Upon entering the city, their books were confiscated and taken to the scribes .

Then , Leonardo Di Vinci introduced the ‘ royalty ‘ system .

Also, Caliph Omar or Umar was extremely famous in Islamic history as the 2nd caliph and the conqueror of Jerusalem, one of the holy cities. (Especially celebrated by the Sunni, considering that the Shia did not acknowledge his legitimacy.) Islamic rules on how to treat Christians and Jews were pseudepigraphically attributed to him, via this document, The Pact of Umar, believed by many scholars to have been written at least two centuries later.

I know nothing about this library story, but the dates and people fit the ballpark pretty closely.

Hasan, the generally accepted date for the flight is 622 CE. More chronology here. The spread of Islam was pretty fast. Here is another page that puts the conquest of Egypt at 642 CE.

Seeing as Muhammad’s flight to Medina was in 712, the dates are impossible. The title caliph was adopted by Muhammad’s successors, so Omar could not have used it.

Kamau: According to Singh it was Pythagoras who came up with the idea of proof. People before him knew how to calculate a lot of stuff (and “geometry” literally means “measuring the Earth”) but weren’t interested in proving theorems. So that would make modern mathematics a Greek invention.

As for science, the scientific method wasn’t in widespread use until the Enlightenment, i.e., the late 16th century. Francis Bacon gets credit for being the first to articulate the idea so perhaps we should think of modern science as an English invention.

Statemments that include “everybody knows” are immediately suspect.

“…and Greek mathematics went up in smoke.”

Why Greek mathematics? Alexandria is in Egypt (Norhtern Africa)and everybody knows that the basis of mathematics and science was developed (discovered) in Egypt. The Greeks were students to the Egyptians for many centuries.

As I noted in my entry:
http://goatee.net/2003/05.html#_11su
The destruction via Omar is best considered “an allegation”:
http://www.ehistory.com/world/articles/ArticleView.cfm?AID=9