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Philips' Planisphere, ca. 1900. In astronomy, a planisphere (/ ˈ p l eɪ. n ɪ ˌ s f ɪər, ˈ p l æ n. ɪ-/) is a star chart analog computing instrument in the form of two adjustable disks that rotate on a common pivot. It can be adjusted to display the visible stars for any time and date.
The stereographic projection, also known as the planisphere projection or the azimuthal conformal projection, is a conformal map projection whose use dates back to antiquity. Like the orthographic projection and gnomonic projection , the stereographic projection is an azimuthal projection , and when on a sphere, also a perspective projection .
National standard format is yyyy-mm-dd. [161] dd.mm.yyyy format is used in some places where it is required by EU regulations, for example for best-before dates on food [162] and on driver's licenses. d/m format is used casually, when the year is obvious from the context, and for date ranges, e.g. 28-31/8 for 28–31 August.
11th century – Planisphere invented by Biruni [7] 11th century – Universal latitude-independent astrolabe invented by Abū Ishāq Ibrāhīm al-Zarqālī (Arzachel) [8] 1023 – Hamedan observatory in Persia; c. 1030 – Treasury of Optics by Ibn al-Haytham (Alhazen) of Iraq and Egypt; 1074–92 – Malikshah Observatory at Isfahan used by ...
Planisphere or Planisphaerium, a 2nd-century AD book by Claudius Ptolemy about mapping the celestial sphere onto a flat plane using the stereographic projection to make a star chart Planispheric astrolabe , a device consisting of a planisphere joined to a dioptra, used for observing stars and performing astronomical calculations
[1] They also invented an automatic flute player which appears to have been the first programmable machine. [2] c. 1000 Abū Rayhān al-Bīrūnī invented the Planisphere, an analog computer. [3] He also invented the first mechanical lunisolar calendar which employed a gear train and eight gear-wheels. [4]
An astronomical instrument is a device for observing, measuring or recording astronomical data.They are used in the scientific field of astronomy, a natural science that studies celestial objects and the phenomena that occur in the cosmos, with the object of explaining their origin and evolution over time.
According to A.S.D. Maunder, antecedents of the planetary symbols were used in art to represent the gods associated with the classical planets; Bianchini's planisphere, discovered by Francesco Bianchini in the 18th century, produced in the 2nd century, [27] shows Greek personifications of planetary gods charged with early versions of the ...