163-416: Ḥasan Ibn al-Haytham ( Latinized as Alhazen ; / æ l ˈ h æ z ən / ; full name Abū ʿAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham أبو علي، الحسن بن الحسن بن الهيثم ; c. 965 – c. 1040 ) was a medieval mathematician , astronomer , and physicist of the Islamic Golden Age from present-day Iraq. Referred to as "the father of modern optics", he made significant contributions to
326-401: A matroneum (women's section). The exterior was decorated with elaborate carvings of rich Theodosian-era designs, fragments of which have survived, while the floor just inside the portico was embellished with polychrome mosaics. The surviving carved gable end from the centre of the western façade is decorated with a cross-roundel. Fragments of a frieze of reliefs with 12 lambs representing
489-696: A Christian source, the Crusaders massacred some clerics who had surrendered to them. Much of the interior was damaged and would not be repaired until its return to Orthodox control in 1261. The sack of Hagia Sophia, and Constantinople in general, remained a sore point in Catholic–Eastern Orthodox relations . During the Latin occupation of Constantinople (1204–1261), the church became a Latin Catholic cathedral. Baldwin I of Constantinople ( r. 1204–1205 )
652-429: A Persian from Semnan , and Abu al-Wafa Mubashir ibn Fatek , an Egyptian prince. Alhazen's most famous work is his seven-volume treatise on optics Kitab al-Manazir ( Book of Optics ), written from 1011 to 1021. In it, Ibn al-Haytham was the first to explain that vision occurs when light reflects from an object and then passes to one's eyes, and to argue that vision occurs in the brain, pointing to observations that it
815-614: A deacon of Hagia Sophia and an administrative official in for the patriarchate from Antioch in Pisidia . Both George and Theodore, likely members of Sergius's literary circle, attribute the defeat of the Avars to the intervention of the Theotokos , a belief that strengthened in following centuries. In 726, the emperor Leo the Isaurian issued a series of edicts against the veneration of images, ordering
978-457: A great fire in 859, and again in an earthquake on 8 January 869 that caused the collapse of one of the half-domes. Emperor Basil I ordered repair of the tympanas, arches, and vaults. In his book De caerimoniis aulae Byzantinae ("Book of Ceremonies"), the emperor Constantine VII ( r. 913–959 ) wrote a detailed account of the ceremonies held in the Hagia Sophia by the emperor and
1141-407: A light source and a spherical mirror, find the point on the mirror where the light will be reflected to the eye of an observer." This leads to an equation of the fourth degree . This eventually led Alhazen to derive a formula for the sum of fourth powers , where previously only the formulas for the sums of squares and cubes had been stated. His method can be readily generalized to find the formula for
1304-641: A medieval artifact, near the probable location and is still visible today. The original tomb was destroyed by the Ottomans during the conversion of the church into a mosque. Upon the capture of Constantinople in 1261 by the Empire of Nicaea and the emperor Michael VIII Palaeologus , ( r. 1261–1282 ), the church was in a dilapidated state. In 1317, emperor Andronicus II Palaeologus ( r. 1282–1328 ) ordered four new buttresses ( Medieval Greek : Πυραμίδας , romanized : Pyramídas ) to be built in
1467-623: A mosque was highly controversial. It resulted in divided opinions and drew condemnation from the Turkish opposition, UNESCO , the World Council of Churches and the International Association of Byzantine Studies , as well as numerous international leaders, while several Muslim leaders in Turkey and other countries welcomed its conversion into a mosque. The first church on the site was known as
1630-526: A planned increase in bread prices, after a stoppage of the Cura Annonae rations resulting from the loss of the grain supply from Egypt. The Persians under Shahrbaraz and the Avars together laid the siege of Constantinople in 626; according to the Chronicon Paschale , on 2 August 626, Theodore Syncellus , a deacon and presbyter of Hagia Sophia, was among those who negotiated unsuccessfully with
1793-451: A position with the title of vizier in his native Basra, and became famous for his knowledge of applied mathematics, as evidenced by his attempt to regulate the flooding of the Nile . Upon his return to Cairo, he was given an administrative post. After he proved unable to fulfill this task as well, he contracted the ire of the caliph Al-Hakim , and is said to have been forced into hiding until
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#17330935543171956-659: A prophecy. What was the reason that compelled all to flee to the Great Church? They had been listening, for many years, to some pseudo-soothsayers, who had declared that the city was destined to be handed over to the Turks, who would enter in large numbers and would massacre the Romans as far as the Column of Constantine the Great. After this an angel would descend, holding his sword. He would hand over
2119-464: A timber roof, curtains, columns, and an entrance that faced west. It likely had a narthex and is described as being shaped like a Roman circus . This may mean that it had a U-shaped plan like the basilicas of San Marcellino e Pietro and Sant'Agnese fuori le mura in Rome . However, it may also have been a more conventional three-, four-, or five-aisled basilica, perhaps resembling the original Church of
2282-729: A tribute was paid to the Avars . The Avars attacked the extramural areas of Constantinople in 623, causing the Byzantines to move the "garment" relic (Ancient Greek: ἐσθής , romanized: esthḗs ) of Mary, mother of Jesus to Hagia Sophia from its usual shrine of the Church of the Theotokos at Blachernae just outside the Theodosian Walls . On 14 May 626, the Scholae Palatinae , an elite body of soldiers, protested in Hagia Sophia against
2445-582: Is a common practice for scientific names . For example, Livistona , the name of a genus of palm trees, is a Latinisation of Livingstone . During the age of the Roman Empire , translation of names into Latin (in the West) or Greek (in the East) was common. Additionally, Latinised versions of Greek substantives , particularly proper nouns , could easily be declined by Latin speakers with minimal modification of
2608-467: Is constructed with bricks stamped with brick-stamps dating from the 5th century, but the lower part is of constructed with bricks typical of the 4th century. This wall was probably part of the propylaeum at the west front of both the Constantinian and Theodosian Great Churches. The building was accompanied by a baptistery and a skeuophylakion . A hypogeum , perhaps with an martyrium above it,
2771-439: Is internationally consistent. Latinisation may be carried out by: Humanist names, assumed by Renaissance humanists , were largely Latinised names, though in some cases (e.g. Melanchthon ) they invoked Ancient Greek . Latinisation in humanist names may consist of translation from vernacular European languages, sometimes involving a playful element of punning. Such names could be a cover for humble social origins. The title of
2934-603: Is possible that both they and John the Lydian considered Hagia Sophia a great temple for the supreme Neoplatonist deity who manifestated through light and the sun. John the Lydian describes the church as the " temenos of the Great God" (Greek: τὸ τοῦ μεγάλου θεοῦ Τέμενος , romanized: tò toû megálou theoû Témenos ). Originally the exterior of the church was covered with marble veneer , as indicated by remaining pieces of marble and surviving attachments for lost panels on
3097-634: Is related to systemic and methodological reliance on experimentation ( i'tibar )(Arabic: اختبار) and controlled testing in his scientific inquiries. Moreover, his experimental directives rested on combining classical physics ( ilm tabi'i ) with mathematics ( ta'alim ; geometry in particular). This mathematical-physical approach to experimental science supported most of his propositions in Kitab al-Manazir ( The Optics ; De aspectibus or Perspectivae ) and grounded his theories of vision, light and colour, as well as his research in catoptrics and dioptrics (the study of
3260-459: Is so short as not to be clearly apparent to the beholder." Naturally, this suggests that the colour and form are perceived elsewhere. Alhazen goes on to say that information must travel to the central nerve cavity for processing and: the sentient organ does not sense the forms that reach it from the visible objects until after it has been affected by these forms; thus it does not sense color as color or light as light until after it has been affected by
3423-488: Is sought for itself [but] the truths, [he warns] are immersed in uncertainties [and the scientific authorities (such as Ptolemy, whom he greatly respected) are] not immune from error... Latinization of names Latinisation (or Latinization ) of names , also known as onomastic Latinisation , is the practice of rendering a non - Latin name in a modern Latin style. It is commonly found with historical proper names , including personal names and toponyms , and in
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#17330935543173586-492: Is subjective and affected by personal experience. Optics was translated into Latin by an unknown scholar at the end of the 12th century or the beginning of the 13th century. This work enjoyed a great reputation during the Middle Ages . The Latin version of De aspectibus was translated at the end of the 14th century into Italian vernacular, under the title De li aspecti . It was printed by Friedrich Risner in 1572, with
3749-509: The Magna Ecclesia ( Μεγάλη Ἐκκλησία , Megálē Ekklēsíā , 'Great Church') because of its size compared to the sizes of the contemporary churches in the city. According to the Chronicon Paschale , the church was consecrated on 15 February 360, during the reign of the emperor Constantius II ( r. 337–361 ) by the Arian bishop Eudoxius of Antioch . It was built next to
3912-507: The khagan of the Avars. A homily , attributed by existing manuscripts to Theodore Syncellus and possibly delivered on the anniversary of the event, describes the translation of the Virgin's garment and its ceremonial re-translation to Blachernae by the patriarch Sergius I after the threat had passed. Another eyewitness account of the Avar–Persian siege was written by George of Pisidia ,
4075-468: The 12 apostles also remain; unlike Justinian's 6th-century church, the Theodosian Hagia Sophia had both colourful floor mosaics and external decorative sculpture. At the western end, surviving stone fragments of the structure show there was vaulting , at least at the western end. The Theodosian building had a monumental propylaeum hall with a portico that may account for this vaulting, which
4238-649: The Bibliothèque nationale in Paris in 1834 by E. A. Sedillot. In all, A. Mark Smith has accounted for 18 full or near-complete manuscripts, and five fragments, which are preserved in 14 locations, including one in the Bodleian Library at Oxford , and one in the library of Bruges . Two major theories on vision prevailed in classical antiquity . The first theory, the emission theory , was supported by such thinkers as Euclid and Ptolemy , who believed that sight worked by
4401-479: The Chronicle of John Malalas , during a subsequent earthquake on 7 May 558, the eastern semi-dome collapsed, destroying the ambon , altar, and ciborium . The collapse was due mainly to the excessive bearing load and to the enormous shear load of the dome, which was too flat. These caused the deformation of the piers which sustained the dome. Justinian ordered an immediate restoration. He entrusted it to Isidorus
4564-561: The Column of Theodosius closer to Hagia Sophia; in others, it occurs at the Column of Constantine , which is closer still. Hagia Sophia is mentioned in a hagiography of uncertain date detailing the life of the Eastern Orthodox saint Andrew the Fool . The text is self-attributed to Nicephorus, a priest of Hagia Sophia, and contains a description of the end time in the form of a dialogue, in which
4727-475: The Council of State annulled the 1934 decision to establish the museum, and the Hagia Sophia was reclassified as a mosque. The 1934 decree was ruled to be unlawful under both Ottoman and Turkish law as Hagia Sophia's waqf , endowed by Sultan Mehmed, had designated the site a mosque; proponents of the decision argued the Hagia Sophia was the personal property of the sultan. The decision to designate Hagia Sophia as
4890-511: The Danishmendids at the siege of Kastamon in 1133. After proceeding through the streets on foot carrying a cross with a silver quadriga bearing the icon of the Virgin Mary, the emperor participated in a ceremony at the cathedral before entering the imperial palace. In 1168, another triumph was held by the emperor Manuel I Comnenus , again preceding with a gilded silver quadriga bearing
5053-543: The Fatimid capital of Cairo and earned his living authoring various treatises and tutoring members of the nobilities. Ibn al-Haytham is sometimes given the byname al-Baṣrī after his birthplace, or al-Miṣrī ("the Egyptian"). Al-Haytham was dubbed the "Second Ptolemy " by Abu'l-Hasan Bayhaqi and "The Physicist" by John Peckham . Ibn al-Haytham paved the way for the modern science of physical optics. Ibn al-Haytham (Alhazen)
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5216-668: The Fourth Crusade and the 1204 Sack of Constantinople , was buried in the church. After the fall of Constantinople to the Ottoman Empire in 1453, it was converted to a mosque by Mehmed the Conqueror and became the principal mosque of Istanbul until the 1616 construction of the Sultan Ahmed Mosque . Upon its conversion, the bells , altar , iconostasis , ambo , and baptistery were removed, while iconography , such as
5379-653: The Hagia Sophia Grand Mosque , is a mosque and former church serving as a major cultural and historical site in Istanbul , Turkey . The last of three church buildings to be successively erected on the site by the Eastern Roman Empire , it was completed in AD 537. The site was an Eastern rite church from AD 360 to 1453, except for a brief time as a Latin Catholic church between the Fourth Crusade and 1261. After
5542-832: The Hippodrome of Constantinople , and the second Hagia Sophia was burnt to the ground on 13–14 January 532. The court historian Procopius wrote: And by way of shewing that it was not against the Emperor alone that they [the rioters] had taken up arms, but no less against God himself, unholy wretches that they were, they had the hardihood to fire the Church of the Christians, which the people of Byzantium call "Sophia", an epithet which they have most appropriately invented for God, by which they call His temple; and God permitted them to accomplish this impiety, foreseeing into what an object of beauty this shrine
5705-518: The Mausoleum of Helena ), it is possible it originally had a funerary function, though by 405 its use had changed. A later account credited a woman called Anna with donating the land on which the church was built in return for the right to be buried there. Excavations on the western side of the site of the first church under the propylaeum wall reveal that the first church was built atop a road about 8 m (26 ft) wide. According to early accounts,
5868-481: The Optics ) that other rays would be refracted through the eye and perceived as if perpendicular. His arguments regarding perpendicular rays do not clearly explain why only perpendicular rays were perceived; why would the weaker oblique rays not be perceived more weakly? His later argument that refracted rays would be perceived as if perpendicular does not seem persuasive. However, despite its weaknesses, no other theory of
6031-547: The Oxford mathematician Peter M. Neumann . Recently, Mitsubishi Electric Research Laboratories (MERL) researchers solved the extension of Alhazen's problem to general rotationally symmetric quadric mirrors including hyperbolic, parabolic and elliptical mirrors. The camera obscura was known to the ancient Chinese , and was described by the Han Chinese polymath Shen Kuo in his scientific book Dream Pool Essays , published in
6194-590: The Rus'–Byzantine War of 941 and the death of the Grand Prince of Kiev , Igor I ( r. 912–945 ), his widow Olga of Kiev – regent for her infant son Sviatoslav I ( r. 945–972 ) – visited the emperor Constantine VII and was received as queen of the Rus' in Constantinople. She was probably baptized in Hagia Sophia's baptistery, taking the name of the reigning augusta , Helena Lecapena , and receiving
6357-600: The Rüstem Pasha Mosque and the Kılıç Ali Pasha Complex . The patriarchate moved to the Church of the Holy Apostles , which became the city's cathedral. The complex remained a mosque until 1931, when it was closed to the public for four years. It was re-opened in 1935 as a museum under the secular Republic of Turkey, and the building was Turkey's most visited tourist attraction as of 2019 . In July 2020,
6520-474: The eye emitting rays of light . The second theory, the intromission theory supported by Aristotle and his followers, had physical forms entering the eye from an object. Previous Islamic writers (such as al-Kindi ) had argued essentially on Euclidean, Galenist, or Aristotelian lines. The strongest influence on the Book of Optics was from Ptolemy's Optics , while the description of the anatomy and physiology of
6683-617: The fall of Constantinople in 1453, it served as a mosque until 1935, when it became a museum. In 2020, the site once again became a mosque. The current structure was built by the Byzantine emperor Justinian I as the Christian cathedral of Constantinople for the Byzantine Empire between 532 and 537, and was designed by the Greek geometers Isidore of Miletus and Anthemius of Tralles . It
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6846-533: The magnifying power of a lens . Alhazen was the first physicist to give complete statement of the law of reflection. He was first to state that the incident ray, the reflected ray, and the normal to the surface all lie in a same plane perpendicular to reflecting plane. His work on catoptrics in Book V of the Book of Optics contains a discussion of what is now known as Alhazen's problem, first formulated by Ptolemy in 150 AD. It comprises drawing lines from two points in
7009-587: The mosaic depictions of Jesus, Mary , Christian saints and angels were removed or plastered over. Islamic architectural additions included four minarets , a minbar and a mihrab . The Byzantine architecture of the Hagia Sophia served as inspiration for many other religious buildings including the Hagia Sophia in Thessaloniki , Panagia Ekatontapiliani , the Şehzade Mosque , the Süleymaniye Mosque ,
7172-412: The plane of a circle meeting at a point on the circumference and making equal angles with the normal at that point. This is equivalent to finding the point on the edge of a circular billiard table at which a player must aim a cue ball at a given point to make it bounce off the table edge and hit another ball at a second given point. Thus, its main application in optics is to solve the problem, "Given
7335-527: The retina was also involved. Alhazen's synthesis of light and vision adhered to the Aristotelian scheme, exhaustively describing the process of vision in a logical, complete fashion. His research in catoptrics (the study of optical systems using mirrors) was centred on spherical and parabolic mirrors and spherical aberration . He made the observation that the ratio between the angle of incidence and refraction does not remain constant, and investigated
7498-466: The synthronon . He adds that mules and donkeys were brought into the cathedral's sanctuary to carry away the gilded silver plating of the bema, the ambo, and the doors and other furnishings, and that one of them slipped on the marble floor and was accidentally disembowelled, further contaminating the place. According to Ali ibn al-Athir , whose treatment of the Sack of Constantinople was probably dependent on
7661-735: The " Wilhelmus ", national anthem of the Netherlands , preserves a Latinised form of the name of William the Silent . In English, place names often appear in Latinised form. This is a result of many early text books mentioning the places being written in Latin. Because of this, the English language often uses Latinised forms of foreign place names instead of anglicised forms or the original names. Examples of Latinised names for countries or regions are: Latinisation
7824-517: The "Great Church", likely on 15 April 428. According to the anonymous Letter to Cosmas , the virgin empress, a promoter of the cult of the Virgin Mary who habitually partook in the Eucharist at the sanctuary of Nestorius's predecessors, claimed right of entry because of her equivalent position to the Theotokos – the Virgin Mary – "having given birth to God". Their theological differences were part of
7987-483: The 19th century Hering's law of equal innervation . He wrote a description of vertical horopters 600 years before Aguilonius that is actually closer to the modern definition than Aguilonius's – and his work on binocular disparity was repeated by Panum in 1858. Craig Aaen-Stockdale, while agreeing that Alhazen should be credited with many advances, has expressed some caution, especially when considering Alhazen in isolation from Ptolemy , with whom Alhazen
8150-465: The 4th-century skeuophylakion survived the fire. According to Dark and Kostenec, the fire may only have affected the main basilica, leaving the surrounding ancillary buildings intact. A second church on the site was ordered by Theodosius II ( r. 402–450 ), who inaugurated it on 10 October 415. The Notitia Urbis Constantinopolitanae , a fifth-century list of monuments, names Hagia Sophia as Magna Ecclesia , 'Great Church', while
8313-407: The 4th-century church was not yet known as Hagia Sophia. Though its name as the 'Great Church' implies that it was larger than other Constantinopolitan churches, the only other major churches of the 4th century were the Church of St Mocius , which lay outside the Constantinian walls and was perhaps attached to a cemetery, and the Church of the Holy Apostles . The church itself is known to have had
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#17330935543178476-516: The 5th century Theodosian basilica could have been built surrounded by a complex constructed primarily during the fourth century. During the reign of Theodosius II, the emperor's elder sister, the Augusta Pulcheria ( r. 414–453 ) was challenged by the patriarch Nestorius ( r. 10 April 428 – 22 June 431 ). The patriarch denied the Augusta access to the sanctuary of
8639-458: The Church of the Wisdom, at the top of the window, a large flame of fire issuing forth. It encircled the entire neck of the church for a long time. The flame gathered into one; its flame altered, and there was an indescribable light. At once it took to the sky. ... The light itself has gone up to heaven; the gates of heaven were opened; the light was received; and again they were closed." This phenomenon
8802-645: The Greek historian Doukas , the Hagia Sophia was tainted by these Catholic associations, and the anti-union Orthodox faithful avoided the cathedral, considering it to be a haunt of demons and a "Hellenic" temple of Roman paganism . Doukas also notes that after the Laetentur Caeli was proclaimed, the Byzantines dispersed discontentedly to nearby venues where they drank toasts to the Hodegetria icon, which had, according to late Byzantine tradition, interceded to save them in
8965-404: The Holy Sepulchre in Jerusalem or the Church of the Nativity in Bethlehem . The building was likely preceded by an atrium , as in the later churches on the site. According to Ken Dark and Jan Kostenec, a further remnant of the 4th century basilica may exist in a wall of alternating brick and stone banded masonry immediately to the west of the Justinianic church. The top part of the wall
9128-543: The Justinianic Hagia Sophia revealed the western remains of its Theodosian predecessor, as well as some fragments of the Constantinian church. German archaeologist Alfons Maria Schneider began conducting archaeological excavations during the mid-1930s, publishing his final report in 1941. Excavations in the area that had once been the 6th-century atrium of the Justinianic church revealed the monumental western entrance and atrium, along with columns and sculptural fragments from both 4th- and 5th-century churches. Further digging
9291-420: The Light of the Moon ). In his work, Alhazen discussed theories on the motion of a body. In his On the Configuration of the World Alhazen presented a detailed description of the physical structure of the earth: The earth as a whole is a round sphere whose center is the center of the world. It is stationary in its [the world's] middle, fixed in it and not moving in any direction nor moving with any of
9454-571: The Younger, nephew of Isidore of Miletus, who used lighter materials. The entire vault had to be taken down and rebuilt 20 Byzantine feet (6.25 m or 20.5 ft) higher than before, giving the building its current interior height of 55.6 m (182 ft). Moreover, Isidorus changed the dome type, erecting a ribbed dome with pendentives whose diameter was between 32.7 and 33.5 m. Under Justinian's orders, eight Corinthian columns were disassembled from Baalbek , Lebanon and shipped to Constantinople around 560. This reconstruction, which gave
9617-405: The advance of the Turks. The identity of the emperor was often confused with that of other famous saint-emperors like Theodosius I and Heraclius . The orb was frequently referred to as an apple in foreigners' accounts of the city, and it was interpreted in Greek folklore as a symbol of the Turks' mythological homeland in Central Asia, the "Lone Apple Tree". The orb fell to the ground in 1316 and
9780-414: The all-holy dedicatory offerings". After a successful sally by Renier and his knights, Maria requested a truce, the imperial assault ceased, and an amnesty was negotiated by the megas doux Andronikos Kontostephanos and the megas hetaireiarches John Doukas . Greek historian Niketas Choniates compared the preservation of the cathedral to the efforts made by the 1st-century emperor Titus to avoid
9943-604: The apertures is gradually blocked up." G. J. Toomer expressed some skepticism regarding Schramm's view, partly because at the time (1964) the Book of Optics had not yet been fully translated from Arabic, and Toomer was concerned that without context, specific passages might be read anachronistically. While acknowledging Alhazen's importance in developing experimental techniques, Toomer argued that Alhazen should not be considered in isolation from other Islamic and ancient thinkers. Toomer concluded his review by saying that it would not be possible to assess Schramm's claim that Ibn al-Haytham
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#173309355431710106-414: The area where the Great Palace was being developed. According to the 5th-century ecclesiastical historian Socrates of Constantinople , the emperor Constantius had c. 346 "constructed the Great Church alongside that called Irene which because it was too small, the emperor's father [Constantine] had enlarged and beautified". A tradition which is not older than the 7th or 8th century reports that
10269-450: The army to destroy all icons – ushering in the period of Byzantine iconoclasm . At that time, all religious pictures and statues were removed from the Hagia Sophia. Following a brief hiatus during the reign of Empress Irene (797–802), the iconoclasts returned. Emperor Theophilus ( r. 829–842 ) had two-winged bronze doors with his monograms installed at the southern entrance of the church. The basilica suffered damage, first in
10432-499: The building we now see, it seems to me that they would have prayed that they might see their church destroyed forthwith, in order that the building might be converted into its present form. Upon seeing the finished building, the Emperor reportedly said: "Solomon, I have surpassed thee " ( Medieval Greek : Νενίκηκά σε Σολομών ). Justinian and Patriarch Menas inaugurated the new basilica on 27 December 537, 5 years and 10 months after construction started, with much pomp. Hagia Sophia
10595-434: The building with 4,000 Roman pounds of gold, but he was dismissed from office in October 532. John the Lydian wrote that Phocas had acquired the funds by moral means, but Evagrius Scholasticus later wrote that the money had been obtained unjustly. According to Anthony Kaldellis , both of Hagia Sophia's architects named by Procopius were associated with the school of the pagan philosopher Ammonius of Alexandria . It
10758-457: The building's western face. The white marble cladding of much of the church, together with gilding of some parts, would have given Hagia Sophia a shimmering appearance quite different from the brick- and plaster-work of the modern period, and would have significantly increased its visibility from the sea. The cathedral's interior surfaces were sheathed with polychrome marbles, green and white with purple porphyry , and gold mosaics. The exterior
10921-399: The building. Construction of the church began in 532 during the short tenure of Phocas as praetorian prefect . Although Phocas had been arrested in 529 as a suspected practitioner of paganism , he replaced John the Cappadocian after the Nika Riots saw the destruction of the Theodosian church. According to John the Lydian , Phocas was responsible for funding the initial construction of
11084-635: The caliph's death in 1021, after which his confiscated possessions were returned to him. Legend has it that Alhazen feigned madness and was kept under house arrest during this period. During this time, he wrote his influential Book of Optics . Alhazen continued to live in Cairo, in the neighborhood of the famous University of al-Azhar , and lived from the proceeds of his literary production until his death in c. 1040. (A copy of Apollonius ' Conics , written in Ibn al-Haytham's own handwriting exists in Aya Sofya : (MS Aya Sofya 2762, 307 fob., dated Safar 415 A.H. [1024]).) Among his students were Sorkhab (Sohrab),
11247-520: The celestial bodies would collide with each other. The suggestion of mechanical models for the Earth centred Ptolemaic model "greatly contributed to the eventual triumph of the Ptolemaic system among the Christians of the West". Alhazen's determination to root astronomy in the realm of physical objects was important, however, because it meant astronomical hypotheses "were accountable to the laws of physics ", and could be criticised and improved upon in those terms. He also wrote Maqala fi daw al-qamar ( On
11410-403: The church its present 6th-century form, was completed in 562. The poet Paul the Silentiary composed an ekphrasis , or long visual poem, for the re-dedication of the basilica presided over by Patriarch Eutychius on 24 December 562. Paul the Silentiary's poem is conventionally known under the Latin title Descriptio Sanctae Sophiae , and he was also author of another ekphrasis on the ambon of
11573-466: The church, the Descripto Ambonis . According to the history of the patriarch Nicephorus I and the chronicler Theophanes the Confessor , various liturgical vessels of the cathedral were melted down on the order of the emperor Heraclius ( r. 610–641 ) after the capture of Alexandria and Roman Egypt by the Sasanian Empire during the Byzantine–Sasanian War of 602–628 . Theophanes states that these were made into gold and silver coins, and
11736-528: The city's capture. Despite the ill-repute and empty state of Hagia Sophia after December 1452, Doukas writes that after the Theodosian Walls were breached, the Byzantines took refuge there as the Turks advanced through the city: "All the women and men, monks, and nuns ran to the Great Church. They, both men and women, were holding in their arms their infants. What a spectacle! That street was crowded, full of human beings." He attributes their change of heart to
11899-576: The claim has been rebuffed. Alhazen offered an explanation of the Moon illusion , an illusion that played an important role in the scientific tradition of medieval Europe. Many authors repeated explanations that attempted to solve the problem of the Moon appearing larger near the horizon than it does when higher up in the sky. Alhazen argued against Ptolemy's refraction theory, and defined the problem in terms of perceived, rather than real, enlargement. He said that judging
12062-554: The complex with locals and mercenaries, and despite the strong opposition of the patriarch, made the "house of prayer into a den of thieves or a well-fortified and precipitous stronghold, impregnable to assault", while "all the dwellings adjacent to Hagia Sophia and adjoining the Augusteion were demolished by [Maria's] men". A battle ensued in the Augustaion and around the Milion , during which
12225-534: The concepts of correspondence, homonymous and crossed diplopia were in place in Ibn al-Haytham's optics. But contrary to Howard, he explained why Ibn al-Haytham did not give the circular figure of the horopter and why, by reasoning experimentally, he was in fact closer to the discovery of Panum's fusional area than that of the Vieth-Müller circle. In this regard, Ibn al-Haytham's theory of binocular vision faced two main limits:
12388-565: The construction process. This new church was contemporaneously recognized as a major work of architecture. Outside the church was an elaborate array of monuments around the bronze-plated Column of Justinian , topped by an equestrian statue of the emperor which dominated the Augustaeum , the open square outside the church which connected it with the Great Palace complex through the Chalke Gate . At
12551-549: The contradictions he pointed out in Ptolemy in a later work. Alhazen believed there was a "true configuration" of the planets that Ptolemy had failed to grasp. He intended to complete and repair Ptolemy's system, not to replace it completely. In the Doubts Concerning Ptolemy Alhazen set out his views on the difficulty of attaining scientific knowledge and the need to question existing authorities and theories: Truth
12714-399: The controversy over the title theotokos that resulted in the Council of Ephesus and the stimulation of Monophysitism and Nestorianism , a doctrine, which like Nestorius, rejects the use of the title. Pulcheria along with Pope Celestine I and Patriarch Cyril of Alexandria had Nestorius overthrown, condemned at the ecumenical council, and exiled. The area of the western entrance to
12877-404: The culmination of their dispute with the empress Maria of Antioch , regent for her son, the emperor Alexius II Comnenus . Maria Comnena and Renier occupied the cathedral with the support of the patriarch, refusing the imperial administration's demands for a peaceful departure. According to Niketas Choniates, they "transformed the sacred courtyard into a military camp", garrisoned the entrances to
13040-504: The defenders fought from the "gallery of the Catechumeneia (also called the Makron)" facing the Augusteion, from which they eventually retreated and took up positions in the exonarthex of Hagia Sophia itself. At this point, "the patriarch was anxious lest the enemy troops enter the temple, with unholy feet trample the holy floor, and with hands defiled and dripping with blood still warm plunder
13203-612: The destruction of a city founded on seven hills in the Book of Revelation was frequently understood to be about Constantinople, and the Apocalypse of Pseudo-Methodius had predicted an " Ishmaelite " conquest of the Roman Empire. In this text, the Muslim armies reach the Forum Bovis before being turned back by divine intervention; in later apocalyptic texts, the climactic turn takes place at
13366-757: The destruction of the Second Temple during the siege of Jerusalem in the First Jewish–Roman War . Choniates reports that in 1182, a white hawk wearing jesses was seen to fly from the east to Hagia Sophia, flying three times from the "building of the Thōmaitēs " (a basilica erected on the southeastern side of the Augustaion) to the Palace of the Kathisma in the Great Palace , where new emperors were acclaimed . This
13529-603: The destruction of the Theodosian Hagia Sophia and comparing the new church with the old, Procopius lauded the Justinianic building, writing in De aedificiis : ... the Emperor Justinian built not long afterwards a church so finely shaped, that if anyone had enquired of the Christians before the burning if it would be their wish that the church should be destroyed and one like this should take its place, shewing them some sort of model of
13692-410: The distance of an object depends on there being an uninterrupted sequence of intervening bodies between the object and the observer. When the Moon is high in the sky there are no intervening objects, so the Moon appears close. The perceived size of an object of constant angular size varies with its perceived distance. Therefore, the Moon appears closer and smaller high in the sky, and further and larger on
13855-402: The dome; a burial cloth of Christ shown on Fridays, and on the apse a new depiction of the Virgin Mary holding Jesus, between the apostles Peter and Paul. On the great side arches were painted the prophets and the teachers of the church. According to the 13th-century Greek historian Niketas Choniates , the emperor John II Comnenus celebrated a revived Roman triumph after his victory over
14018-636: The early 19th century, Europe had largely abandoned Latin as a scholarly language (most scientific studies and scholarly publications are printed in English), but a variety of fields still use Latin terminology as the norm. By tradition, it is still common in some fields to name new discoveries in Latin. And because Western science became dominant during the 18th and 19th centuries, the use of Latin names in many scholarly fields has gained worldwide acceptance, at least when European languages are being used for communication. Hagia Sophia Hagia Sophia , officially
14181-445: The eastern and northern parts of the church, financing them with the inheritance of his late wife, Irene of Montferrat ( d. 1314). New cracks developed in the dome after the earthquake of October 1344, and several parts of the building collapsed on 19 May 1346. Repairs by architects Astras and Peralta began in 1354. On 12 December 1452, Isidore of Kiev proclaimed in Hagia Sophia the long-anticipated ecclesiastical union between
14344-672: The edge of the Augustaeum was the Milion and the Regia, the first stretch of Constantinople's main thoroughfare, the Mese . Also facing the Augustaeum were the enormous Constantinian thermae , the Baths of Zeuxippus , and the Justinianic civic basilica under which was the vast cistern known as the Basilica Cistern . On the opposite side of Hagia Sophia was the former cathedral, Hagia Irene. Referring to
14507-439: The edifice was built by Constantius' father, Constantine the Great ( r. 306–337 ). Hesychius of Miletus wrote that Constantine built Hagia Sophia with a wooden roof and removed 427 (mostly pagan) statues from the site. The 12th-century chronicler Joannes Zonaras reconciles the two opinions, writing that Constantius had repaired the edifice consecrated by Eusebius of Nicomedia , after it had collapsed. Since Eusebius
14670-506: The eye was based on Galen's account. Alhazen's achievement was to come up with a theory that successfully combined parts of the mathematical ray arguments of Euclid, the medical tradition of Galen , and the intromission theories of Aristotle. Alhazen's intromission theory followed al-Kindi (and broke with Aristotle) in asserting that "from each point of every colored body, illuminated by any light, issue light and color along every straight line that can be drawn from that point". This left him with
14833-417: The eye, only the ray that reached it directly, without being refracted by any other part of the eye, would be perceived. He argued, using a physical analogy, that perpendicular rays were stronger than oblique rays: in the same way that a ball thrown directly at a board might break the board, whereas a ball thrown obliquely at the board would glance off, perpendicular rays were stronger than refracted rays, and it
14996-416: The eye, using a mechanical analogy: Alhazen associated 'strong' lights with perpendicular rays and 'weak' lights with oblique ones. The obvious answer to the problem of multiple rays and the eye was in the choice of the perpendicular ray, since only one such ray from each point on the surface of the object could penetrate the eye. Sudanese psychologist Omar Khaleefa has argued that Alhazen should be considered
15159-417: The eye, which he sought to avoid. He maintained that the rays that fell perpendicularly on the lens (or glacial humor as he called it) were further refracted outward as they left the glacial humor and the resulting image thus passed upright into the optic nerve at the back of the eye. He followed Galen in believing that the lens was the receptive organ of sight, although some of his work hints that he thought
15322-406: The fact that this treatise allowed more people to study partial eclipses of the sun, it especially allowed to better understand how the camera obscura works. This treatise is a physico-mathematical study of image formation inside the camera obscura. Ibn al-Haytham takes an experimental approach, and determines the result by varying the size and the shape of the aperture, the focal length of the camera,
15485-417: The first Hagia Sophia was built on the site of an ancient pagan temple, although there are no artefacts to confirm this. The Patriarch of Constantinople John Chrysostom came into a conflict with Empress Aelia Eudoxia , wife of the emperor Arcadius ( r. 383–408 ), and was sent into exile on 20 June 404. During the subsequent riots, this first church was largely burnt down. Palladius noted that
15648-441: The form of color or light. Now the affectation received by the sentient organ from the form of color or of light is a certain change; and change must take place in time; .....and it is in the time during which the form extends from the sentient organ's surface to the cavity of the common nerve, and in (the time) following that, that the sensitive faculty, which exists in the whole of the sentient body will perceive color as color...Thus
15811-680: The former sieges of Constantinople by the Avar Khaganate and the Umayyad Caliphate . According to Nestor Iskander's Tale on the Taking of Tsargrad , the Hagia Sophia was the focus of an alarming omen interpreted as the Holy Spirit abandoning Constantinople on 21 May 1453, in the final days of the Siege of Constantinople. The sky lit up, illuminating the city, and "many people gathered and saw on
15974-467: The former cathedral Hagia Irene is referred to as Ecclesia Antiqua , 'Old Church'. At the time of Socrates of Constantinople around 440, "both churches [were] enclosed by a single wall and served by the same clergy". Thus, the complex would have encompassed a large area including the future site of the Hospital of Samson . If the fire of 404 destroyed only the 4th-century main basilica church, then
16137-421: The founder of experimental psychology , for his pioneering work on the psychology of visual perception and optical illusions . Khaleefa has also argued that Alhazen should also be considered the "founder of psychophysics ", a sub-discipline and precursor to modern psychology. Although Alhazen made many subjective reports regarding vision, there is no evidence that he used quantitative psychophysical techniques and
16300-564: The horizon. Through works by Roger Bacon , John Pecham and Witelo based on Alhazen's explanation, the Moon illusion gradually came to be accepted as a psychological phenomenon, with the refraction theory being rejected in the 17th century. Although Alhazen is often credited with the perceived distance explanation, he was not the first author to offer it. Cleomedes ( c. 2nd century) gave this account (in addition to refraction), and he credited it to Posidonius ( c. 135–50 BCE). Ptolemy may also have offered this explanation in his Optics , but
16463-512: The icon of the Virgin from the now-demolished East Gate (or Gate of St Barbara, later the Turkish : Top Kapısı , lit. 'Cannon Gate') in the Propontis Wall , to Hagia Sophia for a thanks-giving service, and then to the imperial palace. In 1181, the daughter of the emperor Manuel I, Maria Comnena , and her husband, the caesar Renier of Montferrat , fled to Hagia Sophia at
16626-541: The impact of perpendicular projectiles on surfaces was forceful enough to make them penetrate, whereas surfaces tended to deflect oblique projectile strikes. For example, to explain refraction from a rare to a dense medium, he used the mechanical analogy of an iron ball thrown at a thin slate covering a wide hole in a metal sheet. A perpendicular throw breaks the slate and passes through, whereas an oblique one with equal force and from an equal distance does not. He also used this result to explain how intense, direct light hurts
16789-415: The interlocutor, upon being told by the saint that Constantinople will be sunk in a flood and that "the waters as they gush forth will irresistibly deluge her and cover her and surrender her to the terrifying and immense sea of the abyss", says "some people say that the Great Church of God will not be submerged with the city but will be suspended in the air by an invisible power". The reply is given that "When
16952-460: The kingdom, together with the sword, to some insignificant, poor, and humble man who would happen to be standing by the Column. He would say to him: "Take this sword and avenge the Lord's people." Then the Turks would be turned back, would be massacred by the pursuing Romans, and would be ejected from the city and from all places in the west and the east and would be driven as far as the borders of Persia, to
17115-461: The lack of recognition of the role of the retina, and obviously the lack of an experimental investigation of ocular tracts. Alhazen's most original contribution was that, after describing how he thought the eye was anatomically constructed, he went on to consider how this anatomy would behave functionally as an optical system. His understanding of pinhole projection from his experiments appears to have influenced his consideration of image inversion in
17278-417: The last sentient's perception of color as such and of light as such takes place at a time following that in which the form arrives from the surface of the sentient organ to the cavity of the common nerve. Alhazen explained color constancy by observing that the light reflected from an object is modified by the object's color. He explained that the quality of the light and the color of the object are mixed, and
17441-594: The late 5th-century Column of Leo . A large lintel of the skeuophylakion 's western entrance – bricked up during the Ottoman era – was discovered inside the rotunda when it was archaeologically cleared to its foundations in 1979, during which time the brickwork was also repointed . The skeuophylakion was again restored in 2014 by the Vakıflar . A fire started during the tumult of the Nika Revolt , which had begun nearby in
17604-420: The mathematical devices Ptolemy introduced into astronomy, especially the equant , failed to satisfy the physical requirement of uniform circular motion, and noted the absurdity of relating actual physical motions to imaginary mathematical points, lines and circles: Ptolemy assumed an arrangement ( hay'a ) that cannot exist, and the fact that this arrangement produces in his imagination the motions that belong to
17767-466: The military supremacy of the Islamic caliphate over the Christian empire. In Niccolò Barbaro 's account of the fall of the city in 1453, the Justinianic monument was interpreted in the last days of the siege as representing the city's founder Constantine the Great, indicating "this is the way my conqueror will come". According to Laonicus Chalcocondyles , Hagia Sophia was a refuge for the population during
17930-500: The motion of the planets, whereas the Hypotheses concerned what Ptolemy thought was the actual configuration of the planets. Ptolemy himself acknowledged that his theories and configurations did not always agree with each other, arguing that this was not a problem provided it did not result in noticeable error, but Alhazen was particularly scathing in his criticism of the inherent contradictions in Ptolemy's works. He considered that some of
18093-542: The one who submits to argument and demonstration, and not to the sayings of a human being whose nature is fraught with all kinds of imperfection and deficiency. The duty of the man who investigates the writings of scientists, if learning the truth is his goal, is to make himself an enemy of all that he reads, and ... attack it from every side. He should also suspect himself as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency. An aspect associated with Alhazen's optical research
18256-627: The original word. During the medieval period , after the Empire collapsed in Western Europe , the main bastion of scholarship was the Roman Catholic Church , for which Latin was the primary written language. In the early medieval period, most European scholars were priests and most educated people spoke Latin, and as a result, Latin became firmly established as the scholarly language for the West. By
18419-462: The patriarch. Early in the 10th century, the pagan ruler of the Kievan Rus' sent emissaries to his neighbors to learn about Judaism, Islam, and Roman and Orthodox Christianity. After visiting Hagia Sophia his emissaries reported back: "We were led into a place where they serve their God, and we did not know where we were, in heaven or on earth." In the 940s or 950s, probably around 954 or 955, after
18582-403: The planets does not free him from the error he committed in his assumed arrangement, for the existing motions of the planets cannot be the result of an arrangement that is impossible to exist... [F]or a man to imagine a circle in the heavens, and to imagine the planet moving in it does not bring about the planet's motion. Having pointed out the problems, Alhazen appears to have intended to resolve
18745-406: The principles of optics and visual perception in particular. His most influential work is titled Kitāb al-Manāẓir ( Arabic : كتاب المناظر , "Book of Optics"), written during 1011–1021, which survived in a Latin edition. The works of Alhazen were frequently cited during the scientific revolution by Isaac Newton , Johannes Kepler , Christiaan Huygens , and Galileo Galilei . Ibn al-Haytham
18908-430: The problem of explaining how a coherent image was formed from many independent sources of radiation; in particular, every point of an object would send rays to every point on the eye. What Alhazen needed was for each point on an object to correspond to one point only on the eye. He attempted to resolve this by asserting that the eye would only perceive perpendicular rays from the object – for any one point on
19071-439: The problem using conic sections and a geometric proof. His solution was extremely long and complicated and may not have been understood by mathematicians reading him in Latin translation. Later mathematicians used Descartes ' analytical methods to analyse the problem. An algebraic solution to the problem was finally found in 1965 by Jack M. Elkin, an actuarian. Other solutions were discovered in 1989, by Harald Riede and in 1997 by
19234-405: The reflection and refraction of light, respectively). According to Matthias Schramm, Alhazen "was the first to make a systematic use of the method of varying the experimental conditions in a constant and uniform manner, in an experiment showing that the intensity of the light-spot formed by the projection of the moonlight through two small apertures onto a screen diminishes constantly as one of
19397-465: The refractive interfaces between air, water, and glass cubes, hemispheres, and quarter-spheres provided the foundation for his theories on catoptrics . Alhazen discussed the physics of the celestial region in his Epitome of Astronomy , arguing that Ptolemaic models must be understood in terms of physical objects rather than abstract hypotheses – in other words that it should be possible to create physical models where (for example) none of
19560-487: The relations between the angle of incidence, the angle of refraction and the angle of deflection. This apparatus was a modified version of an apparatus used by Ptolemy for similar purpose. Alhazen basically states the concept of unconscious inference in his discussion of colour before adding that the inferential step between sensing colour and differentiating it is shorter than the time taken between sensing and any other visible characteristic (aside from light), and that "time
19723-404: The repairs. He erected again and reinforced the fallen dome arch, and rebuilt the west side of the dome with 15 dome ribs. The extent of the damage required six years of repair and reconstruction; the church was re-opened on 13 May 994. At the end of the reconstruction, the church's decorations were renovated, including the addition of four immense paintings of cherubs; a new depiction of Christ on
19886-571: The second church in Kiev, Saint Sophia's , was founded in anno mundi 6460 in the Byzantine calendar , or c. 952 . The name of this future cathedral of Kiev probably commemorates Olga's baptism at Hagia Sophia. After the great earthquake of 25 October 989, which collapsed the western dome arch, Emperor Basil II asked for the Armenian architect Trdat , creator of the Cathedral of Ani , to direct
20049-419: The sentient perceives that the visible object is luminous and that the light seen in the object is other than the color and that these are two properties. The Kitab al-Manazir (Book of Optics) describes several experimental observations that Alhazen made and how he used his results to explain certain optical phenomena using mechanical analogies. He conducted experiments with projectiles and concluded that only
20212-501: The shape and intensity of the light source. In his work he explains the inversion of the image in the camera obscura, the fact that the image is similar to the source when the hole is small, but also the fact that the image can differ from the source when the hole is large. All these results are produced by using a point analysis of the image. In the seventh tract of his book of optics, Alhazen described an apparatus for experimenting with various cases of refraction, in order to investigate
20375-411: The standard binomial nomenclature of the life sciences. It goes further than romanisation , which is the transliteration of a word to the Latin alphabet from another script (e.g. Cyrillic ). For authors writing in Latin, this change allows the name to function grammatically in a sentence through declension . In a scientific context, the main purpose of Latinisation may be to produce a name which
20538-528: The steps outside the atrium of the Constantinian Old St Peter's Basilica in Rome. Near the staircase, there was a cistern, perhaps to supply a fountain in the atrium or for worshippers to wash with before entering. The 4th-century skeuophylakion was replaced in the 5th century by the present-day structure, a rotunda constructed of banded masonry in the lower two levels and of plain brick masonry in
20701-404: The study of vision, while burning mirrors focused on the properties of light and luminous rays. On the shape of the eclipse is probably one of the first attempts made by Ibn al-Haytham to articulate these two sciences. Very often Ibn al-Haytham's discoveries benefited from the intersection of mathematical and experimental contributions. This is the case with On the shape of the eclipse . Besides
20864-413: The subsequent Sack of Constantinople in 1204, the church was further ransacked and desecrated by the Crusaders, as described by Choniates, though he did not witness the events in person. According to his account, composed at the court of the rump Empire of Nicaea , Hagia Sophia was stripped of its remaining metal ornaments, its altar was smashed into pieces, and a "woman laden with sins" sang and danced on
21027-432: The sum of any integral powers, although he did not himself do this (perhaps because he only needed the fourth power to calculate the volume of the paraboloid he was interested in). He used his result on sums of integral powers to perform what would now be called an integration , where the formulas for the sums of integral squares and fourth powers allowed him to calculate the volume of a paraboloid . Alhazen eventually solved
21190-477: The sun at the time of the eclipse, unless it is total, demonstrates that when its light passes through a narrow, round hole and is cast on a plane opposite to the hole it takes on the form of a moonsickle." It is admitted that his findings solidified the importance in the history of the camera obscura but this treatise is important in many other respects. Ancient optics and medieval optics were divided into optics and burning mirrors. Optics proper mainly focused on
21353-483: The text is obscure. Alhazen's writings were more widely available in the Middle Ages than those of these earlier authors, and that probably explains why Alhazen received the credit. Therefore, the seeker after the truth is not one who studies the writings of the ancients and, following his natural disposition, puts his trust in them, but rather the one who suspects his faith in them and questions what he gathers from them,
21516-406: The third. Originally this rotunda, probably employed as a treasury for liturgical objects, had a second-floor internal gallery accessed by an external spiral staircase and two levels of niches for storage. A further row of windows with marble window frames on the third level remain bricked up. The gallery was supported on monumental consoles with carved acanthus designs, similar to those used on
21679-706: The time was so comprehensive, and it was enormously influential, particularly in Western Europe. Directly or indirectly, his De Aspectibus ( Book of Optics ) inspired much activity in optics between the 13th and 17th centuries. Kepler 's later theory of the retinal image (which resolved the problem of the correspondence of points on an object and points in the eye) built directly on the conceptual framework of Alhazen. Alhazen showed through experiment that light travels in straight lines, and carried out various experiments with lenses , mirrors , refraction , and reflection . His analyses of reflection and refraction considered
21842-482: The title Opticae thesaurus: Alhazeni Arabis libri septem, nuncprimum editi; Eiusdem liber De Crepusculis et nubium ascensionibus (English: Treasury of Optics: seven books by the Arab Alhazen, first edition; by the same, on twilight and the height of clouds). Risner is also the author of the name variant "Alhazen"; before Risner he was known in the west as Alhacen. Works by Alhazen on geometric subjects were discovered in
22005-695: The titles zōstē patrikía and the styles of archontissa and hegemon of the Rus'. Her baptism was an important step towards the Christianization of the Kievan Rus' , though the emperor's treatment of her visit in De caerimoniis does not mention baptism. Olga is deemed a saint and equal-to-the-apostles ( Ancient Greek : ἰσαπόστολος , romanized : isapóstolos ) in the Eastern Orthodox Church. According to an early 14th-century source,
22168-793: The varieties of motion, but always at rest. The book is a non-technical explanation of Ptolemy's Almagest , which was eventually translated into Hebrew and Latin in the 13th and 14th centuries and subsequently had an influence on astronomers such as Georg von Peuerbach during the European Middle Ages and Renaissance . In his Al-Shukūk ‛alā Batlamyūs , variously translated as Doubts Concerning Ptolemy or Aporias against Ptolemy , published at some time between 1025 and 1028, Alhazen criticized Ptolemy 's Almagest , Planetary Hypotheses , and Optics , pointing out various contradictions he found in these works, particularly in astronomy. Ptolemy's Almagest concerned mathematical theories regarding
22331-413: The vertical and horizontal components of light rays separately. Alhazen studied the process of sight, the structure of the eye, image formation in the eye, and the visual system . Ian P. Howard argued in a 1996 Perception article that Alhazen should be credited with many discoveries and theories previously attributed to Western Europeans writing centuries later. For example, he described what became in
22494-471: The visual system separates light and color. In Book II, Chapter 3 he writes: Again the light does not travel from the colored object to the eye unaccompanied by the color, nor does the form of the color pass from the colored object to the eye unaccompanied by the light. Neither the form of the light nor that of the color existing in the colored object can pass except as mingled together and the last sentient can only perceive them as mingled together. Nevertheless,
22657-453: The western Catholic and eastern Orthodox Churches as decided at the Council of Florence and decreed by the papal bull Laetentur Caeli , though it would be short-lived. The union was unpopular among the Byzantines, who had already expelled the Patriarch of Constantinople, Gregory III , for his pro-union stance. A new patriarch was not installed until after the Ottoman conquest. According to
22820-457: The whole city sinks into the sea, how can the Great Church remain? Who will need her? Do you think God dwells in temples made with hands?" The Column of Constantine , however, is prophesied to endure. From the time of Procopius in the reign of Justinian, the equestrian imperial statue on the Column of Justinian in the Augustaion beside Hagia Sophia, which gestured towards Asia with right hand,
22983-451: The year 1088 C.E. Aristotle had discussed the basic principle behind it in his Problems , but Alhazen's work contained the first clear description of camera obscura . and early analysis of the device. Ibn al-Haytham used a camera obscura mainly to observe a partial solar eclipse. In his essay, Ibn al-Haytham writes that he observed the sickle-like shape of the sun at the time of an eclipse. The introduction reads as follows: "The image of
23146-503: Was abandoned for fear of harming the structural integrity of the Justinianic building, but parts of the excavation trenches remain uncovered, laying bare the foundations of the Theodosian building. The basilica was built by architect Rufinus. The church's main entrance, which may have had gilded doors, faced west, and there was an additional entrance to the east. There was a central pulpit and likely an upper gallery, possibly employed as
23309-506: Was an early proponent of the concept that a hypothesis must be supported by experiments based on confirmable procedures or mathematical reasoning – an early pioneer in the scientific method five centuries before Renaissance scientists , he is sometimes described as the world's "first true scientist". He was also a polymath , writing on philosophy , theology and medicine . Born in Basra , he spent most of his productive period in
23472-455: Was born c. 965 to a family of Arab or Persian origin in Basra , Iraq , which was at the time part of the Buyid emirate . His initial influences were in the study of religion and service to the community. At the time, society had a number of conflicting views of religion that he ultimately sought to step aside from religion. This led to him delving into the study of mathematics and science. He held
23635-744: Was clad in stucco that was tinted yellow and red during the 19th-century restorations by the Fossati architects. The construction is described by Procopius in On Buildings ( Greek : Περὶ κτισμάτων , romanized : Peri ktismatōn , Latin: De aedificiis ). Columns and other marble elements were imported from throughout the Mediterranean, although the columns were once thought to be spoils from cities such as Rome and Ephesus. Even though they were made specifically for Hagia Sophia, they vary in size. More than ten thousand people were employed during
23798-509: Was crowned emperor on 16 May 1204 in Hagia Sophia in a ceremony which closely followed Byzantine practices. Enrico Dandolo , the Doge of Venice who commanded the sack and invasion of the city by the Latin Crusaders in 1204, is buried inside the church, probably in the upper eastern gallery . In the 19th century, an Italian restoration team placed a cenotaph marker, frequently mistaken as being
23961-452: Was destined to be transformed. So the whole church at that time lay a charred mass of ruins. On 23 February 532, only a few weeks after the destruction of the second basilica, Emperor Justinian I inaugurated the construction of a third and entirely different basilica, larger and more majestic than its predecessors. Justinian appointed two architects, mathematician Anthemius of Tralles and geometer and engineer Isidore of Miletus , to design
24124-471: Was discovered before 1946, and the remnants of a brick wall with traces of marble revetment were identified in 2004. The hypogeum was a tomb which may have been part of the 4th-century church or may have been from the pre-Constantinian city of Byzantium . The skeuophylakion is said by Palladius to have had a circular floor plan, and since some U-shaped basilicas in Rome were funerary churches with attached circular mausolea (the Mausoleum of Constantina and
24287-622: Was emulated by Ottoman mosques a thousand years later. It has been described as "holding a unique position in the Christian world " and as an architectural and cultural icon of Byzantine and Eastern Orthodox civilization. The religious and spiritual centre of the Eastern Orthodox Church for nearly one thousand years, the church was dedicated to the Holy Wisdom . It was where the excommunication of Patriarch Michael I Cerularius
24450-418: Was extremely familiar. Alhazen corrected a significant error of Ptolemy regarding binocular vision, but otherwise his account is very similar; Ptolemy also attempted to explain what is now called Hering's law. In general, Alhazen built on and expanded the optics of Ptolemy. In a more detailed account of Ibn al-Haytham's contribution to the study of binocular vision based on Lejeune and Sabra, Raynaud showed that
24613-429: Was formally called the Church of God's Holy Wisdom (Greek: Ναὸς τῆς Ἁγίας τοῦ Θεοῦ Σοφίας , romanized: Naòs tês Hagías toû Theoû Sophías ) and upon completion became the world's largest interior space and among the first to employ a fully pendentive dome. It is considered the epitome of Byzantine architecture and is said to have "changed the history of architecture". The present Justinianic building
24776-577: Was officially delivered by Humbert of Silva Candida , the envoy of Pope Leo IX in 1054, an act considered the start of the East–West Schism . In 1204, it was converted during the Fourth Crusade into a Catholic cathedral under the Latin Empire , before being returned to the Eastern Orthodox Church upon the restoration of the Byzantine Empire in 1261. Enrico Dandolo , the doge of Venice who led
24939-463: Was only perpendicular rays which were perceived by the eye. As there was only one perpendicular ray that would enter the eye at any one point, and all these rays would converge on the centre of the eye in a cone, this allowed him to resolve the problem of each point on an object sending many rays to the eye; if only the perpendicular ray mattered, then he had a one-to-one correspondence and the confusion could be resolved. He later asserted (in book seven of
25102-535: Was perhaps St Elmo's fire induced by gunpowder smoke and unusual weather. The author relates that the fall of the city to "Mohammadenism" was foretold in an omen seen by Constantine the Great – an eagle fighting with a snake – which also signified that "in the end Christianity will overpower Mohammedanism, will receive the Seven Hills , and will be enthroned in it". The eventual fall of Constantinople had long been predicted in apocalyptic literature . A reference to
25265-413: Was replaced by 1325, but while it was still in place around 1412, by the time Johann Schiltberger saw the statue in 1427, the "empire-apple" ( German : Reichsapfel ) had fallen to the earth. An attempt to raise it again in 1435 failed, and this amplified the prophecies of the city's fall. For the Turks, the "red apple" ( Turkish : kızıl elma ) came to symbolize Constantinople itself and subsequently
25428-407: Was supposed to presage the end of the reign of Andronicus I Comnenus ( r. 1183–1185 ). Choniates further writes that in 1203, during the Fourth Crusade , the emperors Isaac II Angelus and Alexius IV Angelus stripped Hagia Sophia of all gold ornaments and silver oil-lamps in order to pay off the Crusaders who had ousted Alexius III Angelus and helped Isaac return to the throne. Upon
25591-405: Was the bishop of Constantinople from 339 to 341, and Constantine died in 337, it seems that the first church was erected by Constantius. The nearby Hagia Irene ("Holy Peace") church was completed earlier and served as cathedral until the Great Church was completed. Besides Hagia Irene, there is no record of major churches in the city-centre before the late 4th century. Rowland Mainstone argued
25754-440: Was the first to correctly explain the theory of vision, and to argue that vision occurs in the brain, pointing to observations that it is subjective and affected by personal experience. He also stated the principle of least time for refraction which would later become Fermat's principle . He made major contributions to catoptrics and dioptrics by studying reflection, refraction and nature of images formed by light rays. Ibn al-Haytham
25917-533: Was the seat of the Patriarchate of Constantinople and a principal setting for Byzantine imperial ceremonies, such as coronations . The basilica offered sanctuary from persecution to criminals, although there was disagreement about whether Justinian had intended for murderers to be eligible for asylum. Earthquakes in August 553 and on 14 December 557 caused cracks in the main dome and eastern semi-dome . According to
26080-554: Was the third church of the same name to occupy the site, as the prior one had been destroyed in the Nika riots . As the episcopal see of the ecumenical patriarch of Constantinople , it remained the world's largest cathedral for nearly a thousand years, until the Seville Cathedral was completed in 1520. Beginning with subsequent Byzantine architecture, Hagia Sophia became the paradigmatic Orthodox church form , and its architectural style
26243-425: Was the true founder of modern physics without translating more of Alhazen's work and fully investigating his influence on later medieval writers. Besides the Book of Optics , Alhazen wrote several other treatises on the same subject, including his Risala fi l-Daw' ( Treatise on Light ). He investigated the properties of luminance , the rainbow , eclipses , twilight , and moonlight . Experiments with mirrors and
26406-605: Was thought by the original excavators in the 1930s to be part of the western entrance of the church itself. The propylaeum opened onto an atrium which lay in front of the basilica church itself. Preceding the propylaeum was a steep monumental staircase following the contours of the ground as it sloped away westwards in the direction of the Strategion , the Basilica, and the harbours of the Golden Horn . This arrangement would have resembled
26569-641: Was understood to represent the emperor holding back the threat to the Romans from the Sasanian Empire in the Roman–Persian Wars , while the orb or globus cruciger held in the statue's left was an expression of the global power of the Roman emperor. Subsequently, in the Arab–Byzantine wars , the threat held back by the statue became the Umayyad Caliphate , and later, the statue was thought to be fending off
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