People who use science in their work

The expectations link a skill to a problem and a contribution to a community. For each person you read about, note who needed the work, what problem it answered and what the record says of how it was done.

The TDV entry on the astronomer's science holds that astronomy in its proper sense began in Islam with translation ². Under the caliph al-Mansur an Indian Sanskrit work by Brahmagupta, written around 770 CE, was translated under the title al-Sindhind, and from Indian writings Muslims learned the first concepts of trigonometry ². Ptolemy's Almagest was translated into Arabic toward the end of the eighth century, and many scholars studied it, wrote commentaries and summaries ². This is the record on the astronomer.

The sources used for this lesson contain no sentence in which al-Jazari or Ibn al-Shatir says why he chose his work. For al-Jazari TDV shows a patron: a book commissioned by Nasir al-Din Mahmud ³. For Ibn al-Shatir, Haji Khalifa says he studied the astronomical instruments closely and found that they did not serve every task at every latitude ⁴. These are reports by named writers about the work, not statements by the men themselves.

A marble dial on a minaret can sound like the start of timekeeping. The record on Ibn al-Shatir's sundial says this is not invention of shadows or the world's first clock, but a specific refinement within a long history of astronomical measurement and timekeeping manufacture ^5 6.

The astronomer's tables, the engineer's pump and the timekeeper's dial each answered a need. For which of the three do the records show most clearly who needed the work and what problem it answered, and what is missing for the others?

• The astronomer: zijes, observatories and who paid for them.
• Al-Jazari: the engineer, his patron and his book of devices.
• Ibn al-Shatir's polar-axis sundial: the marble dial and its hour readings.
• Ibn al-Shatir: the Damascus timekeeper and his instruments.