Segments in this Video

Islamic Influence on Astronomy (02:11)


The heavens have fueled mythologies and much of our science. Ibn Al-Khalili, a half-Iraqi physics professor, will investigate Islamic astronomers whose discoveries influenced Western scientists.

Copernicus (01:54)

Copernicus argued that Earth and other planets orbit the sun. Previous theory held that Earth was stationary and planets orbited it.

Al Battani and Copernicus (02:04)

Copernicus is credited with launching Europe's scientific revolution, but few consider where he got his ideas. He himself credits ninth century Muslim astronomer Al Battani

Tusi Couple (02:42)

Copernicus' book leaves clues of Islamic sources besides Al Battani; his work is the culmination of 500 years of Islamic astronomy. He used the Tusi Couple, a mathematical idea developed by Al-Tusi, and geometric ideas similar to those of Ibn al-Shatir.

Seeking Origins of Muslim Astronomy (02:02)

Al-Khalili will examine what inspired Muslim astronomers. We visit a mosque on a search of a sundial created by al-Shatir.

Islam and Time (02:15)

Marking time is essential to Islam; adherents must pray at precise times each day. Many mosques had sundials. We find the al-Shatir's sundial, designed to be accurate throughout the year.

Measuring Length of Year (03:01)

Islamic astronomers brought unprecedented standards of accuracy to astronomy. Al Battani spent forty years measuring the length of the year, based on his observations of the equinox compared with those of a Greek astronomer.

Al Battani's Accomplishments (01:25)

With an astrolabe and other devices, but no telescope, Al Battani measured the Earth's tilt and discovered that the apogee differs from year to year. Copernicus used Al Battani's tables showing the sun's and moon's position.

Ptolemaic Theory (02:38)

Islamic astronomers' observations suggested to them that Ptolemaic theory was flawed. Ptolemy had other heavenly bodies on crystal spheres rotating around earth.

Doubt (01:55)

Al Battani's data didn't fit Ptolemy's theory. This led to further Islamic questioning of Greek cosmological tradition. Their writings increasingly include the word "doubt."

Doubts on Ptolemy (03:04)

Ptolemy held that everything revolves around earth, but his math requires an arbitrary "equant" center to make it work. Ibn Al Haytham argued that science must be mathematically consistent and challenged astronomers to improve on Ptolemy.

al-Tusi's Castle (02:04)

Nasir al-Din al-Tusi rewrote Ptolemy's theory. We visit the secluded castle at Al a Mut, where he and other scholars lived.

Tusi Couple Replaces Equant (01:22)

Al-Tusi eliminated Ptolemy's equant in favor of two nested circles rotating around each other- a Tusi couple, later used by Copernicus. Al-Tusi sought a consistent mathematical description of astronomic motion but needed better equipment.

Al-Tusi's Observatory (03:07)

Al-Tusi persuaded the leader of the conquering Mongols to him to make him his head scientist and build him the largest observatory the world had ever seen. Al-Tusi brought in astronomers from as far away as Morocco and China.

Al-Tusi's Revolution (02:15)

Al-Tusi's team sought a mathematically rigorous cosmic model. They overthrew Ptolemy but continued to place earth at the cosmic center, forcing them to use epicycles and other complicating factors.

Copernican Revolution as Legacy of Islam (02:14)

Copernicus completed the work of the Islamic revolution in astronomy, deriving from them mathematical models and the drive for mathematical consistency. Newton finally fulfilled al-Haytham's dream of a mathematically coherent astronomy.

Venice and the Spread of Ideas (01:39)

We will study why Islam's astronomic project was completed in Europe rather than the Middle East. Venice was a merchant town with a deep relationship with the Muslim world.

Arab Ideas Come West (02:12)

Arab cultural influence and books came to Venice along with trade, on subjects such as algebra, astronomy and medicine.

Europe, Science, and the Koran (01:43)

The engine of science moved from Islam to Europe in the 1500s. We meet the professor who discovered the first printed copy of the Koran, on an island on Venice, and wonder why it was printed here rather than in the Arab world.

Failure of Printed Koran (01:47)

The Koran we are examining was printed by non-native Arabic speakers and contains mistakes. Muslims didn't accept the printing press for centuries.

Language, Printing Press and Science (01:56)

Arab as a precise, common language fueled Muslim scientific success. Arabic is harder than Latin to set to type, which helps explain why Europe spread ideas and accelerated into the scientific lead with the invention of the printing press.

Attacks on Islamic Empire (03:06)

The decline of the Islamic Empire from the 1200s, under attack from Mongols, Crusaders, and Christian conquerors of Spain, contributed to the decline of Islamic science.

Science Follows Money (02:02)

The discovery of the New World brought wealth to European royalty; science follows money. Britain's wealth gave Newton access to data, making his achievements possible.

European Denial of Islamic Achievements (03:18)

To legitimize their colonization, Europeans encouraged the idea that Middle Eastern civilizations and sciences were declining, which has led to Islamic achievements being forgotten.

Cloning and Science in Muslim World (02:08)

The West has made most scientific discoveries in recent centuries. Today, however, Iran's government funds controversial stem cell and cloning research; we visit a laboratory

Truth and Nature as Universal (02:25)

Nature's rules transcend culture and politics. Medieval Islamic scientists synthesized knowledge from around the world. Science is the universal human language.

Credits: The Power of Doubt: Science and Islam--The Golden Age (00:49)

Credits: The Power of Doubt: Science and Islam--The Golden Age

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The Power of Doubt: Science and Islam--The Golden Age

Part of the Series : Science and Islam: The Golden Age
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Challenging the scholarly establishment in the 11th century with his paper “Doubts on Ptolemy,” Ibn al-Haytham sparked a paradigm shift in the way that learned people regarded the movement of planets and stars. In this program physics professor Jim Al-Khalili visits Italy, Egypt, and Syria to show how the spirit of inquiry among Islamic astronomers helped bring about the Copernican Revolution in Europe. But why was the work that began at the great Maragheh observatory completed in Europe and not in the Middle East? Al-Khalili also goes to Tehran to examine the role of science in Islam today. Part of the series Science and Islam: The Golden Age. (59 minutes)

Length: 60 minutes

Item#: BVL47838

ISBN: 978-1-62102-622-8

Copyright date: ©2009

Closed Captioned

Reviews & Awards

“Anyone interested in medieval Islam or the history of science will welcome this enjoyable and informative presentation. Jim Al-Khalili is an engaging guide and teacher....He is to be commended for discussing the significance of each discovery, as well as the motivations behind the enterprises. Moving diagrams and animations illustrate his explanations of advances in astronomy, mathematics, and other areas to great effect. Even better is the extent to which he shows how science advanced....Recommended.”  Educational Media Reviews Online


“An easy and comprehensive way of grasping the incredible Islamic contributions that laid the foundation for scientific discoveries in the West in mathematics, medicine, chemistry, and astrophysics....informative, accurate, thought-provoking, and entertaining. Moreover, the cinematography was outstanding...”  Science Books & Films (Editor’s Choice)

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