that
12:14it's upside down.
12:15The battlements should be at the top, and they're at the bottom, and the moat should be at the bottom,
12:19and it's at the top.
12:20And that in itself is proof that light travels in straight lines.
12:23Because it means that light from the bottom, from the moat, has come through the hole, and gone up to
12:27the top of the screen.
12:29And light from the battlements at the top has come through the hole, and down to the bottom of the
12:33screen.
12:33Very, very neat.
12:35And then, we've set up three lamps. You see, there are two lamps here together, and one somewhere away.
12:40And if I ask Marty if he can switch that one off.
12:42Marty, can you turn the lamp off?
12:46There, it's gone off.
12:47And on again.
12:50There, you see.
12:51Now that is proof that the light is coming from that lamp.
12:55It's not from somewhere else, it's not from inside the shed.
12:57It's coming from that lamp, through the hole, and onto the screen.
13:00Now for us, that's obvious, because we're used to things being projected.
13:03But in those days, they weren't.
13:05They hadn't seen anything projected.
13:07This must have been absolutely amazing, to see a real image of the outside world.
13:13Let me show you it the right way up.
13:15Look, if I put my hands over it like this, and just turn the camera around.
13:18Right, that should be about right.
13:20Now, with luck, you'll see me upside down, and the image the right way up.
13:25And you can see people here walking across to look at the castle.
13:29And there's quite a lot of evidence that some of the Renaissance painters, like Canaletto, Reynolds, Vermeer,
13:35actually used the camera obscura to make sure they could get really accurate reproductions
13:40of complicated things in the world.
13:42Because then you can trace things in incredible detail.
13:45So there we are, light travelling in straight lines, courtesy of Al-Haytham.
13:50Meanwhile, in 10th century Egypt, other important advances were being made.
13:55Water was precious.
13:57And getting it to where it was needed was one of the foremost technical challenges of the day.
14:02According to the Greek writer Herodotus, Egypt is the gift of the Nile.
14:06But to irrigate their crops, they had to come up with effective ways of transferring their water from one level
14:12to the next.
14:13This is one of the earliest water lifting devices, the Shaduth, and it's still used in Egypt today.
14:26As you can see, ingenious for the Shaduth is, it's really hard work.
14:31So engineers needed to come up with more efficient ways of lifting water.
14:37One of the cleverest was Al-Jazari from Turkey.
14:40He was fascinated with the innovation and development of mechanical devices.
14:44A great engineer and skilled draftsman, he came up with an ingenious device for lifting huge amounts of water without
14:52lifting a finger.
14:54It's called, snappily enough, the crank connecting rod system.
14:58But how did it actually work?
15:01The crank connecting rod system was Al-Jazari's most important contribution to technology.
15:07And I've got one here.
15:08This wonderful machine is a pump.
15:11I'm going to pour water out of the moat through that flexible black hose, pump it through this machine,
15:17and make a magnificent fountain right up into the castle.
15:20Well, in that direction anyway.
15:22This is how it works.
15:23I'm going to wind this handle, and this will turn that gear at the back.
15:28These are exactly the sort of gears that Al-Jazari used.
15:31Alright, you can see that going round.
15:32And that one turns round this gear at the bottom.
15:35And as that goes round, you can see that there's a big chunky black pin here.
15:42It slides up and down in this black box.
15:45And it pushes this black box backwards and forwards like that.
15:49And that pushes these connecting rods here.
15:53Backwards and forwards across the circle.
15:59Okay, what that does is this.
16:01It pushes a plunger along inside this pipe.
16:04I don't think Al-Jazari had plastic sewerage pipe, but he had something like that.
16:08And it pushes water up here through this valve.
16:12In fact, he used little flap valves like that made of copper.
16:16They would let the water in and then not let it out again.
16:18So the water is pushed up there.
16:20And then when I pull the plunger back, the water can't come down there,
16:24but it'll come up from below through another ball valve.
16:27And so when I pull it back, it'll fill the whole pipe again.
16:31So there we are.
16:31And all we need is an animal to drive it.
16:35Marty.
16:36Hey, that's brilliant.
16:39Marty's coming out all over here.
16:40It does leak a little bit.
16:42Oh, wow.
16:43Hey, that's brilliant.
16:45That's fantastic.
16:46Go on, harder, harder.
16:47We want to wet the castle.
16:49That is brilliant.
16:51This is a fabulous machine.
16:53And this is what led to a great revolution in engineering,
16:57the principle of the crank,
16:59which finally ended up with the finest form of transport known to man,
17:04the bicycle.
17:09Even without the bicycle, the Arabs still had to get around
17:13in this arid and unforgiving landscape.
17:16As the Islamic Empire expanded, so did the opportunities for trade and exploration.
17:26Goods and ideas of all descriptions sailed east and west across oceans of sand and rock,
17:35carried naturally by the ship of the desert.
17:47By the Middle Ages, long trains of camels were a familiar sight.
17:52Called caravans, they helped link the far-flung corners of the Islamic Empire.
17:59At the time, the Islamic world was the only medieval superpower to have achieved a rapid military expansion.
18:07Within 100 years of Prophet Muhammad's death in 632, Muslim armies had conquered the Middle East,
18:14North Africa, Asia and most of Spain.
18:17But by the 13th century, constant wars meant that the caliphs in Baghdad had lost most of their power.
18:24Three separate dynasties then arose.
18:27The Mughals in India, the Safaviyye in Iran and the Ottomans in Turkey, the longest survivor.
18:33In 1922, after the First World War, it was converted into the Turkish Republic.
18:40For 1200 years, the Islamic world was a powerhouse of knowledge, military might and innovation.
18:48All driven by the massive economy that spanned Europe, Africa and Asia.
18:54The treasures of the world were brought back and sold in the hustle and bustle of great Islamic cities like
19:01Cairo.
19:15Goods would be sold in suits like these.
19:18This is Khayna Khalili in Cairo and it's not that different to how it would have looked a thousand years
19:22ago.
19:23A covered marketplace, protected from the glare of the sun, selling everything a girl could want to buy.
19:44The markets in Cairo were amongst the most important in the Islamic world.
19:49As well as exotic spices, incense, herbs, wheat and grains, there also came something even more precious, ideas.
19:57And one such idea pointed the way to a source of limitless energy that didn't need the flow of water
20:03at all.
20:10Around the world, water has always been an essential source of energy, used to grind wheat.
20:15So what do you do when you find you're hundreds of miles away from the nearest river?
20:25Almost wherever you are on Earth, you have wind.
20:28And with a great leap of imagination, they realised they could extract the energy from that invisible wind.
20:34The first reference we have is AD 644, a Persian millwright who set up a mill probably in western Afghanistan.
20:43And it seems that the idea was brought back to western Europe by the Crusaders in the 12th century.
20:53Hey Marty, it's terrific!
20:55And with a vertical shaft!
20:57I can't hear a thing!
20:58Give me the catcher!
21:00Oh, it's very noisy wind in this part of the country, isn't it?
21:03Yeah, it is, isn't it?
21:03So, show me how. You've got a vertical shaft.
21:05There's a vertical shaft, OK?
21:07At the top, there's a bearing at the top.
21:08Right.
21:09The shaft comes down.
21:10And then, sticking out of the vertical shaft, we've got six of these veins.
21:15Right.
21:15And the veins are actually made of just sort of wattling.
21:17They're like sails, really?
21:18Yeah, they're like sails, they're made of bits of twig and stuff.
21:21Right.
21:21And that turns this bit at the bottom.
21:24Right.
21:24And the really cunning thing is round that side.
21:26If you go round there, you will notice that on this side, there is a bit of shuttering.
21:35To stop the wind.
21:35To stop the wind.
21:36So it can only blow through this side.
21:38Exactly, so it blows through that side, which means that it's only blowing against these veins.
21:42Pushing all the sails round this way.
21:43So these veins don't get pushed against, so it always goes the same way round.
21:46That's very cunning.
21:47And of course, in that part of the world, they have the 120 day wind, which always blows
21:51from the same direction.
21:52So they knew which way to build the buildings, presumably.
21:54Yeah.
21:54Dead cunning.
21:56Now, tell me about the bottom end.
21:58Right.
21:58Okay.
21:59The bottom of the shaft, we've got all this gubbins here.
22:02This is just your grain silo here.
22:05Okay.
22:05Just sort of grain in there.
22:06And then, when I open that, the grain comes out.
22:09Okay.
22:09And falls into here.
22:10Okay.
22:11And the black discs.
22:13Right.
22:13Those are actually the millstones here.
22:14These are the grindstones.
22:16You've got quite small ones here.
22:17Yeah, we've got quite small ones.
22:18Scale grindstones.
22:19These things were huge.
22:20Now, the really clever bit is what's going on at the bottom bearing, which you can't really
22:24see.
22:24But basically, the bottom bearing is just a spike.
22:27Okay.
22:27Sticking up into the shaft.
22:28This shaft sits on that spike.
22:30Okay.
22:31And by adjusting that bottom bearing up and down, you can change the position, if I move
22:36that out of the way, of the top grindstone.
22:39So you can make the gap between the grindstones bigger or smaller.
22:42That's really important.
22:44The point is that if the gap gets too small and those grindstones are touching, all that
22:48comes out is dust, and that's completely useless.
22:50And if it gets too big, if they get worn away, then the whole grain comes out and it
22:54doesn't get ground at all.
22:55So it's really important to be able to adjust that gap.
22:58Well, I want to grind some grain.
23:00Can we run it again?
23:01Yeah, sure.
23:02More wind.
23:03Let's have more wind.
23:06There she blows.
23:08Terrific.
23:14Inventions like the windmill spread right across the world.
23:18But what came with them was something more valuable even than water or gold.
23:23Because what the Islamic Empire exported in bulk was knowledge.
23:38In Baghdad of the ninth century, the caliph, al-Mu'mun, founded the House of Wisdom.
23:46It was a vast library dedicated to translating the works of the Greeks into Arabic.
23:52He was especially interested in books on philosophy and science.
24:01built in 830 AD, the House of Wisdom contained over 6,500 translated volumes of Greek astronomy
24:09and architecture, and over 18,000 volumes of translated classical works from all around the world.
24:20Muslim scholars knew that it was vital to find out what scientists from other cultures had discovered.
24:25And one famous saying instructed them to seek knowledge even unto China.
24:32When a scholar brought the caliph, a text he translated from a foreign language into Arabic,
24:38he'd give them, in return, the weight of the book in gold.
24:41A financial incentive, if ever there was one, to translate the biggest book you could find.
24:49Three of the men the caliph recruited to work in the House of Wisdom were the Benu Musa brothers.
24:54They were part of a leisured class in Baghdad that were fascinated by trick inventions,
24:59sophisticated mechanical devices that were in fact far cleverer than mere toys.
25:05The Benu Musa brothers fed their peers' obsession by designing and making trick inventions of their own.
25:11Their book of ingenious devices lists over a hundred.
25:18So what were these toys? Were they really just ancient executive toys?
25:33Executive toys? Maybe. But those brothers produced a whole lot of devices that were not only witty,
25:40but also extraordinarily ingenious. Marty, what have you got?
25:44Fancy a drink of water first, Adam.
25:46That's not very ingenious.
25:47Well, here you go.
25:48All right, all right.
25:49They put huge effort into what are really conjuring tricks.
25:53Oh, I'm sorry, Adam.
25:55Water run out.
25:56That's not very fair.
25:57I think I'll pour myself a little glass of wine as well.
26:01Hang on a sec.
26:02You said there wasn't any left.
26:04Oh, well, I'll see what I've got left.
26:07Marty!
26:08Sorry, I have the last bit.
26:09You're a rotten sheet.
26:10Well, actually, I'm really rather thirsty, so I'm going to take a second wine glass as well, so...
26:18That is very clever.
26:20So whenever you pour for me, there isn't any.
26:22There's none.
26:23And when you pour for you, you've got as much as you want.
26:25Yeah.
26:25Go on, tell me how it works.
26:26Oh, all right, then, if you must.
26:27It's a trick.
26:28It is a trick.
26:29It's a Banu Musa trick.
26:30Go on, then.
26:30Let's move these out of the way.
26:32It all comes down, and I have a convenient...
26:35Demonstration.
26:35...see-through version here.
26:37It's really very simple.
26:39It's very ingenious.
26:39Actually, the jug has two chambers.
26:42Okay.
26:42It's separated by this sort of wooden plate here.
26:44Okay?
26:45The bottom chamber is sealed from the air.
26:47Okay.
26:47That's important.
26:48Except for two things.
26:50First, there's a double siphon here.
26:52The sort of C-shaped thing?
26:53Yeah, that C-shaped thing there.
26:55Right.
26:55And secondly, there's a hole here...
26:57Right.
26:57...which goes into the handle, along the handle, up there, and it comes out at the top.
27:02Okay.
27:02And there's a hole at the top, which I can cunningly place my thumb over.
27:05Right.
27:06Now, if I take another glass here, like this, just move this wine glass out of the way.
27:10Right.
27:11I can obviously pour water out of the top compartment.
27:14Because that's just ordinary...
27:14Because that's just there.
27:15An ordinary jug.
27:16So long as I have my thumb over the hole, it appears to run dry.
27:20Ah!
27:21Because you need air to get in there to let the water out.
27:24Exactly.
27:24So all I have to do is release my thumb a little bit, like that.
27:27Right.
27:27Take my thumb off.
27:28Right.
27:28And now, if I pour...
27:30Oh, and it comes all the way around through the sea.
27:32It comes flooding out through the sea.
27:33And then you put your thumb back on.
27:34Thumb back on, and it stops.
27:35Stop.
27:36That's very cunning.
27:37And I'm glad to say they also produced some devices that were rather more practical.
27:49One of the brothers' devices that's still in use today is the grab.
27:53And according to them, it would extract pearls and valuables from the bottom of the sea,
27:59and find things that have been dropped into wells and rivers and so on.
28:02It's a sort of mechanical...
28:04And then, Adam, of that, I'll show you how it works.
28:07Let's get this untangled.
28:08Now, this is an incredibly simple device.
28:11Right.
28:11All it consists of is a pair of jaws.
28:13Quite vicious, those two.
28:14Yeah, we deliberately did that.
28:16Right, okay.
28:16It's two half bits of tube with jaws on so that you can grab things from the bottom of the
28:21sea.
28:21Okay.
28:21Now, this is the clever bit which you've tangled up, which is the stringing of it.
28:26Because if I hold onto these set of strings here...
28:28Right.
28:29...it stays open.
28:30Okay, let me hold those.
28:31Okay, you hold those.
28:31Yeah.
28:31Okay, and then you drop that down to the bottom of the sea.
28:34When you're over what you want to pick up, you pull on the other string, and it shuts.
28:38That's very cunning.
28:39Let go again.
28:40So, that goes down open, and when you get there, you pull the middle one, and it shuts.
28:44Yeah.
28:45It's not going to work, is it?
28:46Yeah, sure it will.
28:46We just need something to pick up.
28:48Okay, something to...
28:48Ah!
28:49Your pen.
28:51Try that.
28:52Get your pen back.
28:53Here we go.
28:55Right.
28:56We need a camera.
28:57We need a camera to see this.
29:00So, yeah.
29:00Are you ready?
29:01Here we go.
29:02Yeah, in you go.
29:07Down she goes.
29:08It's not going to get to the bottom.
29:10You'll only get a rock anyway.
29:12Or an old boot.
29:13There, look.
29:14I've hit the bottom.
29:15So now, slowly, slowly, slowly.
29:28You haven't got anything there.
29:29I don't believe it.
29:30Hey, look at that.
29:31It's gold.
29:32Well, I'll have that.
29:33You get my pen back.
29:37Marty!
29:40Marty!
29:48This is the Al-Hamra in Granada, Spain.
29:52When the Islamic Empire was at its height, it represented its most westerly point.
29:57For four centuries, the Caliphs of the Nasrid dynasty ruled this region, Andalusia, from this magnificent complex of palaces.
30:08The Al-Hamra is also widely recognized as one of the finest examples of early Islamic architecture in the world.
30:16Begun in the 11th century, these elegant chambers hide an extraordinary technical achievement.
30:27The Benny Musa brothers made many other wonderful devices that played with water.
30:31But perhaps the greatest expression of Islamic love of water are fountains.
30:40These were a show of ultimate wealth.
30:43Water was scarce, and a display like this was regarded as a thing of wonder.
30:48Fountains became a cornerstone of Islamic art and architecture.
30:55These beautiful fountains in the Lion Gardens of Al-Hamra in Spain are nearly a thousand years old.
31:02Carved from marble, they would originally have been richly painted, mostly in gold.
31:08They are said to be based on a description from the Bible of Solomon's fountains at the entrance of the
31:14Temple of Jerusalem.
31:15Around the edge of the fountain is a poem written by a poet called Ibn Zamraq.
31:21The poem praises the beauty of the fountains and the power of the lions,
31:25but it also describes the ingenious hydraulic systems of how the fountains work.
31:30And to this day, the fountains work the same, gravity and water pressure.
31:39The water to power them comes from over there.
31:42Snow melt and rain from the Sierra Nevada mountains.
31:45Through a system of channels cut into their sides, the water eventually arrives here.
31:55The Al-Hamraq was the ultimate expression of 9th century Islamic wealth and power.
32:01Safe within these walls and cut off from the real world, the Caliph and his court were able to enjoy
32:06life to an incredibly refined degree.
32:12One man who also lived in 9th century Spain left a lasting impression.
32:17His name was Zerab and his influence came not from an invention, but from changing the way we behave.
32:23He introduced us to the idea of etiquette, fashion and fine dining.
32:30Zerab was a freed slave who rose to become the foremost trendsetter of his age.
32:35He lived at a time when this region, Andalusia, from the Arabic word Al-Andalus, was the centre of a
32:41great Muslim civilization.
33:01Zerab decreed that meals should start with soup, followed by a main course of meat, fish or fowl, and then
33:08finished off with fruit and nuts.
33:09He even changed the metal drinking goblets of the day to fine delicate crystal.
33:14So, if you enjoy a good three course meal, and believe in good manners, you owe something to Zerab.
33:22Zerab's refinements brought many new fashions to the halls of the rich and powerful.
33:26But one of the more elegant changes came about in ceramics, and was discovered by the early alchemists.
33:34For more than a thousand years, the Muslim countries produced the best ceramics in the world.
33:41It all started at the Battle of Samarkand in 751, when people from the Abbasid dynasty captured some Chinese potters.
33:49And they said, hey, why don't you make us some lovely porcelain, white porcelain, the stuff that we used to
33:54call China.
33:55But of course, around Baghdad, all the raw materials were quite different, and so they couldn't do that.
33:59And it took them a lot of trial and error to find they could make wonderful white glazes using tin
34:05oxide.
34:06But then, the next stage of the process needed exactly what those alchemists had been waiting for.
34:15This may seem like a strange place to find one of the jewels of Islamic art,
34:20but behind these incredible gates lies one of alchemy's greatest legacies.
34:32Behind this door lies an Aladdin's cave of hidden treasures.
34:49These amazing vases were originally used for storing oils and grains,
34:54but in the palaces of the caliphs, their designs took on an extraordinary beauty.
34:59Those who saw them then thought they must have been made from precious metals.
35:06So beautiful.
35:12Jug of the gazelles.
35:14This is an exact replica of one in Alhamra.
35:17It's about 900 years old.
35:20It's pretty amazing.
35:21You can see all the Arabic.
35:23Over here, the calligraphy.
35:27Al-ghazal.
35:29Gazelle.
35:32Stunning.
35:33Absolutely stunning.
35:36But Islam decrees that eating off gold and silver is a shameful and frivolous waste of money.
35:42So the very rich had been forced to look for something else that had the same sheen,
35:47but wouldn't offend the religion.
35:51We're all drawn to beauty, and the Islamic empire was no exception.
35:55That's why the Arabs invented the technique that makes these clay pots into art.
36:01A technique that in those days seemed just like alchemy.
36:07In the eighth century, potters working in what is now Iraq developed a mysterious process called lustre.
36:14This was described as an extraordinary metallic sheen which rivals even precious metals in its effect,
36:21all but turning objects of clay into gold.
36:39We have our own tame alchemist here, Nick Cage-Smith. You don't mind being called an alchemist, do you?
36:43No, that's fine.
36:44Good. And you understand how this lustreware works?
36:47I do indeed. I've got two bowls, Adam, here. One for you to decorate and one for me.
36:52Oh, excellent.
36:53Now this clay stuff in front of us is a clay paste with vinegar and metal compounds in it.
37:00Right.
37:01And the Arabs applied metal compounds as decoration to glaze
37:10and discovered exactly how to reduce it in a kiln to produce something that looked lustrous, shining metal.
37:19OK, OK. So that's what lustreware is.
37:22That's what lustreware is.
37:25You ready to turn over yet?
37:26Turn the whole thing over.
37:27Right.
37:33We've got metal compounds in here. This is what sort of metals?
37:37This is silver and copper compounds in here.
37:39Right.
37:39And when they go into the kiln, they're, in this case, silver oxalate and copper sulphide.
37:46Silver oxalate, copper sulphide.
37:48That's right.
37:48And we reduce them in there.
37:50And when we starve them of oxygen at the critical temperature.
37:53We strip off the oxalate.
37:54They will be converted back to silver and copper.
37:56Right.
37:56And they'll settle in a very thin layer on the surface of the glaze.
37:59And if we're lucky, we'll be able to rub the clay off afterwards.
38:02And what we'll find underneath is a nice, shiny, lustrous layer on the surface.
38:07I'll believe it when I see it.
38:11You're doing a brilliant, a brilliant job over there considering that you've got no turn device at all.
38:17No, it's the skill that I lack.
38:19Nick, I've got to say.
38:24No, I'm not going to do any more to that.
38:26Okay, so can we put them in?
38:28Fine.
38:28Is this hot?
38:30This isn't hot at the moment.
38:31Good, good, good.
38:32You have to be a bit careful not to ruin your work, don't you, at this point?
38:34You've got to be very careful not to touch anything in the wrong place.
38:37I'm not going to touch it.
38:38Right, I'll lift yours up.
38:39You can ruin my beautiful artwork.
38:43Okay, shut it up.
38:45Now we can close up.
38:48So this is alchemy in action.
38:51Absolutely.
38:52After four hours in the kiln at 620 Celsius, Nick has thrown in some pine cones to help create smoke
38:59and soak up the oxygen.
39:02It's time to see whether the magic has worked.
39:05Will those dull clay pots have been turned into gold?
39:08They haven't shattered into a thousand pieces.
39:10If we hear a loud crack we know something's gone wrong.
39:13Now I have to say it doesn't look very beautiful yet.
39:15No, it's very muddy and dirty looking, isn't it?
39:17We're going to take a cloth.
39:18Right.
39:19And simply rub off.
39:21And rub very simply on the surface.
39:22I'm just going to rub very slightly on the surface where the clay has created a layer.
39:31That is amazing.
39:32Look.
39:32It's like Aladdin and his lamp.
39:34Look at that.
39:36Fantastic.
39:37As you wipe the clay around it'll actually be lightly abrasive on the other surfaces so you can...
39:42Smooth it down.
39:43Happily, happily rub across the whole surface of the piece.
39:47Fantastic.
39:47Lustrous.
39:49Making lust aware was like alchemy.
39:52It was like a dark secret that held the promise of enormous wealth.
39:57But actually transforming things from the ordinary to the truly beautiful was happening all over the Islamic world.
40:24What links these 9th century Islamic alchemists to Dior, Givenchy, Lancôme and Chanel?
40:30Well, today's multi-billion pound perfume industry owes it all to a process first developed in search of the fifth
40:37element, the quintessence.
40:39A process known to you and me as distillation.
40:44The allure of fragrant goods is as old as mankind.
40:47But special gifts like saffron, frankincense and myrrh were so expensive to make that they were reserved only for emperors
40:55and kings.
40:58But as the passion for eastern spices, ointments and essences expanded into Europe, scientists of the empire managed to come
41:05up with a novel way of getting from this to this.
41:12The Islamic chemists became masters in the art of distillation.
41:15Al-Kindi's 9th century book describes no fewer than 107 methods and recipes for perfume making.
41:24And even the equipment such as this, the alambic or still, continues to bear its Arabic name.
41:32Their ideas eventually migrated here, near Grasse, in the south of France.
41:37A perfect climate and the right kind of soil has meant that the perfume industry still flourishes here after 700
41:43years.
41:47Once the flowers have been harvested, it's now time to distill them.
41:50And Michelle here is going to show me how to do it.
42:00The water is warmed to just under 100 degrees, using a pressurised boiler.
42:05The resulting steam traps the essential oil as it passes through the alambic, full of lavender stalks.
42:12The water oil vapour is carried up and out of the vat, through the gooseneck.
42:16The gases then travel around coiled tubes that are immersed in cold water.
42:21The cooled mixture condenses and funnels out through a lead-off pipe into a collecting flask.
42:27So basically what's happening is the oil is rising to the top because it's lighter than the water.
42:32And then you're able to drain off the pure oil mix into this.
42:36So how much would you make, Michelle?
42:38We need 50 kilos of lavender to make one liter of essence.
42:41So that's basically about 30 of these bunches that would make one of these bottles?
42:47Yeah.
42:48Wow, that's a lot of hard work.
42:49And we need to carry, to pick up some more lavender, so hurry up.
42:54These 9th century scholars evolved chemistry from an occult art to a scientific discipline.
43:00Their systematic approach led to another distillation discovery that today affects every person and every nation on Earth.
43:07It is perhaps the most precious substance on the planet.
43:13Who would have thought that this black sludge, known in Arabic as naft, could hold so many uses?
43:19Without distillation of crude oil, we'd have no petrol, cooking gas, plastics and diesel.
43:25In fact, it has over 4,000 uses.
43:29I'm going to distill orange juice and create pure water for your drinking pleasure.
43:34Here in the lab, we're going to show just how easy it is to distill anything.
43:39This is almost an exact replica of a 9th century still.
43:43That's the orange juice in there boiling, which will produce steam.
43:46OK.
43:47And then of course what happens is the steam comes up, it goes in that hole there.
43:50Yeah.
43:51And then it comes into the top part.
43:53That's the glass lid.
43:54Into the glass lid.
43:55Yeah.
43:55And then the glass lid, in round here there will be water and ice.
43:59So this will be cold and that will condense the steam into water.
44:02OK.
44:03Like any still.
44:03And then what happens is the water will collect in this trough round here.
44:07Inside the glass.
44:08Inside the glass.
44:09And there's a hole at the bottom there, and a pipe, and the water will trickle out of that pipe
44:13and fall out of the end.
44:14OK.
44:15And?
44:16Like that.
44:17Yeah, look.
44:18It's beginning to come up.
44:19There are drops of water condensing on the inside of that glass lid.
44:24Trickling down.
44:24Water's condensing like mad now.
44:26The steam's condensing, turning back to water.
44:27Hey, this heats up fairly quickly.
44:29Does it?
44:30Trickling down here and into the glass.
44:33Now look, Marty, I want to taste this.
44:34Go on then.
44:35I've got another glass here.
44:37Ready?
44:38Yep.
44:38In you go.
44:39Now.
44:40What's it taste like?
44:41Well, it smells very faintly of orange or something like that.
44:45Really?
44:45But it's quite clear it's not orange.
44:52Taste anything?
44:53I can't taste the orange.
44:57Of course, the Arabs distilled all sorts of things, including alcoholic mashes.
45:01If you take fermented apples or grain, when you've distilled it, you would get alcohol.
45:07It's another Arabic word.
45:09They didn't drink it.
45:11They used the alcohol for medical things.
45:13And, indeed, a whole lot of their medical treatments they got by this process of distillation.
45:26Here in Cairo, cures and treatments for everyday ills have been handed down since ancient times.
45:40This family-run pharmacy relies on a whole range of natural ingredients for many of its cures.
45:48Pharmacology took root in Islam during the ninth century, when it became independent from medicine.
45:53And even in the early days, pharmacists were licensed professionals threatened with humiliating corporal punishments if they adulterated drugs.
46:01Islamic pharmacists became experts in preparing and instructing herbs for medicinal purposes.
46:11This particular herb is from a plant, but it looks like a scorpion. So that's the name that they've given
46:17it.
46:18If you've got high cholesterol, this is the one that you need to use.
46:24This herb is grown just on the borders of Egypt, just bordering with Libya.
46:28And, apparently, it's for diabetes. It helps people who are diabetics.
46:34These seahorses are, apparently, used as good luck charms. And, also, people have them for, like, vitamins.
46:45My herb man over here has just said that it's very good if you're just about to get a cold
46:50or you feel run down.
46:51It gives you lots of energy. It gives you a bit of a buzz.
46:54Shukran.
47:17One of the most eminent of all scientists was Ibn Sina. He was, by all accounts, a precocious youth.
47:23At the age of 10, he knew the entire Qur'an by heart. And, by the time he was 16,
47:28he was studying and practicing medicine.
47:30He wasn't the only famous medical practitioner. Al-Zahrawi was held by many to be the greatest Muslim surgeon of
47:38the Middle Ages.
47:39He invented lots of surgical instruments, many of which are still used with modifications today.
47:45He promoted the use of antiseptics on wounds and described how to remove cataracts, an Arabic innovation.
47:52Another great name in medieval medicine was Al-Razi, who worked in Baghdad in the ninth century.
47:58Legend has it that he hung lumps of meat all around the city.
48:03And he went and inspected them. And where the meat rotted most slowly, that's where he sighted his hospital.
48:11In fact, the very idea of a hospital comes from that time.
48:14He aimed to provide all sorts of facilities, from treatment and convalescence, to asylum and retirement home.
48:21And actually, the hospitals then were very much precursors of the NHS, because treatment was available for rich and poor,
48:28and as a Muslim, you're honour-bound to care for the sick.
48:33But Al-Razi's greatest leap forward was in basic hygiene.
48:56Islam places a high value on cleanliness, and the ritual of washing your hands and feet before you go into
49:02a mosque is strictly observed.
49:04That's why there are so many fountains outside them.
49:10But cleanliness in general was also expected.
49:14In the year 993, there were 1,500 public baths like this one in the city of Barthed.
49:22Besides washing and socialising, bathing was also about spiritual purification.
49:31But it's difficult to keep properly clean without soap.
49:43The classical world lacked effective detergents, and used anything from olive oil to pumice stones to keep clean.
49:51But in the ninth century, Al-Razi mentions that hard soap was already in wide use in bathhouses like this.
49:58In Europe, at the same time, soap was unheard of, and people either stayed dirty or washed in water.
50:04It wasn't until the 18th century that Europeans cleaned up their act.
50:09A recently discovered manuscript from the 13th century actually details the recipe for making soap.
50:15But that's all they knew. How and why it worked would remain a mystery for centuries.
50:31That ancient recipe suggests you make soap by taking dark sesame oil and heating it up with potash and alkali,
50:39that's another Arabic word, and lime.
50:41But actually, it doesn't need to be as complicated as that. Let me show you.
50:44What you need is some oil, and this is ordinary cooking oil, and I'll slosh a bit of that in
50:50there, and some caustic soda.
50:52Here we are, sodium hydroxide, and we'll bung that lot in there, don't get it on your hands.
50:56And we stir that up a bit, and then I'll put it on the fire here.
51:02And you need to heat this up, preferably without boiling it, for an hour or two.
51:07And after a bit, it goes sort of gloopy like this one, a bit like porridge.
51:12And when you reckon it's about as thick as it's going to get, you take it out and let it
51:17cool, and what you wind up with is hard soap.
51:21You have to put it in a dish to cool, preferably non-stick, and this is what you wind up
51:25with.
51:25Look at this, lovely hard soap.
51:28And what they discovered was that to get hard soap, you don't use potash, potassium hydroxide, you use sodium hydroxide,
51:36caustic soda.
51:36Look at that. And you add a little pinch of salt, and that gives you lovely hard soap.
51:42Let me explain to you how it works.
51:46Oil comes in long ribbon-like molecules, like that. This might be oil or grease.
51:53They're actually hydrocarbon chains, these, and they don't dissolve in water.
51:57They're hydrophobic, they don't like water.
52:01Soap, a soap molecule, this is magnified a million, million, million times or something like that, has tails that look
52:07like oil molecules.
52:09Long, thin, hydrocarbon tails that are hydrophobic.
52:12But it also has a hydrophilic end, this is like water, this enjoys water, and will dissolve in water.
52:19So it's a combination of the two.
52:21When you get dirt on your skin, it's always mixed with the natural grease and oil that's on your skin.
52:27And all the dirt sticks with the grease, and if you put that in water, it doesn't come off, because
52:31the grease won't dissolve in the water.
52:33But if you use a soap molecule, the hydrophobic ends mix with the grease, because it's the same sort of
52:39stuff, and pick up the dirt.
52:41And when you go into the water, then the hydrophilic end dissolves in the water, comes away, and pulls the
52:47tails with it, pulls the grease off your hand, and takes the dirt along with it.
52:55All over the Islamic world, chemists were in great demand.
52:59Their discoveries had brought innovations and great wealth.
53:02Apart from oils, perfumes, and medicines, there was one sinister development in the 9th century that would profoundly change the
53:11world.
53:17This is the Al-Qasaba, or castle, of Al-Maria in southern Spain, built by the Umayyad Caliph, Abdul Al
53:24-Rahman III, in 995 AD.
53:27For nearly 500 years, it dominated the most successful trading port in the region, and was also the base of
53:35the powerful Umayyad naval fleet.
53:38Here, as elsewhere, the Caliph's power lay in the weapons he could command.
53:43Developments in 9th century chemistry meant that some had access to the most fearsome devices of the time.
54:02Exactly who invented gunpowder is a contentious issue.
54:06The Chinese certainly developed saltpeter, one of gunpowder's ingredients.
54:10But it seems that at first, they only used it for fireworks.
54:14Other research has shown that Muslim chemists developed a powerful formula for gunpowder,
54:19and may well have used it in the first firearms.
54:21But one thing's for certain, whoever was responsible probably had no idea how profoundly it would change the course of
54:29civilisation.
54:41For the Islamic armies led by Saladin in 1249 AD, the mastery of gunpowder in war proved decisive.
54:52At the Battle of Mansoura in Egypt, Muslim incendiary devices were so terrifying and destructive that the French Crusader army
55:00was routed,
55:00and King Louis IX was taken prisoner.
55:05An Arab scholar from Syria, Hassan al-Rama, wrote a book about military technology.
55:11He called it the Book of Horsemanship and Ingenious War Devices.
55:16And he described in it all sorts of things like guns, cannons, rockets, pistols, grenades, and the world's first torpedo.
55:30Now, out there is an enemy warship, and we've launched our torpedo straight at it.
55:36I don't think they've noticed, so with luck we can destroy that ship just like that.
55:43The device, first mentioned in al-Rama's book around 1295 AD, was a cleverly modified rocket designed to skim along
55:51the surface of the water.
55:53Made from sheet iron, it was packed with oil, metal filings, and saltpeter.
55:59The rocket tails at the back also acted as rudders, while the spear at the front was designed to lodge
56:06the torpedo in the wooden hull of the enemy ship.
56:10It's a tense moment.
56:22Wow!
56:24I think we can safely say that is now an ex-ship.
56:28If it hasn't sunk already, it'll be down in minutes, I would say.
56:33Fantastic.
56:43The Arab and Muslim world has had a profound and lasting influence on our lives today.
56:49The list is long and full of surprises, but perhaps the most important thing that the Islamic Empire did for
56:55us
56:55was to preserve, refine, and improve all the knowledge left by the scholars of the ancients.
57:03And without that work by the Muslim scholars, all of that knowledge might have been lost and our lives would
57:09have been much the poorer.
57:17To receive a free Open University leaflet, which accompanies this series, and details of Open University programmes,
57:24telephone 0870 900 0352 or go to bbc.co.uk slash history.
57:31Next time, join me to explore the golden age of ancient Chinese technology.
57:35The Chinese have the oldest civilisation in the world and they invented many things long before the West,
57:41from paper to kites and from gunpowder to bridges.