Person: Al-Jawhari, al-Abbas ibn Said
Al-Jawhari was an Islamic mathematician whose main work was a commentary on Euclid's Elements.
Mathematical Profile (Excerpt):
- Al-Jawhari was employed in the service of al-Ma'mun in Baghdad, although we do not know exactly when he began his work there.
- Al-Jawhari, although best known as a geometer, made observations in Baghdad from 829 to 830 while working for al-Ma'mun.
- The main work by al-Jawhari was Commentary on Euclid's Elements which is listed in the Fihrist (Index), a work compiled by the bookseller Ibn an-Nadim in 988.
- Commentary on Euclid's Elements is almost the same work described by Nasir al-din al-Tusi (although al-Tusi gives a slightly different title for al-Jawhari's work: Emendation of the Elements).
- This work contained nearly fifty propositions additional to those given by Euclid and included an attempt by al-Jawhari to prove the parallel postulate.
- Al-Tusi quotes six of the nearly fifty propositions which together form what al-Jawhari believed was a proof of the parallel postulate.
- This means that, as far as we are aware, al-Jawhari was the first Arabic mathematician to attempt such a proof.
- In the short treatise al-Jawhari presents three additions to Book V of Euclid's Elements, which are meant prove Definition 5 which defines equal ratio, and Definition 7 which defines greater ratio.
- Al-Jawhari's "proofs" are examples of early attempts by Muslim mathematicians to understand the difficult concepts in Euclid's Elements.
Born about 800, possibly Baghdad, Iraq. Died about 860, possibly Baghdad, Iraq.
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Tags relevant for this person:
Ancient Arab, Origin Iraq
Thank you to the contributors under CC BY-SA 4.0!
Adapted from other CC BY-SA 4.0 Sources:
- O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive