Torquetum
Encyclopedia
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
instrument designed to take and convert measurements made in three sets of coordinates: Horizon, equatorial, and ecliptic. In a sense, the Torquetum is an analog computer
Analog computer
An analog computer is a form of computer that uses the continuously-changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved...
.
The first torquetum is thought to have been built by Jabir ibn Aflah
Jabir ibn Aflah
Abū Muḥammad Jābir ibn Aflaḥ was a Muslim astronomer and mathematician from Seville, who was active in 12th century Andalusia. His work Iṣlāḥ al-Majisṭi influenced Islamic, Jewish and Christian astronomers....
(Geber) in the 12th century or 13th century, though the only surviving examples date from the 16th century.
The Ambassadors (Holbein)
The Ambassadors is a painting by Hans Holbein the Younger in the National Gallery, London. As well as being a double portrait, the painting contains a still life of several meticulously rendered objects, the meaning of which is the cause of much debate...
(1533) by Hans Holbein the Younger
Hans Holbein the Younger
Hans Holbein the Younger was a German artist and printmaker who worked in a Northern Renaissance style. He is best known as one of the greatest portraitists of the 16th century. He also produced religious art, satire and Reformation propaganda, and made a significant contribution to the history...
. It is placed on the right side of the table, next to and above the elbow of the ambassador clad in a long brown coat or robe. The painting shows much of the details of the inscriptions on the disk and half disk, which make up the top of this particular kind of torquetum.
See also
- Astronomical clockAstronomical clockAn astronomical clock is a clock with special mechanisms and dials to display astronomical information, such as the relative positions of the sun, moon, zodiacal constellations, and sometimes major planets.-Definition:...
- Antikythera mechanismAntikythera mechanismThe Antikythera mechanism is an ancient mechanical computer designed to calculate astronomical positions. It was recovered in 1900–1901 from the Antikythera wreck. Its significance and complexity were not understood until decades later. Its time of construction is now estimated between 150 and 100...
- Armillary sphereArmillary sphereAn armillary sphere is a model of objects in the sky , consisting of a spherical framework of rings, centred on Earth, that represent lines of celestial longitude and latitude and other astronomically important features such as the ecliptic...
- AstrolabeAstrolabeAn astrolabe is an elaborate inclinometer, historically used by astronomers, navigators, and astrologers. Its many uses include locating and predicting the positions of the Sun, Moon, planets, and stars, determining local time given local latitude and longitude, surveying, triangulation, and to...
- OrreryOrreryAn orrery is a mechanical device that illustrates the relative positions and motions of the planets and moons in the Solar System in a heliocentric model. Though the Greeks had working planetaria, the first orrery that was a planetarium of the modern era was produced in 1704, and one was presented...
, a free-standing solar system modelSolar system modelSolar System models, especially mechanical models, called orreries, that illustrate the relative positions and motions of the planets and moons in the Solar System have been built for centuries. While they often showed relative sizes, these models were usually not built to scale... - PlanetariumPlanetariumA planetarium is a theatre built primarily for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation...
- Prague OrlojPrague OrlojThe Prague Astronomical Clock or Prague Orloj is a medieval astronomical clock located in Prague, the capital of the Czech Republic, at . The clock was first installed in 1410, making it the third-oldest astronomical clock in the world and the oldest one still working.-Description:The Orloj is...
- Celestial sphereCelestial sphereIn astronomy and navigation, the celestial sphere is an imaginary sphere of arbitrarily large radius, concentric with the Earth and rotating upon the same axis. All objects in the sky can be thought of as projected upon the celestial sphere. Projected upward from Earth's equator and poles are the...