##### How did the religion of Islam influence science during the Islamic Golden Age?

Awesome Astronomy

One of the main teachings of Islam is that people pray 5 specific times a day facing the city of Mecca. In an age before cell phones and email reminders this could be a difficult task to keep up with. For this reason Islamic scholars invented the astrolabe which allowed users to determine the time and location on earth by measuring the angle of the sun and stars. From China, the Arabs borrowed and perfected the magnetic compass to help them determine the direction in which they should pray. One astronomer plotted out the points they would need to find the direction of Mecca from all over the globe- even the North Pole.

The Islamic calendar is based on the lunar cycle with each month starting at the sighting of the crescent moon. To help people keep track of it all-especially during Ramadan a month of fasting and prayer for Muslims- new calendars and astronomical charts were created to more accurately predict the phases of the moon.

From the Greeks, the Arabs built on the theories of Aristotle and Ptolemy who made predictions about the circumference of the earth. Now, pretty much everyone knew that the earth was round- even 2,000 years ago. What Muslim mathematicians did was calculated the size of the earth. They were surprisingly accurate. The circumference of the earth is 24,901 miles- the Arabs were off by only 9 miles....pretty impressive in the days before satellites.

Arab scholars also corrected the works of Ptolemy by coming up with more precise calculations of the winter and summer solstice, as well as the number of days in a year.

With money flowing in from the Caliph, Arab scientists worked on everything from inventing windmills (you thought those were from Holland, huh?) to the first projector (called the Camera Obscura) to new forms of irrigation using gears and shafts.

##### Al Khwarizimi

## What the Ancients Knew

###### Amazing Mathematics

From India, the Arabs borrowed the concept of zero and the number system (known as Hindi or Hindi-Arabic numerals) that we still use today (1,2,3). Before that people had been using their own systems which had certain weaknesses.

Using this new number system. Arabic mathematicians created complex algorithms (a set of rule for solving a mathematical unknown...for example (2x+3y= ?)

In fact, the word algorithm comes from the name of its creator- Mohammad Ibn Musa Al Khwarizimi who wrote books about al-jabr (Algebra) which in Arabic means "to restore" and other complex mathematical theories.

However, Al Khwarizmi used words rather than symbols like X and Y to represent unknown numbers. This made early algebra even more frustrating than it is today, but over the centuries mathematicians have built on his ideas to give us all sorts of fun mathematical fields like calculus and trigonometry!