The Antikythera mechanism ( ANT -i-ki- THEER - "English respelling pronunciation"> ANT -I KITH -? r -? ) is an ancient Greek analogue computer and warehousing used to predict astronomical and eclipse positions for the calendars and aims of astrology of previous decades. It could also track a four-year cycle of athletic games similar to Olympiad, the ancient Olympic cycle.
The artifact was discovered on May 17, 1902 by archaeologist Valerios Stais, among the ruins taken from a junk off the Greek island of Antikythera. The instrument is believed to have been designed and built by Greek scientists and has been variously dated to around 87 BC, or between 150 and 100 BC, or up to 205 BC, or in a generation before the shipwreck, which was about 70-60 BC.
The device, which is placed in remnants of 340 millimeters (13 inches) ÃÆ'â € "180-millimeter (7.1Ã, Â) 90-millimeter (3.5 in) wooden box, is found as a lump, then separated into three main part. fragments that are now divided into 82 separate fragments after the work of conservation. These four fragments contain gears, while inscriptions are found on many others. The largest tooth is about 140 millimeters (5.5 inches) in diameter and initially has 223 teeth.
This is a complex clock mechanism consisting of at least 30 bronze meshing teeth. A team led by Mike Edmunds and Tony Freeth at Cardiff University used modern x-ray computer tomography and high-resolution surface scanning for images within fragments of the crust-coated mechanism and read the most vague inscriptions ever covering the engine's outer casing.
The detailed imaging of this mechanism shows that it has 37 gears that allow it to follow the motion of the moon and the sun through the zodiac, to predict the eclipse and even to model the irregular moon's orbit, where the moon's velocity is higher in the perigee than in its apogee. This movement was studied in the 2nd century BC by astronomer Hipparchus of Rhodes, and it was speculated that he might have been consulted in the construction of the machine.
This knowledge of technology disappeared at some point in ancient times, and technological work approached the complexity and workmanship did not emerge again until the development of mechanical astronomical clocks in Europe in the fourteenth century. All known fragments of the Antikythera mechanism are preserved at the National Archaeological Museum in Athens, along with a number of artistic/replica reconstructions of how they appear and function.
Video Antikythera mechanism
History
Antikythera Mechanism Discovery
The Antikythera mechanism was taken from 45 meters (148Ã, ft) of water on the Antikythera ship from the Glyphadia Point on the Greek island of Antikythera in 1901, most probably in July. The wreck was discovered in April 1900 by a group of Greek sponge divers who took many great artifacts, including bronze and marble statues, pottery, unique glasses, jewelry, coins, and mechanics. All were transferred to the National Museum of Archeology in Athens for storage and analysis. The mechanism was merely a bronze and rusting piece of wood at that time and escaped attention for two years, while the museum staff worked to unite the more vivid sculptures.
On May 17, 1902, archaeologist Valerios Stais discovered that one piece of stone had a gear embedded in it. He initially believed that it was an astronomical clock, but most experts thought the device was pro-synchetic, too complex to be built during the same period with other parts that have been found. Investigation of the object was dropped until the British science historian and Yale University professor Derek J. de Solla Price became interested in 1951. In 1971 Price and the Greek nuclear physicist Charalampos Karakalos made an X-ray and gamma-ray image of 82 fragments.. The price published a 70-page paper on their findings in 1974.
It is not known how this mechanism occurred on cargo ships, but it has been suggested that it was brought from Rhodes to Rome, along with other spoils, to support the victory parade staged by Julius Caesar.
Origin
The Antikythera mechanism is generally referred to as the first known analogue computer. The quality and complexity of making mechanisms show that he has found a predecessor made during the Hellenistic period. Its construction depends on the theory of astronomy and mathematics developed by Greek astronomers, and is thought to have been made around the end of the second century BC.
In 1974, the Derek de Solla Price was closed from the gear arrangement and the inscription on the face of a mechanism made about 87 BC and disappeared only a few years later. Jacques Cousteau and his companion visited shipwrecks in 1976 and found coins dated between 76 and 67 BC. Sophisticated corrosion conditions have made it impossible to perform accurate compositional analyzes, but it is believed that the tool is made of bronze alloys with low lead (about 95% copper, 5% tin). The instructions are arranged in Koine Greek.
In 2008, further research by the Antikythera Mechanics Research Project suggested that the concept for such a mechanism may have originated from the Corinthian colonies, as they identified a calendar on the Metonic Spiral originating from Corinth or one of its colonies in northwestern Greece or Sicily.. Syracuse is a Corinthian colony and the home of Archimedes, and the Antikythera Mechanism Research project argued in 2008 that may imply links with the Archimedes school. However, it has recently been shown that the calendar on the Metonic Spiral is indeed of the Corinthian type but can not be from Syracuse. Another theory suggests that the coin was invented by Jacques Cousteau on a shipwreck site in the 1970s during the construction period of the device, and argues that its origins may have originated from the ancient Greek town of Pergamon, the home of the Pergamum Library. With many scrolls of art and science, the second most important is the Library of Alexandria during the Hellenistic period.
The ship carrying the device also contains vases in the Rhodian style, leading to the hypothesis that it was built in an academy founded by the philosopher Stoic Posidonius on the Greek island. Rhodes is a busy trading port of ancient times and a center of astronomy and mechanical engineering, home to Hipparchus active astronomers from about 140 BC to 120 BC. This mechanism uses the theory of Hipparchus for the moon movement, which suggests the possibility that he may have designed or at least worked on it. Moreover, it has recently argued that the astronomical events in the Parapegm of Antikythera Mechanism work best for latitudes in the range of 33.3-37.0 degrees north; The island of Rhodes lies between latitude 35.85 and 36.50 degrees north.
In 2014, a study by Carman and Evans argued for a new date of about 200 BC based on identifying an early date on Dial Saros as an astronomical lunar month beginning shortly after the new April 28, 205 BC. In addition, according to Carman and Evans, the Babylonian arithmetic style of prediction is much better with device prediction models than traditional Greek trigonometric styles. A study by Paul Iversen published in 2017 the reason that the prototype for the device did indeed originate from Rhodes, but this particular model was modified for clients from Epirus in northwestern Greece, and possibly built in a shipwreck generation.
Further diving is underway in the hope of finding more mechanisms.
Maps Antikythera mechanism
Description
The original mechanism seems to come out of the Mediterranean as a single-piece piece. Immediately after that it cracks into three main parts. Other small pieces have been temporarily suspended from cleaning and handling, and others found on the seafloor by the Cousteau expedition. Other fragments may still be stored, not found since their initial recovery; Fragment F was revealed in that way in 2005. Of the 82 known fragments, seven are mechanically significant and contain the majority of mechanisms and inscriptions. There are also 16 smaller sections containing fractional and incomplete inscriptions.
Main Fragment
Minor Fragment
Many of the smaller fragments found do not contain clear values; However, some have some inscriptions on them. Fragment 19 contains significant back door inscriptions including one "... 76 years old...." referring to the Callippic cycle. Other inscriptions seem to describe the function of a back-and-forth call. In addition to these important minor fragments, 15 further minor fragments have remains of inscriptions on them.
Mechanism
Information on specific data collected from debris by a recent investigation is detailed in Freeth's 2006 article Nature supplement.
Operation
On the front face of the mechanism (see reproduction here) there is a fixed ring representing the ecliptic, the twelve zodiac signs marked with the same 30-degree sector. This fits the Babylonian custom of assigning one twelfth ecliptic to each of the zodiac signs evenly, although the constellation limits are variable. Outside the dial it is another ring that can be played, marked by the moon and day of the Sothic Egyptian calendar, twelve months from 30 days plus five days turkey. The months are marked by Egyptian names for the months transcribed into the Greek alphabet. The first task, then, is to turn the Egyptian calendar ring to match the current zodiac point. The Egyptian calendar ignores leap days, so the calendar passes through a full zodiac sign in 120 years.
The mechanism is operated by rotating the small hand crank (now lost) connected through the crown tooth to the largest gear, the four-finger gear visible on the front of fragment A, the tooth is named b1. This moves the date pointer on the front play button, which will be set to the correct Egyptian calendar day. The year can not be selected, so it is necessary to know the current year set, or by looking at the cycles shown by various calendar cycle indicators on the back of the Babylonian ephemeris table for this year's current day, as most calendar cycles are out of sync with the year. Engkol moves the pointer around 78 days per full cycle, so hitting a certain day on lap will be easy to do if the mechanism is in good working condition. The act of twisting the hand crank will also cause all the interconnected gears in the mechanism to rotate, resulting in simultaneous calculations of the Sun and Moon positions, moon phases, eclipses, and calendar cycles, and possibly the locations of the planets.
The operator should also be aware of the position of the spiral dial pointer on two large dial on the back. The pointer has a "follower" that tracks the spiral incision in the metal as the dial combines four and five full rotations of the pointer. When the pointer reaches the terminal moon location at both ends of the spiral, the pointer follower must manually move to the end of the spiral before proceeding further.
Face
Front face
The front dial has two concentric circular scales that represent the ecliptic path through the sky. The outer ring is characterized by civilian Egyptian calendar days of 365 days. In the inner ring, the second dial marks the Greek signs of the Zodiac, with division into degrees. This mechanism preceded the reform of the Julian calendar, but the Sothic and Callippic cycles have shown the 365-day sun year, as seen in Ptolemy III's failed calendar reform 238 BC . Unreliable calls to reflect the proposed leap (Epag 6), but the outer calendar calendar can be moved to the inner circle to compensate for the effects of extra-quarters day in the solar year by changing the reverse scale one day every four years.
The sun's position on the ecliptic corresponds to the current date of the year. The orbits of the moon and the five planets known to the Greeks are quite close to the ecliptic to make it the right reference to determine their position as well.
The following three months of Egypt were written in Greek letters in pieces of the surviving outer rings:
- ????? (Pachon)
- ????? (Payni)
- ????? (Epiphi)
The other months have been reconstructed, although some reconstruction mechanisms eliminate 5 days of Egyptian turkey moon. The Zodiac dial contains Greek inscriptions of Zodiac members, which are believed to be adapted to the tropical moon version rather than sidereal:
- ????? (Krios [Ram], Aries)
- ?????? (Tauros [Bull], Taurus)
- ??????? (Didymoi [Twins], Gemini)
- ???????? (Karkinos [Crabs], Cancer)
- ???? (Leon [Lion], Leo)
- ???????? (Parthenos [Maiden], Virgo)
- ????? (Chelai [Scorpio's Claw or Zygos], Libra)
- ???????? (Skorpios [Scorpion], Scorpio)
- ??????? (Toxotes [Archer], Sagittarius)
- ????????? (Aigokeros [Goat-horned], Capricorn)
- ???????? (Hydrokhoos [Water carrier], Aquarius)
- ?????? (Ichthyes [Fish], Pisces)
Also on the zodiac dial are a number of single characters at certain points (see reconstruction here :). They are locked into the parapegma , the predecessor of modern almanacs written on the front face above and below the call. They mark the location of longitude on the ecliptic for certain stars. The parapegma above quickly reads (square brackets indicate the text inferred):
The parapegma under the disc reads:
At least two pointers indicate the position of the body on the ecliptic. The moon indicator indicates the position of the moon, and the sunlight indicator is also indicated, possibly doubling as the current date pointer. The position of the moon is not a simple average moon indicator that will show a uniform movement around a circular orbit; it approximates the acceleration and deceleration of the elliptical orbit of the moon, through the earliest use of existing epicyclic teeth.
It also tracks the precession of the elliptical orbit around the ecliptic in the 8.88 year cycle. The sun's meaningful position is, by definition, the current date. It is speculated that since such pain is taken to obtain the correct position of the moon, there is also the possibility of being a "true sun" indicator in addition to sunlight indicator as well, to trace the sun's elliptical anomaly (Earth's orbit around the sun), but none evidence among the ruins of the mechanism found to date. Similarly, there is no evidence of planetary orbital pointers for the five planets known to the Greeks among the ruins. See the proposed planetary indication Installation Plan below.
Finally, engineer Michael Wright has shown that there is a mechanism to supply the moon phase in addition to its position. The indicator is a small ball embedded in a lunar pointer, half white and half black, which is rotated to show the phases (new, first quarter, half, full third, full, and back) graphically. Data to support this function is available given the position of the sun and the moon as angular rotation; in essence, it is the angle between the two, translated into ball rotation. It requires differential gear, setting the summing or differentiation of the two angle inputs.
Rear face
In July 2008, scientists reported new findings in the journal Nature that indicate that the mechanism not only tracks Metonic calendars and solar eclipse predictions, but also calculates the timing of several panhellenic athletic games, including the Ancient Olympics. The inscription on the instrument fits perfectly with the names of the moon used on the calendar of Epirus in northwestern Greece and with the island of Corfu, which in ancient times was known as Corcyra
At the back of the mechanism, there are five buttons: two large screens, Metonic and Saros, and three smaller indicators, called Olympiad Dial, recently renamed the Olympic Calls for not tracking the Olympiad year (the four-year cycle he tracked closest is Halieiad), Callippic, and Exeligmos.
The Metonic Dial is the main top dial on the back of the mechanism. The Metonic cycle, defined in some physical units, is a synodic 235 moons, which is very close (in less than 13 one-million) to 19 tropical years. Therefore it is an appropriate interval to change the calendar of the moon and the sun. The Metonic Button covers 235 months in 5 rounds of rotation, following a spiral path with a follower on a pointer that tracks the spiral layer. The pointer points to a synodic moon, calculated from the new moon to the new moon, and the cell contains the name of the Corinthian moon.
- ?????????? (Phoinikaios)
- ???????? (Kraneios)
- ??????????? (Lanotropios)
- ???????? (Machaneus, "mechanic" , referring to Zeus the inventor)
- ?????????? (Dodekateus)
- ???????? (Eukleios)
- ?????????? (Artemisios)
- ??????? (Psydreus)
- ????????? (Gameilios)
- ????????? (Agrianios)
- ??????? (Panamos)
- ????????? (Apellaios)
Thus, setting the correct sun time (in days) on the front panel shows the current lunar month on the back panel, with resolution within a week or so.
Based on the fact that the names of the calendar months are consistent with all the evidence of the Epirote calendar and that the Match dial mentions the very small Naa game of Dodona (in Epirus), it has recently been argued that the calendars on the Antikythera Mechanism are likely to be Epirote calendars, and that this calendar might be adopted from the Corinthian colonies in Epirus, possibly Ambracia. It has also been argued that the first month of the calendar, Phoinikaios, is ideally the month in which the falling equinox falls, and that the calendar start date shortly after the new moon of astronomy on August 23, 205 BC.
Call Call is the upper left secondary dial, which follows the 76-year cycle. Callippic cycle is four Metonic cycles, so this dial shows the current Metonic cycle in the whole Callippic cycle.
The Games dial is the right top secondary dial; this is the only indicator on the instrument moving counter-clockwise along with the progress of time. Calls are divided into four sectors, each of which is written with the year's indicator and the names of the two Panhellenic Games: "crown" games from Isthmia, Olympia, Nemea, and Pythia; and two lower games: Naa (held at Dodona), and the sixth and last set of Games recently outlined as the Halieia of Rhodes. The inscriptions on each of the four divisions are:
The Saros button is the main downward spiral dial on the back of the mechanism. The Saros cycle is 18 years old and 11 1 / 3 long day (6585,333... days), which is very close to 223 synod month (6585,3211 days). This is defined as the cycle of positional repetition required to cause solar and lunar eclipses, and therefore, can be used to predict them - not just months, but days and times. Note that the cycle is about 8 hours longer than the number of integer days. Translated into global rounds, that means the eclipse occurs not only eight hours later, but one-third of the rotation farther west. The glyphs in 51 of the 223 cells of the synodic month of call determine the occurrence of 38 moons and 27 solar eclipses. Some abbreviations in glyphs read:
The glyph indicates whether the specified eclipse is the sun or moon, and gives the day of the moon and hour; obviously, the solar eclipse may not be visible at some point, and the lunar eclipse is only visible if the moon is above the horizon at the given hour. In addition, the inner lines at the cardinal points of the Saros dial indicate the beginning of a new full moon cycle. Based on the distribution of eclipse time, it has recently been argued that the Saros dial start dates shortly after the new moon of astronomy on April 28, 205 BC.
Exeligmos Dial is a secondary dial under the back of the mechanism. The Exeligmos cycle is a triple cycle of Saros for 54 years whose length is 19,756 days. Since the length of the Saros cycle is one-third of a day (eight hours), then the full Exeligmos cycle returns the count to the integer day, then the inscription. Labels in three divisions are:
- Empty or o? (representing zero, assumed, not observed)
- H (number 8) means adding 8 hours to the time mentioned on the screen
- me? (number 16) means adding 16 hours to the time mentioned on the screen
Thus the dial pointer shows how many hours should be added to the Saros dial machine to calculate the exact eclipse time.
Doors
The mechanism has a wooden casing with the front and rear doors, both of which contain inscriptions. The back door appears to be a "manual instruction". In one fragment, "76 years, 19 years" represents the Callippic and Metonic cycles. Also written is "223" for the Saros cycle. In one of its fragments, it says "in the spiral subdivision 235" refers to the Metonic button.
Gearing
This mechanism is remarkable for the degree of miniaturization and the complexity of its parts, which is comparable to the fourteenth century astronomical clock. It has at least 30 gears, although expert mechanism Michael Wright has suggested that the Greek period is capable of applying systems with more gears.
There is much debate as to whether the mechanism has indicators for all five planets known to the ancient Greeks. No gears for such a planetary view survive and all gears are taken into account - with the exception of one tooth 63 (r1) if not found in fragment D.
The purpose of the front face is to position the body of astronomy with respect to the celestial sphere along the ecliptic, referring to the observer's position on Earth. It is irrelevant to the question of whether the position is calculated using a heliocentric or geocentric view of the solar system; both computational methods must, and not, produce the same position (ignoring ellipticity), in error factor mechanisms.
Ptolemy's epicyclic solar system (still 300 years in the future from a clear date of the mechanism), was brought forward with more epicycles, more accurately predicting the planet's position than Copernicus's view, until Kepler introduced the possibility that the orbit was an ellipse.
Evans et al. suggested that to show the average position of five classical planets would require only 17 further teeth that could be positioned in front of a large moving gear and indicated using an individual coiled grill on the face.
Tony Freeth and Alexander Jones model and detail details of versions that use multiple gear gears that are mechanically similar to the moon anomaly system that allows an indication of the planet's position and the synthesis of solar anomalies. Their system, they claim, is more authentic than the Wright model because it uses skills known to the Greeks in that period and does not add excessive complexity or internal pressure to the machine.
The dental gear is in the form of an equilateral triangle with an average 1.6 mm circular tone, an average wheel thickness of 1.4 mm and an average air gap between 1.2 mm teeth. Teeth may be created from an empty bronze spin using hand tools; this is proven because not everything is even. Due to advances in imaging technology and X-rays it is now possible to know the exact number of teeth and size of teeth in fragments. Thus the basic operation of the device is no longer a mystery and has been accurately imitated. The main uncertainty remains the question of the existence and nature of any planetary indicator.
A table of gears, their teeth, and expected rotation and is calculated from the following important gear wheels. The gear function comes from Freeth et al. (2008) and those for the bottom of the table from Freeth and Jones 2012. The calculated value begins with 1 year/revolution for the b1 tooth, and the rest is calculated directly from the gear ratio of the teeth. The gears marked with an asterisk (*) are missing, or the predecessor is missing, from a known mechanism; This tooth has been calculated with a reasonable amount of dental tooth.
Catatan table:
There are several gear ratios for each planet that produce a close match with the correct values ​​for the sinodic periods of the planet and the sun. The ones chosen above seem to provide good accuracy with a reasonable amount of teeth, but special teeth that may have been used, and probably will remain, unknown.
Known gear schema
It is likely that there is a planetary call, because of the complicated movements and periodicities of all the planets mentioned in the manual mechanism. The exact positions and mechanisms for planetary gears are unknown. There is no coaxial system but only for months. Fragment D which is an epicycloidal system is considered as planetary equipment for Jupiter (Moussas, 2011, 2012, 2014) or teeth for the Sun movement (University of Thessaloniki group). Sun Teeth is operated from a hand-operated crank (connected to a1 gear, steers a large four-headed sun teeth, b1) and in turn moves the rest of the set of gears. The sun's teeth are b1/b2 and b2 has 64 teeth. This directly moves the date/average of the sunlight indicator (there may be a second pointer, the "true sun" that displays the solar ellipse anomaly, this is discussed below in Freeth reconstruction). In this discussion, the reference is to model the rotation period of various instructions and indicators; they all assume an input rotation of a 360 degree bevel gear, corresponding to a tropical year, and are calculated solely on the basis of the named gear ratios.
The Moon train starts with b1 teeth and continues through c1, c2, d1, d2, e2, e5, k1, k2, e6, e1 and b3 to the front months pointer. The k1 and k2 gears form an epicyclic dental system; they are an identical pair of identical gears, but rather, they operate face-to-face, with short pins on k1 inserted into slots in k2. Both gears have different rotation centers, so the pins must move back and forth inside the slot. It increases and decreases the radius at which k2 is moved, it must also vary its angular velocity (which assumes lower k1 velocity) in some parts of the rotation than others. During the entire revolution, the average velocity is the same, but the variations slowly model the elliptical orbital effects of the moon, as a result of Kepler's second and third laws. Rotation period of the month indicator model (average more than one year) is 27,321 days, compared to the modern day month of sidereal month 27.321661 days. As mentioned, the driving pin/slot of the k1/k2 gear varies in displacements over a year of time, and the installation of two teeth in e3 gear supplied precessional progression to elliptical modeling with a period of 8,8826 years, compared to the current value of the 8-month precession period, 85 years.
This system also modeled the moon phase. The moon indicator holds an axis along its length, where a small tooth called r is attached to a sun pointer in B0 (the relationship between B0 and the remaining B is not visible in the original mechanism, so whether b0 is the current date/sunlight indicator or a hypothetical sunlight indicator that is not actually known). The gear runs around the dial with the moon, but also directed to the sun - the effect is to perform a differential dental operation, so the gear rotates in the synodic moon period, measuring its effect, the difference angle between sunlight and moon hints. The gears move a small ball that appears through the hole in the lunar face, painted half-long white and half-black, displaying the phase in picture. It turns out with a 29.53 day rotation model; the modern value for the synod month is 29.530589 days.
The Metonic train is driven by the train train b1, b2, l1, l2, m1, m2, and n1, connected to the pointer. The rotation period modeled from the pointer is a length of 6939.5 days (above the entire spiral of five rotations), while the modern value for the Metonic cycle is 6939.69 days.
The Olympic Train is driven by b1, b2, l1, l2, m1, m2, n1, n2, and o1, which mount the pointer. It has a modeled rotation period calculated exactly 4 years, as expected. Incidentally, this is the only pointer to a mechanism that rotates counterclockwise; all others rotate clockwise.
Callippic Train is driven by b1, b2, l1, l2, m1, m2, n1, n3, p1, p2, and q1, which mount the pointer. It has a modeled rotation period calculated 27758 days, while the modern value is 27758.8 days.
Saros Train is driven by b1, b2, l1, l2, m1, m3, e3, e4, f1, f2, and g1, which mount the pointer. The rotation period modeled from the Saros pointer is 1646.3 days (in four rotations along the spiral pointing path); modern value is 1646.33 days.
The Exeligmos train is driven by b1, b2, l1, l2, m1, m3, e3, e4, f1, f2, g1, g2, h1, h2 and i1, mounting the pointer. The rotation period modeled from the Exeligmos pointer is 19,756 days; the modern value is 19755.96 days.
Apparently, gears m3, n1-3, p1-2, and q1 do not survive in the rubble. The function of the pointer is deduced from the remnants of the disk at the back of the face, and the appropriate and appropriate fit to fulfill the proposed functions, and is generally accepted.
Proposed gear scheme
Due to the large space between the average solar fixture and the front of the casing as well as the size and mechanical features in the average of the solar fixtures, it is likely that the mechanism contains further gearing that is missing or submerged in shipwreck or has been removed before being loaded onto the vessel. The lack of evidence and the nature of the front of the mechanism has led to many attempts to replicate what the Greeks have done at that time and, of course, because of the lack of evidence many solutions have been put forward.
Michael Wright was the first to design and build models with not only known mechanisms, but also, with emulation of a potential planetarium system. He suggested that along with the moon anomaly, adjustments would be made to deeper and more fundamental solar anomalies (known as "first anomalies"). He included instructions for this "true sun", Mercury, Venus, Mars, Jupiter, and Saturn, in addition to "meaningful sun" (current time) and moon clues.
Evans, Carman, and Thorndike publish solutions with significant differences from Wright. Their proposal centered on what they observed as irregular distances from inscriptions on the front dial faces, which seemed to them to indicate the setting of sun indicators outside the center; this will simplify the mechanism by removing the need to simulate solar anomalies. They also suggest that rather than an accurate planet indication (given impossible by an offset inscription) there will be a simple call for each individual planet that shows information such as important events in planetary cycles, early and late appearance in the night sky, and clear directions. change. This system will lead to a simplified gear system, with much less power and complexity, than the Wright model.
Their proposal used simple impermeable teeth and accounted for previously described 63 toothed teeth in fragment D. They proposed two face plates layout, one quickly spaced evenly, and another with a crack at the top of the face to account for criticism about them not using apparent fixtures on the teeth b1. They propose that weather rather than bearings and pillars for gears and axles, they are only held and seasonal icons are shown through the window.
In a paper published in 2012, Carman, Thorndike, and Evans also proposed an epicyclic gearing system with pin and follower slots.
Freeth and Jones publish their proposal in 2012 after extensive research and work. They come with a compact and feasible solution for planetary indication questions. They also proposed showing the solar anomaly (ie, clear sun position in the zodiac dial) on a separate pointer from the date indicator, indicating the average sun position, as well as the date on the lunar dial. If both buttons are synchronized correctly, their front panel display is essentially the same as Wright. Unlike the Wright model, this model has not been built physically, and only a 3-D computer model.
The systems for synthesizing solar anomalies are very similar to those used in Wright's proposals. Three gears, one fixed in the center of the b1 gear and attached to the spindle of the sun, the second one mounted on one of the radius (in their proposal in the lower left) which acts as an empty gear, and the latter is positioned next to that one, the final tooth is equipped with offset pin and, more than the word pin, the arm with the slot which in turn, attached to the sun spindle, pushes the anomaly as the sun wheel which means to change.
Inferior planetary mechanisms including the sun (treated as planets in this context), Mercury, and Venus. For each of these three systems there is an epicyclic gear whose axis is mounted on b1, so that the base frequency is Earth year (as is, in fact, for epicyclic motion in the sun and all planets - except for only months). Each mesh with teeth is earthed into the mechanism frame. Each has a pin attached, potentially a one-sided extension of the tooth that enlarges the tooth, but does not disturb the teeth; in some cases the distance required between the center of the gear and the pin is further away from the spokes of the gear itself. A bar with a slot along its length extends from the pin toward the corresponding coaxial tube, at the other end is an object pointer, out in front of the front dial. The blades can be full gears, though there is no need to throw away the metal, because the only part that works is the slot. Also, using the bar avoids interference between three mechanisms, each of which is set on one of four radii b1. Thus there is a new ground gear (one identified in the ruins, and the second divided by two of the planets), a tooth used to reverse the anomalous direction of the sun, three epicyclic teeth and three coaxial bars/tubes/pointers, which will qualify as other supplies. Five gears and three iron bars at all.
The superior planetary systems - Mars, Jupiter, and Saturn - all follow the same general principle of the moon's anomaly mechanism. Similar to inferior systems, each has a pivot center gear on the b1 extension, and is lined with ground gear. It presents a pin and a central axle for an epicyclic tooth that has a slot for the pin, and that connects with the fixed gear to the coaxial tube and from there to the pointer. Each of the three mechanisms can enter in the quadrant of extension b1, and they are all on one plane parallel to the front-plate plates. Each uses a milled teeth, a driving gear, a driving gear, and a coaxial tube/pointer, so that there are twelve additional gears at all.
In total, there are eight coaxial spindles of various nested sizes to transfer rotation in a mechanism to eight pointers. So in all, there are 30 original gears, 7 gears added to complete calendar functions, 17 gears and three slotted bars to support six new pointers, for a grand total of 54 gears, three bars, and eight pointers at Freeth and Jones' Design.
In the visual representation provided by Freeth on paper, the pointers on the zodiacal zodiac have small identification stones and rounded. Interestingly, he cited quotations from ancient papyrus:
... a voice comes to you speaking. Let the stars be arranged on the board according to their nature except the Sun and the Moon. And let the Sun be gold, silver Moon, Kronos [Saturn] from obsidian, Ares [Mars] from red onyx, Aphrodite [Venus] lapis lazuli engraved with gold, Hermes [Mercury] turquoise; let Zeus [Jupiter] be (whitish?) stone, crystal (?)...
Accuracy
Investigations by Freeth and Jones revealed that their simulation mechanism was not very accurate, the Martian pointer rising up to 38 Â ° off at times. This is not because of the inaccuracies in the gear ratios in the mechanism, but rather on the insufficiency in Greek theory. The accuracy can not be fixed until Ptolemy first proposed his Planetary Hypothesis in the second half of the second century AD and later the introduction of Kepler's Second Law in the early 17th century.
In a nutshell, Antikythera Mechanism is a machine designed to predict the celestial phenomenon according to today's advanced astronomical theory, the only witness to the lost history of brilliant engineering, the concept of pure genius, one of the great wonders of antiquity. the world - but it does not really work properly!
In addition to theoretical accuracy, there is a matter of mechanical accuracy. Freeth and Jones noted that the inevitable "leeway" in the mechanisms due to hand-made teeth, with triangular teeth and friction between the gears, and in the bearing surface, may flood the more delicate sun and moon correction mechanisms built into it. :
Although this technique is remarkable for its time, recent research has shown that its design concept exceeds engineering engineering with a wide margin - with large cumulative inaccuracies in the dashboard, which will undo many of the fine anomalies built into the design.
While the device itself may have struggled with inaccuracies because of hand-made triangular teeth, calculations are used and technology is implemented to create elliptical paths of planets and retrograde movements of the moon and Mars using a work-hour type of gear with the addition of pin-and-slot mechanisms precedes that the first hour known to have been discovered in antiquity in medieval Europe by more than 1000 years. Archimedes's development of the approximate value of pi and his theory of the center of gravity along with the steps he made to develop the calculus all show that the Greeks had access to more than sufficient mathematical knowledge beyond that of only the Babylonian algebra to be able to model the traits elliptical planetary motion.
Which is very fun for physicists, Moon mechanism uses a special bronze wheel trains, two of which connect with the axis slightly offset, to indicate the position and phase of the moon. As is known today from the Law of the Kepler Planet Motion, the moon moves at different speeds as it orbits the Earth, and this speed difference is modeled by Antikythera Mechanism, although the ancient Greeks were unaware of the true elliptical shape of the orbit.
Similar tools in ancient literature
Cicero's De re publica, a philosophical dialogue of the 1st century BC, mentions two machines considered by some modern writers as a kind of planetarium or orrery, predicting the movement of the Sun, Moon and the five planets known at the time. They were both built by Archimedes and brought to Rome by Roman general Marcus Claudius Marcellus after the death of Archimedes on the siege of Syracuse in 212 BC. Marcellus greatly respected Archimedes and one of these machines was the only item he kept from the siege (the latter offered to the temple of Virtus). The device was kept as a family heirloom, and Cicero had Philus (one of the participants in a conversation Cicero had imagined going on in a villa owned by Scipio Aemilianus in 129 BC) who said that Gaius Sulpicius Gallus (consul with Marcellus's niece in 166 BC, and credited by Pliny the Elder as the first Romans who had written a book explaining the solar and lunar eclipses) provided "learned explanations" and demonstrations of the devices.
I often hear the sky ball or the ball is mentioned because of the great fame of Archimedes. His appearance, however, did not seem to me very striking. There is another, more elegant in form, and more commonly known, formed by the same Archimedes, and kept by the same Marcellus, at the Temple of Virtue in Rome. But as Gallus began to explain, with his lofty science, the structure of this machine, I felt that the geometric Sicilians must have possessed a genius superior to anything we would normally consider our natural possessions. Gallus assures us that the solid and solid globe of the earth is a very ancient discovery, and that the first model of it has been presented by Thales of Miletus. That Eudoxus of Cnidus, a disciple of Plato, had traced the surface of the stars that appeared in the sky, and years later, borrowed from Eudoxus's design and this beautiful representation, Aratus has described it in his verses, not by astronomical science , but the poetic description ornament. He added that the figure of the ball, which displays the motions of the Sun and the Moon, and the five planets, or wandering stars, can not be represented by a primitive sphere of the earth. And that in this case, Archimedes's discovery is remarkable, for he has calculated how a revolution must maintain uneven and diversified development in different movements.
When Gallus moves this world, he shows the relationship of the Moon with the Sun, and there is the same number of twists on the bronze device as the number of days in the real world ball. Thus it shows the same solar eclipse as in the world [of the sky], and shows the Moon entering the shadow of the Earth when the Sun is marching... [lost text] [i.e. It shows a solar and lunar eclipse.]
Pappus of Alexandria stated that Archimedes had written a missing script on the construction of this device entitled On Sphere-Making . The surviving texts from the Library of Alexandria describe many of his works, some even containing simple images. One such tool is the odometer, the exact model which was then used by the Romans to place their mile markers (described by Vitruvius, Heron of Alexandria and in the time of Emperor Commodus). The pictures in the text appear to work, but the attempt to make them as described fails. When the gears are depicted, which have square teeth, replaced with gears of the type in the Antikythera mechanism, which are tilted, the device works perfectly. Is this an example of a device created by Archimedes and described by the missing text in the burning of the Library of Alexandria, or whether it is a device based on his invention, or whether it has anything to do with him at all, is debatable..
If Cicero's account is correct, then this technology has been around since the 3rd century BC. Archimedes's devices are also mentioned by later Roman writers such as Lactantius ( Divinarum Institutionum Libri VII ), Claudian ( In Archimedes sphaeram ), and Proclus ( Comment on the first book of Euclid's Elements of Geometry) in the 4th and 5th centuries.
Cicero also said that such other devices were built "recently" by his friend Posidonius, "... each of the revolutions that carry the same movement in the Sun and the Moon and five stars wandering [the planet] as it is carried every afternoon and night in paradise... "
It is unlikely that one of these machines was the Antikythera mechanism found on the shipwreck because both devices were made by Archimedes and mentioned by Cicero who was in Rome at least 30 years later from the estimated shipwreck date, and the third device is almost certainly in hand Posidonius on that date. Scientists who have reconstructed the Antikythera mechanism also agree that it is too sophisticated to be a unique device.
This evidence suggests that the Antikythera mechanism does not uniquely add support to the idea that there was an ancient Greek tradition of complex mechanical technology that was then, at least in part, transmitted to Byzantine and Islamic world, where complex mechanical devices, albeit simpler than Antikythera mechanisms, were built during the Middle Ages. Parts of the calendar directed at the sundial, of the 5th or 6th century Byzantine Empire, have been found; the calendar may have been used to assist in timing. In the Islamic world, Ban? M? S? S Kitab al-Hiyal , or The Ingenious Devices , was commissioned by the Khalifah of Baghdad in the early 9th century. This text describes more than a hundred mechanical devices, some of which may be derived from ancient Greek texts stored in monasteries. Gender calendars similar to Byzantine devices have been described by al-Biruni scientists around 1000, and the surviving 13th-century astrolabe also contains the same clock device. It is possible that this medieval technology may have been transmitted to Europe and contribute to the development of mechanical clocks there.
Popular culture
In 2012, the Antikythera mechanism is now featured as part of a temporary exhibit on the Antikythera Shipwreck, accompanied by reconstructions made by Ioannis Theofanidis, Derek de Solla Price, Michael Wright, University of Thessaloniki and Dionysios Kriaris. Another reconstruction is on display at the American Computer Museum in Bozeman, Montana, at the Manhattan Children's Museum in New York, at Astronomisch-Physikalisches Kabinett in Kassel, Germany, and at Musà © e des Arts et Mà © à © tiers in Paris.
The National Geographic Naked Science documentary has an episode dedicated to Antikythera Mechanism entitled "Star Clock BC" which aired on January 20, 2011. A documentary film, First Computers in the World , is produced in 2012 by Antikythera mechanism researchers and filmmaker Tony Freeth. In 2012 BBC Four aired Old Two-thousand Year Computers ; it also aired on April 3, 2013 in the United States on NOVA, the PBS science series, under the name Ancient Computers . This document discovery and investigation of 2005 mechanism by Antikythera Mechanism Research Project.
The fictional version of this device is the central plot point in the film Stonehenge Apocalypse (2010), where it is used as an artifact that saves the world from the impending doom. On May 25, 2010, the first episode of the History Channel series Ancient Aliens presented it as one of the many ancient alien astronomical "proofs" that visited Earth and abandoned technology. In Assassin's Creed IV: Black Flag, a game in the popular video game series Assassin's Creed, Antikythera Mechanism is brought into the game's knowledge through in-game text. It is a fairy tale to be a small part of a much larger device that is used to "predict the future" through massive probability calculations, and is used by ancient races to accurately send messages to the series' protagonist, Desmond Miles.
The fully functional Lego reconstruction of the Antikythera mechanism was built in 2010 by the hobbyist Andy Carrol, and featured in short films produced by Small Mammal in 2011.
Several exhibitions have been staged all over the world, leading to the main "Antikythera shipwreck" exhibition at the National Archaeological Museum in Athens, Greece.
On May 17, 2017, Google marked the 115th anniversary of the discovery with Doodle.
See also
References
Further reading
Books
Journal
More
External links
- 3D model simulation at Antikythera Mechanism Research Project
- Antikythera Mechanism Research Project. "Video". YouTube . Retrieved July 24 2017 .
- Exhibition of Antikythera Mechanism by the National Hellenic Research Foundation .
- Antikythera Mechanism at Wolfram Demonstrations Project.
- YAAS - Een 3D interactive virtual reality simulator in VRML
- "Virtual Reconstruction Mechanism of Antikythera (by M. Wright & Vicentini)". Inherited Key. August 25, 2009 - via YouTube.
- Antikythera (Adobe Flash) Nature , July 30, 2008
Source of the article : Wikipedia
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