Geocentric concept watch puts an orrery on your wrist Geocentric concept watch puts an orrery on your wrist View gallery - 2 images When it comes to timepieces I’m firmly in the camp that thinks the digital watch is the pinnacle of time telling technology. It imparts its information at a glance with no need to waste time adding or subtracting minutes in multiples of five, or estimating if the big hand is two or three minutes between markers – if there are markers at all. I will concede, however, that for many people watches are as much a fashion statement as a means to tell time and as such designers are always looking to redefine the humble watch in different and interesting ways. The latest eye-catching timepiece to catch our eye is the Geocentric concept watch that uses a motion similar to planets rotating around a sun to tell time. The brainchild of designer Geoffrey Cooper , the Geocentric watch displays the time through the position of three rotating rings on the face of the watch, giving it the appearance of a mini orrery – the mechanical devices used to illustrate the relative positions and motions of the planets and moons in the solar system.

That appears to be Cooper’s intention, stating that the watch was inspired by science and science fiction. As with an orrery, the rings are in constant motion and the visibility of the watch’s interior mechanism only adds to what Copper calls, “a mesmerizing spectacle". It isn’t clear exactly how one reads time from the device, but presumably it is based on where each of the rings comes into contact with each other. Although the Geocentric watch is only a concept at this stage, it’s an analogue watch I’m willing to make time for. ... and in case you were wondering, we're indebted to Charles Boyle, Earl of Orrery (1676–1731) for the wonderful term given an apparatus that represents the position and motion of the planets. One of the first modern orrerys was made for Boyle in the early 1700s by George Graham and Thomas Tompion, although the idea has been around since classical times. 1000+ images about Orrery on Pinterest | Solar system, Solar system model and Museums Forward This project explores the use of plywood to make mechanical, decorative, and structural parts. This instructable is about how to build a desktop orrery.

An orrery is a mechanical model of the movement and position of the planets in our solar system. The device accurately depicts where the earth is with respect to other planets, the sun, and the moon and how they move relative to one another. It can be used for education, decoration, demonstration, a gift, and a fun project to build. I built… See More Human Orrery More orrery photographs from Miruna Popescu Mechanical Orrery by Gilkerson An orrery is a mechanical device designed to illustrate the motions of the planets in their orbits about the Sun. It was invented in around 1700 by George Graham and is named after Charles Boyle, 4th Earl of Orrery who had one made for him in about 1712 by John Rowley. Mark Bailey, Apostolos Christou and David Asher have developed ideas for a new outdoor exhibit in the Observatory grounds, called `The Human Orrery'. This will feature an accurate scale model of the positions and orbits of the six naked-eye planets, two comets, and an asteroid.

The objective is to engage visitors to Armagh in a thought-provoking and inspiring open-air exhibit, and to use accompanying leaflets and activity sheets to introduce fundamental ideas about the Earth's position in space. The Orrery, which is the first major addition to the Armagh Observatory Grounds and Astropark for more than a decade, will be located in an area roughly 24 metres across located south of the existing Library between the Robinson Dome and the planned new Library, Archive and Historic Scientific Instruments building. It will help educators to communicate and explain key ideas in solar system astronomy, particularly orbits and time-dependent phenomena, and will eventually provide pointers to galactic and extragalactic objects. The orbits of the six naked-eye planets, two comets (1P/Halley and 2P/Encke) and the main-belt asteroid (1)Ceres. Tiles are indicated at 16-day intervals for the terrestrial planets (Mercury, Venus, Earth and Mars), at 80-day intervals for Ceres and the two comets, and 160-day intervals for Jupiter and Saturn. The indicated scale is in metres.

The most dynamic feature of the Human Orrery is its capacity to explain Kepler's laws of planetary motion in a fun and interesting way. A leader has simply to clap out time intervals of 16 days, and his or her assistants move around the Orrery tracing out the orbit and speed of each object. For example, little Mercury whizzes round, followed by Venus, the Earth and a more sedate Mars, while Jupiter and Saturn creep forward, making just one revolution for every approximately 12 and 29 of the Earth respectively. This is a great way to appreciate the decrease of Keplerian velocity with heliocentric distance, and for the Educator to demonstrate concepts such as parallax and the occasional retrograde motion of Mars. Even a cursory inspection of the model can be used to illustrate the division of the inner planetary system into two principal parts, while the heliocentric ecliptic coordinate system provides an introduction to astronomical frames of reference.

The model shows that the planetary orbits (especially those of Mercury and Mars) are distinctly elliptical with the Sun not at the centre but at a focus (Kepler's First Law), whilst detailed measurements of the separation and radial distances of successive tiles will allow investigations of the law of equal areas (Kepler's Second Law). Similarly, measurements can be used to illustrate the fact that the squares of the orbital periods of revolution of the planets are proportional to the cubes of their mean distances from the Sun (Kepler's Third Law). In this way, the Human Orrery can be used by educators as a rich, innovative and dynamic outdoor exhibit. It is intended that these and other concepts will be developed through a series of Human Orrery leaflets and activity sheets. For example, each numbered tile will be labelled with the planet's heliocentric distance, true anomaly and ecliptic longitude, so that a look-up table can be used to locate the positions of the planets `tonight', or when you were born, or at any other potentially interesting date.

Visitors to the Observatory grounds will be able to identify planetary alignments, transits of Mercury and Venus, the morning and evening visibility of these and other planets, and indulge in a host of other engaging, interactive pursuits. Although the Human Orrery is primarily a tool to explain astronomy, the questions of distance-scales, time-scales, and the dynamics and spatial interrelationships of solar system bodies lead naturally to issues such as the calendar, seasons, the equation of time, and precession of the equinoxes. This leads to a possible extension of the basic model so as to incorporate a circular band, indicated in the Figure beyond Saturn's ellipse as simply a red circular path, which will display ecliptic longitude, the First point of Aries, and the boundaries of the 13 zodiacal constellations through which the Sun passes in the course of a year, as well as the directions to various Galactic and extragalactic objects. The Human Orrery and its possible extension provides a further important opportunity for the Observatory to reach out to new audiences, and to explain why our modern world-view is so very different from that considered, for example, by the ancient Greeks or during much of recorded history.

It is planned that the Human Orrery will be constructed during 2004 towards the end of the main work associated with the HLF Telescopes and Telescope Domes restoration project . Some leaflets have been prepared for visitors to the Human Orrery and they are available here in PDF format. Orrery Store|Beautiful orrery for sale|Buy orrery|Build A Model Solar System|orrery shop|Orrery Kit|Scale model of solar system|太陽系模型|Build Orrery|Orrery Model|the best mechanical brass orrery in the world View Cart An orrery is a mechanical device that demonstrates the motions and relative positions of the planets and moons in the Solar System in a heliocentric model. They are typically driven by a motor or a clockwork mechanism with a globe representing the Sun at the centre, and with a planet at the end of each of the arms. An orrery can be seen as a scale model of our solar system, it can range widely in size from hand-held to room-sized..

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 to the Earl of Orrery — whence the name came. History The first modern orrery was made circa 1704 by Thomas Tompion and George Graham. Graham gave the first model or its design to the celebrated device maker named John Rowley, who lived in London,in order to produce a copy for Prince Eugene of Savoy. Rowley produced another one for his patron Charles Boyle, 4th Earl of Orrery, from which the model took its name. This device was given to Charles' son John as present, later the 5th Earl. Its importance was partially in that mechanical scale models of the solar system and the universe, correctly named planetariums gained the name Orrery. There were planetary models before 1704, indeed according to Roman philosopher Cicero, who was writing in the first century BC, Posidonius made a planetary model.

The Antikythera mechanism, which was discovered in 1904 in 42m of water off the Greek island of Antikythera, illustrated the five known planets and the diurnal motions of the sun, moon. The Antikythera mechanism is now considered to be one of the earliest orreries, but was not mentioned in the 1967 Science Museum booklet. For many years The Antikythera mechanism was ignored, because it seemed too complex to be genuine. It was geocentric, used as a mechanical calculator designed to calculate astronomical positions. In the Western religious teaching of a geocentric universe,the sun rotated around the earth,but Copernicus in De Revolutionibus Orbium Coelestium published in Nuremberg in 1543 challenged this. He found that a heliocentric universe had been proposed by some Greek philosophers. This simplified the apparent epicyclic motions of the planets and make it feasible to represent the planets path as a simple circle, which could be modelled by the use of gears.

Tycho Brahe's improved devices made precise observations of the skies (1576–1601), from which Johannes Kepler (1621) proved that planets orbited the sun in ellipses. The cause of this motion was explained in Isaac Newton's theory of gravitation In 1687. Christian Huygens calculated the gear trains which were needed to represent 365.242 days year length, and using which to make the cycles of the principal planets. As late as 1650, P. Schirleus has made a Geocentric planetarium ,it showed the sun as a planet with Mercury and Venus moving around it as moons. Christian Huygens built a heliocentric planetary model while resident in Paris between 1665 and 1681, and in 1703 he published details of the model. A picture hangs in Derby Museum and Art Gallery named "A Philosopher giving a Lecture on the Orrery in which a lamp is put in place of the Sun" by Joseph Wright (ca.

1766), features three children, three men, and a lone woman, listening to a lecture by a 'natural philosopher'— the only light is from the "sun" in the brass orrery, which, in this case, has rings that cause it to look like an armillary sphere. The demonstration was thereby able to show eclipses. To put this in context, longitude was allowed to be accurately measured by John Harrison's Chronometer in 1762,and also in 1766 Titius first who was an astronomer demonstrated that the mean distance of the planets could be represented by the progression . That is, 0.4, 0.7, 1.0, 1.6, 2.8, 5.2, 10.0 ... The numbers refer to astronomical units, that is 93 x 10^8 miles(1.496 x 10^8 km). The Derby Orrery doesn't show mean distance, but demonstrated the relative planetary movements: all part of a process understanding contemporary cutting edge scientific thinking.

Eisinga's "Planetarium" was made from 1774 to 1781 in his home in Franeker, in the Netherlands. This "Planetarium" displays the planets across the width of a room's ceiling, and has been in operation almost continually since it was built. This orrery was a planetarium in both senses of the word- firstly a complex planetary instrument, and secondly it was displayed in a special room, which was a sort of theatre for observers. the Dutch Royal family, by who gave him a pension, bought Eisinga house. A 1766 Benjamin Martin Orrery, used at Harvard Benjamin Martin created a new type of planetary instrument in 1764. In this new planetary instrument the planets were carried on brass arms leading from a series of coaxial or concentric tubes. With this construction it was difficult to get the moons to turn around the planets, and to make the planets revolve.

Benjamin Martin thought that there were three parts that the conventional orrery should consist of: The lunarium which showed the rotations of the moon around the earth, the tellurian(tellurion) which showed the inclined axis of the earth and how it revolved around the sun, and the planetarium where the planets revolved around the sun. In an orrery, these three motions could be assembled on a common table and separately using the central spindle as a prime mover. James Ferguson's Mechanical Paradox Orrery James Ferguson's Mechanical Paradox Orrery Click to enlarge the engraving. “This machine is so much of an ORRERY, as is sufficient to shew [sic] the different lengths of days and nights, the vicissitudes of the seasons, the retrograde motion of the nodes of the Moon’s orbit, the direct motion of the apogeal point of her orbit, and the months in which the Sun and Moon must be eclipsed.” - James Ferguson, 1764 This is an interpretation of an Orrery built by the Scottish Astronomer James Ferguson in 1750 for use in lectures about the solar system.

Our goal is to recreate what you'd get if you dropped into an 18th century scientific instrument maker's shop in London and placed an order. Each Orrery is individually built from brass, precision ball bearings, and sustainably harvested Honduran Mahogany using a blend of 18th century handwork and 21st century CNC automation - no two are exactly alike. The base is about 10" in diameter and the mechanism is about 4" high. Each Orrery comes with a 40 page booklet explaining the Orrery in detail, the history of the mechanism and its inventor James Ferguson, and a few pictures from the workshop. The Orrery is not just decorative - this is a valuable teaching instrument. You can follow in Ferguson's footsteps by showing people how the Earth maintains its orientation as it orbits the Sun, why seasons happen and summer and winter are reversed between hemispheres. The Orrery illustrates how eclipses can happen when the nodes of the Moon's orbit intersect light coming from the Sun, and how the nodes and apogee of the Moon's orbit move over time. Today's modern technologies have not replaced people's basic curiosity about the Earth and Moon.

The Orrery is visually fascinating and can be used to facilitate talks to astronomy groups, Boy and Girl Scout troops, science classes, and more. You'll be amazed at the conversations stimulated by the Orrery. The differential motions of the Earth, nodes, and apogee are fascinating to mechanically inclined people even if they're not astronomy buffs. The term "Orrery" is a bit of a misnomer - the word "Tellurian" is a better term for a teaching device focused on the Sun, Earth, and Moon. We use the term Orrery here to be faithful to Ferguson's writings. The Orrery Illustration by Lindsey Whittemore This Orrery is unusual because it illustrates the movement of the nodes and apogee of the Moon's orbit, instead of the Moon's position. The Moon's orbit is elliptical, with an eccentricity of about 5.49%. The difference in the perceived size of the Moon between the perigee (the closest approach to the Earth) and apogee (the farthest point from the Earth) is about 14%. The distance to the Moon is about 50,000Km closer at perigee than at apogee.

People noticed the difference over the years because the Moon is about 30% brighter when closer to the Earth. When the Moon is near the apogee its slightly smaller size leads to an annualar eclipse, when we see a ring of sunlight all around the Moon. The moonrise on May 5 2012 coincided with the Moon being at perigee, sometimes called a "super moon" A recent annualar eclipse (descending node) was May 10, 2013 . The precession of the apogee around the Earth is just less than nine years. The pointer fixed to the large bottom plate represents the position of the apogee of the Moon's orbit. The Moon’s orbit is inclined 5.14° from the plane of the ecliptic (the plane of the Earth’s orbit around the Sun). The points where the Moon’s orbit intersects the ecliptic are called the nodes. The conditions for an eclipse require that a node intersect the line of light from the Sun to the Earth and that the Moon be present at the node at the same time. These nodes recess around the Earth with a period of about 18-1/2 years.

The sloped ring on the orrery represents the Moon’s orbit. The Earth’s axis is inclined 23.5° with respect to the ecliptic and remains fixed in that orientation with respect to the zodiac. The Orrery illustrates this with a zodiac inscribed on the ring representing the plane of the ecliptic. The day/ night indicator mounted to the frame facilitates conversations about the seasons and different lengths of days and nights throughout the year. The calendar ring on the base illustrates both the conventional 365-day calendar and the western zodiac with 360 divisions. Ferguson’s 1764 engraving shows the effect of Britain’s adoption of the Gregorian calendar in 1752, Ferguson's original model does not survive, but there is much information about it in Ferguson's writings. The Science Museum in London does have a related instrument by Ferguson which works with rope and pulleys instead of gears. The Paradox A simplified version of the paradox reads: "Three wheels on the same axis mesh with one thick wheel. Turn the thick wheel.

One of the thin wheels goes forward, one backwards, and one goes no way at all!" What Ferguson was really doing with his Mechanical Paradox was emphasizing the importance of defining “rotation” with respect to a fixed frame of reference. The “paradox” arises when in a train of gears – A, B, and C – gear A is fixed and gears B and C have epicyclic motion around it. Gear A is the gear under the sun and is fixed to the base. When all three gears have the same number of teeth, gear B rotates twice for each rotation and gear C maintains its orientation to a fixed frame of reference. That keeps the Earth’s axis pointed in the same direction. When gear C has fewer teeth than gears A and B, it turns in the direction opposite the mechanism, in this case illustrating the regression of the nodes. When gear C has a few more teeth, it will slowly turn in the same direction as that of the mechanism, illustrating the advancement of the apogee of the Moon’s orbit. James Ferguson James Ferguson (1710-1776) was the self-educated son of a Scottish crofter.

At age seven he learned to read by listening to his father teach his elder brother to read the catechism. He developed an early aptitude for mechanics. The story is told of young Ferguson’s fascination with mechanics being inspired by watching his father use a large lever to adjust the roofline of their house. By the age of ten, he was studying the stars while tending sheep and making models of spinning wheels and mills. He later built a wooden clock and a watch with whalebone springs. His education was enhanced by several servant positions with people who recognized his talents and contributed to his interests. One of his servant positions was with a neighbor who engaged him to clean clocks. Moving to Edinburgh in 1734, Ferguson began to support himself as a limner (painting miniatures). He moved to Inverness, where he published his Astronomical Rotula for showing the motions of the planets, places of the Sun and Moon, etc. (The Rotula is similar to an ephemeris, but uses circular rotating volvelles.) He built his first orrery in 1742, and then made his final move to London in 1743.

By 1748 Ferguson began to give lectures on scientific subjects, and his apparatus facilitated these lectures significantly. In 1763 Ferguson became a Fellow of the Royal Society of London. Ferguson’s famous Select Mechanical Exercises, with a Short Account of the Life of the Author was published in 1773. Besides being one of the first popularisers of science, his influence extended considerably, with Thomas Paine and William Herschel reportedly studying his books. George III, while Prince of Wales, attended Ferguson’s lectures and rewarded him with an annual pension of £50 from the Privy Purse until his death in 1776. He designed orreries and a number of clocks. He knew Benjamin Franklin and apparently was inspired by Franklin's famous 3-wheeled clock, later designing his own versions. Ferguson was a very prolific inventor, making many devices for use in research and lecture demonstrations. For Sale Armstrong Metalcrafts is building a limited number of these for sale. The retail price is $995. To inquire about a purchase, please use our contact form or send an email to "sales" at armstrongmetalcrafts.com.

Publications These books have the best descriptions for this orrery. You can find links for these in Armstrong Metalcrafts Bookstore . Buick, Tony. Orrery 2014; New York, Springer. Ferguson, James. The description and use of a new machine, called the mechanical paradox; invented by James Ferguson, F.R.S. 1764; London (Reprinted in Select Mechanical Exercises..., 1773; London) King, Henry C. Geared to the Stars. 1978; Toronto, University of Toronto Press. Millburn, John R. 1988. Wheelwright of the Heavens. 1988; London, Vade-Mecum Press. Copyright © Armstrong Metalcrafts 2011-2017 Orrery - Wikipedia, Photos and Videos Orrery NEXT GO TO RESULTS [51 .. 100] WIKIPEDIA ARTICLE This article is about the mechanical device. For the British peerage, see Earl of Orrery .

A small orrery showing earth and the inner planets An orrery is a mechanical model of the solar system that illustrates or predicts the relative positions and motions of the planets and moons , usually according to the heliocentric model . It may also represent the relative sizes of these bodies; but since accurate scaling is often not practical due to the actual large ratio differences, a subdued approximation may be used instead. 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 to Charles Boyle, 4th Earl of Orrery – whence came the name. They are typically driven by a clockwork mechanism with a globe representing the Sun at the centre, and with a planet at the end of each of the arms. Contents Antikythera mechanism (main fragment), ca.

125 BC Carlo G Croce, reconstruction of Dondi's Astrarium , originally built between 1348 and 1364 in Padova Astronomical clock (Venus-Mercury side), Eberhard Baldewein et al., Marburg-Kassel, 1563–1568 - Mathematisch-Physikalischer Salon, Dresden - DSC08057 The Antikythera mechanism , discovered in 1900 in a wreck off the Greek island of Antikythera and extensively studied, exhibited the diurnal motions of the Sun , Moon , and the five known planets . It has been dated between 150 and 100 BC. The Antikythera hand driven mechanism is now considered one of the first orreries, but for many decades was ignored as it was thought to be far too complex to be genuine. [1] It was geocentric and used as a mechanical calculator designed to calculate astronomical positions. According to Cicero , the Roman philosopher who was writing in the first century BC, Posidonius constructed a planetary model.

In 1348, Giovanni Dondi built the first known clock driven mechanism which displays the ecliptical position of Moon , Sun , Mercury , Venus , Mars , Jupiter and Saturn according to the complicated ptolemeic planetary theories. [2] [3] The clock itself is lost, but Dondi left a complete description of the astronomic gear trains of his clock. As late as 1650, P. Schirleus built a geocentric planetarium with the Sun as a planet, and with Mercury and Venus revolving around the Sun as its moons . [4] At the court of William IV, Landgrave of Hesse-Kassel two complicated astronomic clocks were built in 1561 and 1563-1568, which show on four sites the ecliptical position of Sun , Mercury , Venus , Mars , Jupiter and Saturn , the Moon , Sun and Dragon (Nodes of the Moon) according to Ptolemy , a Calendar, the Sunrise and Sunset and an automated celestial sphere with an animated Sun symbol which, for the first time on a celestial globe, show the real position of the sun, including the equation of time.

[5] [6] The clocks are now on display in Kassel at the Astronomisch-Physikalisches Kabinett and in Dresden at the Mathematisch-Physikalischer Salon. In De revolutionibus orbium coelestium , published in Nuremberg in 1543, Nicolaus Copernicus challenged the Western teaching of a geocentric universe in which the Sun revolved daily around the Earth . He observed that some Greek philosophers had proposed a heliocentric universe. This simplified the apparent epicyclic motions of the planets, making it feasible to represent the planets' paths as simple circles. This could be modelled by the use of gears. Tycho Brahe 's improved instruments made precise observations of the skies (1576–1601), and from these Johannes Kepler (1621) deduced that planets orbited the Sun in ellipses . In 1687 Isaac Newton explained the cause of elliptic motion in his theory of gravitation . [7] A Philosopher Lecturing on the Orrery (ca.

1766) by Joseph Wright of Derby Clock makers George Graham and Thomas Tompion built the first modern orrery around 1704 in England. [8] Graham gave the first model, or its design, to the celebrated instrument maker John Rowley of London to make a copy for Prince Eugene of Savoy . Rowley was commissioned to make another copy for his patron Charles Boyle, 4th Earl of Orrery , from which the device took its name in English . [9] This model was presented to Charles' son John, later the 5th Earl of Cork and 5th Earl of Orrery . Independently, Christiaan Huygens published details of a heliocentric planetary machine in 1703, which he built while resident in Paris between 1665 and 1681. He calculated the gear trains needed to represent a year of 365.242 days, and used that to produce the cycles of the principal planets. [4] Joseph Wright 's painting A Philosopher giving a Lecture on the Orrery in which a lamp is put in place of the Sun (ca.

1766), which hangs in Derby Museum and Art Gallery , depicts a group listening to a lecture by a natural philosopher . The Sun in a brass orrery provides the only light in the room. The orrery depicted in the painting has rings, which give it an appearance similar to that of an armillary sphere . The demonstration was thereby able to depict eclipses . [10] To put this in chronological context, in 1762 John Harrison 's marine chronometer first enabled accurate measurement of longitude . In 1766, astronomer Johann Daniel Titius first demonstrated that the mean distance of each planet from the Sun could be represented by the following progression: 4 . . {\displaystyle {\frac {4+0}{10}},{\frac {4+3}{10}},{\frac {4+6}{10}},{\frac {4+12}{10}},{\frac {4+24}{10}},{\frac {4+48}{10}},.....} That is, 0.4, 0.7, 1.0, 1.6, 2.8, 5.2 ...

The numbers refer to astronomical units , the mean distance between Sun and Earth, which is 1.496 × 10⁸ km (93 × 10⁶ miles). The Derby Orrery does not show mean distance, but demonstrated the relative planetary movements. Eisinga's Planetarium was built from 1774 to 1781 by Eise Eisinga in his home in Franeker , in the Netherlands. It displays the planets across the width of a room's ceiling, and has been in operation almost continually since it was created. [11] This orrery is a planetarium in both senses of the word: a complex machine showing planetary orbits, and a theatre for depicting the planets' movement. Eisinga house was bought by the Dutch Royal family who gave him a pension. A 1766 Benjamin Martin Orrery, used at Harvard In 1764, Benjamin Martin devised a new type of planetary model, in which the planets were carried on brass arms leading from a series of concentric or coaxial tubes. With this construction it was difficult to make the planets revolve, and to get the moons to turn around the planets.

Martin suggested that the conventional orrery should consist of three parts: the planetarium where the planets revolved around the Sun, the tellurion (also tellurian or tellurium) which showed the inclined axis of the Earth and how it revolved around the Sun, and the lunarium which showed the eccentric rotations of the Moon around the Earth. In one orrery, these three motions could be mounted on a common table, separately using the central spindle as a prime mover. [1] Explanation[ edit ] All orreries are planetariums or planetaria (alternative plural). The term orrery has only existed since 1714. A grand orrery is one that includes the outer planets known at the time of its construction. The word planetarium has been captured, and now usually refers to hemispherical theatres in which images of the night sky are projected onto an overhead surface. Planetariums (orreries) can range widely in size from hand-held to room-sized. An orrery is used to demonstrate the motion of the planets, while a mechanical device used to predict eclipses and transits is called an astrarium .

An orrery should properly include the Sun, the Earth and the Moon (plus optionally other planets). A model that only includes the Earth, the Moon and the Sun is called a tellurion or tellurium, and one which only includes the Earth and the Moon is a lunarium . A jovilabe is a model of Jupiter and its moons. [12] Planet 122 -6.4 days A planetarium will show the orbital period of each planet and the rotation rate, as shown in the table above. A tellurion will show the earth with the moon revolving around the sun. It will use the angle of inclination of the equator from the table above to show how it rotates around its own axis. It will show the earth's moon, rotating around the earth. [13] A lunarium is designed to show the complex motions of the moon as it revolves around the earth. Orreries are usually not built to scale . Some fixed Solar System scale models have been built and are often many kilometres in size. Human orreries, where humans move about as the planets, have also been constructed, but most are temporary.

There is a permanent human orrery at Armagh Observatory in Northern Ireland , which has the six ancient planets, Ceres , and comets Halley and Encke . Uranus and beyond are also shown, but in a fairly limited way. Another is at Sky's the Limit Observatory and Nature Center in Twentynine Palms, CA. This is a true to scale (20 billion to one), true to position (accurate to within four days) human orrery. The first four planets are relatively close to one another, but the next four require a certain amount of hiking in order to visit them. A normal mechanical clock could be used to produce an extremely simple orrery with the Sun in the centre, Earth on the minute hand and Jupiter on the hour hand; Earth would make 12 revolutions around the Sun for every 1 revolution of Jupiter. Note however that Jupiter's actual year is 11.86 Earth years long, so this particular example would lose accuracy rapidly. A real orrery would be more accurate and include more planets, and would perhaps make the planets rotate as well.

Projection orreries[ edit ] Many planetariums (buildings) have a projection orrery , which projects onto the dome of the planetarium a Sun with either dots or small images of the planets. These usually are limited to the planets from Mercury to Saturn , although some include Uranus . The light sources for the planets are projected onto mirrors which are geared to a motor which drives the images on the dome. Typically the Earth will circle the Sun in one minute, while the other planets will complete an orbit in time periods proportional to their actual motion. Thus Venus, which takes 224.7 days to orbit the Sun, will take 37 seconds to complete an orbit on an orrery, and Jupiter will take 11 minutes, 52 seconds. Some planetariums have taken advantage of this to use orreries to simulate planets and their moons. Thus Mercury orbits the Sun in 0.24 of an Earth year, while Phobos and Deimos orbit Mars in a similar 4:1 time ratio. Planetarium operators wishing to show this have placed a red cap on the Sun (to make it resemble Mars) and turned off all the planets but Mercury and Earth.

Similar tricks can be used to show Pluto and its five moons. An orrery made by Robert Brettell Bate , circa 1812. Now in Thinktank, Birmingham Science Museum . Shoemaker John Fulton of Fenwick, Ayrshire, built three between 1823 and 1833. The last is in Glasgow's Kelvingrove Art Gallery and Museum . The Franeker Planetarium built by a wool carder named Eise Eisinga in his own living room, in the small city of Franeker in Friesland , is in fact an orrery. It was constructed between 1774 and 1781. The "face" of the model looks down from the ceiling of a room, with most of the mechanical works in the space above the ceiling. It is driven by a pendulum clock, which has 9 weights or ponds. The planets move around the model in real time. [14] An innovative concept is to have people play the role of the moving planets and other Solar System objects. Such a model, called a human orrery, has been laid out with precision at the Armagh Observatory .

The Passau Footpath of the Planets[ edit ] The project was instigated in 2007 and was known as the “Passauer Planetenpfad” i.e. “Passau Footpath of the Planets” by the Passau secondary schools "Giselagymnasium", "Gymnasium Leopoldinum" primarily led by "Fachoberschule/Berufsoberschule Passau” under the direction of senior teacher Dr. Reinhold Haggenmüller. A depiction of the Sun at heart of the "Passau Footpath of the Planets". It starts at the utmost point of the headland of the ancient City of Passau , called "Ort” (which means: place), where all of the three rivers ( Danube , Inn and Ilz ) meet, with a depiction of the sun. On a scale of 1:1 Billion (1:109) it’s diameter is 55,12 inches (140 cm) and the thickness of its satin-finished wall made of bronze is 0.31 inches (8 mm).

It’s weight is 661.38 pounds (300 kg) and it was produced by the bell foundry of Perner at Passau, that has been well known for it’s magnificent bells and now has withdrawn it’s service. Next to it some additional plates are showing details of the solar system. True to scale of the real distances all over the path steles made of granite have been erected, each representing one planet resp. 1 asteroid of our solar system. Every single stele as well as the splendid sculpture of the sun has been sponsored by local companies. The height of the steles amount to 1.09 yard (1m) in front, the side length is 12.99 inches (33 cm) and the tilt angle of the plates is 50°. On each of them an information panel made from steel is fixed (size app. 12.21 x 15.35 inches, i.e. 31 x 39 cm), sustaining the depiction of one of the following planets resp. the asteroid “Passau” in the adequate scale in half-relief right in the order of their appearance: 1. Mercury, 2.

Venus, 3. Earth, 4. Mars, 5. the asteroid called Passau, 6. Jupiter, 7. Saturn, 9. Uranus, 10. Neptun as well as further specifications. To scale the length of the path reaches a total of 5 miles (5914 m) towards south-west/south up the river Inn. The whole construction was finalized in 2011. The York Solar System Model Orrery[ edit ] The York Solar System Model Orrery, was constructed over a period of about 6 months at the end of 1999. [15] This scale model of the Solar System is spread out along 6.4 miles of the old East Coast main-line railway. Along it you can find scale models of all the planets in our solar system as well as models of the Cassini and Voyager spacecraft. The Sun is made from 2 fibreglass hemispheres manufactured for a septic tank. A hole was cut into one of the hemisphere and then the two halves were fiber glass together. Next the internal steel work to support the Sun was installed and the sphere sealed before being painted gold.

The supporting steel-work was manufactured by Minster Engineering. The foundations were prepared, 10 tons of concrete poured in and finally the finished model was installed. Meccano Planetaria[ edit ] The first Meccano Orrery was described in June 1918 Meccano Manual, though it is in the last quarter of the 20th century that Alan Partridge, John Nuttall, Pat Briggs and Michael Whiting have experimented with the limitations and possibilities of this medium. There are six methods of building orreries: [16] Telescopic concentric tubing, though the tubing is not a Meccano part. For a full 9-planet system, 18 concentric tubes and 19 geared motions are needed Nested hollow turntables with internal gearing. A 1984 Jovilabe showing Jupiter and the 14 then known moons required 14 turntables and 324 gears; it is accurate to within 0.01% Fixed central rod, with top drive and sun and planet gearing. In this method, the sun drives the first planet and this then drives the second and so on.

The errors are thus cumulative, but non-Meccano gearing can keep this within 0.02% Fixed central tube, with bottom drive and sun and planet gearing. This removes the need for an overhead gantry, improving the appearance Two component epicyclic gearing. Fixed Central Rod, Epicyclic gearing, top drive by 'by-pass gearing' from below. Salish Sea Walk of the Planets[ edit ] The Salish Sun - Heart of the Salish Sea Walk of the Planets Orrery. The eye is clearly and intentionally off-center symbolizing the imbalance in the Earth's biosphere and especially in the Salish Sea.The fish are herring, the critical fish needed by the food chain and now dangerously reduced from the billions that used to be there so few years ago.Overall the circular shape is that of the Salish whorl used in Coast Salish Art. The Salish symbols dominate all objects in the sculpture. The "Eye" will align with the rising sun on the summer solstice. Created by First Nations Coast Salish Artist, Chris Paul circa 2015.

The first virtual orrery was created inside Google Maps in 2013 by Cattle Point Foundation [17] volunteers at Cattle Point DARK SKY Urban Star Park. [18] The orrery is called "The Salish Sea Walk of the Planets". [19] It was built on Google Maps as there was a contentious local issue that the vernal pools by the edge of the Salish Sea , where the globally rare Macoun's Meadowfoam and Victoria Owl-Clover [20] exist, might be damaged by creating steles , or cairns and by encouraging walkers to explore the Orrery. As well as highlighting the plight of the rare plants, the Orrery has served to put the spotlight on the Coast Salish and specifically the local clan, the Lkwungen [21] upon whose traditional land Cattle Point Star Park lies. [22] The same spotlight also illuminates the unique Salish Sea "stories" from several sciences. Biologists recognize that the marine waters off Cattle Point DARK SKY Star Park are critical habitat for the Orcas of the Salish Sea .

The sea is also a good habitat for the Giant Pacific Octopus ; and, in the Southern Salish Sea, the greatly overfished Pacific Herring - resulting in the relatively low abundance of birds; [23] Ornithologists appreciate the Marbled Murrelets , and Rhinoceros Auklets which are of great interest to visiting birdwatchers especially flying by day and night, in and out of the DARK SKY star park; noting that Cattle Point is surrounded by the historic Victoria Harbour Migratory Bird Sanctuary (est. Oct.27, 1923) . This was established to control hunting in 1923, and now harbours amazing urban life; geologists note that the Orrery's SUN sits on top of the Leech River/Devils Mountain fault line ; and archaeologists celebrate the large number of archaeological sites from the SUN to MERCURY (i.e. within the Star park down along the seafront to the mouth of Bowker Creek), all part of an ancient Lkwungen seaport known as Sitchanalth [24] hypothesized to have been destroyed by the great Tsunami of 930AD.

[25] The Orrery quickly evolved from being contained within the Star Park, to taking on a size previously unimagined by the volunteers. It is now over 8,500 km (5,300 mi) in size reaching out to communities along the Salish Sea's North West Pacific edge and then up along the West coast of Vancouver Island. As an example, the furthest "planet" PLUTO is located in Bamfield. [26] The most distant "object" in the Solar System is the Oort Cloud and has been positioned (approximately, virtually and symbolically) at the Canadian Embassy in Beijing . [27] This effectively serves to illustrate the enormous distances involved in the solar system. "The Salish Sea Walk of the Planets" name symbolizes the fictional journey of the Coast Salish riding inbound inside a long period Comet from Proxima Centauri to Earth many thousands of years ago. In popular culture[ edit ] A large orrery is a key feature in the climactic scene of the film Lara Croft: Tomb Raider (2001). An orrery is used to determine when total eclipses occur in Pitch Black .

The orrery is an artificial construct consisting of life-sized planets and a sun in Green Lantern: New Guardians . [28] The third level of Fireproof Games' popular smartphone game The Room occurs in and around a Talisman Co. Heliocentric Orrery. An orrery is one of the rooms in Andrew Plotkin 's interactive fiction game The Dreamhold . It contains multiple items vital to completing the game. An orrery can be seen on board the spaceship Juggernaut in Prometheus . A complex orrery is used in a pivotal scene of The Dark Crystal . In Prince of Persia: The Forgotten Sands , the Prince manoeuvers through a gigantic water-powered orrery to get to the other side of one of the palace's towers; it is inaccurately named "the Astrolabe" in-game.

Question: An orrery is a mechanical device used to illustrate what ?
Answer: SOLAR SYSTEM