Ancient Moon 'computer' revisited (Antikythera)

[Bounty]

Beeb

The delicate workings at the heart of a 2000-year-old analogue computer have been revealed by scientists.

The Antikythera Mechanism, discovered more than 100 years ago in a Roman shipwreck, was used by ancient Greeks to display astronomical cycles.

Using advanced imaging techniques, an Anglo-Greek team probed the remaining fragments of the complex geared device.

The results, published in the journal Nature, show it could have been used to predict solar and lunar eclipses.

The elaborate arrangement of bronze gears may also have displayed planetary information.

"This is as important for technology as the Acropolis is for architecture," said Professor John Seiradakis of the Aristotle University of Thessaloniki in Greece, and one of the team. "It is a unique device."

However, not all experts agree with the team's interpretation of the mechanism.

Technical complexity

The remains of the device were first discovered in 1902 when archaeologist Valerios Stais noticed a heavily corroded gear wheel amongst artefacts recovered by sponge divers from a sunken Roman cargo ship.

A further 81 fragments have since been found containing a total of 30 hand-cut bronze gears. The largest fragment has 27 cogs.

Researchers believe these would have been housed in a rectangular wooden frame with two doors, covered in instructions for its use. The complete calculator would have been driven by a hand crank.

Although its origins are uncertain, the new studies of the inscriptions suggest it would have been constructed around 100-150 BC, long before such devices appear in other parts of the world.

Writing in Nature, the team says that the mechanism was "technically more complex than any known device for at least a millennium afterwards".

Although much of it is now lost, particularly from the front, what remains has given a century's worth of researchers a tantalising glimpse into the world of ancient Greek astronomy.

One of the most comprehensive studies was done by British science historian Derek Solla Price, who advanced the theory that the device was used to calculate and display celestial information.

This would have been important for timing agricultural and religious festivals. Some researchers now also believe that it could have been used for teaching or navigation.

Although Solla Price's work did much to push forward the state of knowledge about the device's functions, his interpretation of the mechanics is now largely dismissed.

A reinterpretation of the fragments by Michael Wright of Imperial College London between 2002 and 2005, for example, developed an entirely different assembly for the gears.

The new work builds on this legacy.

Eclipse funtion

Using bespoke non-invasive imaging systems, such as three-dimensional X-ray microfocus computed tomography, the team was able to take detailed pictures of the device and uncover new information.

The major structure they describe, like earlier studies, had a single, centrally placed dial on the front plate that showed the Greek zodiac and an Egyptian calendar on concentric scales.

On the back, two further dials displayed information about the timing of lunar cycles and eclipse patterns. Previously, the idea that the mechanism could predict eclipses had only been a hypothesis.

Other aspects are less certain, such as the exact number of cogs that would have been in the complete device.

However, what is left gives an insight into the complexity of the information the mechanism could display.

For example, the Moon sometimes moves slightly faster in the sky than at others because of the satellite's elliptic orbit.

To overcome this, the designer of the calculator used so called "epicyclical gearing", in which an outer gear revolves around a central gear, and a "pin and slot" mechanism introduced the necessary variations.

"When you see it your jaw just drops and you think: 'bloody hell, that's clever'. It's a brilliant technical design," said Professor Mike Edmunds.

Planetary display

The team was also able to decipher more of the text on the mechanism, doubling the amount of text that can now be read.

Combined with analysis of the dials, the inscriptions hint at the possibility that the Antikythera Mechanism could have also displayed planetary motions.

"Inscriptions mention the word 'Venus' and the word 'stationary' which would tend to suggest that it was looking at retrogressions of planets," said Professor Edmunds.

"In my own view, it probably displayed Venus and Mercury, but some people suggest it may display many other planets."

One of those people is Michael Wright. His reconstruction of the device, with 72 gears, suggests it may have been an orrery that displayed the motions of the five known planets of the time.

"There is a feature on the front plate that could have made provision for a bearing with a spindle, that carried motion up to a mechanism used to model the planets of Mars, Jupiter and Saturn as well," he told the BBC News website.

"That's how I see it and my reconstruction shows it works well."

Intriguingly, Mr Wright also believes the device was not a one-off.

"The designer and maker of the device knew what they wanted to achieve and they did it expertly; they made no mistakes," he said.

"To do this, it can't have been very far from their every day stock work."

[SirNitram]

Steam power, rudimentary computing..

It's truly amazing what was made, but never survived.

[Cao Cao]

Steam power, rudimentary computing..

It's truly amazing what was made, but never survived.

Obviously our Atlantean overlords deemed us not ready for such advances.

Seriously though, it is a shame things like that were nothing more than curiosities since society didn't percieve a need for them.

[GrandMasterTerwynn]

Steam power, rudimentary computing..

It's truly amazing what was made, but never survived.

Obviously our Atlantean overlords deemed us not ready for such advances. 8)

Seriously though, it is a shame things like that were nothing more than curiosities since society didn't percieve a need for them.

There was apparently a need for them though. At least in the classical world. As the article says, the lack of errors in the manufacture and fitting of the Bronze Age solar system simulator indicates that it wasn't a one-off deal, and wasn't far outside their stanadard capabilities.

It is, however, still a fair jump between a specialized celestial ephemeris generator like the Antikythera Mechanism and a general-purpose arithmetic engine (and thus closer to a true computer,) which was still beyond them due to a variety of reasons, such as their rather queer notion of number representation, which required that arithmetic be a bit on the needlessly complex side.

[CaptainChewbacca]

Clearly Killik was right, and the 'ancients' did indeed have powerful secrets which can only be uncovered by maverick scientists.

[Frank Hipper]

Steam power, rudimentary computing..

It's truly amazing what was made, but never survived.

Obviously our Atlantean overlords deemed us not ready for such advances.

Seriously though, it is a shame things like that were nothing more than curiosities since society didn't percieve a need for them.

There was apparently a need for them though. At least in the classical world. As the article says, the lack of errors in the manufacture and fitting of the Bronze Age solar system simulator indicates that it wasn't a one-off deal, and wasn't far outside their stanadard capabilities.

It is, however, still a fair jump between a specialized celestial ephemeris generator like the Antikythera Mechanism and a general-purpose arithmetic engine (and thus closer to a true computer,) which was still beyond them due to a variety of reasons, such as their rather queer notion of number representation, which required that arithmetic be a bit on the needlessly complex side.

"One off" may be overstating it a bit, but it could definitely be the product of a single workshop within the lifetime of a singlularly adept person or team.

[Stark]

Well when I learned in childhood that the Romans had plumbing and proper mechanical locks - not seen for a millenium afterwards - I expected stuff like this. After all, they had the technology, the means, the time and the need, so...

[Zor]

I am not suprised that the romans came up with a complicated Do-dad like this. They were talented engineers (especially in stuff for killing people) and it's not like this thing would require super complex tools.

Zor

[Tolya]

Clearly Killik was right, and the 'ancients' did indeed have powerful secrets which can only be uncovered by maverick scientists.

I wonder what forum is he tormenting now with his omniscient brilliance

Anyways, it may as well turn out to be a steam powered analogue horoscope computer used to extract coin from naive massess. Sort of like an automated Tarot.

No gypsy today even dreams of such equipment. Ancients, I salute thee!

[The Spartan]

Please, please tell me that they're going to start offering replicas to the general public. I have been fascinated by this thing for years and would absolutely love to have one.

[Coyote]

Between steam power, clockwork computers, and other innovations that they were aware of... itis stunning to think that they probably had the ingredients lying around for other advances such as gunpowder and trains-- lacking only the conceptualizing of these ideas to implement them.

If the Romans, thousands of years ago, had known to put a few things together and make new things of them, they could have jumped to a level of technology comperable to the Industrial Revolution.

It is difficult to image what life today would be like if things such as steam engines, rifles, and early cars and heavier-then-air flight had been invented a thousand + years earlier. We'd probably just about have the solar system colonized by now.

[Mange]

Technological advancements and an inclusive society... Then Christianity came along...

[Surlethe]

Between steam power, clockwork computers, and other innovations that they were aware of... itis stunning to think that they probably had the ingredients lying around for other advances such as gunpowder and trains-- lacking only the conceptualizing of these ideas to implement them.

If the Romans, thousands of years ago, had known to put a few things together and make new things of them, they could have jumped to a level of technology comperable to the Industrial Revolution.

Wouldn't they need calculus and the scientific method first?

[CaptainChewbacca]

Technological advancements and an inclusive society... Then Christianity came along...

Well, first barbarians destroyed civilization, THEN Chrsitianity came along and kept the crappy status-quo.

[Gil Hamilton]

Wouldn't they need calculus and the scientific method first?

There is alot of good evidence that the Greeks and therefore Romans had the starts of rudimentary calculus, but it didn't survive very much. For instance, it's pretty much agreed upon that they understood the basic idea of an integral, but it never flowered or at least we don't know how much it did.

That's the thing. The Greeks and Romans both had all the makings of an industrial revolution. What they didn't have, and I've heard this from multiple historians independantly, was the right mindset. The Romans had machines that could accurately measure a mile and even some forms of steam power, but it didn't dawn on them that machines really could do the work of men. They thought "Why would I build a machine to till my fields? I have slaves, which are cheap and not as hard to break."

Culturally, if the Romans had been a bit different, they may well have had a real industrial revolution and history would have looks alot different.

[Gil Hamilton]

Well, first barbarians destroyed civilization, THEN Chrsitianity came along and kept the crappy status-quo.

It was more:

Christianity came along, barbarians (some of whom were Christian, so weren't) destroyed civilization, and then Christianity kept with the status quo or destroyed old knowledge because it was pagan and therefore responsible for all the evil in the world. The Romans adopted Christianity before things went completely to crap and for the most part it didn't change much about what was going to happen to the Roman Empire, which in one form or another existed until the Bolshevik Revolution (Romans > Byzantines > Imperial Russians).

[GrandMasterTerwynn]

Wouldn't they need calculus and the scientific method first?

There is alot of good evidence that the Greeks and therefore Romans had the starts of rudimentary calculus, but it didn't survive very much. For instance, it's pretty much agreed upon that they understood the basic idea of an integral, but it never flowered or at least we don't know how much it did.

That's the thing. The Greeks and Romans both had all the makings of an industrial revolution. What they didn't have, and I've heard this from multiple historians independantly, was the right mindset. The Romans had machines that could accurately measure a mile and even some forms of steam power, but it didn't dawn on them that machines really could do the work of men. They thought "Why would I build a machine to till my fields? I have slaves, which are cheap and not as hard to break."

Culturally, if the Romans had been a bit different, they may well have had a real industrial revolution and history would have looks alot different.

It was the ancient Greeks between the time of Alexander and the Roman invasion, who had all the right pieces and the mindset needed for an industrial revolution to take place . . . if they'd had a couple more centuries in which to develop. Remember, the Western European industrial revolution was a revolution in name only. There were a bunch of incremental improvements and innovations that allowed dramatic increases in production, rather than out-of-the-blue advances by brilliant polymaths. For example: To go from a boiler and pressure vessel setup like Heron's to a proper steam engine took Enlightenment-era Europeans a bit over a century to accomplish, and they had a much better grasp of science and mathematics, and a better tech-base to start with. The Greeks at Alexandria had enormous potential, but they needed a few more centuries to develop.

Crucially, they needed to develop the notion of understanding the basic, general scientific principles behind technological devices . . . i.e. they needed to have developed dynamics beyond the realm of pure pragmatism. The number of people knowledgeable in science and engineering would've needed to grow too . . . until you had enough that science and engineering progress would become self-sustaining. And they also needed to have developed more extensive usage of energy-dense power sources (the sort that would make advanced metallurgy and steam engines possible, for instance.)

Unfortunately for them, they were invaded by the Romans, the Library at Alexandria was burned, and Alexandria itself went into decline shortly thereafter, with the rise of Imperial Rome. The Romans carried off the immediately useful technical aspects of Greek knowledge, (Romans were good at implementing and using technology, so long as it had some immediate, obvious practical usage, but they weren't very innovative, preferring to solve problems by application of force and sheer scale,) discarded the rest, and hopelessly diluted what they took. They essentially used the fruits of Greek scientific development, without really contributing anything or encouraging further development.

Indeed, scientific progress didn't resume until after the Muslims conquered the predominantly Greek parts of the Greco-Roman world, and began to piece together the fragmentary knowledge while combining it with their own fairly rigorous standards of evidence. (Early Islamic philosophy required that an assertion have some sort of backing evidence proving the assertion. So they were well on their way to developing actual science, until they essentially got lazy and eventually deemed that the assertion, when made with sufficient authority, was enough.)

[Winston Blake]

Wouldn't they need calculus and the scientific method first?

There is alot of good evidence that the Greeks and therefore Romans had the starts of rudimentary calculus, but it didn't survive very much. For instance, it's pretty much agreed upon that they understood the basic idea of an integral, but it never flowered or at least we don't know how much it did.

IIRC there was a palimpsest found a few years back which showed that Archimedes developed some methods of infinite slices that allowed him to do lots of real calculus problems in a somewhat inelegant way.

Also, calculus was invented in order to understand mechanics. Once people see the utility in the widespread development of machines, they'd be demanding advances in technical understanding.

That's the thing. The Greeks and Romans both had all the makings of an industrial revolution. What they didn't have, and I've heard this from multiple historians independantly, was the right mindset. The Romans had machines that could accurately measure a mile and even some forms of steam power, but it didn't dawn on them that machines really could do the work of men. They thought "Why would I build a machine to till my fields? I have slaves, which are cheap and not as hard to break."

That's basically the crux as I see it: slaves. Or rather, 'huge, highly organised slave power'. Necessity is the mother of invention, after all.

[Surlethe]

There is alot of good evidence that the Greeks and therefore Romans had the starts of rudimentary calculus, but it didn't survive very much. For instance, it's pretty much agreed upon that they understood the basic idea of an integral, but it never flowered or at least we don't know how much it did.

The Greeks (Archimedes in particular, IIRC) understood the idea of infinite division, and managed to apply it to nice functions and intervals like x^2 over the interval 0,1. They did not have the integral calculus in its full power; its development had to wait for Newton.

That's the thing. The Greeks and Romans both had all the makings of an industrial revolution. What they didn't have, and I've heard this from multiple historians independantly, was the right mindset. The Romans had machines that could accurately measure a mile and even some forms of steam power, but it didn't dawn on them that machines really could do the work of men. They thought "Why would I build a machine to till my fields? I have slaves, which are cheap and not as hard to break."

The point I was making was that the Romans and Greeks had no way of objectively describing the world around them, and therefore no efficient development; the best they could do is trial-and-error. Without calculus, you can't describe rates of change or, really, any physics or thermodynamics. Without understanding those, you can't hope to have engineering; without engineering, I can't see a real industrial revolution.

Culturally, if the Romans had been a bit different, they may well have had a real industrial revolution and history would have looks alot different.

That would have been most amazing.

[Surlethe]

Also, calculus was invented in order to understand mechanics. Once people see the utility in the widespread development of machines, they'd be demanding advances in technical understanding.

Careful; mechanics in this sense refers to the behavior of bodies under the influence of forces. It's not the same as "referring to machines".

[Kuroneko]

The Greeks (Archimedes in particular, IIRC) understood the idea of infinite division, and managed to apply it to nice functions and intervals like x^2 over the interval 0,1. They did not have the integral calculus in its full power; its development had to wait for Newton.

Archimedes could handle pretty much any quadratic curve or surface, although our particular concept of "the integral" not only did not exist, but could not even be properly described without the work of Descartes. In the plane, his quadrature problems found results like the area of regions enclosed by a parabola and a line that intersects it twice. To a certain extent, I suspect that if only Archimedes had some method of neatly describing curves of higher powers, or Descartes' results in general, he could have been called the founder of calculus today.

[skotos]

To a certain extent, I suspect that if only Archimedes had some method of neatly describing curves of higher powers, or Descartes' results in general, he could have been called the founder of calculus today.

Archimedes was truly a victim of his time. Not only did Archimedes not have access to Descartes' results, he had access to neither the decimal system nor to any general way of handling algebra in a non-geometric way.

Still, if Archimedes is not considered the father of calculus today, I believe he can still be considered a direct ancestor, because the Hindus who created the decimal system and the first systematic approach to algebra (as opposed to "algebra by example" as known by the Babylonians, or the "algebra by geometry" of the Greeks) were influenced by the work of the Greeks, especially Archimedes. Or so I was taught in high school, anyway.

Needless to say, any later day Romans would have suffered greatly from the same lack, only more so, no matter how many prototype steam engines they had.

[Winston Blake]

Also, calculus was invented in order to understand mechanics. Once people see the utility in the widespread development of machines, they'd be demanding advances in technical understanding.

Careful; mechanics in this sense refers to the behavior of bodies under the influence of forces. It's not the same as "referring to machines".

I was referring to Newton studying dynamics.

[Fingolfin_Noldor]

Greek civilization was in decline and was exhausted by the time the Romans came marching. Alexander the Great and the wars between his successors drained both the manpower and the energies of the Greeks quite substantially. Suffice to say, the Romans managed to revitalise it but they never quite regained fully the intellectual rigor of the past. Archimedes is pretty much one of last great Greek intellectuals.

That aside, the Muslims fortunately continued the work and wrote that book called Algebra... and the Indians furthered it.

Europe was in too much chaos with all the inter-factional fighting to care about anything else.