Did Hypatia invent the Astrolabe?
With Hypatia’s work rendered to dust, it is difficult to definitively say she invented the astrolabe or other mechanical gadgets. Several sources of her history note that much of what is written about her is fiction.
There are some remaining original clues, however, to Hypatia’s life, which Michael A. B. Deakin describes in The Primary Sources for the Life and Work of Hypatia of Alexandria (1995).
Especially relevant are letters from Synesius to Hypatia. Six letters and a fragment survive, which have been translated to English by A. FitzGerald in The Letters of Synesius of Cyrene (London: Oxford University Press, 1926).
In Fitzgerald’s translation, the letters to “To The Philosopher (Hypatia)” are Nos. 10, 15, 16, 33 (the fragment), 81, 124 and 154. In addition, Hypatia is referenced in a letter to Paeonius, where Synesius describes the astrolabe he had produced and presented to Paeonius. It is seen as an important document in the history of astronomy. (Deakin):
I am therefore offering you a gift most befitting for me to give, and for you to receive. It is a work of my own devising, including all that she, my most revered teacher,1 helped to contribute, and it was executed by the best hand to be found in our country in the art of the silversmith. (Fitzgerald, page 262)
1 The footnote in Fitzgerald’s translation assumes the “she” is Hypatia.
Alas, it is clear to me that she did not invent the astrolabe, but collaborated on the design of a unique and artistic rendition which was produced by a silversmith. Synesius, like so many male scholars throughout history, has perhaps not given enough credit to his co-designer.
Synesius references the great Ptolemy and the “devine band of his successors” with the invention of the astrolabe…”for the sixteen stars made it sufficient for the night clock. Hipparchus merely transposed these stars and inserted them in the instrument.” (page 263) Apollonius (ca. 225 BC), Hipparchus (ca. 180 BC), Vitruvius (ca. 88 BC), Ctesibius, and Ptolemy (ca. AD 150) studied astrolabe and stereographic projection, from which eventually came the planisphere and astrolabe.
Highlights of the Design
Synesius describes to Paeonius the features of the astrolabe he has enlosed with the letter:
We [Hypatia and her silversmith?] worked it out and elaborated a treatise, and studded it thickly with the necessary abundance and variety of theorems. (page 264)
…executed a most fair image of the cosmic expanse.
Thus the Antarctic circle has been inscribed greater than the greatest, and the relative distances of the stars have been lengthened according to that plan of project [mentioned in the previous paragraph of the letter]. (page 265)
As to the epigrams, they are of solid gold… [one written by Ptolemy and one by Synesius] (page 265) [In this paragraph, Synesius mentions that he himself constructed the instrument. Has he forgotten his collaborator?]
It professes to show the places of the stars, not their position in respect to the zodiac, but in respect to the equator. (page 265)
To further suggest that Hypatia did not invent the astrolabe, but had a hand in a designing a more elaborate version of it, I point to James E. Morrison. In Astrolabe History, he writes extensively on the history of astrolabes and notes in his email interview that Hypatia most certainly did not invent the instrument.
No one knows exactly when the stereographic projection was actually turned into the instrument we know today as the astrolabe. Theon of Alexandria (ca. 390) wrote a treatise on the astrolabe that was the basis for much that was written on the subject in the Middle Ages. Synesius of Cyrene (378-430) apparently had an instrument constructed that was arguably a form of astrolabe. This is plausible since Synesius was a student of Hypatia, Theon’s daughter.
Some authors attribute Hypatia with invention of the astrolabe and planosphere, which may be based on recent writings and not on the historical documents that continue to be uncovered, retranslated, and reviewed with new eyes. It is interesting, that women authors seem to attribute the invention to Hypatia where the male authors do not. Who’s research is correct–more valid? Of course, we’ll never know, as we cannot go back in time (yet).
Perhaps it was her gruesome retelling of her alleged murder that encouraged scholars to make statements like: “Most of Hypatia’s writing originated as texts for her students. None has survived intact, although it is likely that parts of her work are incorporated in the extand treatise of Theon. (Alic, page 24).
Another biography of Hypatia says she wrote instructions for making an astrolabe but in the next paragraph, contributes the invention to her (Tiffany Lunk & Sasha Velez, Andrews University). Inventions.org says that practical technology was Hypatia’s main interest and that she perfected the plane astrolabe so it could accurately solve problems in spherical astronomy. Perhaps this is what many scholars think of as “invent”. Improvements are certainly part of necessary evolution in technologies. Society tends to focus on who did what first rather than who made the most contribution, which, women often did, as they were in many cases delegated to rather than managers of projects involving inventions.