Antikythera mechanism

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The Antikythera mechanism is an ancient mechanical calculator (also described as the first "mechanical computer"^[1][2]) designed to calculate astronomical positions. It was discovered in the Antikythera wreck off the Greek island of Antikythera, between Kythera and Crete, in 1900. Subsequent investigation, particularly in 2006, dated it to about 150-100 BC, and hypothesised that it was on board a ship that sank en route from the Greek island of Rhodes to Rome, perhaps as part of an official loot. Technological artifacts of similar complexity did not reappear until a thousand years later.^[3]

Contents 1 Discovery 2 Origins 3 Function 4 Speculation about its purpose 5 Similar devices in ancient literature 6 Investigations and reconstructions 6.1 Derek J. de Solla Price 6.2 Allan George Bromley 6.3 Michael Wright 6.4 The Antikythera Mechanism Research Project 6.4.1 New discoveries 7 See also 8 References 9 Further reading 10 External links

[edit] Discovery

Sometime before April of 1900, a Greek sponge diver named Elias Stadiatis discovered the wreck of an ancient large cargo ship off Antikythera island at a depth of 42 m (138 ft) to 60 m (200 ft). Sponge divers retrieved several statues (including the famous Antikythera Ephebe, and a characterful head of a Stoic Philosopher) and other artifacts from the site, known as the Antikythera wreck. The mechanism itself was discovered on 17 May 1902, when archaeologist Valerios Stais noticed that a piece of rock recovered from the site had a gear wheel embedded in it. Examination revealed that the "rock" was in fact a heavily encrusted and corroded mechanism that had survived the shipwreck in three main parts, and dozens of smaller fragments. The device itself was surprisingly thin, about 33 cm (13 in) high, 17 cm (6.7 in) wide, and 9 cm (3.5 in) thick, made of bronze and originally mounted in a wooden frame (a very small part of it is still in the museum). It was inscribed with a text of over 3,000 characters, most of which have only recently been deciphered. These characters were part of a manual, which describes how to set up the instrument and how to use it for observations, with references to the Sun, the motion of the planets (stationary points), Aphrodite (Venus), Hermes (Mercury), and eclipses.

Jacques-Yves Cousteau visited the wreck for the last time in 1978,^[4] but found no more remains of the Antikythera Mechanism. Professor Michael Edmunds of Cardiff University who led the study of the mechanism said: "This device is just extraordinary, the only thing of its kind. The design is beautiful, the astronomy is exactly right. The way the mechanics are designed just makes your jaw drop. Whoever has done this has done it extremely carefully." and added: "in terms of historic and scarcity value, I have to regard this mechanism as being more valuable than the Mona Lisa."^[5][6]

The device is displayed in the Bronze Collection of the National Archaeological Museum of Athens, accompanied by a reconstruction made and offered to the museum by Derek de Solla Price. Other reconstructions are on display at the American Computer Museum in Bozeman, Montana and the Children's Museum of Manhattan in New York.

[edit] Origins

The mechanism is the oldest known complex scientific instrument. It has several accurate scales, and is essentially an analog computer made with gears. It is based on theories of astronomy and mathematics developed by Greek astronomers. Based on the shape of the Greek letters used in the manual of the instrument, it is estimated that it was constructed around 150 to 100 BC. The circumstances under which it came to be on the cargo ship are unclear. The ship is estimated to have sunk between 80 to 60 BC and was a Roman or Greek ship with cargo for Rome, perhaps part of official loot. It contained more than 100 statues similar to the ones the Romans took to Italy after their conquest of Greece. Consensus among scholars is that the mechanism itself was made in Greece.^[6] All the instructions of the mechanism are written in Greek.

One hypothesis is that the device was constructed at an academy founded by the ancient Stoic philosopher Posidonius on the Greek island of Rhodes, which at the time was known as a centre of astronomy and mechanical engineering. Investigators have suggested that the ship could have been carrying it to Rome, together with other treasure looted from the island to support a triumphal parade being staged by Julius Caesar.^[7]

As the new finds of the Antikythera Mechanism Research Project suggest that it was made around 150 to 100 BC, well before the time of Posidonius, it is possible that the great astronomer Hipparchus is behind the genius engineer who constructed it. Hipparchus was at that time the most important astronomer and worked for a long period in Rhodes, Greece. The Mechanism contains a lunar mechanism which uses Hipparchus' theory for the motion of the Moon and this also suggests strong ties of the Mechanism to Hipparchus.

[edit] Function

The device is remarkable for the level of miniaturization and complexity of its parts, which is comparable to that of 18th century clocks. It has over 30 gears, although Michael Wright (see below) has suggested as many as 72 gears, with teeth formed through equilateral triangles. When a date was entered via a crank (now lost), the mechanism calculated the position of the Sun, Moon or other astronomical information such as the location of other planets. It is possible that the mechanism is based on heliocentric principles, rather than the then-dominant geocentric view espoused by Aristotle and others. The heliocentric view proposed by Aristarchus of Samos (310 BC - c. 230 BC) did not receive widespread recognition, but provides for the possibility of the existence of such a system at this time.

The mechanism has three main dials, one on the front, and two on the back.

The front dial has two concentric scales. The outer ring is marked off with the days of the 365-day Egyptian calendar, or the Sothic year, based on the Sothic cycle. Inside this, there is a second dial marked with the Greek signs of the Zodiac and divided into degrees. The calendar dial can be moved to adjust, to compensate for the effect of the extra quarter day in the year (there are almost 365.25 days per year) by turning the scale backwards one day every four years. Note that the Julian calendar, the first calendar of the region to contain leap years, was not introduced until about 46 B.C., up to a century after the device was said to have been built (and it was implemented with errors until the early first century).

The front dial probably carried at least three hands, one showing the date, and two others showing the positions of the Sun and the Moon. The Moon indicator is adjusted to show the first anomaly of the Moon's orbit. It is reasonable to suppose the Sun indicator had a similar adjustment, but any gearing for this mechanism (if it existed) has been lost. The front dial also includes a second mechanism with a spherical model of the Moon that displays the lunar phase.

There is reference in the inscriptions for the planets Mars and Venus, and it would have certainly been within the capabilities of the maker of this mechanism to include gearing to show their positions. There is some speculation that the mechanism may have had indicators for all the five planets known to the Greeks. None of the gearing, except for one unaccounted gear, for such planetary mechanisms survives.

Finally, the front dial includes a parapegma, a precursor to the modern day Almanac, which was used to mark the rising and setting of specific stars. Each star is thought to be identified by Greek characters which cross reference details inscribed on the mechanism.

The upper back dial is in the form of a spiral, with 47 divisions per turn, displaying the 235 months of the 19 year Metonic cycle. This dial contains a smaller subsidiary dial which displays the 76 year Callippic cycle. (There are 4 Metonic cycles within 1 Callippic cycle.) Both of these cycles are important in fixing calendars.

The lower back dial is also in the form of a spiral, with 223 divisions showing the Saros cycle; it also has a smaller subsidiary dial which displays the 54 year "Triple Saros" or "Exeligmos" cycle. (The Saros cycle, discovered by the Chaldeans, is a period of approximately 18 years 11 days 8 hours -- the length of time between occurrences of a particular eclipse.)

[edit] Speculation about its purpose

While a century of research is finally answering the question of what the mechanism did, we are actually no nearer to answering the question what it was for. There are numerous suggestions, any of which could be right. In order to understand the significance of this device at the period of its manufacture (c. 150 B.C.) one should be aware of the known scientific and cultural status at that period and take into account that:

1. The law of gravity was not discovered, so the reason why the heavenly bodies moved was not understood.
2. The theory of planetary motion was not complete.
3. The only means to transmit knowledge was either speech or hand-written manuscripts.

There was a huge scientific and cultural gap between the very few educated elite that understood basic rules of solar, lunar and planetary motion and the common people who were ignorant about those things. Many ancient references from Cicero, Pliny, Plato, Seneca, Ptolemy and Aristotle et al indicate that common people viewed solar and lunar eclipses as superstitious events, linked with fear: ".. easy for the ignorant to imagine that all has become confusion and doom"^[8] .

Practical uses of this device have been said also to include the following:

• Astrology was commonly practiced in the ancient world. In order to create an astrological chart, the configuration of the heavens at a particular point of time is needed. It can be very difficult and time-consuming to work this out by hand, and a mechanism such as this would have made an astrologer's work much easier.
• Setting the dates of religious festivals connected with astronomical events.
• Adjusting calendars, which were based on lunar cycles as well as the solar year.

Price suggested that it might have been on public display, possibly in a museum or public hall in Rhodes. The island was known for its displays of mechanical engineering, particularly automata, which apparently were a specialty of the Rhodians. Pindar, one of the nine lyric poets of ancient Greece, said this of Rhodes in his seventh Olympic Ode:

"The animated figures stand

Adorning every public street

And seem to breathe in stone, or

move their marble feet."

Arguments against it being on public display include:

a) The device is rather small, indicating that the designer was aiming for compactness (it has been compared to a modern laptop computer) and, as a result, the size of the front and back dials is unsuitable for public display. A simple comparison with size of the Tower of the Winds in Athens could give us a hint to suggest that the aim of the Antikythera mechanism manufacturer was rather the mobility of this device, than the public display of it in a fixed place (such as a university, a temple, a museum or public hall).

b) The mechanism had door plates attached to it that contain at least 2000 characters, forming what members of the Antikythera mechanism research project often refer to as an instruction manual of the mechanism. The neat attachment of this manual on the mechanism itself implies ease of transport and personal use.

c) The existence of this "instruction manual" implies that the device was constructed by an expert scientist and mechanic in order to be used by a non-expert traveller (the text gives a lot of information associated with well known geographical locations of the Mediterranean area^{[citation needed]}).

The device is unlikely to have been intended for navigation use because:

a) Some data, such as eclipse predictions, are unnecessary for navigation.

b) The harsh environment of the sea would corrode the gears in a short period of time, rendering it useless.

[edit] Similar devices in ancient literature

Cicero's De re publica, a 1st century BC philosophical dialogue, mentions two machines that function as a planetarium or orrery, predicting the movements of the Sun, the Moon, and the five planets. The first device was built by Archimedes and brought to Rome by the Roman general Marcus Claudius Marcellus after the death of Archimedes at the siege of Syracuse in 212 BC. Marcellus had a high respect for Archimedes and this was the only item he kept from the siege. The device was kept as a family heirloom, and Cicero was shown it by Gallus about 150 years later. Gallus gave a 'learned explanation' of it and demonstrated it for Cicero.

hanc sphaeram Gallus cum moveret, fiebat ut soli luna totidem conversionibus in aere illo quot diebus in ipso caelo succederet, ex quo et in [caelo] sphaera solis fieret eadem illa defectio, et incideret luna tum in eam metam quae esset umbra terrae, cum sol e regione

When Gallus moved the globe, it happened that the Moon followed the Sun by as many turns on that bronze [contrivance] as in the Earth itself, from which also in the sky the Sun's globe became [to have] that same eclipse, and the Moon came then to that position which was [its] shadow [on] the Earth, when the Sun was in line.^[9]

Pappus of Alexandria stated that Archimedes had written a now lost manuscript on the construction of these devices entitled On Sphere-Making.^[10][11] The surviving texts from the Library of Alexandria describe many of his creations, some even containing simple blueprints. One such device is his odometer, the exact model later used by the Romans to place their mile markers (described by Heron of Alexandria and in the time of Emperor Commodus).^[12] The blueprints in the text appeared functional, but attempts to build them as pictured had failed. When the gears pictured, which had square teeth, were replaced with gears of the type in the Antikythera mechanism, which were angled, the device was perfectly functional.^{[citation needed]} Whether this is an example of a device created by Archimedes and described by texts lost in the burning of the Library of Alexandria, or if it is a device based on his discoveries, or if it has anything to do with him at all, is debatable.

If Cicero's account is correct (and there is reason to doubt it)^{[citation needed]} then this technology existed as early as the 3rd century BC. Archimedes' device is also mentioned by later Roman era writers such as Lactantius (Divinarum Institutionum Libri VII), Claudian (In sphaeram Archimedes), and Proclus (Commentary on the first book of Euclid's Elements of Geometry) in the 4th and 5th centuries.

Cicero also says that another such device was built 'recently' by his friend Posidonius, "... each one of the revolutions of which brings about the same movement in the Sun and Moon and five wandering stars [planets] as is brought about each day and night in the heavens..."^[13]

It is unlikely that either of these machines were the Antikythera mechanism found in the shipwreck, because both the devices mentioned by Cicero were located in Rome at least 50 years later than the estimated date of the shipwreck. So we know of three such devices. The modern scientists who have reconstructed the Antikythera mechanism also agree that it was too sophisticated to have been a one-off device.

It is probable that the Antikythera mechanism was not unique, as shown by Cicero's references to such mechanisms. This adds support to the idea that there was an ancient Greek tradition of complex mechanical technology that was later transmitted to the Islamic world, where similarly complex mechanical devices were built by Muslim engineers and astronomers during the Middle Ages. In the early 9th century, the Banū Mūsā's Kitab al-Hiyal (Book of Ingenious Devices), commissioned by the Caliph of Baghdad, describes over a hundred mechanical devices, some of which may date back to ancient Greek texts preserved in monasteries. Similarly complex astronomical instruments were constructed by al-Biruni and other Muslim astronomers from the 11th century.^[14] Such knowledge could have yielded to or been integrated with European clockmaking and medieval cranes.^{[citation needed]}

[edit] Investigations and reconstructions

The Antikythera mechanism is one of the world's oldest known geared devices. It has puzzled and intrigued historians of science and technology since its discovery. A number of individuals and groups have been instrumental in advancing the knowledge and understanding of the mechanism including: Derek J. de Solla Price (with Charalampos Karakalos); Allan George Bromley (with Frank Percival, Michael Wright and Bernard Gardner); Michael Wright; The Antikythera Mechanism Research Project and Dionysios Kriaris, a mathematician from Greece.

[edit] Derek J. de Solla Price

Following decades of work cleaning the device, in 1951 British science historian Derek J. de Solla Price undertook systematic investigation of the mechanism.

Price published several papers on "Clockwork before the Clock".^[15][16] and "On the Origin of Clockwork",^[17] before the first major publication in June 1959 on the mechanism: "An Ancient Greek Computer".^[18] This was the lead article in Scientific American and appears to have been initially published at the prompting of Arthur C. Clarke, according to the book Arthur C. Clarke's Mysterious World (see end of chapter 3). In "An Ancient Greek Computer" Price advanced the theory that the Antikythera mechanism was a device for calculating the motions of stars and planets, which would make the device the first known analog computer. Until that time, the Antikythera mechanism's function was largely unknown, though it had been correctly identified as an astronomical device, perhaps being an astrolabe.

In 1971, Price, by then the first Avalon Professor of the History of Science at Yale University, teamed up with Charalampos Karakalos, professor of nuclear physics at the Greek National Centre of Scientific Research "DEMOKRITOS". Karakalos took both gamma- and X-ray radiographs of the mechanism, which revealed critical information about the device's interior configuration.

In 1974, Price wrote "Gears from the Greeks: the Antikythera mechanism — a calendar computer from ca. 80 B.C.",^[19] where he presented a model of how the mechanism could have functioned.

Price's model, as presented in his "Gears from the Greeks", was the first theoretical attempt at reconstructing the device. According to that model, the front dial shows the annual progress of the Sun and Moon through the zodiac against the Egyptian calendar. The upper rear dial displays a four-year period and has associated dials showing the Metonic cycle of 235 synodic months, which approximately equals 19 solar years. The lower rear dial plots the cycle of a single synodic month, with a secondary dial showing the lunar year of 12 synodic months.

One of the remarkable proposals made by Price was that the mechanism employed differential gears, which enabled the mechanism to add or subtract angular velocities. The differential was used to compute the synodic lunar cycle by subtracting the effects of the Sun's movement from those of the sidereal lunar movement.

[edit] Allan George Bromley

An ingenious variant on Price's reconstruction was built by Australian computer scientist Allan George Bromley of the University of Sydney and Sydney clockmaker Frank Percival. Bromley went on to make new, more accurate X-ray images in collaboration with Michael Wright. Some of these were studied by Bromley's student, Bernard Gardner, in 1993.

[edit] Michael Wright

Michael Wright, formerly Curator of Mechanical Engineering at The London Science Museum, and now of Imperial College, London, made a completely new study of the original fragments together with Allan George Bromley. They used a technique called linear X-Ray tomography which was suggested by retired consultant radiologist, Alan Partridge. For this, Wright designed and made an apparatus for linear tomography, allowing the generation of sectional 2D radiographic images.^[20] Early results of this survey were presented in 1997, which showed that Price's reconstruction was fundamentally flawed.^[21] However, Bromley was already suffering from Hodgkin's disease and he died in 2002.

Further study of the new imagery allowed Wright to advance a number of proposals. Firstly he developed the idea, suggested by Price in "Gears from the Greeks", that the mechanism could have served as a planetarium. Wright's planetarium not only modelled the motion of the Sun and Moon, but also the Inferior Planets; Mercury and Venus, and the Superior Planets; Mars, Jupiter and Saturn^[22][23]

Wright proposed that the Sun and Moon could have moved in accordance with the theories of Hipparchus, and the five known planets moved according to the simple epicyclic theory suggested by the theorem of Apollonios. In order to prove that this was possible using the level of technology apparent in the mechanism, Wright produced a working model of such a planetarium.^[24][25]

Wright also increased upon Price's gear count of 27 to 31^[23] including 1 in Fragment C that was eventually identified as part of a Moon phase display.^[26] He suggested that this is a mechanism that shows the phase of the Moon by means of a rotating semi-silvered ball, realized by the differential rotation of the sidereal cycle of the Moon and the Sun's yearly cycle. This precedes previously known mechanism of this sort by a millennium and a half.

More accurate tooth counts were also obtained,^[27] allowing a new gearing scheme to be advanced^[28] This more accurate information allowed Wright to confirm Price's perceptive suggestion that the upper back dial displays the Metonic cycle with 235 lunar months divisions over a five-turn scale. In addition to this Wright proposed the remarkable idea that the main back dials are in the form of spirals, with the upper back dial out as a five-turn spiral containing 47 divisions in each turn. It therefore presented a visual display of the 235 months of the Metonic cycle (19 years ≈ 235 Synodic Months). Wright also observed that fragmentary inscriptions suggested that the pointer on the subsidiary dial showed a count of four cycles of the 19-year period, equal to the 76-year Callippic cycle.^[29]

Based on more tentative observations, Wright also came to the conclusion that the lower back dial counted Draconic Months and could perhaps been used for eclipse prediction.^[30]

All these findings have been incorporated into Wright's working model,^[29] demonstrating that a single mechanism with all these functions could not only be built, but would also work.

Despite the improved imagery provided by the linear tomography Wright could not reconcile all the known gears into a single coherent mechanism, and this led him to advance the theory that the mechanism had been altered, or modified, with some astronomical functions removed, and others added.^[29]

Finally, as an outcome of his considerable research,^{[31][32][33][34][35][20][29]} Wright also conclusively demonstrated that Price's assumption of the existence of a differential gearing arrangement was incorrect.^[29][26]

Michael Wright's research on the Mechanism is continuing in parallel with the efforts of the Antikythera Mechanism Research Project. Recently Wright modified slightly his model of the mechanism to incorporate the latest findings of the Antikythera Mechanism Research Project regarding the function of the pin and slot engaged gears that brilliantly simulate the anomaly in the Moon's angular velocity. On the 6th of March 2007 he presented his model in the National Hellenic Research Foundation in Athens, Greece.

[edit] The Antikythera Mechanism Research Project

The Antikythera mechanism is now being studied by the Antikythera Mechanism Research Project,^[36] a joint program between Cardiff University (M. Edmunds, T. Freeth), the National and Kapodistrian University of Athens (X. Moussas, Y. Bitsakis), the Aristotle University of Thessaloniki (J.H. Seiradakis), the National Archaeological Museum of Athens, X-Tek Systems UK^[37] and Hewlett-Packard USA, funded by the Leverhulme Trust and supported by the Cultural Foundation of the National Bank of Greece.^[38]

The mechanism's fragility precluded its removal from the museum, so the Hewlett-Packard research team^[39] and X-Tek Systems had to bring their devices to Greece. HP built a 3-D surface imaging device, known as the "PTM Dome," that surrounds the object under examination. X-Tek Systems developed a 12 ton 450 kV microfocus computerised tomographer especially for the Antikythera Mechanism.

It was announced in Athens on 21 October 2005 that new pieces of the Antikythera mechanism had been found. There are now 82 fragments. Most of the new pieces had been stabilized but were awaiting conservation.

On 30 May 2006, it was announced that the imaging system had enabled much more of the Greek inscription to be viewed and translated, from about 1,000 characters that were visible previously, to almost 3,000 characters, representing about 95% of the extant text. The team's findings shed new light concerning the function and purpose of the Antikythera mechanism. Research is ongoing. The first results were announced at an international conference in Athens (Greece), November 30 and December 1, 2006.^[40]

[edit] New discoveries

On 30 November 2006, the science journal Nature published a new reconstruction of the mechanism based on the high resolution X-ray tomography described above.^[41] This work doubled the amount of readable text, corrected prior transcriptions, and provided a new translation. The inscriptions lead to a dating of the Mechanism around 100 BC. It is evident that they contain a manual with an astronomical, mechanical and geographical section. The name ISPANIA (ΙΣΠΑΝΙΑ, Spain in Greek) in these texts is the oldest reference to this country under this form, as opposed to Iberia.

The new discoveries confirm that the mechanism is an astronomical analog computer or orrery used to predict the positions of heavenly bodies in the sky. This work proposes that the mechanism possessed 37 gears, of which 30 survive, and was used for prediction of the position of the Sun and the Moon. Based on the inscriptions, which mention the stationary points of the planets, the authors speculate that planetary motions may also have been indicated.

On the front face were graduations for the solar scale and the zodiac together with pointers that indicated the position of the Sun, the Moon, the lunar phase, and possibly the planetary motions.

On the back, two spiral scales (simple Archimedean spirals, with two centers) with sliding pointers indicated the state of two further important astronomical cycles: the Saros cycle, the period of approximately 18 years separating the return of the Sun, Moon and Earth to the same relative positions and the more accurate exeligmos cycle of 54 years and one day (essential in eclipse prediction, see Eclipse cycle). It also contains another spiral scale for the Metonic cycle (19 years, equal to 235 lunar months) and the Callippic cycle that proposed a more accurate periodicity of 940 lunar months in approximately 76 years.

The Moon mechanism, using an ingenious train of gears, two of them linked with a slightly offset axis and pin in a slot, shows the position and phase of the Moon during the month. The velocity of the Moon varies according to the theory of Hipparchus, and to a good approximation follows Kepler's second law for the angular velocity, being faster near the perigee and slower at the apogee (see Kepler's laws of planetary motion).

[edit] See also

• Astrarium
• Classical planets

[edit] References

[edit] Further reading

[edit] External links

• Cox, John. "Decoding the 2,000-year-old Antikythera Mechanism", Network World, 2007-11-29. 
• Cox, John. "Follow-up: Details of the Antikythera Mechanism mysteries unveiled", Network World, 2007-11-26. 
• Seabrook, John. "Fragmentary Knowledge", The New Yorker, 2007-05-14. 
• Wilford, John Noble. "An Ancient Computer Surprises Scientists", New York Times, 2006-11-29. Retrieved on 2006-12-06. 
• Wilford, John Noble. "Early Astronomical ‘Computer’ Found to Be Technically Complex", New York Times, 2006-11-30. Retrieved on 2006-12-06. 
• "Antikythera Mechanism". John H. Lienhard. The Engines of Our Ingenuity. NPR. KUHF-FM Houston. 1995. No. 1031. Transcript.
• Price, Derek J. de Solla.. Geartrain diagram.
• Decoding an ancient computer.
• Pastore, Giovanni (2006). ANTIKYTHERA E I REGOLI CALCOLATORI.
• Phillips, Tony.. The Antikythera Mechanism I.
• Phillips, Tony.. The Antikythera Mechanism II.
• Bill Casselman. Java Animation.
• Tatjana van Vark. Essence of the Antikythera Mechanism.
• The Antikythera Calculator (Italian and English versions).
• The Antikythera Mechanism Research Project.
• Provisional translation of the text inscribed on the mechanism.
• An emulator of the Antikythera Mechanism, under Squeak EToys.
• Unearthing Mysteries (audio). BBC Radio 4 (2006-12-12).
• Article in The Times on results published in "Nature".
• Roumeliotis, Manos. Antikythera Mechanism MOV files.
• Photographs of the mechanism's exhibit at the National Museum of Archaeology in Athens.
• Mr Michael Wright - staff page at Imperial College, London.
• Rien van de Wijgaert -- Photographs Antikythera Mechanism 2002.
• Ancient Greek star calculator finally yields up its secrets.. Irish Independent News.
• BBC News - Ancient Moon 'computer' revisited.
• Preview of research results announced at Athens conference (2006-11-30).
• Report includes six slides, indexed. (2006-11-26).
• Google Maps satellite image of relevant part of Mediterranean.
• HP imaging helps scientists figure out world's oldest mechanical calculator. San Francisco Chronicle (2006-11-30).
• Hero of the Industrial Revolution - an alternative history story featuring the Antikythera computer.
• Mysteries of computer of 65BC are solved. The Guardian (2006-11-30).
• Compendium article combines an article from the The Economist with a Scientific American article..
• Jay Garmon. Geek Trivia: Ahead of its time(piece) - What ancient shipwreck artifact suggests the ancient Greeks could build complex clockwork devices?. TechRepublic.
• Decoding an ancient computer - Photos of the Antikythera Mechanism. TechRepublic.
• Weijgaert, R. van der, (2005). A Greek Time Machine.
• Rice, R. S. (1993). Gears, Galleys, and Geography - The Antikythera Mechanism's Implications (Text of the 1993 APA Abstract).
• Enigma of ancient computer solved. Cosmos Magazine (30 November 2006).
• Astronomy Picture of the Day, 2006 December 5. NASA APOD Site (5 December 2006).
• Antikythera Mechanism: study, presentation and experiments in Mixed Reality spaces. An online prototype of a Mixed Reality Museum for the Antikythera Mechanism..

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