Ancient Skies & The Ptolemaic Crisis
Which ancient civilization used the morning rising of the star Sirius to predict the annual flooding of the Nile River?
Ancient Egypt.
In what century was the great astronomer Nasireddin Tusi born?
The 13th century (Born in 1201).
The famous "Tusi Couple" theorem uses two rotating circles to create what kind of geometric line?
A perfectly straight line.
Which European astronomer used Tusi's geometric models to prove that the Earth revolves around the Sun?
Nicolaus Copernicus.
In what year was the modern Shamakhi Astrophysical Observatory opened in Azerbaijan?
1960.
According to the geocentric system of Aristotle and Ptolemy, which celestial body sits stationary at the center of the universe?
The Earth.
Inside which famous mountain castle did Tusi live and work for over 20 years to escape the Mongols?
Alamut Castle.
Tusi calculated the length of a calendar year so accurately that he only missed modern calculations by how many seconds?
11 seconds.
What language were the original scientific diagrams written in that Copernicus copied from Tusi?
Arabic.
Why are observatories built high up on mountains like Mount Pirkuli, away from big cities?
To avoid light pollution (city lights) and get clearer skies.
What do we call the illusion where a planet looks like it is moving backward in the night sky?
Retrograde motion.
What specific object did Tusi roll down a mountain to prove to Hulagu Khan that understanding the cause of an event eliminates fear?
A massive bronze (or brass) cauldron.
Tusi's famous star catalog, "Zij-i Ilkhani," mapped out the coordinates of what celestial bodies?
The Sun, Moon, and planets.
Which famous ruler and astronomer built a replica of Maragheh Observatory in Samarkand?
Ulugh Beg.
What do scientists study when they break down starlight into colors to find out what a star is made of?
Light / Chemical composition of stars.
Who was the famous ancient Greek astronomer who created the geocentric system used for over 1,000 years?
Ptolemy.
What is the name of the famous, massive observatory founded by Tusi in Southern Azerbaijan in 1259?
The Maragheh Observatory.
Tusi was the first to separate which branch of mathematics from astronomy, making it a separate field?
Trigonometry.
What object on the surface of the Moon is permanently named after Nasireddin Tusi?
A crater.
What is the size (diameter) of the main telescope mirror at the Shamakhi Observatory?
2 meters.
What was the name of the famous library and research center in Baghdad during the Islamic Golden Age?
The House of Wisdom (Bayt al-Hikma).
Which Mongol ruler did Tusi convince to fund and build the Maragheh Observatory?
Hulagu Khan.
Tusi was the first to systematically write down the Law of _____ for spherical triangles. (Fill in the blank).
Sines (The Law of Sines).
Besides a feature on the Moon, what kind of space rock orbiting the Sun is named "4446 Tusi"?
An asteroid.