File:Khalili_Collection_Islamic_Art_sci_0430_back.jpg · Wikimedia Commons · See Wikimedia Commons

EntityQ164992· pop 77· linked from 695 articles

astrolabe

AI overview

An astrolabe is a brass instrument with intricate fretwork and engraving, historically used for astronomical and navigational purposes. It remains culturally and scientifically significant as an example of sophisticated medieval craftsmanship, with artisans continuing to make them by hand in places like Iran today.

AI-generated from the Wikipedia summary — may contain errors.

Wikidata facts

Image: Planispheric astrolabe.png

Show 2 more facts

Commons gallery: Astrolabe
Commons category: Astrolabes

Sources (6)

via Wikidata · CC0

~26 min read

Article

17 sections

Contents

Applications
Etymology
History
Ancient era
Medieval era
Astrolabes and clocks
Construction
Mathematical basis
Designing a tympanum through stereographic projection
The tropics and the equator define the tympanum
The horizon and the measurement of altitude
The meridians and the measurement of azimuth
See also
Footnotes
References
Bibliography
External links

An astrolabe (; ; ) is an astronomical instrument dating to ancient times. It serves as a star chart and physical model of the visible half-dome of the sky. Its various functions also make it an elaborate inclinometer and an analog calculation device capable of working out several kinds of problems in astronomy. In its simplest form it is a metal disc with a pattern of wires, cutouts, and perforations that allows a user to calculate astronomical positions precisely. It is able to measure the altitude above the horizon of a celestial body, day or night; it can be used to identify stars or planets, to determine local latitude given local time (and vice versa), to survey, or to triangulate. It was used in classical antiquity, the Byzantine Empire, the Islamic Golden Age, the European Middle Ages and the Age of Discovery for all these purposes.