Zarok's astronomical clock: Difference between revisions
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==Construction== | ==Construction== | ||
===Mater=== | ===Mater=== | ||
The mater was the main body of the astrolabe. The edge of the mater was called the limb, on which the degree scale and scale of hours were engraved. The hollowed-out part of the mater was called the womb and contained latitude | The mater was the main body of the astrolabe. The edge of the mater was called the limb, on which the degree scale and scale of hours were engraved. The hollowed-out part of the mater was called the womb and contained a latitude plate.<ref name="astrolabeparts">{{Cite web|url=https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/astronomy/medieval-astrolabe/parts-astrolabe|site=Whipple Museum|title=The Parts of an Astrolabe|retrieved=February 5, 2025}}</ref> | ||
=== | ===Latitude plate=== | ||
To an observer on the [[earth]] it appeared that the planet was at the centre of an immense sphere with the [[stars]] and other heavenly bodies located on its inside surface. Called the celestial sphere, it appeared to rotate around the earth. | To an observer on the [[earth]] it appeared that the planet was at the centre of an immense sphere with the [[stars]] and other heavenly bodies located on its inside surface. Called the celestial sphere, it appeared to rotate around the earth.<ref name="astrolabeparts"/> | ||
The celestial sphere was mapped on the plate of an astrolabe using a mathematical technique called stereographic projection. This technique allowed the 3-dimensional sphere to be represented on the 2-dimensional flat plate. Each latitude needed its own projection, and so most astrolabes came with a variety of plates for particular latitudes, usually stacked one on top of the other, within the astrolabe. It is unknown whether Zarok's astrolabe had multiple plates. | The celestial sphere was mapped on the plate of an astrolabe using a mathematical technique called stereographic projection. This technique allowed the 3-dimensional sphere to be represented on the 2-dimensional flat plate. Each latitude needed its own projection, and so most astrolabes came with a variety of plates for particular latitudes, usually stacked one on top of the other, within the astrolabe.<ref name="astrolabeparts"/> It is unknown whether Zarok's astrolabe had multiple plates. | ||
===Ecliptic ring=== | ===Ecliptic ring=== | ||
The ecliptic ring was the annual path of the [[sun]] through the sky, as seen from the earth. A belt extending around 6 degrees north and south of the ecliptic is called the [[zodiac]]. Within this belt the apparent motions of the sun and planets take place. The zodiac is divided into 30-degree intervals giving us the 12 months of the zodiacal calendar. | The ecliptic ring was the annual path of the [[sun]] through the sky, as seen from the earth. A belt extending around 6 degrees north and south of the ecliptic is called the [[zodiac]]. Within this belt the apparent motions of the sun and planets take place. The zodiac is divided into 30-degree intervals giving us the 12 months of the zodiacal calendar.<ref name="astrolabeparts"/> | ||
===Rule=== | ===Rule=== | ||
The rule was a bar which rotated across the front of the astrolabe. It was used to locate positions on the plate, and to relate them to the scale of hours marked on the limb. | The rule was a bar which rotated across the front of the astrolabe. It was used to locate positions on the plate, and to relate them to the scale of hours marked on the limb.<ref name="astrolabeparts"/> | ||
==References== | ==References== | ||
{{Reflist}} | {{Reflist}} | ||
Revision as of 20:01, 5 February 2025
| Zarok's astronomical clock | |||
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| The astrolabe in Zarok's planetarium. | |||
| Type | Astronomical instrument | ||
An astrolabe was an astronomical instrument dating to ancient times. It served as a star chart, and its various functions also made it an analog calculation device capable of working out several kinds of problems in astronomy. It was able to measure the altitude above the horizon of a celestial body, day or night; it could be used to identify stars or planets, to determine local latitude given local time (and vice versa), to survey, or to triangulate.
History
14th century
There was an astrolabe on the floor of the planetarium in Zarok the Sorcerer's castle.[1]
Construction
Mater
The mater was the main body of the astrolabe. The edge of the mater was called the limb, on which the degree scale and scale of hours were engraved. The hollowed-out part of the mater was called the womb and contained a latitude plate.[2]
Latitude plate
To an observer on the earth it appeared that the planet was at the centre of an immense sphere with the stars and other heavenly bodies located on its inside surface. Called the celestial sphere, it appeared to rotate around the earth.[2]
The celestial sphere was mapped on the plate of an astrolabe using a mathematical technique called stereographic projection. This technique allowed the 3-dimensional sphere to be represented on the 2-dimensional flat plate. Each latitude needed its own projection, and so most astrolabes came with a variety of plates for particular latitudes, usually stacked one on top of the other, within the astrolabe.[2] It is unknown whether Zarok's astrolabe had multiple plates.
Ecliptic ring
The ecliptic ring was the annual path of the sun through the sky, as seen from the earth. A belt extending around 6 degrees north and south of the ecliptic is called the zodiac. Within this belt the apparent motions of the sun and planets take place. The zodiac is divided into 30-degree intervals giving us the 12 months of the zodiacal calendar.[2]
Rule
The rule was a bar which rotated across the front of the astrolabe. It was used to locate positions on the plate, and to relate them to the scale of hours marked on the limb.[2]
References
- ↑
MediEvil. Developed by SCEE Cambridge Studio. Published by Sony Computer Entertainment on October 9, 1998.
- ↑ 2.0 2.1 2.2 2.3 2.4 The Parts of an Astrolabe on Whipple Museum. Retrieved February 5, 2025.
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