The Medieval Golden Age, Al-Biruni and the Earth's Radius لبيروني و حجم الارض

[directjet55]

Good work!

Thanks

[anisdalger]

However the Al-Biruni's Method is easier and further accurate: The earth's radius is measured just by a single person from a single location and at any time of the year. You, even if you are alone, have just to choose a mountain on a sea border, anywhere on the earth, and using just an astrolabe you get the earth's radius! Is this not a great achievement!

[StopSpamming1]

I don't understand: more than 1000 years earlier, the Greek Eratosthenes (276–194 BCE) already did this. So what is the great achievement?

During the Arab Golden Age science was advanced, but hardly anything new invented.

[anisdalger]

@StopSpamming1 Eratosthenes' Method: The earth's radius is measured by many people measuring the 4212 miles distance between Alexandria (the location of the obelisk) and Syene (nowadays: Assouan) the location of the pitl (the two cities are in Egypt). Then we could measure the length of the shadow cast by the obelisk of Alexandria at the same time, noon on the summer solstice, June 21st, when 4212 miles away the sunlight shines into the bottom of the pit of Syene! How simple AlBiruni's Method is

[anisdalger]

@StopSpamming1

In this case at midday (and only on June 21st) some people should be on the obelisk of Alexandria ready to measure the shadow when the second team, 4212 miles away, on the pit of Syene, informs them that the sunlight is on the bottom of the pit!

Earth's Radius = (Syene to Alexandria)x(Height of the Obelisk

)/( Length of the Shadow)

[orgolioitalia1]

Allah swt bless you for your work.Ameen