The History and Philosophyof Astronomy (Lecture 5: Alternative Views:China, Mayan Astronomy)Instructor: Volker BrommTA: Jarrett JohnsonThe University of Texas at AustinAstronomy 350L (Fall 2006)Different Traditions of Astronomy“ Western ”Greece/RomeMedieval IslamRenaissance:CopernicusBabylonScientific Revolution:Galileo, Newton, KeplerInca2. Ancient MayaAztecs1. ChineseJapanese/KoreanIndian/Vedic…Chinese Astronomy: Very Brief IntroductionChinese astronomy vital importance to the State!Chinese Astronomy: Very Brief IntroductionChinese astronomy very sophisticated!Armillary SphereEarth-Sun motion on Celestial Sphere:Sun moves along eclipticonce a year!Two branches of Astronomy Calendrical methods (“lifa”)Celestial Occurrences (“tianwen”)(e.g., comets) regularity/cycles unusual phenomena(Novae, supernovae,comets,…)Yang Wei-Te’s `Guest Star’ of AD 1054 Guest Star = Supernova Explosion- unobserved in Medieval EuropeChinese Model of the Universe Inhabited world is at center of universe - flat EarthAxis ofrotationThe Ancient Maya Classical Period: ~ 200 – 900 ADMaya obsessed with time and astronomy!TikalYucatanMaya Hieroglyphic Writing• Maya writing deciphered only quite recently (> 1970s)• Decoded first: number system and calendarCarved Limestone StelaeMaya Number System• base 20 (vigesimal)• place-value system, includes “zero”Maya Calendar• highly complex• cyclical (recurring) and linear elementsMaya Calendar• 1stcycle: Sacred Round (Tzolkin)• 20 name glyphs + 13 numbers = 260 days• no direct astronomical significanceMaya Calendar• 2nd cycle: Vague Year (Haab)• 18 “months” of 20 days + 1 month of 5 days = 365 days• based on solar (seasonal) yearMaya Calendar• cyclic vs linear:• Same combination oftzolkin and haab date(e.g., 1 Imix 4 Mac)recurs every 52 years!• How to measure longertime periods? Long Count!Maya Calendar• Linear series: Long Count • general format: xx.xx.xx.xx.xx• first day = origin of time (universe)=0.0.0.0.0 Aug. 13, 3114 BC (Gregorian)• last day (= end of time?) = 13.0.0.0.0 2012 ADMaya Astronomy Obsession with Venus= KukulcanVenus Astronomy: The BasicsVenus invisiblein glare of SunVenus appearsas morning starVenus appearsas evening star• invisible -- morning star – invisible – evening star8 days + 263 days + 50 days + 263 days = 584 days (synodic period)Venus Astronomy: The Basics• Venus appears always close to Sun!Celestial SphereHorizonEclipticVenus Astronomy: The BasicsVenus Astronomy: The Basics• Morning star: Characteristic pattern of heliacal risingVenus Astronomy: The Basics• Morning star: Characteristic pattern of heliacal rising• 5-fold symmetry (fiverepeating patterns)• Q: Why is that?• A: 584 x 5 = 365 x 8Book of Mayan Astronomy: The Dresden Codex• One of only 4 surviving Maya codices• Contains Eclipse Tables and Venus TablesDresden Codex: Venus Tables236 + 90 + 250 + 8 = 584(morn. star- …- even. star -- ..)Maya Venus Worship and Warfare• Mayan rulers timedtheir attacks accordingto the motion of Venus• Celestial events wereof the utmost importance• astronomy = religion(Mural at Bonampak)Astronomy and Maya Architecture Alignment astronomy again!(Caracol at Chitzen Itza)Astronomy: Alternative Views • Traditions, independent from Western astronomy: - E.g., Ancient China, Ancient Maya- fundamentally different views of the cosmos• Ancient China:- astronomy integral part of state bureaucracy- search for unusual celestial occurrences (comets, novae…)• Ancient Maya: - obsessed with astronomy and timekeeping- crucial role of Venus’s motions governs Maya warfare- Dresden Codex = The book of Mayan
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