Jeffery OsvoldANTH1130-01Dr. Mallery4/26/14

The Antikythera Mechanism

Nearly two thousand years ago, a Roman ship sank near the minute island of

Antikythera, which is sandwiched between the Greek islands of Crete and Peloponnese.

There, approximately sixty meters below the surface of the Aegean Sea, the wreck sat,

lost to the people of the first century B.C., along with its precious cargo, the likes of

which would not be discovered until two millennia later (Marchant). As much as it

sounds like a fairytale or myth- passed down from one generation of treasure hunters to

another, until reaching a character (most likely portrayed by the venerable Nicholas

Cage) who sets out on an all-or-nothing excursion to find said treasure- this is exactly

how the discovery of the world’s oldest analog computer (to date) came to find its way

into the hands of ecstatic archaeologists and mechanical engineers alike. Despite having

been found just over one hundred years ago, the Antikythera Mechanism continues to

astound those involved with its study, consistently revealing the lack of credit mankind

gives to its predecessors.

As stated before, the shipwreck that sank near Antikythera at around 82 B.C. was

discovered two thousand years later, in the year 1900. Yet unmentioned, however, is that

the discovery was a complete stroke of luck made by Elias Stadiatis, a Greek sponge

diver who happened upon the wreck while in the middle of a dive (Seabrook). Stadiatis,

after contacting professionals regarding his discovery, began salvaging the wreck along

with archaeologist, Valerios Stais. Due to the lack of proper diving equipment and

breathing apparatuses, the recovery of the wreck’s contents would take over and entire

year to complete, each dive lasting an average of nine minutes. Furthermore, the salvage

mission would leave one man dead and another two crippled for life (“Ancient

Wisdom”). However, some would say that what they discovered was worth the risks.

Among a number of bronze and marble statues and a plethora of coins, the

explorers found what they initially believed to be a heavily corroded rock with a

wheeling protruding from its side. But, one night in 1902, when Stais was reviewing the

contents of the wreck, he noticed something peculiar about the embedded wheel; it had

teeth. With increased vigor, Stais and his team carefully cleaned the corroded piece of

metal, which turned out to be a bronze gear wheel, as well as the rock, which turned out

to be a bronze faceplate with several dials on it. Checking the rest of the contents from

the wreck, Stais and his team discovered that the Antikythera Mechanism consisted of

three main parts, in addition to dozens of smaller pieces (“The Antikythera…”). What’s

more is that they found the mechanism to be two bronze plates, mounted in a frame of

wood, which had heavily decomposed since its removal from the sea. Over the course of

the next several decades, the mechanism would undergo meticulous cleaning in the

confines of the National Archaeological Museum in Athens until 1951, when professor

Derek de Solla Price of Yale University, would take over the investigation and become

the leading expert in its study (“The Antikythera…”).

Price’s study, thorough as it was, did not uncover much understanding of the

mechanism’s purpose. Due to its fragile state, the mechanism wasn’t to be overly handled

and certainly not picked apart. Therefore, Price’s breakthrough in his research wouldn’t

happen until 1971 when he and physics professor, Charalampos Karakalos, used a

combination of gamma rays and x-rays to take radiographic images of the mechanism,

revealing a complex series of cogs, gears, rods, and all other kinds of mechanical

whatchamacallits (The History of…). Totaling thirty gears, twenty seven of them residing

in the largest fragment, Price set about drawing various potential schematics, all of which

used a system of differential and epicyclic/planetary gearing (“The Antikythera…”;

Phillips).

By using differentials and gears of different sizes, Price theorized that the ancient

Greeks were able to use a ratio to calculate the lunar months and synodic months (the

months between consecutive new moons) over a period of four-year cycles (Freeth and

Jones). This was done by turning a crankshaft on one side of the mechanism, activating

the interior clockwork, which would, in turn, rotate a dial on the front panel marked with

the zodiac. This dial showed the progression of the moon and sun and could be used to

predict solar eclipses. In addition to the front dial, two dials at the back would rotate as

well, tracking the four-year period and each individual synodic month (“Ancient

Wisdom”). Eventually, in the 1980’s, Robert Dereski would put Price’s design to the test,

creating the first proper reconstruction (one had been made years earlier by Loannis

Theofanidis) of the Antikythera mechanism, which now resides in the National

Archaeological Museum in Athens (AMRP).

However, the accuracy and conviction of Price’s work would not be enough to

deter other mechanically minded experts from delving deeper into the mysteries of the

Antikythera Mechanism. Notably, a pair of Australians, Allan Bromley and Frank

Percival- computer scientist and clockmaker, respectively- would attempt to reconstruct

the mechanism, using Price’s schematics, but find themselves unable to achieve the same

results. Believing themselves to be in the right, Bromley and Percival would theorize that

a gap in the mechanism should hold several missing gears. Furthermore, they would

adjust one of the gear trains that Price had altered from its initial number of fifteen and

sixty-three teeth to sixteen and sixty-four, which he believed to be a more workable

number. Thus, a new discovery was made. The mechanism, instead of calculating a four-

year cycle, actually calculated a four cycles of four-and-a-half years, which was equal to

eighteen years, or one cycle of an eclipse (“Ancient Computer”). Excited with their

findings, the two would create their own reconstruction with additional improvements,

which unintentionally re-ignited the scientific community’s interest in the mechanism,

spawning the Antikythera Mechanism Research Project (AMRP).

The AMRP started in 2005 and is still making and publishing new discoveries and

theories today. However, their biggest contribution came from a partnership with X-Tek

Systems Ltd. and Hewlett Packard Inc., who provided technical support for the Cardiff-

based project. Most important of these contributions was the use of X-Tek Systems’

Bladerunner CT scanner, which was previously used to scan aircraft engines for defects

(Ramsey 3). Transporting the eight-ton machine all the way to the original Antikythera

Mechanism fragments in Athens was, itself, a challenge (Seabrook). Yet, everyone

present would adamantly agree that it was worth it. Not only were able to take better x-

rays computed tomography scans of the interior of the mechanism, but they were able to

make polynomial texture mappings (PTM’s) of the exterior, revealing hundreds of

inscriptions made all across the mechanism’s chassis (AMRP).

Amongst the inscriptions on the front were Greek letters, indicating days, months,

and zodiac signs for the five planets known to the people of the first century B.C., which

included Mercury, Venus, Mars, Jupiter, and Saturn. Additionally, the ancient Greeks

included a parapegma, which acted like a legend or star chart (Freeth and Jones). But,

instead of showing the stars’ positions, the parapegma gave the reader an idea of which

stars would be visible during various times of the evening/night, indicating their patterns

of rising and setting. On the back, the inscriptions alluded to the five dials present. The

primary upper dial measured the Metonic cycle, which is a nineteen-year cycle that

measures lunar activity. Meanwhile, a secondary upper dial measured the Olympiad,

determining the proper times for Greeks to hold the Olympic games, and a tertiary upper

dial measured Callippic cycle, a seventy-six year period that is equal to four metonic

cycles. The fourth dial, located at the bottom of the back plate, calculated the Saros cycle,

which is an eighteen-year period that measures eclipses. Lastly, a fifth dial, placed into

the larger fourth dial, showed the Exeligmos cycle, a fifty-four year cycle that is a tripling

of the Saros cycle. In addition to the inscriptions surrounding and located on the dials, a

set of inscriptions appeared on the doors of the device, which were used to open it for

calibrations of repairs. These inscriptions prove to be a set of “instructions,” telling the

reader how to use the instrument.

Based off these precise scans and inscriptions, Michael Wright, a curator of

mechanical engineering at the Science Museum in London, created, what is believed to

be, the most accurate reconstruction of the mechanism to date. Wright’s reconstruction

not only rejects Price’s previous theory of differential gearing, but also includes the

previously unknown function of the mechanism as an orrery, used to predict the motion

and location of the five planets listed above. Furthermore, his reconstruction included a

silver ball, half of which was blackened, that, when connected to a previously missing

gear, rotated according to the phases of the moon. Another radical improvement upon

previous models was his use of a pin and slot mechanism that allowed the instrument to

account for the anomalies in the moon’s angular velocity, which Freeth believes to be

“the most brilliant observation in the history of the mechanism” due to the shear precision

needed for it to function properly (“Ancient Computer”).

Amazing as the Antikythera Mechanism is, it is nothing compared to the theories

that run alongside it and the implications that they hold. Simple things that humans take

advantage of today, like watches, a fairly modern invention, considering that the first one

appeared in the 16th century, can now be viewed in a completely different light. Since the

surfacing of the Antikythera Mechanism, preliminary technology for basic clockwork can

be pre-dated back to approximately 82 B.C., meaning that there is most likely an entire

collection of similar artifacts connecting the two points in time, which have yet to be

found. Lining up with Price’s theory of an ancient Greek tradition of complex mechanical

technology, one must consider the timeline in the opposite direction, reasoning that the

Antikythera Mechanism is a fairly advanced instrument and therefore not the first

occurrence of this kind of technology. Furthermore, the Antikythera Mechanism is small,

measuring only 17cm x 9cm x 33cm (“The Antikythera…”). It’s unlikely that this degree

of engineering was done for the first time in such a small scale. So, one can insinuate that

larger examples of mechanical engineering were present.

The size of the mechanism also points to portability. Considering the fact that it

was found on a ship in the Dodecanese, one can assume that it was meant to be

transported fairly often. Further evidence of this theory is the set of inscriptions on the

panels of the mechanism, which have been translated out to be a type of “instruction

manual.” Were the mechanism designed by a single person for their own personal use, it

is unlikely that they would include a set of instructions for themself. Even if they had,

why would they inscribe it on the mechanism itself and tarnish its surface? More likely,

they would have written a set of instructions on a piece of parchment. As such, one would

assume that the mechanism was inscribed with directions so that the recipient of the

mechanism was able to use it with ease.

Another theory surrounding the device is its origins. Although there is no way of

knowing who made the device, unless a record was kept and survived this long,

archaeologists can only speculate. Currently, the most popular theory is that Posidonius,

an ancient Greek polymath living at the time, created the mechanism. The evidence for

this lies in the writings of the ancient Roman philosopher, Cicero, who mentions an

instrument “recently constructed by our friend Posidonius, which at each revolution

reproduces the same motions of the sun, the moon, and the five planet” (qtd in Marchant).

However, keeping in mind the other theory that multiple devices existed, Cicero may be

writing about a different device that Posidinius created, which could have been similar to

the Antikythera Mechanism or even an exact copy of it, but not the one that was

discovered near Antikythera.

In addition to the mechanisms origins, it’s important to note that Posidinius was a

known scholar who studied at the Greek island Rhodes, which was a hub for astronomy

and mechanical engineering, meaning that Rhodes could be the mechanism’s origin place

of creation. What’s more is that Rhodes was looted by the Romans during one of Julius

Caesar’s campaigns and the mechanism was found on a Roman shipwreck. Therefore, the

mechanism could have been constructed on Rhodes by Posidonius and a number of other

scholars, and then taken by the Romans. But, this is all speculation.

Its no surprise that more technology exists today than was ever thought possible

by those living several hundred years ago. However, it is surprise to discover how much

more technology existed nearly two thousand years ago than mankind thought was

possible today. The Antikythera Mechanism is an example of this peculiarity and,

unfortunately, the only one of its kind that has been discovered. Nevertheless, its

existence has shaken the mold that modern day thinkers use when imagining their

predecessors’ intelligence. With its intricate gearing and almost exact calculation of the

astronomical ratio, its no wonder why scientists look to it in awe and imagine where

mankind would be today, had it not been hampered by centuries of war, oppression, and

Nicholas cage movies.