Presentation on theme: "Roger Bailey NASS, St Louis, 2008"— Presentation transcript:
1Roger Bailey NASS, St Louis, 2008 Ottoman SundialsRoger BaileyNASS, St Louis, 2008
2Ottoman Sundial Topkapi Palace, Istanbul Sundial in Third Garden of Topkapi Palace, near Library of Ahmet III.Designed by Suleyman, the first secretary of the Treasury in the reign of Memhet II, the Conqueror ( )Renovated in 1794 by Seyyid Abdullah
3Ottoman Sundial Missouri Botanical Garden Topkapi Dial design for Ottoman Garden at Missouri Botanical Garden, St LouisPaul Brockman: Project CoordinatorE.L. Bakewell Jr: SponsorFazil Sutcu: ArchitectAbraham Mohler: SculptorRoger Bailey: DesignerFrom Istanbul to St Louis, an interesting project. To understand why we need a historical perspective. Lets go back to 1480 when the original dial was constructed. What was happening in the world at that time? Who were the superpowers, nations that influenced world politics beyond their bordersIn those days what
415th Century Superpowers Holy Roman Empire? Fredrick III,Spain? Isabella & FerdinandEngland? 1485 Henry VII, War of RosesFrance? Louis XI (the Prudent)Florence?, Medici, Papal States? BorgiaChina? Ming Dynasty ( )Ottoman? Mehmet II (the Conqueror)From Istanbul to St Louis, an interesting project. To understand why we need a historical perspective. Lets go back to 1480 when the original dial was constructed. What was happening in the world at that time? Who were the superpowers, nations that influenced world politics beyond their borders in those days. Europe was in turmoil with no dominant or Imperial superpower. The nations that we know today did not exist but were waring fiefdoms whose allegiances depended more on royal marriages than geography, culture or language. China had begun its period of isolation following the remarkable voyages of America was yet to be officially discovered. The Ottomans in Turkey we the force to be reckoned with.
5Mehmet the ConquorerConstantinople, centre of the world, where East meets WestOttoman Turks tookConstantinople in 1453Ended Byzantine Empire started by Constantine in 330Expanded Ottoman Empire in Middle East and Eastern EuropeThe Ottomans, originally Turkish raiders from the steepes of Central Asia were expanding their empire. The key conquest by Mehmet II in 1453 took Constantinople and finished the Byzantine Empire, the eastern remnant of the Roman empire. This made Constantinople the center of the expanding Ottoman Empire.
6Constantinople as at the divide between east and west, Europe and Asia Constantinople as at the divide between east and west, Europe and Asia. The Byzantines were the last remnant in the east of the Roman Empire and Christianity, Islam was the religion of the East and expanding its influence from the days of the prophet Mohamed in Arabia in the 6th century (558)
7Battle of Walachia 1462Count Dracula of Transylvania, Vlad III (the Impaler), rebelled and fought back in Walachia in 1462Impaled 20,000 Turkish prisonersVlad captured and executed but stopped the Ottoman advance across EuropeThere was resistance to the westward expansion History records that Count Dracula from Transilvania stopped the Ottoman forces in Walachia ( Bulgaria). Dracula was also known as Vlad the Impailer for his cruel execution technique. I am not making this up. These were cruel and brutal time that we in the west know little about.
8Battle of Lepanto 1571Ottoman navy defeated by Don Juan and combined fleet of Holy LeagueAt Lepanto, on Oct. 7, 1571, the Ottoman navel fleet battled between the Christians in the strait between the gulfs of Pátrai and Corinth, off Lepanto (Návpaktos), Greece. The fleet of the Holy League commanded by John of Austria (d. 1578) opposed the Ottoman fleet under Uluç Ali Pasha. The allied fleet (about 200 galleys, not counting smaller ships) consisted mainly of Spanish, Venetian, and papal ships and of vessels sent by a number of Italian states. It carried approximately 30,000 fighting men and was about evenly matched with the Ottoman fleet. The battle ended with the virtual destruction of the Ottoman navy (except 40 galleys, with which Uluç Ali escaped). Approximately 15,000 Turks were slain or captured, some 10,000 Christian galley slaves were liberated, and much booty was taken. The victors, however, lost over 7,000 men. Among the allied wounded was Cervantes, who lost the use of his left arm. Lepanto was the first major Ottoman defeat by the Christian powers, and it ended the myth of Ottoman naval invincibility. It did not, however, affect Ottoman supremacy on the land, and a new Turkish fleet was speedily built by Sokollu, grand vizier of Selim II. Nevertheless, the battle was decisive in the sense that an Ottoman victory probably would have made the Ottoman Empire supreme in the Mediterranean.
9Mehmet II Sultan 1453-1481 Emperor, warrior, scholar Built Istanbul: Topkapi PalaceConverted Hagia Sophia to a mosqueMeanwhile back in Constantinople, now known as Istanbul, the Sultan was establishing his government and the Ottoman culture
10Topkapi Ottoman Sundial Drawn by Suleyman Bey, Secretary of the Treasury for Sultan Mehmet IISimilar to sundials at Damascus & Kairouan, TunisiaTwo gnomons, four time systemsRepresents science, culture, religion, and empire
11Hagia Sophia: Istanbul Byzantine Cathedral: “Divine Wisdom”Roman Emperor Justinian 5371453’s Sultan’s Mosque, now museum
15Topkapi Palace Ottoman Sundial This is what the veiled women were viewing. A strange pattern of lines and Arabic writing. What does it mean? The lines are the hour lines for two different sundials and show four different systems of measuring time.
16Ezanic HoursThe called the hours show on the inner dial Ezanic hours. My Italian collegue Gianni Ferrari that In Turkish language ezan or azan is the call to prayer. This is from Arabic, Adhan, the Islamic call for the prayers that have to be recited in Islamic lands five times each day. ezani = pertaining to the azan and ezani saat is the hour as reckoned from sunset. So this sundial is based on the day starting and ending at sunset and regulates the time for prayers.
18Outer Scale: Polar Sundial Hour Lines:AnglesTan (Hour Angle) = Tan (time angle) x Sin (latitude)The outer scale is what we would recognize as a sundial. The thin rod or wire shows by its angle the time of day based on noon being the reference point. The ottoman Turk numbers show noon was 6 o’clock. This is noon as we know it, mid-day when the sun is highest in the sky and due south.Polar Gnomon SupportHour Scale: Based on Noon as 6 o’clock. Ottoman Turk Numbers
19Ibn al-Shatir ‘s Sundial Damascus Umayyad Mosque Horizontal sundial on north Minaret until ~1900By Ibn al-Shatir in 1371Astronomer, mathematician, timekeeper (muwaqqits)Planetary theory like CopernicusFirst polar sundials including Compass CompendiumShowed time relative to sunset, sunrise, noon and afternoonModel for Ottoman sundialsThere are other sundials with similar lines and time systems. The first was the dial designed by Ibn al-ShatReplica in Damascus Museum
20Ezanic Hours At sunset, day ends 12 and starts at 0 Vertical Peg GnomonSummer 21 June11Date Lines:Shadow pathOn solstices and equinox1212Tip of shadowtells time103Lets isolate the butterfly shape in the middle that shows enzanic hours. These are referenced to the length of the shadow from the small vertical peg gnomon. The tip of the shadow tells the time.5Winter 21 June411Ezanic Hours: Sunset 12 off scale to east (left) 24 in Italian HoursBabylonian Hours: Sunrise 12 off scale to west(right). Mirror image
21Moslem Prayer TimesPrayer times based on the length of the shadow are also shown by this curved line. This is for the start of the important afternoon prayer “Asr”. Other dials show more prayer times.Asr starts when shadow length is noon shadow + gnomon heightAsr ends when shadow length is noon shadow + twice gnomon height
28New Mosque Yeni Camii 2 Local hours 20’ Polar Gnomon bent horizontal (Moslem style)
29New Mosque “Yeni Camii” 1 Local hours 20’ Ezanic hours Asr 1 & 2 Zhur? Declination
30New Mosque Yeni Camii 3 Islamic sundial Prayer times Hours? 20’ Overlay confirms declination lines, equinoctial and Asr Prayer line (N + G).Zuhr Prayer line and parallel curved time lines are differentNew MosqueYeni Camii 3Islamic sundialPrayer timesHours? 20’
31Why? Ottoman Sundials Complex and difficult to read but impressive Four time systems:Time systems from east and westReligious and secular timeCall to prayer? Tell time? PerhapsUnderstand and explain our universe?Teach & demonstrate scientific prowessDemonstrate the scope of the Empire
33Missouri Botanical Garden St Louis, MissouriOttoman GardenSame Latitude as IstanbulExotic tulipsWater featuresOttoman SundialNASS ConferenceFred Sawyer NASSDon Snyder NASSMike Olsen MBG
34Ottoman SundialTopkapi Dial design for Ottoman Garden at Missouri Botanical Gardens, St LouisPaul Brockman: Project CoordinatorFazil Sutcu: ArchitectAbraham Mohler: SculptorE.L. Bakewell Jr:SponsorRoger Bailey: DesignerFrom Istanbul to St Louis, an interesting project. To understand why we need a historical perspective. Lets go back to 1480 when the original dial was constructed. What was happening in the world at that time? Who were the superpowers, nations that influenced world politics beyond their bordersIn those days what
36Differences: Topkapi and Missouri Goal: Comprehension not confusionNoon is 12 not 6 on polar dialArabic not Ottoman numbersFewer LinesTime division: 5’ 15’ 30’ not 1’ 4’ 20’Hours & Half hours (30 min) , not 20 minutesPrefered view: from SouthLatitude 41 vs 38.6
37Fer de Vries: ZW 2000 A UNIFORM METHOD TO COMPUTE FLAT SUNDIALS Principle: Convert the sun's position into coordinates for a shadow point on the dial's faceSolve for Altitude and Azimuth knowing Latitude for various times, Declinations, sundial types and orientationsProject the shadow of a point, the tip of a perpendicular gnomon onto the plane of the dialDraw the timelines requiredClip drawing or export as a DXF fileDesign the sundial, based on the timelines timelines
38Polar Sundial DesignOuter dial with the polar gnomon is a simple standard Western designCreate the lines at the correct angles for the location using specific sundial design software “ZW 2000” by Fer de VriesBring the lines into a CAD program “Delta CAD” to trim and fit to design
39Ezanic Sundial : Sunrise NorthSouthWestEastHours from Sunrise1212103468Babylonian Hours are the reverse of ItalianPeg GnomonWinter AM 2 hours after sunriseSunrise 12 &0 off scale to West (left), 24 in Babylonian Hours
40Ezanic Sundial : Sunset NorthSouthWestEast121234511679108Date Lines:Shadow pathOn solstices and equinoxSummer 21 JuneWinter 21 DecemberEquinoxPeg GnomonEzanic Hours: Sunset 12 off scale to east (right) 24 in Italian HoursHours from previous Sunset
41Ezanic Timelines Simplified Timelines seem confusing but are quite simpleGo back to the Bible: Third, Sixth, Ninth Hour etc.Look at the Equinox, 12 hour days, mid-day is 6All the hours are the same, crossing on the EquinoxEastWest1Equinox2345678910111212Red: Italian SunsetBlue: Babylonian111
42Moslem Prayer HoursFor devout Moslems, there are five prayer times, all determined by the altitude of the sunFajr (morning): twilight to dawnZuhr (noon): Shadow length: noon + ¼ gnomon heightAsr (mid pm): Shadow length: noon + gnomon height to noon + 2 gnomon heightsMaghrib (sunset): sundown to end of twilightIsh (night): twilight to dawnZuhr and Asr are (were) set by shadow lengthsHorizontal sundials with perpendicular gnomons
43Monastic Moslem Daily Prayer Times Prime Matins Triece Sext Nones VespersComplinezuhrasrmaghribishafajrMoslemduhaMidnightMiddaySunriseSunsetDaybreakNightfallDaily Prayer Times
44Moslem Prayer TimesNoonDefined by altitude of sun determined by shadow lengthsZuhr = Noon + ¼ gnomon heightAsr = Noon + gnomon height to Noon + 2 gnomon heightsZuhrAsrGnomon
45Moslem Prayer Timelines Zon 2000Istanbul: Latitude 41º NHorizontal with Vertical Gnomon
46Qibla: Direction to Pray Moslems pray towards Mecca, generally EastThe direction is as important as the timeMihrab (niche), in the Mosque is oriented to MeccaOttoman sundials often show the Qibla directionThis symbol represents the Mosque, Mihrab & QiblaGreat Circle Qibla St Louis to Mecca is N 47.2º E
49Two Gnomon ProblemZX 2000 does all the required timelines but for one gnomon heightPolar gnomon is 10 cm at origin, peg gnomon is 5 cmDo two designs and merge DXF files
50Merge DXF Files File Conversions 1.Rename ZW *.dxf as *. Txt End of First DXF*VERTEX8L_A100.000020SEQENDENDSECEOFStart of Second DXFSECTION2ENTITIESLINE8L_$1020*File Conversions1.Rename ZW *.dxf as *. Txt2. Edit as *.txt3. Save and rename*.txt as *.dxf4. Import into CAD5. Trim lines to design in CAD6. Print final as pdf to print full size at any copy shop
52Construction: Abraham Molher 11 March – Marble 1 April – Carving7 April – Gnomons9 May – Installation16 May -Dedication
53People think sundials are wrong. They are not People think sundials are wrong. They are not. Clocks need to be corrected to the true local solar time as used before the railroadsSundials tell true local solar time based on noon being the time when the sun is due south and at it’s highest elevationDaylight savings is the biggest correction, 1 hour less than standard timeClocks show averaged time for the center of their time zone. There is a correction for longitude, 4 min/degreeThe correction at St Louis (90º25’15”) is only 1’02”Clocks need to be corrected due real changes in the length of the day caused by the tilt and elliptical orbit of the earthThis correction is called the Equation of TimeThe Equation of Time varies up to +/- 15 min through the year
54Orientation Error!After careful design, engraving, construction and alignment with the sun, the dial was arbitrarily reorientedIt “looks better lined up with the sidewalk”, ~ 9º off NorthErrors are significant:14 to 37 minutesWorst when shadows are longWinter, early AM and late PMError obvious from date lines
55Orientation Error Check Dial Reads 10:17 SolarPicture taken 11:31 CDT, 5 July by Don SnyderCorrections to clockDaylight savings -1:00:00Equation of Time :41Longitude 25’15” :02Clock to Solar 10:25Observed Error 8 minPredicted Error 15 min
60Ottoman Sundial Missouri Botanical Garden Sundial is unique and significantOnly Islamic dial in public use in AmericaOnly dial with Italian and Babylonian hoursOnly dial with prayer times or QiblaShows what western civilization gained from the peak of Islamic science and cultureAppropriate for the Ottoman GardensThere are some small Islamic dials in museums, gallaries and private collections
61Islamic Culture and Science Astronomy and Mathematics Arabic names for starsBabylonian Deg:Min:SecGreek astronomyCelestial SphereAstrolabe and sundialsMathematicsZero and Arabic numbersGreek geometryAlgebra, algorithmSpherical trigonometryDark Ages in EuropeBuilt on the best of East and WestReintroduced texts and knowledge of Greeks and RomansPtolemy’s “Almagest”Focus: Marking timeCalendar, lunar monthPrayer timesDirection to Mecca
62The End Library Hagia Sophia One Book: Koran Islam peaked with the Ottomans 500 years ago. Why?Narrow science focus: timekeeping. One book: KoranWarfare, repression, militancy, terrorismPoor Government: Decadence and corruptionReligious fundamentalism, theocracyPopulation and PovertyLoss of arable land: overgrazing, erosion, exhaustionClimate change? Deserts? Cause or Effect?Back to the Middle Ages:No Enlightenment, Reformation or RevolutionsOne Book: Koran
63References and Photo Credits Istanbul Topkapi Palace, Sundial of the Month, Dec 2005” Joel Robic“Principle and Use of Ottoman Sundials” Atilla Bir“OSMANLILARDA GÜNEŞ SAATLERİ” Prof. Dr. Atilla Bir“Sundials in Medieval Islamic Science and Civilization” Len Berggren, NASS, 8-2 June 2001“Astronomy in the Service of Islam”, David A. King, Variorum 1983.“In Synchrony with the Heavens” V1 “The Call of the Muezzin” D. A. King, Brill 2001“A Uniform Method to Compute Flat Sundials” Fer de Vries: ZW 2000“Error Analysis of the Horizontal Sundial – IX Dial Rotation” T. J. Lauroesch and J. R. Edinger, Jr. , NASS Compendium 4-4 Dec 1997Les cadrans solaires de monde de l’Islam (Sundials in the Islamic World), Chapter X, Les cadrans solaires, histoire, théorie,practique” René Rohr, Oberlin, 1986 (This section is In European editions not North American editions in English, U o f T 1970 or Dover 1996)The Meridian of Ibn Al Shatir –Umayyad Mosque in Damascus” Gianni Ferrari, unpublished personal communicationSlide 1: Atilla Bir “Principle and Use of Ottoman Sundials”Slide 2,13,14,16: Alain Ferreira, Joel Robic, “Istanbul Topkapi Palace”Slide 3,34,35, 51,52, 54, 56: Don SnyderSlide 32: Ian Adams, Missouri Botanical Garden,Slide 33, 57: Laila Wessel, Missouri Botanical Garden