The Book That Started It All

They can't harm you, if they can't find you! Use code SYVERSEN at the link below and get 60% off an annual plan: https://incogni.com/syversen Join my mailing list: https://ben-syversen.kit.com Patreon for early previews, ad free versions of the videos, and support the channel: https://patreon.com/BenSyversen Credits: Written, produced, animated, edited by Ben Syversen Illustrations and 3d Baghdad marketplace scene: Kendall Eddy Oud: Hadi Eldebek Special thanks to Professor Jeffrey Oaks for all of his help and input with this project ***A note from Professor Oaks about the spelling/pronunciation/transliteration that I used in this video for our protagonist: Until recently, people in Europe tended to transliterate the region south of the Aral Sea as "Khwarezm", and the Baghdad scholar's name as "al-Khwārizmī. Of course, there is a disagreement on that vowel, one with an "e" and the other with an "i". Also, we have for some decades now rendered the three Arabic vowels as "a", "i", and "u", so there should have been no "e" in the first place. Recently historians and linguists have rectified the name of the region by writing "Khwarazm" (as the Wikipedia page reflects), so it is only reasonable to write "al-Khwārazmī" as well. The medieval person who transliterated our protagonist's name into Latin as "Algorizmi" did not know what name he was reading, since he substituted the letter khāʾ (our "kh") with a jīm ("g"). The two differ only by a dot, as you see here: ج خ [Ben's note: Prof. Oaks sent images of the characters as they would have appeared in the 9th century. These are the standalone characters that show the same dots] It is very common for copyists to leave off the dots, and sometimes a dot is misplaced. So our transliterator likely did not know that that letter should be a khāʾ. That means that he did not know what the name was, and so could not have known what the one short vowel should be, or even if there was a vowel there at all. The same confusion about the same letter is at play in whether we should write "al-Karajī" or "al-Karkhī". Some manuscripts have the dot above, and others have the dot below, and the vocalization changes from one reading to the other. So the first "i" in "Algorizmi" cannot be declared to be correct. Perhaps more important, short vowels were not all fixed in stone across the entire Islamicate world. For example, in a 1305 commentary al-Hawārī, working in (what is now) Morocco, related that the word jidhr ("root") is spoken with either an "i" or an "a", and that his teacher Ibn al-Bannāʾ thought that the "a" was more appropriate. Pronunciations were---and remain---fluid, and how we transliterate words and names from centuries ago often depends on the educated guesses of modern scholars. So if people want, they can go ahead and continue to write "al-Khwārizmī". We cannot know how he pronounced his own name, after all. *** _______ Resources and suggested reading: The legacy of al-Khwārazmī in history of algebra - Jeffrey Oaks (2016) The Series of Problems in al-Khwārizmī’s Algebra - Jeff Oaks Al-Khwarizmi: The Beginnings of Algebra - Roshdi Rashed (2010) The Development of Arabic Mathematics: Between Arithmetic and Algebra - Roshdi Rashed (1996) - Boston Studies in the Philosophy of Science J.A. Oaks, H.M. Alkhateeb, Simplifying equations in Arabic algebra, Historia Mathematica (2006), doi:10.1016/j.hm.2006.02.006 What is “Geometric Algebra” and what has it been in historiography? - Jens Høyrup (2016) Stages in the History of Algebra with Implications for Teaching - Victor J Katz - Educational Studies in Mathematics (2007) 66: 185–201 DOI: 10.1007/s10649-006-9023-7 A History of Mathematics: An Introduction, 3rd Edition - Victor J Katz (2009) Baghdad: City of Peace, City of Blood, Justin Marozzi (2015) - a wonderful book about the history of Baghdad; this is the source of the claim, with no primary source cited, about Baghdad’s circular layout being inspired by Euclid. The claim is repeated in this excerpt in The Guardian: https://www.theguardian.com/cities/2016/mar/16/story-cities-day-3-baghdad-iraq-world-civilisation Excerpt from a forthcoming book by Keith Devlin and Jeffrey Oaks on this topic: https://maa.org/math-values/algebra-its-not-what-it-was/ More from Keith Devlin: https://devlinsangle.blogspot.com/2016/04/algebraic-roots-part-1.html Additional resources and image credits: https://docs.google.com/document/d/1gHY9UJfd5Ha8YwSFrzNaX51inim4bhrpfqOteI1jiOY/edit?usp=sharing Time Stamps: 00:00 Intro 01:15 I - The Abbasid Caliphate 03:01 I - What Al-Khwārazmī Knew: The Greeks 05:31 I - What Al-Khwārazmī Knew: The Babylonians 10:39 I - What Al-Khwārazmī Knew: Practical Math 15:25 I - Civil War + The Rise of Al-Ma'mun 18:39 II - Al-Khwārazmī's Book 22:18 II - Why Modern Algebra Looks Strange to Al-Khwārazmī 31:00 III - Later Arabic Algebra 33:11 III - Transmission to Europe 36:48 III - Diophantus and Brahmagupta 38:08 III - The Chain of Transmission