Editing Astrolabe (section)

===Ancient era===
An astrolabe is essentially a plane (two-dimensional) version of an [[armillary sphere]], which had already been invented in the [[Hellenistic period]] and probably been used by [[Hipparchus]] to produce his star catalogue. [[Theon of Alexandria]] ({{circa|335–405}}) wrote a detailed treatise on the astrolabe.{{sfn|Lewis|2001}} The invention of the plane astrolabe is sometimes wrongly attributed to Theon's daughter [[Hypatia]] (born {{circa|350–370}}; died {{nobr|415 {{sc|ce}}),}}<ref>
{{cite episode
 |first=Michael |last=Deakin
 |date=3 August 1997
 |title=Hypatia of Alexandria
 |series=Ockham's razor
 |publisher=[[Australian Broadcasting Corporation|ABC]] [[ABC Radio (Australia)|Radio]] 
 |type=radio program
}} Accessed 10&nbsp;July 2014.
</ref><ref name=Theodore>
{{cite book
 |last=Theodore |first=Jonathan
 |year=2016
 |title=The Modern Cultural Myth of the Decline and Fall of the Roman Empire
 |location=Manchester, UK
 |publisher=Palgrave, Macmillan
 |page=183
 |isbn=978-1-137-56997-4
 |url=https://books.google.com/books?id=3QPWDAAAQBAJ&pg=PA183  |via=Google
}}
</ref><ref name=Deakin2007>
{{cite book
 |last=Deakin |first=Michael A.B.
 |year=2007
 |title=Hypatia of Alexandria: Mathematician and martyr
 |location=Amherst, NY
 |publisher=Prometheus Books
 |pages=102–104
 |isbn=978-1-59102-520-7
 |url=https://books.google.com/books?id=P6X1DJ7UIb4C&pg=PA135  |via=Google
}}
</ref><ref name=Bradley>
{{cite book
 |last=Bradley |first=Michael John
 |year=2006
 |title=The Birth of Mathematics: Ancient times to 1300
 |location=New York City, NY
 |publisher=Infobase Publishing
 |page=63
 |isbn=9780816054237
 |url=https://books.google.com/books?id=EIdtVPeD7GcC&pg=PA63  |via=Google
}}
</ref>
but it is known to have been used much earlier.<ref name=Theodore/><ref name=Deakin2007/><ref name=Bradley/>
The misattribution comes from a misinterpretation of a statement in a letter written by Hypatia's pupil [[Synesius]] ({{circa|373–414}}),<ref name=Theodore/><ref name=Deakin2007/><ref name=Bradley/>
which mentions that Hypatia had taught him how to construct a plane astrolabe, but does not say that she invented it.<ref name=Theodore/><ref name=Deakin2007/><ref name=Bradley/>
Lewis argues that [[Ptolemy]] used an astrolabe to make the astronomical observations recorded in the ''[[Tetrabiblos]]''.{{sfn|Lewis|2001}} However, [[Emilie Savage-Smith]] notes
:"there is no convincing evidence that Ptolemy or any of his predecessors knew about the planispheric astrolabe".<ref name=SavageSmith-1992>
{{cite book
 |last=Savage-Smith |first=E. |author-link=Emilie Savage-Smith
 |url=https://press.uchicago.edu/books/HOC/HOC_V2_B1/Volume2_Book1.html
 |title=The History of Cartography
 |volume=2, Book&nbsp;1: Cartography in the traditional Islamic and South Asian societies
 |date=1992
 |place=Chicago, IL
 |publisher=University of Chicago Press
 |isbn=0226316351
 |editor1-last=Harley |editor1-first=J.B.
 |series=The History of Cartography
 |chapter=Celestial mapping
 |editor-last2=Woodward |editor-first2=David
 |chapter-url=https://press.uchicago.edu/books/HOC/HOC_V2_B1/HOC_VOLUME2_Book1_chapter2.pdf
}}
</ref>

In chapter&nbsp;5.1 of the ''[[Almagest]]'', Ptolemy describes the construction of an [[armillary sphere]], and it is usually assumed that this was the instrument he used.

Astrolabes continued to be used in the [[Byzantine Empire]]. Christian philosopher [[John Philoponus]] wrote a treatise ({{circa|550}}) on the astrolabe in Greek, which is the earliest extant treatise on the instrument.<ref>
Modern editions of [[John Philoponus]]' treatise on the astrolabe are
:
{{cite book
 |first=John |last=Philoponus  |author-link=John Philoponus
 |year=1839  |orig-year={{circa|550}}
 |title=De usu astrolabii eiusque constructione libellus |lang=la
 |trans-title=On the Use and Construction of the Astrolabe
 |editor-first=Heinrich |editor-last=Hase
 |place=Bonn, DE
 |publisher=E. Weber
 |OCLC=165707441
}}<br/>
or<br/>
{{cite book
 |first=John |last=Philoponus  |author-link=John Philoponus
 |year=1839  |orig-year={{circa|550}}
 |title=De usu astrolabii eiusque constructione libellus |lang=la
 |trans-title=On the Use and Construction of the Astrolabe
 |edition=reprint
 |series=Rheinisches Museum für Philologie
 |volume=6 |pages=127–171
}}
:
repr. and translated into French<br/>
{{cite book
 |first=Alain Philippe |last=Segonds
 |title=''Jean Philopon,'' traité de l'astrolabe |lang=fr, la
 |place=Paris, FR
 |publisher=Librairie Alain Brieux
 |year=1981  |orig-year={{circa|550}}
 |OCLC=10467740
 |others=[[John Philoponus|Philoponus, John]] (''Jean Philopon'', original author)
}} 
:
translated into English and included as part of<br/>
{{cite book
 |first=John |last=Philoponus  |author-link=John Philoponus
 |year=1932  |orig-year={{circa|550}}
 |section=On the Use and Construction of the Astrolabe [''De usu astrolabii eiusque constructione libellus'']
 |lang=en
 |translator-first=H.W. |translator-last=Green
 |editor-first=R.T.     |editor-last=Gunther
 |title=The Astrolabes of the World
 |volume=1 (of 2)
 |publisher=Oxford
 |OL=18840299M
}}<br/>
: which was reprinted in 1976:
{{cite book
 |first=John |last=Philoponus  |author-link=John Philoponus
 |year=1976  |orig-year={{circa|550}}
 |title=On the Use and Construction of the Astrolabe |lang=en
 |trans-title=De usu astrolabii eiusque constructione libellus
 |translator-first=H.W. |translator-last=Green
 |edition=reprint
 |place=London, UK
 |publisher=Holland Press
 |OL=14132393M
 |pages=61–81
}}
</ref>
[[Mesopotamian]] bishop [[Severus Sebokht]] also wrote a treatise on the astrolabe in the [[Syriac language]] during the mid-7th century.{{efn|
"The most distinguished Syriac scholar of this later period was [[Severus Sebokht]] (d.&nbsp;666–667), Bishop of Kennesrin. ... In addition to these works ... he also wrote on astronomical subjects (Brit. Mus. Add.&nbsp;14538), and composed a treatise on the astronomical instrument known as the astrolabe, which has been edited and published by F.&nbsp;Nau (Paris, 1899)."<ref>
{{cite book
 |last = O'Leary |first = de Lacy |author-link=de Lacy O'Leary
 |title = How Greek Science Passed to the Arabs
 |date = 1948
 |publisher = Routledge and Kegan Paul
 |url = http://www.aina.org/books/hgsptta.htm
}}
</ref> {{right|{{nobr| — {{harvp|O'Leary|1948}}}} }}<br/><br/>
:
Severus' treatise was translated by {{harvp|Smith Margoliouth|1932}}.<ref>
{{cite book
 |first=Jessie Payne |last=Smith Margoliouth
 |year=1932
 |editor-first=R.T. |editor-last=Gunther
 |title=Astrolabes of the World
 |publisher=Oxford
 |pages=82–103
 |others=[[Severus Sebokht|Sebokht, Severus]] (original author)
}}
</ref>
}}
Sebokht refers to the astrolabe as being made of brass in the introduction of his treatise, indicating that metal astrolabes were known in the Christian East well before they were developed in the Islamic world or in the Latin West.<ref>
{{cite web
 |first=Severus |last=Sebokht
 |title=Description of the astrolabe
 |website=Tertullian.org
 |url=http://www.tertullian.org/fathers/severus_sebokht_astrolabe_01_trans.htm
}}
</ref>