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Announcements. First exam is two weeks from today (February 19 ). Will cover chapters 1, 2, 3, 4 & 5. Sample questions have been posted. Format will be 15 MC’s (3 points each) and 3 essays (18 points each) from a list of 5
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Announcements • First exam is two weeks from today (February 19). Will cover chapters 1, 2, 3, 4 & 5. Sample questions have been posted. Format will be 15 MC’s (3 points each) and 3 essays (18 points each) from a listof 5 • 1st Quarter Observing Night tomorrow night. Set-up starts 45 minutes before the start time so meet here at 6:45pm • Start Chapter 4for next time. Think of some discussion questions tobring to class
Much of the “science” went on in the “House of Wisdom” Established in Bagdad in the late 8th Century as a center for translations. Eventually becomes the Islamic equivalent of the Library of Alexandria
The Islamic Calendar is a lunar calendar Months are 29 or 30 days. The year is 354 days long.
Each month would only begin with the sighting of the Waxing Crescent Moon
Eventually, calculations are made to assist in the observations Early calculations resulted in tables of “visibility” for each latitude and some longitudes
Prayer Times required means of telling the time Early on “folklore” astronomy was used. Some used sand clocks or hour glass “clocks” to determine the times. Eventually, muwaqqit’s, official time keepers are appointed for each mosque.
al-Khwarizmi was the first to produce prayer time tables His tables were for Bagdad but modern prayer tables can be found for any location on Earth
Also important was the direction to Mecca Not only should you pray towards Mecca, mosques and other structures should be aligned to Mecca
Islamic Observatories tended to not survive very long Taqial-Din at his observatory in Istambul The Maragha Observatory in Iran
The Observatory of Ulugh Beg was the most elaborate The chief observer was Ulugh Beg, the governor and then Sultan of Timur(current day Uzbekistan, Tajikistan, Turkmenistan, Kyrgyzstan and Kazakhstan The quadrant was over 130 feet long and still survives today
The Islamic astronomers especially didn’t like Ptolemy’s equant The solution: add epicycles to the epicycle
The Astrolabe The astrolabe is a combination planisphere and time keeper. It allows you to determine the time given your location and the visible stars. It can also compute the position of the Sun or Moon
The Astrolabe in pieces Check out the Astrolabe website
Islamic Astronomy began to fall behind after the invention of the telescope