Hagia Sophia: Istanbul's Ancient Mystery | Full Documentary | NOVA | PBS
7ENpKObiarw • 2023-06-22
Transcript preview
Open
Kind: captions Language: en foreign [Music] for nearly a thousand years the largest enclosed building on earth its Heavenly Dome soars 180 feet high supported by archers that Inspire awe to this day for their strength and resilience when it opened gold mosaics covered over four acres of its walls and ceilings Builders construct construct such a magnificent Monument there's nothing practical about Hagia Sophia it's all Innovation built nearly 1500 years ago in Constantinople modern day Istanbul Paya Sophia has survived clashing Empires by transforming from church to mosque to museum Harry's about the history of Christianity and Islam within its walls most remarkably Haya Sophia has survived centuries of city-busting earthquakes did ancient Architects actually design an earthquake-proof structure or will the next big Quake bring Haya Sophia down to find out a team of Engineers is monitoring the building and constructing a giant model placing it on a hydraulic platform and hitting it with powerful simulated earthquakes can they unlock hia Sophia's seismic Secrets before Istanbul's next big quake there is always this Fear Factor fear of saying unexpected collapses right now on Nova Haya Sofia Istanbul's ancient mystery [Music] thank you [Music] Haya Sophia completed in the year 537 is one of the most magnificent buildings ever constructed its size alone is awe-inspiring only the pyramids surpassed it in height for almost a thousand years [Music] is a glittering gold Dome that spans over a hundred feet across and soars 180 feet above its marble floor the Statue of Liberty can fit beneath its Dome with room to spare [Music] how did ancient Builders nearly 1500 years ago construct such a gigantic Dome [Music] since it's complete hire Sophia has withstood the rise and fall of Empires it is transformed from Christian Church to Muslim Mosque to secular Museum influences a number of mosques and it became a model for Christian churches as well it's Innovative ambitious design and its Monumental scale speak to people across cultures faiths and religions how can one building be a symbol for two different religions and continue to inspire people to this day oh yes Sophia is a unique building there are only a few structures in the world that present different layers of history in the last two thousand years but perhaps the greatest mystery is why it still stands at all For Hire Sophia is in Istanbul known as Constantinople in ancient times the city straddles two continents Europe and Asia and a major earthquake fault over the last century the north Anatolian fault has Unleashed a series of quakes the most recent in 1999 was just 60 miles from Istanbul and it was devastating leveling hundreds of buildings across the city and killing thousands of people the damage caused by 99.8 is extensive plus there is a huge human loss about we lost about 17 000 people but somehow Haya Sophia is still standing in fact Haya Sophia has withstood every major earthquake for nearly 1500 years what is the secret to its survival as Istanbul braces for the next big one a team of Engineers searches for Answers by building an enormous scale model hitting it with a series of simulated earthquakes in the process they will uncover the building's strengths and weaknesses weaknesses that could ultimately threaten Haya Sophia's survival is director of the earthquake engineering Lab at wazichi University she is tasked with monitoring the structural Integrity of Haya Sophia slanted floors and leaning columns may appear alarming but chotti is most concerned about Haya Sophia's core structure that core structure comes down to a few key elements the enormous Dome resting on four huge arches which in turn are buttressed by four giant piers and two semi-domes [Music] a particular concern are the four arches of any fail the Dome could collapse to monitor the Arches her team has placed sensors at strategic points the sensors can detect the faintest of movements the data that we obtain from here is very important in terms of understanding the general structural behavior of this huge building nation is transmitted to screens at Istanbul's earthquake Center each of the multicolored lines represents vibrations detected by a motion sensor normally the lines are nearly flat but when an earthquake strikes there's a dramatic Spike from results of years of monitoring chalk DC's two places of potential Danger these are the vertical vibrations on both arches on the east and west side two of the great arches are moving more than they have in the past could have serious implications for the future if an earthquake comes strong enough I think there is a real chance it can receive damage will the next big Quake finally topple Haya Sofia um to investigate what danger Haya Sophia might be in trotti is turning to a tried and true technique a seismic Shake table test it's worked before in 2012 Chucky teamed up with engineering team Aaron caliphat and korhanorao to analyze the structural Integrity of the Mustafa Pasha mosque in Macedonia they built this large-scale model placed it on a motorized steel platform then shook it violently to simulate an earthquake the idea is that wherever damage appears on the model is where damage would appear on the actual building Engineers important insights to protect the real structure it worked for the Mustafa Pasha mosque but will it work with Haya Sophia a building larger heavier and more complex the model team has doubts the main issue is scale the core structure must be precisely scaled down for the shake table experiment to be accurate if trakti chooses a scale of 10 to 1 the Dome at just over a hundred feet wide would be 10 feet wide on the model but that's still too big for the shake table has a kept in terms of its dimensions and in terms of the power that it can create capacity of this shake table is 10 tons the scaled tract he wants to use will make the model too big so she must scale it down after intense recalculations it looks like a 26 to 1 scale could work based on paper we are always nervous whether it will work the scale model is an ambitious project with no guarantee of success but it pales in comparison to the challenge of building the real higher Sofia [Music] why Haya Sophia is built at a major Crossroad in history the decline of the Roman Empire and the rise of the Byzantine Empire in 324 A.D after Rome is ravaged by Civil War emperor Constantine establishes a new capital in the city of Byzantium it's renamed after him he Embraces a new religion Christianity and Constantinople becomes the center of the Byzantine Empire as Rome fades in importance Empire thrives but in the early 6th Century a power struggle erupts after a new emperor ascends the throne Justinian riots break out challenging his authority Theodora his much younger wife and rumored ex courtesan persuades him to fight rather than flee Justinian rallied to the challenge he called the rebels looking as if he was going to meet their demands met them in the Hippodrome had the doors closed and had the Army slaughter them all tens of thousands are killed and Justinian emerges Victorious during the riots the rebels burned down much of the city including an older Imperial Church also called Haya Sophia this is All That Remains much of the city of Constantinople had been destroyed in the great riots and this allowed Justinian the opportunity to in effect rebuild Constantinople and the Church of Hagia Sophia in his own image Justinian needed a building to convey both his power as Emperor and piety as a Christian so what to build [Music] Branham is a professor of art history at Providence College and an expert on how Builders designed Sacred Space she's at Sun Giovanni Evangelista a church in Ravenna Italy although rebuilt many times its floor plan dates to when Christianity becomes a state religion for the first few centuries Christians worshiped in private in homes and small buildings but this completely changes in the 4th century Christianity had been an underground cult Christians persecuted but when Christianity becomes the official religion of the Roman Empire Christians face a different problem what should a church look like early church Builders looked at biblical prototypes like the Temple of Solomon described in the Hebrew Bible but it's actually a secular Roman building that is adapted for early Christian use that building is the Basilica used for courts of Law and other public gatherings its floor plan a large Central Nave flanked by two Isles and culminating in an apps becomes the model for churches an ideal space for worshipers to gather Embraces the church's rectangular shape to demonstrate his Christian piety but he still needs something to symbolize his Imperial power he looks to the Dome of the pantheon in Rome the ultimate symbol of the might and glory of the Roman Empire but the Pantheon's Dome sits on a thick circular base Justinian wants his Dome to be centered over a rectangular Christian basilica [Music] Justinian sets out to do something that has never been done before he wanted to merge to architectural structures into a mammoth hybrid space so where do you find Builders to create something on a scale that's never been done before Justinian turns to Greek mathematicians Justinian hired Antonius of trellis and isadores of milletis both at experienced as mathematicians and physicists and scientists of their day they were asked to create the most impressive biggest building ever built Justinian puts these University professors in charge of a hundred contractors and 10 000 workers and gives them the mere treasury of the Byzantine Empire the emperor is taking a big gamble there's nothing practical about Hagia Sophia it's all Innovation it's geometric Flights of Fancy beyond what a practical architect would ever attempt to build their first challenge is how to support the Dome and still keep a huge space for worshipers below if they built walls or columns the space would not be open like this it would be much smaller and narrower in order to make it as large and as Heavenly as possible they need a big space and that can only be accomplished by building large arches a giant Dome will need giant arches to support it the original Architects should have been very concerned about how to support this huge Dome over there the team back at the earthquake Center faced the same challenge building their model will their arches be strong enough to support the Dome stic to find out they add sacks of cement to simulate the weight of the Dome weighs about 50 pounds and they expect the arch to support about 10 of them but as the fifth bag is placed [Music] foreign luckily nobody is hurt as the arch collapses with only about 200 pounds on it it collapsed before we were expecting the collapse to take place I think that happened because we didn't wait for the mortar to set fully while this might seem to be a setback for the team trotti insists this kind of unanticipated collapse illustrates one of the main advantages of building a physical model it is always interesting to see the failure mechanism in real life when you do it on computers you develop an idea of how the failure is going to happen but it is only during the tests of this kind where we see the collapse better [Music] the slow motion replay of the collapse shows that the downward force of the sacks pushes the arch out sideways the weight of the Dome exerts the same force on the arches in the real Haya Sofia the arch wants to push out and fall down so you have to hold the arch together like bookends to create those bookends anthonyus and his adoras the Greek mathematicians build four buttress peers massive weights of brick and mortar and two semi-domes push back against the Arches canceling out the sideways force caused by the Dome but anthonius and Isadora still have one more problem to solve how to rest the Dome on the tips of the arches The Architects had to transition from a circle to a square this they accomplished by building what is called pendentives it is this triangular shape that fills in the corners of the square the pendentus together with the Arches transform the circular base of the Dome into a square and the semi-domes stretch that square into a rectangle Justinian has it all the classic rectangular shape of the Basilica capped by the enormous circular Dome Antonius and his adora's complete Haya Sophia in only six years and do indeed spend nearly the entire treasury of the Byzantine Empire in 537 Emperor Justinian and his wife Theodora unveiled their Church to the world all who enter are awed by its size and the richness of its decorations columns crowned by Capital so finely carved they look like lace [Music] floors and walls of marble dazzle worshipers with patterns of swirling colors Justinian brought marbles from all parts of the empire the great purple columns that we see in the corners for example come from the Imperial quarries of Egypt elsewhere in the building we see Stones brought from as far away as the Pyrenees in Spain an eyewitness account reports that the Dome looks as though it was suspended from heaven by a Golden Chain like the church before it Justinian christensen's this Monument higher Sophia which in Greek means holy wisdom [Music] but the Dome that Justinian first sees is not the same Dome that sits atop higher Sophia today just 20 years after Haya Sophia is unveiling its Dome collapses in a catastrophic earthquake we really don't know what Justinian did when the first dome collapsed we can imagine he wasn't very happy fortunately for Isidore and anthemius they were dead by that point when the Dome collapsed in 558 the business of rebuilding it was given to the architect isidores the younger a nephew of the original architect chuckmuck believes isadoris the younger redesigns the Dome to reduce its weight he installs 40 windows at its base the windows serve two purposes one is to get rid of the bricks that you need which led additional weight and to let light in Haya Sophia is put to the test in at least another dozen major earthquakes the Dome suffers two partial collapses which were repaired so visitors today cast their eyes up to the same Dome built by isadoris the younger nearly 1500 years ago [Music] but Haya Sophia has withstood more than just seismic activity it's also been resilient to cultural upheavals 600 years after Justinian Constantinople continues to flourish but its riches Inspire Envy in 1204 European Christian Crusaders on their way to the Holy Land sacked the city and loot Treasures from the Byzantine Christian Haya Sophia yeah then a new religion challenges the old order Islam its forces lay Siege to Constantinople seven times over eight centuries finally in 1453 Sultan Mamet conquers the weakened City and makes it the capital of his Ottoman Empire Mehmet enters the Church of Haya Sophia on a Tuesday and by that Friday he is praying in the mosque of Haya Sophia remember the Conqueror Hagia Sophia was really the ultimate Conquest that was the symbol he was after for his new Empire but how can a church become a mosque from an architectural perspective it isn't difficult there was the addition of the Min bar from which the Imam would give the sermon gave the sacred Direction orientation to Mecca later the Ottomans add large discs calligraphied with sacred words from the Quran plaster over Christian mosaics an outside construct minarets for the call to prayer but Haya Sophia's vast Dome most easily makes the conversion the Dome itself had religious meaning for both Christian worshipers and now Muslim worshipers for both it was a symbol of the heavens the structure at the heart of Haya Sophia the round Dome on the square base works as powerfully for Islam as it did for Christianity is so admired in the Islamic World it becomes the classic Model for mosques throughout the Ottoman Empire today Haya Sophia is a museum a Showcase of its religious and cultural history when you enter the building you look to your left and you see a beautiful Mosaic panel from the Byzantine Empire and you look at your right and you see a wonderful calligraphic quotation from the Quran you see the history of the whole city in a sense the whole region in a nutshell but deciding which layers of its history to display is a battle that continues on its walls stepping onto the battlefield is researcher hitoshi takanazawa he's on a hunt for Christian mosaics that were plastered over when Haya Sophia was converted into a mosque challenge is how 'd the Byzantine mosaics without damaging the ottoman decorations [Music] secret weapon is this electromagnetic scanner normally it's used to find structural faults in things like Bridges nobody has ever used it to find Jesus we are developing new equipment for investigation it is crucial we find the technology that can deduce whether a mosaic exists without destroying anything an engineer Satoshi Baba carefully run the scanner against the wall foreign what might they find a tantalizing Taste of Haya Sophia in its full Mosaic Splendor is here the Church of San Vitale in Ravenna Italy also built during Justinian's Reign nearly 1500 years ago teen visitors [Music] and it was through the mosaics that this happened they were a vehicle to bring the visitor into contact with the divine that Divine glow of Byzantine mosaics is what makes them so awe-inspiring and the Mystery material that gives them that glow is what will help in the search for Haya Sofia's hidden mosaics Luciano not turning and Gabrielle War are using the same materials to make mosaics today they begin with glass discs carefully breaking them into smaller pieces until they become tiny cubes called tessery no tourney places each tessera piece by piece into a design she's drawn on the mortar and carefully angles them to reflect the light [Music] It is believed that especially in the Byzantine mosaics the positioning of the tessery was directly connected to where the light was coming from so where the windows where where the main light sources were and to make that light Shimmer they add something else to the mix it has a thin layer of gold leaf and the fact that it does have golden it makes it very reflective and very luminescent the gold tessery give the Byzantine mosaics a Heavenly glow because gold is metal it may be the key to rediscovering the Lost mosaics in Haya Sophia that design is made by Metric Teslas so we believe we hope to find mosaics by our instruments talking is always scanner sends electromagnetic signals below the surface of the plaster if the waves strike a buried metal tessera they are reflected back creating an image of the inside of the wall with this a scanning line five times and this green zone that's made of metals we can see here Design This is truly made by mang Hong the scanner is working it has detected a mosaic Circle beneath the plaster but takanazawa isn't searching just for circles [Music] or image of the Christ [Music] the walls of Haya Sophia are hiding more than mosaics they also hold secrets to its seismic strength high above the streets of Istanbul a team is repairing a wall as part of Haya Sophia's ongoing restoration sonai shakar is the lead architect s what we are doing is assessment from surface use the they'll repair the layer of bricks we've uncovered her team must replace crumbling cement from a restoration in the 1950s she's using a more resilient mortar one formulated from the original recipe Limestone sand water and a secret ingredient ground up bricks it turns out the best way to preserve Haya Sofia for the future is to use materials from the pasta is certainly more flexible than modern mortar so it adapts to the structural deformations caused by earthquakes the flexibility of the mortar is crucial but so is how it's applied [Music] differs from other structures because the layer of mortar is thicker than the bricks modern brick buildings have thin layers of mortar but higher Sophia's layers are so thick they act like cushioning higher Sophia's bricks also play a role in earthquake protection here is an original brick from Aya Sofia and here is a modern as you can see the original brick is significantly lighter than the modern brick which turns out to be very important if you make the weight light then the building can Sway With the earthquakes like a tree in the Wind flexible but strong fifteen hundred years ago other Architects built heavy and massive to protect against Earthquakes [Music] the Greek Architects did the opposite they built light and flexible the principle of modern seismic engineering [Music] but will this world treasure survive into the future and her team are building a model of Haya Sophia's core structure to investigate their Arch problems solved they move on to their next challenge the semi-domes they create a mortar that mimics the materials of the real semi-domes and spread it over a wooden mold we have worked on paper for a long time on how to get it right how to make it and then what would be the thickness what would be the material after the mortar dries they remove the wooden mold and as they take off the mold suddenly appears at the top cracks at this stage mean the semi-dome is clearly too weak for the shake table test foreign [Music] they break apart the semi-dome to get a closer look at the mortar s we have four centimeter coming from that side and for somebody coming from just that but the failure part was too thin it is almost a half centimeter a problem with the way the mortar was applied caused the top of the semi-dome to be much thinner than planned some shrinkage occurs after drying of the mortar we may consider to introduce some elements to the mortar so that its strength properties will improve the team must rebuild the semi-dome and they'll need to come up with a better method for building the final piece of their model the large Central Dome and that will take some time for hidden Byzantine mosaics hitoshi takanazawa is heading to the uppermost level of Haya Sophia a thin ledge that runs beneath the main arches the building is so huge he must narrow down his search it's very difficult to decide where we do the research because this space it's a very enormous size so I have to guess literally this part was decorated this figure of the Saints or Archbishop like there because these niches on the Northern wall are filled with Mosaic figures takanizawa believes the Southern Wall may have been too but have the Mosaic survived to find out they run the electromagnetic scanner along the wall we found a strong reflection under the plaster so we suppose it should be the remains of the mosaics it is a 70 percent confidence the team takes a closer look at the scan they find metal behind the plaster but not the gold takanazawa is hoping for the only horizontal lines it was seen it is not a mosaic but rather a metal structural support talking is always guess is wrong no mosaics have survived in this niche the challenge is that his scanner measures about two feet at a time and higher Sophia's surface area is over 200 000 square feet to narrow down his search takanazawa has come to bellinsona Switzerland to explore the state archives inside archivist Carlo aliati shows him an astonishing record of Haya Sophia's Byzantine mosaics in 1847 the sultan entrusted the architect gaspari fosati with the task of restoring the mosque of Hagia Sophia these drawings were made by the fosati brothers Swiss Architects were hired to renovate the Aging building which was then a mosque in the 1840s the fosatis began stripping plaster from the walls and were astonished by what they found Discovery during the restoration hidden under the plaster was definitely least extraordinary Byzantine mosaics [Music] they quickly documented every image before covering them with plaster once again [Music] while some of the mosaics recorded in the drawings had been uncovered others have never been found [Music] one in particular catches takanazawa's eye is [Music] but the exact location is still the subject of Tibet the sketch depicts Christ framed by a cross in a circle near Haya Sophia the Church of Cora contains a strikingly similar image found in the crown of a dome [Music] takanizawa believes the fosati sketch depicts a similar Mosaic in a dome in Haya Sofia and he has a hunch where to find it a very plausible hypothesis is that there is a large depiction of the face of Jesus Christ at the top of Haya Sofia's immense Dome but there's a problem currently it's covered by plaster and by quranic verses but one day with our scanner we would like to discover this image this is my dream [Music] it's a dream takanazawa could realize because as part of Haya Sophia's ongoing restoration this this enormous scaffold is about to reach the Dome but if takanazawa does find Christ beneath the quranic verse what should be shown it's a question at the heart of Haya Sophia's identity question with a long history religiously it was a Greek Orthodox church and during The Fourth Crusade it was taken over became a Catholic Church when the Muslims came they made it into a mosque finally it became a museum which we thought was the solution to the problem but unfortunately the Greeks would like to make it back into a church and the Muslims would like to make it back into a mosque and the conflict controversy continues but whether Haya Sophia remains a museum or is converted back to a church or mosque could prove irrelevant if there is an earthquake the more pressing question is will it be converted into a pile of rubble Esser charti hopes the shake table test will provide some answers the semi-domes are carefully rebuilt from mortar but mortar will be too fragile for the main dome which like the real thing will be built from brick we came to the conclusion that having a brick Dom is much easier to construct and it's more realistic so don't wise I'm confident with what will happen with respect to the semi-doms there I have doubts because it's much more fragile before the test the seven ton model must first survive the move to the shake tape [Music] largest model ever to be made in our lab we need to be very careful that to a lift up everything should be perfectly horizontal otherwise we may damage the model [Applause] the model is so heavy it bends the steel plate that supports it which puts pressure on the structure it settles onto the shake table but has it suffered any damage as the wooden molds Come Away Chuck day looks for cracks oh if the model breaks at this stage they will be unable to perform the earthquake test months of work will have been for nothing okay there is some yeah we have observed some cracks on the semitones but we don't see them from outside these are just interior cracks tracty believes the cracks do not compromise the structural Integrity of the model so the team moves on installing motion sensors in similar locations as the sensors in the real Haya Sophia we'll be able to compare vibrations that we record during the shake table test with those obtained from the real structure the model is a scaled down version of Haya Sophia's core structure the main Dome four great arches four buttress piers and the two semi-domes but will the model move on the shake table in a similar way as the real building moves in an earthquake astonishingly overnight the sensors get an unexpected trial run a real earthquake it's about 4 AM we had an earthquake near Istanbul its magnitude was 3.6 so by pure chance we have now recordings of that earthquake recorded on the model and we have the same earthquake recorded by our instruments inaya Sofia the parallel recordings verify that the sensors on the model and in the real building are reacting in a similar way now it's time to see how the model will react to a more powerful quote they calibrate the shake table to simulate the impact of the devastating 99 earthquake magnitude 7.4 the duration of the test is scaled down to match the size of the model about three seconds the sensors capture every twist and turn the model seems to have taken the impact without damage anyone really really stand up to an even stronger earthquake to find out the team must push the power of the shake table beyond anything they've tried before the simulated Quake is measured in G's its gravitational force we are increasing the amplitude it will go for 2.4 they hit the model with a simulated earthquake stronger than any in Istanbul's recorded history X Out the damn I see one new crack in this Arch but surprisingly there is nothing new with the semi-doms we were afraid about them but they are as they have been before the higher Sophia model has survived two enormous earthquakes in quick succession with minimal damage but the team isn't done yet we have passed the known capacity of our Shake table and then it appears the mechanics have allowed us to go further cable pushed the National lapse they hit it with everything they've got thank you [Applause] foreign at this stage the model has been hit by the equivalent of a major earthquake every day for a week and although it Teeters on the edge of collapse it still stands there are two vulnerable Parts the semidomes and then the Arches it is just the matter of time to see which one will go first one's eyes on the semi-dome [Music] [Applause] the great Dome comes Crashing Down thank you I'm a little bit surprised now because I would have expected the main Arch to go and then instead of the main arches the main Dome went the slow motion replay reveals that the semi-domes separated from the structure and with the main arches damaged support for the Dome was severely compromised compromised [Music] my masterpiece is collapsed now but for a scientific observation I can accept it [Music] to its 10 same time being analysis and interpretation this is at the bright range but it needs to be done [Music] it's too early to draw any firm conclusions but the model going 15 rounds against the most powerful simulated earthquakes the shake table could produce explains Haya Sophia's supposedly miraculous survival if there's a miracle it is in its design it was contracted to survive the balances between its structural elements appear to create a dance the dorms are just semi-doms but research they behave in harmony though the model lies in Ruins chakti believes the data captured in this experiment will provide new insights into higher Sophia's structural strength and how it can be preserved for the future scientists have spent decades trying to analyze the structural system of Hagia Sophia [Music] Sofia today you don't see structure we're not meant to understand how the great Dome is supported we see only the weightless quality of the building that was what was most important we understand the interior of the building as an experience that's completely different from anything else on Earth after nearly 1500 years Haya Sophia continues to astonish Modern Builders with its ancient secrets of seismic engineering and for its resilience not only as a structure but also as a symbol of the great civilizations that have adopted it [Music] we don't think of Aya Sofia based on the meanings other people assigned to it isof has an identity of its own [Music] it is a special building our goal is to pass it down to the next Generations Haya Sophia will have to endure many more shifts in the ground that Lies Beneath it and the cultures to which it is entrusted hopefully its Majestic Beauty and Innovative design will inspire people of all religions and cultures detected for generations to come [Music] thank you [Music] foreign [Music] [Applause] [Music] foreign
Resume
Categories