Forgotten Ages Research

A Computer for All Ages— How Old is the Antikythera Machine?

Report Topics:

• Background to the undersea discovery of ancient gear-wheel pieces off the Aegean island of Antikythera
• Initial analysis of the first century B.C.E. Greek machine by Derek J. de Sola Price, using X-ray photography
• A detailed look at the various dial components within the mechanism and their purposes for calculating astronomical cycles both backward and forward
• Questions concerning the true origins and real age of the internal gear-work
• More recent intensive investigations, and the construction of working replicas of the ancient computer device
• Today’s ongoing efforts by the Antikythera Mechanism Research Project—some puzzles solved, other mysteries deepen
• Report Update—Latest Aspects About the Greek Astronomical Calculator
• Report Update—The Ancient Greek Gearing Machine Still Stands as a Unique Artifact

Full Report:

A few days before Easter Sunday in 1900, two small ships of Greek sponge divers, seeking shelter from a storm, anchored near Glyphadia Point located just off of the small barren island of Antikythera, situated between Kythera and Crete in the Aegean Sea.

After the squall had passed the captain of the fleet, Demetros Kondos, decided to explore the sea shelf located 140 feet beneath them in hopes of finding unharvested sponges. What his divers discovered instead were the remains of a 164-foot long ancient ship filled with bronze and marble statues, coins, gold jewelry, pottery, and other miscellaneous pieces.

Recognizing the value of the find, Kondos contacted archaeological authorities in Athens, and within the next year a government salvage expedition worked to recover the sunken treasure. From the type of amphorae (wine containers), Hellenist and Roman pottery found, the shipwreck remains were initially dated between 85 and 50 B.C.E. At a later date Roman coins found in the wreck narrowed the time to closer to 85 B.C.E.

Despite this evidence, the shipwreck nevertheless contained a number of chronological anomalies. Many of the bronze statues retrieved from the debris dated back to the fourth century B.C.E., while certain of the marble works, while supposedly a product of the first century B.C.E., were later deemed to be copies of earlier masterpieces several centuries older. In 1964 a piece of the ship’s hull planking that managed to survive intact on the sea floor gave a curious radio-carbon date of 220 B.C.E. plus or minus 43 years. This discrepancy was explained as the plank having been from an “old tree cut.” But if this is the case, why would a shipbuilder use a 150-year old piece of wood to fashion his vessel, especially the hull?

Some of the marbles of the statues were traced to Delos, the amphorae came from Cos or Rhodes, and a single lamp uncovered was of a type from Ephesus and the Asia Minor coast. Based on these remains, archaeologists first conjectured that the wreck had been a Greek cargo ship of the first century B.C.E., carrying a commercial load from the eastern Aegean westward, presumably to Rome. Entering the treacherous waters around Antikythera, the ship foundered in a storm and sank.

Another speculation is that the doomed vessel was transporting part of the booty acquired by the Roman General Sulla who raided Athens in 86 B.C.E. The Greek writer Lucian recorded that one of Sulla’s trophy ships sank in a storm in the area of Antikythera on its way back to Italy. The fact that over a hundred of the sunken objects were works of art strongly suggests this had indeed been part of someone’s treasure trove that met an ill-fated end.

Among the various finds brought to the surface from the wreck was a small formless lump of corroded bronze and rotted wood. Nothing was thought much of it, but was sent along with the other artifacts to the National Museum of Greece in Athens for further study.

Soon after as a result of the wood fragments drying and shrinking from exposure to air, the lump split open in several places. On May 17, 1901, archaeologist Valerios Stais, in making a preliminary examination of the shipwreck artifacts, was the first to notice metallic gears protruding from the drying wood. Further inspection by Museum officials revealed inside the outlines of a series of gear wheels like a modern clock. Inscriptions found in corroded bronze plates also within, however, indicated that the mechanism had something to do with astronomical cycles.

In the years following the Antikythera discovery several researchers attempted to unravel the mystery of the strange geared device, but with no definite conclusions. Finally, in 1951, the ancient machine came to the attention of Dr. Derek de Solla Price, of Cambridge University and the Institute of Advanced Studies at Princeton. Beginning in 1958, working with a select group of specialists over a fourteen-year period, and using advanced techniques such as gamma-radiography (a form of X-ray investigation), Dr. Price successfully reconstructed the machine’s appearance and use.

What amazed Dr. Price and the other contributing experts was how compact the whole device had been. The original mechanism was enclosed in a rectangular wooden box with metal plate doors hinged to the front and back, the box being about the size, as Price described it, of a “thick folio encyclopedia volume.” Originally it measured 13 inches high, 6.75 inches wide and just 3.5 inches thick. Yet it contained more than two dozen intermeshing gear wheels. Nothing of a mechanical nature this compact or intricately made appeared until the advent of eighteenth century European clocks.

All the metal moving parts inside the machine were cut from a single sheet of special low tin non-leaded bronze about one-sixteenth inch in thickness. Each of the gear wheels, now estimated to be about 31 in number, had teeth of the same size and 60-degree angle. Within the mechanism the gear wheels were fixed to a bronze plate at the center of the box. Input was provided by an axle-shaft that passed through the side of the box and turned a crown wheel. This set in motion a large four-spoke driving wheel connected to several sets of gears with turntable-shafts that moved a number of pointers at various speeds around dials located on the front and back of the box.

There is evidence the machine was repaired at least twice—one of the drive-wheel spokes shows signs of having been mended, and a broken tooth on a small wheel was replaced. The machine was thus used and received wear.

Without a doubt the most amazing feature of the internal mechanism is that it incorporated the very sophisticated use of a differential gear assembly for taking the difference between two rotations, a technological feat that is truly “out-of-place.”

On the outer casing of the machine box were three main dials, one on the front and two on the backside. The front dial was encompassed by two annuli or rings. The inner ring was fixed in position, while the outer ring was moveable.

Both the inner and outer rings are scaled with short marks every degree and long marks every thirty degrees. Portions of the inner ring are in a good state of preservation, and in one segment one can read the Greek world Chelai, the sign of Libra. In the segment preceding this appears part of the word Virgo. The inner ring thus showed the Zodiacal divisions of the year.

Straddling the first degree mark of the Libra segment there appears a small letter alpha. Spanning the eleventh, fourteenth and sixteenth degrees of the same sign are the letters beta, gamma and delta. In the first degree of Scorpio appears an epsilon—and so forth around the dial until one arrives at an omega in the eighteenth degree of Virgo. These letters are footnote indicators that are linked to inscriptions found on the front casing surrounding the front dial. One portion reads: “omicron—the Hyades rise in the morning; pi—Gemini begins to rise; rho—Altair rises in the evening; sigma—Arcturus sets in the morning.” The letters thus indicated at their appropriate times when the heliacal risings and settings of the bright stars and major constellations took place during the year.

The outer moveable ring of the front dial also contains names given in division, and these are found to be the names of the months in the Graeco-Egyptian calendar. Because this calendar contained no leap year, each return of the sun to the same place in the Zodiac was a quarter of a day more than cycle of months indicated, and for this reason the outer ring was moveable so that it could be slipped a quarter of a degree to correspond to the actual year.

It was this displacement factor that helped pinpoint the date of the machine’s use. Price discovered an incised mark near the lower edge of the front dial which he believes was put there to show the position of the month cycle at that time. The position he calculated indicates a date of 87 B.C.E.

The dating of the mechanism and the suspected place of its origins led Price to initially believe the device had been built by Geminus of Rhodes, a Greek astronomer and mathematician who lived between 110 and 40 B.C.E. He also believes that the astronomical information inherent in the machine’s design points back to the influence of Hipparchus or Rhodes, who lived a generation earlier, and was the first Hellenic astronomer to make a catalog of the positions of the stars.

Another likely candidate was another contemporary of the machine, the Greek inventor Posidonius. The first century B.C.E. Roman orator and author Cicero wrote that Posidonius had in his possession a device “which at each revolution reproduces the same motions of the sun, the moon and the five planets that take place in the heavens every day and night.”

True to Cicero’s description, an examination of the Antikythera gear work directly beneath the front dial reveals that the gearing system turned pointers around the dial and rings showing the annual movements of the sun and moon.

An unaccounted for space exists between some of the gearing, and there is good evidence that this space held a gearing system now missing, which served to exhibit the rotations of all the planets on the front dial as well. In his 1974 book Gears of the Greeks, Price concluded that the mechanism was originally meant to show the motions of the Moon, the Sun, all the then known, the rising of the major stars, plus major solar and lunar eclipses, all against the backdrop of the celestial Zodiac.

As Price noted, the arrangement of the existing wheels shows that the gears could be moved forward and backward with ease at any speed. The device was thus not a clock but more like a calculator that could show the positions of the heavens past, present and future for reference, for study or for prediction.

Off to one corner of the dial beneath the casing a mysterious drum-like component was discovered built onto a disc with a small hole and what appears to be a sliding bracket. From its construction it is very likely the remains of a crank handle that fit over the input axle-shaft and was used to turn the gear work. The bracket device and hole indicate the handle was collapsible, so that it could more easily fit into its storage compartment when the machine was not in use. Prince commented: “Such a crank-like device is quite remarkable for this period.”

On the backside were two more dials. The upper dial had four slip-rings and one fixed ring, the lower had three slip-rings and one fixed. Each of these dials also had subsidiary dials like the second-hand dial on an old-fashioned watch. Unfortunately, the outer surfaces of these dials and rings are heavily corroded, and their divisions and inscriptions for the most part are indecipherable. The gear work beneath the dials, however, tells us something of the various dials’ functions.

Deep within the mechanism the differential turntable took the solar and lunar revolutions shown in the front dial and subtracted the first from the second to come up with the cycles known as the Synodic months.

This is confirmed by the gearing ratios which introduced numbers for calculating the Metonic cycle of 19 solar years as corresponding with the 235 Lunations and 254 Sidereal revolutions of the Moon. This information was transmitted and exhibited on the lower dial, its central figure indicating the cycle through a single Synodic month and its subsidiary dial showing the Lunar year of thirteenth months.

The upper dial appears to be divided into 47 or 48 divisions which is interpreted to calculate out a four-year cycle either of 47 Synodic months or 48 Egyptian months of 30 days each with inter-calendral days included. The subsidiary dial is thought to represent either a Metonic 235 months or an eclipse cycle of 223 Synodic months.

As on the front casing, inscriptions covered the back casing around the dials and these too contained footnote data, indicating either navigational winds and corresponding tides interlinked with the Moon, or may simply pointed out directions of lunar events in the sky. Inscriptions also covered the inner surfaces of the front and back metal plate doors that were hinged to the metal box, and closed to protect the dials when the machine was not in use.

The front door inscriptions are badly fragmented, but the back door inscriptions survived better intact, and their subject matter dealt with explaining the ring and pointer readings on the back dials. Here we find references to the Metonic, Callippic and other cycles.

One important point should be noted about the machine inscriptions as a whole. The script appears to have been the work of one hand, and according to Professor Benjamin Merritt the lettering is characteristic of the Augustan period, or the first century B.C.E. Some critics, in attempting to explain the out-of-place sophistication of the Antikythera device, have argued that the machine was actually made many centuries later, and by accident was dropped overboard by a passing ship, to settle among the remains of the ancient sunken vessel.

But the epigraphic dating of the machine script, as a confirmation independent of the date of the wreck, shows that the machine was indeed at least two thousand years old and not of a later manufacture.

When you look at the sum total of evidence from the internal gearing, the dials and inscriptions, it is clear that the purpose of the Antikythera machine was to mechanically calculate short-range and long-range astronomical cycles. In its capacity to do so, the small computer stands out as a contradiction to all previous concepts of ancient mechanics. Dr. Price, speaking in Washington D.C. in 1959, said: “Finding a thing like this is like finding a jet plane in the tomb of Tutankhamen. Nothing like this instrument is preserved elsewhere.”

So where did it come from?

Some historical scholars would equate the machine with the mechanical planetariums constructed by the Greek Sicilian Archimedes, in about 250 B.C.E., whose work was later revived by an avid student, Posidonius of Rhodes, and still later by Geminus of Rhodes. But there are serious problems with ascribing to them the invention of the Antikythera device.

First, the descriptions of the orreries of Archimedes and Posidonius indicate that they were large and elaborate ornate works of art showing the orbs of heaven in three dimensional form. The Antikythera device in contrast was compact, portable, completely devoid of ornamentation, a truly scientific instrument that exhibited the astronomical cycles in flat, circular projections marked off in scaled, graduated degrees, a technique employed nowhere else in the classical world, and not fully comprehended as a technological possibility until the late medieval period.

Second, there is the very real anomaly of the sophistication of the Antikythera gearing, in particular the differential turntable. This feature was in reality several steps beyond the mechanical abilities of Archimedes or Posidonius. In fact, as Price himself admitted: “In my experience it is difficult even today to explain the theory of this gear work to the bulk of people in a modern audience familiar with a host of mechanical and electrical devices.”

In European civilization, differential gearing did not appear until 1575, used in the clock of Eberhart Baldewin of Kassel, Germany—and this after over five centuries of continuous experimentation by early mechanists. No such background of development existed in the known Greek world, yet the Antikythera device, over two millennia old, exhibits a sophistication that even outshines the Renaissance clock.

Compounding the mystery further there is reason to believe that the gearing of the Antikythera machine is older than what was originally thought.

When the bronze of the gear work was subjected to metallurgical and spectrographic analysis by Professor Earle R. Caley of Ohio State University, it was discovered to contain 4.1 percent tin, alloyed with the main component, copper, with a marked absence of lead. What is curious about this finding is that all late Greek and Roman bronzes, especially those of the first century B.C.E., contained large amounts of lead, in many cases larger than the tin content.

Non-leaded bronzes, however, were a feature characteristic of much earlier periods by several centuries. On a piece of one of the graduated dials that was used to correct the Greek calendar of 365 days with a true solar year of 365.25 days, Price found a clear marking that he believes points back to the date when the correlation between the two calendars was first made. The date he calculated occurred in 586 B.C.E.—in the midst of the time when non-leaded bronzes were being utilized. Here is one indication that the calculator had been in use for at least five centuries before it was lost.

More than this, the outer box could be one age, while the gearing may in fact be even older. The internal machinery could have actually been built long before the machine’s present outer box, with its dials and inscriptions. The Greeks may have only re-discovered the original device, and had nothing to do with inventing the machinery. They simply remodeled and updated the outer dials and inscriptions to suit their needs and studies. The Greeks knew enough of how to interpret the pointers, without really understanding the machinery itself.

There is, too, the evidence of wear and tear on the gearing, with repairs having been made, indicating that it had been in use for considerable periods of time before the latest casing box was added.

The elements of Egyptian calendral principles and Babylonian sixty-degree angling in the gear works point back to these earlier civilizations as the source. But once again, the evidence cannot be found of a background development for the machine’s invention in either location.

It is more likely that the device brought from the bottom of the Aegean had its true origins ages long before, and in a land far removed, now unknown. Passed on from culture to culture, each studying its mechanical form and adding their own marks, the Antikythera device still harks to an original homeland that once boasted a lost machine age—one that in many ways was comparable to what modern civilization possesses today.

Since the time of Dr. Price’s initial research on the Antikythera mechanism, a number of other important investigations and discoveries have been made.

In 1993, Australian computer scientist Allan George Bromley of the University of Sydney, in cooperation with a Sydney-based clockmaker named Frank Percival, began improving on Dr. Price’s original suggested design of the Antikythera gear work by first building a working reconstruction. This was further enhanced based on more accurate internal images of the mechanism remains done in 1997 in collaboration with Michael Wright, Curator of Mechanical Engineering at Imperial College in London. They used a technique called linear X-ray tomography which allows the generation of sectional three-dimensional radiographic imaging.

One aspect that Bromley and Percival focused on was the making of the gear wheels themselves. They noted how remarkably precise the gears had been cut and mounted, allowing all the wheels to turn without slippage or getting stuck when moved either forward or backward. This is due to the nearly absolute perfection of the 60 degree angles of all the gear teeth, which allows for a gap tolerance of less than five hundredths of an inch. The two experts failed more than once in trying to cut identical bronzes using today’s best cutting tools with the same level of perfection exhibited in the ancient computer gears. As Bromley remarked:

“I do not pretend to have all the answers to how the Antikythera mechanism was made, any more than I pretend to have a complete knowledge of its function or the mathematics of its gear work. The only inescapable fact is that, however it was done, the Antikythera mechamism was made by true craftsmen.”

Even more remarable than the overall perfection of the gears is the one minute imperfection. It now appears that two connected gear wheels were deliberately misaligned very minutely, with a small pin inserted into one of the gears so that it could be moved slightly out of its place to simulate the irregular elliptical orbit of the Moon around the Earth. As British astrophysicist professor Michael Edmunds observed after he discovered this almost microscopic variation: “When you see that, you think, ‘bloody hell, that’s clever—that’s brilliant technical design.’”

One unofficial explanation has been voiced by more than one expert that the Antikythera gears may have been cut with some form of laser. In a recent intensive microscopic study of the calculator’s metal surfaces, additional lettering was discovered, and astonishingly some of the letters measured only eight hundredths of an inch in size—far too small to have been etched with any type of ordinary metal tool. The only way possible would have been using a tiny concentrated beam of laser light.

After Bromley’s death in 2003, Wright continued in his studies and proposed an improved design which modeled the motions of not only the Sun and Moon, but also of both the Inferior and Superior Planets—from Mercury through Saturn. He also found evidence that the Antikythera machine showed the solar and lunar movements to be in accordance with the theories of Hipparchus, and the planetary oscillations occurred in harmony with the epicycles of Appolonius. In the meantime, from his X-ray work Wright was able to increase the original machine’s gear count from 27 to 31.

Despite these new findings, however, Wright could no longer reconcile all of the gears into a single coherent mechanism, leading him to believe that the device had been altered or modified over a long period of time, with some features removed and others added. This goes to confirm the notion that the Antikythera computer is far older than suspected, and that it may have passed through the hands of several ancient cultures who were the source of its design changes.

In more recent years, Wright has also discovered these new aspects about the Greek computer:

*Part of the display mechanism shows the phases of the Moon using a rotating silver-plated ball

*The main back dials were made in the form of spirals, to more accurately portray the Metonic, Synodic, Saros and Exeligmos cycles

*A pointer on the subsidiary dial helped calculate the more obscure Callippic and Draconic cycles for eclipse prediction

*Confirmation was made on the function of a pin-and-slot device placed in a slightly offset axis that accurately simulates the minute irregularities in the Moon’ss orbit and angular velocity—the motion today known as the First Lunar Anomaly

Presently, Wright’s research now parallels the efforts of the Antikythera Mechanism Research Project, a joint program involving Cardiff University, several Universities in Greece, the National Archaeological Museum in Athens, as well as several computer companies including Hewlett-Packard. The latter helped develop a highly specialized micro-focus tomographer especially made to study the Antikythera machine in the greatest detail possible.

Just recently, on a return flight from a trip to Egypt, I stopped off in Athens for a few days and had a chance to visit the National Museum, where I spent most of my time examining those portions of the Antikythera machine on public display, in the Museum’s Bronze Collection, as well as Dr. Price’s replica model of the computer device. I was also given a specially arranged private tour of the Museum’s off-limits area where the Hewlett-Packard instrumentation was being used to take close-up X-ray images of other pieces of the ancient machine. I was very encouraged to see how much technological attention was being given to re-discovering the secrets of this very important out-of-place artifact, and only wished that so many other such objects—long neglected in other museums and institutions—might someday receive comparable scientific recognition and scrutiny.

In 2005, it was announced from Athens that new pieces of the Antikythera device had been found, increasing the fragments to 82 in number. A year later, members of the Research Project announced at an international conference that the new advanced imagery had resulted in a thousand more inscription characters being identified and translated, increasing the number known by two-fold, and representing nearly 95 percent of the entire lost text, composed of 3,000 characters. Equally significant, new evidence suggested the mechanism had possessed a total of 37 gears, filling the gaps in its internal workings and their inter-meshing.

Based on these updated findings, research done by other independent investigators has made several remarkable and curious discoveries. The addition of more gears has demonstrated that the original machine—now clearly classified as an astronomical analog computer—calculated an Earth-Moon relationship to a higher degree of accuracy than previously suspected. There is also revealed in the gearing ratios the Tropical Year for Venus, as well as hidden gematric formulas and the use of sacred numbers. Some of the new inscriptions found, especially on the machine’s front dial, confirm its division based on the Sothic Cycle of the Egyptians.

Even more remarkable, a number of the Antikythera gearing ratios and resulting cycles match those of the Maya calendar day periods. Was this link to Mesoamerica possibly through Atlantis, dating the origins of the mechanism back twelve thousand years?

In the latest attempts at reconstructing the Antikythera machine, missing gaps in the mechanism suggest that there may have been as many as 70 gear-wheels all told. References in the device’s Greek inscriptions indicate that part of the missing gearing had been utilized to calculate the positions of the planets Mercury, Venus and Mars, and there is good additional evidence that other gears were employed to show the movements of the outer known planets as well. If further research proves this possibility to be true, then the device would have also served as a miniature planetarium.

Above and beyond even this, researcher Richard Sanders, writing in Science and Technology Magazine, stated his belief that the reason why the Anitkythera device focused so much attention on calculating the movements of the Moon was that it was used as an instrument for finding longitude. He noted:

“The only reason for a sailor or navigator to study the Moon is to predict eclipses and to forecast lunar distances, both for finding longitude. If you are using the Moon to determine longitude, you must have with you a book of tables, in which the position of the Moon for a point of reference would be given relative to various stars, preferably over a period of nineteen years. The advantage of a geared mechanism such as that from Antikythera would be that you could dispense with the tables. All you would have to do is crank the handle for the number of days since you left port, and that would give you the longitude of the Moon for that day, for your home base, or place of reference. Then you could measure the Moon’s position relative to some appropriate bright star, and you would know your longitude.”

This anticipated similar mechanical developments for measuring longitude which would not appear in Europe until the eighteenth century.

A member of the Antikythera Mechanism Research Project, Athens University physicist Yanis Bitsakis, found evidence from his studies that the ancient device was “an all-in-one astronomical device. In a single machine, the designer tried to put all the knowledge available about astronomical phenomena.” He concluded, as had Dr. Price decades before, that the Antikythera artifact “had helped track the cycles of the solar system and calculate the motions of the sun, moon and the planets.” Commenting further on this, astrophysicist Michael Edmunds of Cardiff University made these significant observations:

“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. In terms of history and scarcity value, I have to regard this mechanism as being more valualbe than the Mona Lisa. We must now ask: What else could they do? Who knows what else may be lost?”

From the latest findings by the Project and their detailed analysis of the Greek script employed, it is now calculated that the present form of the computer was built between 150 and 100 B.C.E. This time period pre-dates Posidonius and Geminus, and points back instead to the influence of the early astronomer Hipparchus of Rhodes. The device used lunar calculations based on Hipparchus’ theories concerning the movements of the Moon, so he may have had a direct hand in its design. Or is it possible he learned about the lunar movements by studying the mechanism, already existing in his lifetime?

A number of experts have also voiced their opinion that the computer’s overall design was based on the heliocentric concepts of Aristarchus of Samos, going back to the fourth century B.C.E. Aristarchus’ belief that the Sun was the real center of our planetary system fell out of favor before Aristotle’s more predominant theory of geocentricity, yet was eventually proven the more correct by Copernicus, Galileo and Kepler almost two thousand years later.

But again, we may well ask the question, which had come first, the precocious genius of Aristarchus or the mechanism?

What experts of the Antikythera machine are slowly beginning to realize is that the device is far too sophisticated to have been a one-time fluke of technology, merely the product of a single person who happened to be far ahead of his contemporaries. Both the advanced mechanical as well as the astronomical knowledge exhibited in its design and functions could only have been the result of an extraordinarily long period of experimentation and observation, as well as the intelligent cooperative input of untold numbers of generations.

Yet nowhere among the Greeks, or any other of the known classical ancient civilizations, do we find evidence for such a background. However, we know it had to have existed somewhere and some time in the unknown past, and that it was inherited by the Hellenic leading thinkers and experimenters who could barely understand it themselves. This undisclosed body of mechanical wisdom was later transmitted to the medieval Arabic world, most likely through surviving Greek manuscripts, where it reappeared in such Islamic works as the ninth century Book of Ingenius Devices by Banu Musa, and the eleventh century astronomical instruments of Al-Baruni.

Remaining unanswered is the question, had there been other mechanisms like the Antikythera computer, and if so, what happened to them? As science correspondent Ian Samples noted:

“One explanation could be that bronze was often recycled in the period the device was made, so many artifacts from that time have long ago been melted down and erased from the archaeological record. The fateful sinking of the ship carrying the Antikythera mechanism may have inadvertently preserved it.”

Whether there was one or several devices, we still are in the dark about the true origins of such machines and their inherent advanced astronomical knowledge. Hopefully, still more study of the original Greek computer may one day provide us with the answers we seek. As researcher-writer Rob S. Rice concluded:

“The Antikythera device’s very existence should prompt us to something besides skepticism. Only when all the implications of its discovery are understood and acted upon, then modern scholarship shall truly be said to have understood the Antikythera technology.”

Research Update—In an article published in the July, 2008 issue of Nature, a member of the Antikythera Mechanism Research Project, Tony Freeth, offered the lastest analysis of the ancient computer. In his conclusion he remarked, “It is a jaw-dropping astonishing device. I still don’t know how they did it.”

Working with Alexander Jones, an expert in ancient astronomy, it has been determined that the Greek script used on the machine originated from Corinth, located on the Peloponessus peninsula in the western part of the Aegean region. Different early Hellenic city states used their own particular variations for the names of the calendar months—and the nomenclature utilized in the descriptive astronomical passages on the device was clearly identified as Corinthian.

Historically, we know that the Romans destroyed Corinth in 146 B.C.E., so the etched lettering on the machine must date from before this period, or at least was made by someone who had survived and fled to the eastern Aegean. Here is where the small computer is thought to have originated and from which the ship carrying it floundered in a storm over two millennia ago.

Report Update—Latest Aspects About the Greek Astronomical Calculator

In another article by expert researcher Tony Freeth, published in the December, 2009 issue of Scientific American, several new salient points are presented.

Where before Corinth was identified as the possible origin for the device, attention has now shifted to the Corinthian colony of Syracuse, in Sicily. This had been the home of the great thinker and early mechanist, Archimedes. Was he the one who constructed it?

But the focal question is, did Archimedes somehow originate all the sophisticated principles incorporated in the machine that in reality were several steps beyond his abilities—or did the machine already exist, and served as the major inspiration in his own inventive experiments?

What is becoming increasingly apparent is the prominent role that Babylonian arithmetic-progression astronomical cycles took in the design of the mechanism’s calculations. Its upper back dial is based on the lunar Metonic cycle, supposedly discovered by the fifth century B.C.E. astronomer Meton of Athens—yet which we now know was understood and utilized by Babylonian sky-gazers centuries earlier.

Even the second century B.C.E. theory put forth by Hipparchus to explain the moon’s “anomaly” irregularities by using a system of epicycles—which is clearly preserved in the machine’s gearing design—could not have been possible without a reliance on several centuries’ worth of observations recorded in the Babylonian Saros Canon.

Rob S. Rice, in a paper entitled, “The Antikythera Mechanism—Physical and Intellectual Salvage from the 1st Century B.C.”, presented to the U. S. Naval Academy’s Eleventh History Symposium, made these remarks regarding the early Greeks falling far short of the knowledge necessary to have constructed the machine that many erroneously attribute to them:

“Geminus’s surviving book shows him making a determined effort to bring the transmitted data of the Babylonian astronomers to the attention of his Greek readers in the first century B.C. In the preceding century Hipparchus had laid the groundwork for Geminus’s efforts to popularize Babylonian astronomy by working their surviving eclipse data into his own astronomical writings. Modern scholars of scientific history have yet to pay Hipparchus his due honor for his failure to construct a planetary system of his own even as he catalogued the observable stars.

“Although he had used observed parallax to make an extremely close estimate of the moon’s distance from the earth, Hipparchus had the scientific honesty to state that there was insufficient data in his time to understand the true arrangement of the solar system.”

Yet the reality of the machine certainly exists, which means it had to come from somewhere that was far more advanced than either the Greeks or their Babylonian predecessors. Rice concluded his paper with these significant words:

“With the evidence before our faces, do we continue to believe that the ancients were technologically inept, and that our sources can be easily discarded? Or do we accept the existence of ancient advanced technology, study its implications, and look for deeper meaning in what we have difficulty understanding? Much has been learned about ancient technology and ancient seafaring. With the right set of minds and purpose, it is clearly possible to learn a great deal more.”

In his article, Freeth focused part of his research on the mechanism’s lower of the two back dials:

“Certain fragments were clearly all part of a spiral dial in the lower back. An estimate of the total number of divisions in the dial’s four-turn spiral suggested 220 to 225.

“The prime number 223 was the obvious contender. The ancient Babylonians had discovered that if a lunar eclipse is observed—something that can happen only during a full moon—usually a similar lunar eclipse will take place 223 full moons later. Similarly, if the Babylonians saw a solar eclipse—which can take place only during a new moon—they could predict that 223 new moons later there would be a similar one.

“The Babylonians also knew that within the 223-month period, eclipses can take place only in particular months, arranged in a predictable pattern and separated by gaps of five or six months. The distribution of symbols around the dial exactly matched that pattern.”

The enigmatic builders of the device were even able to predict where the solar eclipses were going to take place, something that was supposed to be beyond first millennium B.C.E. ancient abilities. Texts near the lower back dial include such specific geographical references to “Pharos” (in Egypt) and “from the south around (beyond) Spain ten (degrees?),” as well as directional details where the eclipsed sun path could be best seen.

The latest evidence is that the presently existing machine was constructed (or re-fashioned) between 150 and 100 B.C.E.—slightly earlier than previously suggested—and was lost at sea during its transportation to Rome circa 80 to 60 B.C.E. This means it could have been operational for almost a century, which explains the wear and repair work seen in several of its internal parts.

In its final adjusted form, a correlation analysis with historic eclipse data indicates that over the period from as early as 400 B.C.E. to a projected date of 1 B.C.E., the sequence of eclipses marked by the identified machine glyphs exactly matched 121 possible start dates. What this suggests is that the existing device was based on an earlier model whose calculations stretched back two and a half centuries before the present model was supposedly “built.”

In his latest article, Freeth announced that all the gear numbers could be explained as synchronized with various known astronomical cycles—except for one small gear that remains a mystery to this day.

The researcher also discovered that one dial in particular—a small subsidiary circle that is positioned inside the Metonic back dial—is divided into four quadrants and contains the names NEMIA, ISTHMIA, PYTHIA, NAA, OLYMPIA, plus one other name that has not yet been deciphered. These refer to the locations of major physical competitive contest games enacted at certain times of the year in the classic Greek world—one of these, of course, the one held at Olympia, having been revived in our modern age.

As Freeth commented, the existence of this “Olympiad dial” gave the use of the machine “an entirely unexpected social function.”

In truth, calendar devices—especially those that could accurately calculate dates in advance—were important to set the times not only for game contests, but also for agricultural planting and harvesting, fixing religious celebrations among the various temples, as well as forecasting such omen-filled sky events as solar and lunar eclipses.

And they were likewise employed for such mundane yet mystical practices as setting up horoscopes and formulating astrological charts for the future. Such star-casting was well known in the contemporary Hellenic and Ptolemaic worlds—and a machine that could perform such calculations would have been considered very valuable.

As other investigators have observed:

“Is it not more reasonable to say that astrology, like religion, has served its purpose in the advancement of human knowledge? It is widely acknowledged that Isaac Newton had astrological and alchemical beliefs, but ultimately the world was changed by Newton’s description of mechanistic physics and not by his belief in the power of Mercury rising.

“In fact, the majority of scientific treatises published in the world up to 1700 were astrological in nature. The development of numbers, mathematics, spherical trigonometry, logarithms, even celestial mechanics itself, were done at the insistence of astrologers. Not astronomers. They were late comers. The mathematics necessary for astrology is still in excess of what is used for astronomy, as a glance at current computer astrological programs will prove.”

On the main gear wheel at the front of the mechanism are the remains of bearings that must have been part of a lost epicyclic system involving the planets Mercury, Venus, Mars, Jupiter and Saturn. Machine reconstructionist Michael Wright has extrapolated that there may be another 40 extra gear wheels missing that were used to calculate the intricate movements of all these orbs. Where could this vanished portion of the machine possibly be today?

This brings us to what directions new explorations concerning the device’s remaining mysteries could take.

To date, the x-ray teams have now identified and interpreted a total of 3,000 characters out of an estimated 15,000 that were engraved in various different places on the machine. Some of these inscriptions are irretrievably lost due to heavy corrosion, but a notable number still have yet to be fully detected and enhanced. Hopefully, this will lead to new areas of more information to be revealed.

Even among the signs that are clearly seen, there are puzzles not yet understood. Why, for example, is there a perfect pentagon inscribed in the center of the gear wheel designated as e5?

Another possibility is to put together another underwater expedition and return to Antikythera and the original shipwreck site. Were their other pieces of the device that were overlooked by the 1901 salvagers? Could the extra 40 gear wheels involved with its planetary calculations still exist on the sea floor, at a depth of 160 feet down?

Yet another possibility is that long ago some of the ancient ship remains may have made it onto land, by now having long dried out and are gathering dust somewhere. Between the time of the wreck’s discovery and when the salvage operation returned a year later, villagers from the local town of Simi were known to have pilfered the sunken site. Reports tell of “many bronze pieces” being brought to the surface and eventually sold in the antiquity markets of Alexandria. Are lost pieces of the mechanism in the hands of the present-day family descendants of private collectors who have no idea what they possess?

Report Update—The Ancient Greek Gearing Machine Still Stands as a Unique Artifact

There has been remarks recently made on-line made by armchair skeptics who dismiss the existence of the Antikythera mechanism as simply an expression of the technology that was known by the ancient Greeks who lived at the time the mechanism was lost more than two millennia ago, and was supposedly described in the existing contemporary literature.

In truth, these kinds of fallacious statements are expressions of personal opinions only, based on a total ignorance of the real background situation regarding the limitations of Hellenic mechanical knowledge.

If the Antikythera mechanism is not unique, then please show us the remains of a second such machine. How about even another single contemporary gear wheel comparable to it in design and manufacture.

In reality, nothing of the sort exists.

And to say that we have accounts of duplicate astronomical calculators like the one found off Antikythera is also false, because what were described in Greek literature were orreraries, or large and cumbersome three-dimensional contraptions. These were clearly a far cry from the flat and compact layered complex gearing design seen in the Antikythera machine.

Which brings us to the very heart of the uniqueness of the gearing itself. As one modern manufacturing design expert so succinctly pointed out:

“Making machine gears requires precision tools and considerable expertise. These had to have a high level of precision to operate so many gears in the drive train. Below a certain level of precision the inefficiency of the gearing would make the whole thing inoperable.

“To make a large thin gear on a shaft with very small gear teeth mesh without wobbling, run in both directions, and control dials and pointers several gear sets away without much play or lash, requires a level of sophistication in metallurgy, machine design and precision machining on a level with the concept, deisgn and purpose of this incredible mechansism.”

All this begs the question, where else do we discover the exact same comparable sophstication exhibited in any other sample in the ancient Greek mechanical repertoire?

The answer, once again, comes back to a single conclusion—no where else.

[Copyright 2009, 2010. Joseph Robert Jochmans. All Rights Reserved.]