Why is 'x' the unknown? | Terry Moore

Why is 'x' the unknown? | Terry Moore

Why is X the Unknown?

In this section, the speaker explores the origin of why the letter X represents the unknown in various contexts.

The Logic of Arabic Language

  • Arabic language is highly logical and precise, with each part of a word or sentence carrying significant information.
  • Western science, mathematics, and engineering owe much to the Persians, Arabs, and Turks who developed these fields in the early centuries of the Common Era.
  • Algebra, derived from the Arabic term "al-jebr," meaning "the system for reconciling disparate parts," is one example of their contributions.

Translation Challenges from Arabic to European Languages

  • Arabic mathematical texts containing valuable knowledge reached Europe through Spain in the 11th and 12th centuries.
  • Translating this wisdom into European languages posed challenges due to differences in sounds between Arabic and European languages.
  • The letter "sheen" in Arabic represents a sound similar to "sh" but doesn't exist in Spanish or other European languages.
  • Medieval Spanish scholars created a convention where they borrowed the "ck" sound from classical Greek (represented by Kai) when translating into Spanish.
  • Later translations into Latin replaced Greek Kai with Latin X.

The Unknown Thing

This section delves into how the word "shayun" (meaning "something") and its association with al-shayun ("the unknown thing") influenced mathematical terminology.

Al-Shayun as an Early Mathematical Term

  • The word shayun appears frequently in early mathematics as a way to refer to an undefined or unknown thing.
  • It carries significance in algebraic derivations and root calculations.

Translation Challenges for Medieval Spanish Scholars

  • Medieval Spanish scholars faced difficulties translating al-shayun due to lacking the "sh" sound in Spanish.
  • They adopted the "ck" sound from classical Greek (represented by Kai) to represent the Arabic sheen sound.
  • Later translations into Latin replaced Greek Kai with Latin X, solidifying its association with the unknown.

The transcript continues beyond this point, but these are the key points covered in the provided section.

Channel: TED
Video description

http://www.ted.com Why is 'x' the symbol for an unknown? In this short and funny talk, Terry Moore gives the surprising answer. TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes. Featured speakers have included Al Gore on climate change, Philippe Starck on design, Jill Bolte Taylor on observing her own stroke, Nicholas Negroponte on One Laptop per Child, Jane Goodall on chimpanzees, Bill Gates on malaria and mosquitoes, Pattie Maes on the "Sixth Sense" wearable tech, and "Lost" producer JJ Abrams on the allure of mystery. TED stands for Technology, Entertainment, Design, and TEDTalks cover these topics as well as science, business, development and the arts. Closed captions and translated subtitles in a variety of languages are now available on TED.com, at http://www.ted.com/translate If you have questions or comments about this or other TED videos, please go to http://support.ted.com