Al-Biruni applied mathematics to geography.As a student,
Al-Biruni calculated the latitude of his home town by measuring the angle of shadows
when the sun reached its highest point.
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Al-Biruni calculated the circumference of the Earth.To calculate the circumference of the earth, he measured the shadows of arrows planted in the ground. The length of the shadow changed in a regular pattern as he traveled north or south. He used trigonometry to calculate the circumference of the earth, based on the angle and length of the shadows. |  |
Al-Biruni used latitude and longitude.He also agreed with the ancient Greek scientist Hipparkos that he could determine a location east and west by comparing when it was noon. Since the earth rotates on its axis, the sun hits its noon height at different times in different places. This progression east and west is called longitude. By combining latitude (north and south) and longitude (east and west), Biruni was famous for pinpointing the location of cities. |  |