How Ancient Mechanics Thought About Machines

friedo writes "The NYTimes has an interesting piece about Prof. Mark Schiefsky, a Harvard classicist with an interest in the history of science. Schiefsky pores over ancient texts in Greek, Latin, and Arabic to decipher the origin of knowledge that's been taken for granted for millennia. For example, a Greek treatise published a generation before Archimedes' proofs of the lever laws explains why, if you were a galley slave, you'd want to work the oars near the center of the ship instead of closer to the hull."

Oh, the irony!

[Chris Burke]

"For example, a Greek treatise published a generation before Archimedes' proofs of the lever laws explains why, if you were a galley slave, you'd want to work the oars near the center of the ship instead of closer to the hull."

Not a very useful treatise since if you were a galley slave, you probably couldn't read! Oh, and they wouldn't let you off the ship to visit the library and check out the treatise anyway.

Those poor, poor galley slaves.

Re:Oh, the irony!

[mschuyler]

The galley slaves didn't need to read about it. They knew by experience. This proof was for the academics who only thought about rowing, but were not condemned to do it.

Re:

[NateTech]

Maybe we need some IT-related and sysadmin related "journals" for the academics then, too?

Not all slaves would be illiterate ...

[pbhj]

I'm no historian but I think it's fair to say that slaves come via a variety of routes. For example being captured in a war. Abducted by pirates (the non copyright infringing kind). Simply abducted by people pulling a boat up at your village, killing a few people and carrying you off (do they count as pirates?).

Now granted literacy through the ages hasn't perhaps been as high as it could but some of those galley slaves are going to be literates that couldn't be trusted with book work or who's masters wished

Re:

[Chris Burke]

I'm no historian either, which is why I used the weasel word "probably".

Which is pretty accurate, if you were *alive* at the time this treatise was written, you were "probably" illiterate.

Re:

[pbhj]

I think it's fair to say I was going to castigate you for weasel words ...

L-O-L

Re:

[kalidasa]

Literacy rates in the fourth century aren't known, but for Athens itself, at least, the literacy rates might have been very high. There is a lot of controversy on this subject. We do know that a number of dramatic works intended for public production introduced characters about whom a point was made that they could not read, but we aren't sure if their illiteracy was intended as comic relief (if illiteracy was unusual) or just a marker of class or status (if illiteracy was common). Keep in mind that the Ath

Re:Not all slaves would be illiterate ...

[trb]

Literacy rates in the fourth century aren't known, but for Athens itself, at least, the literacy rates might have been very high.

Of course they were literate. They knew ancient Greek!

Being a bastard and jumping in OT

[drachenstern]

This has got to be the highest percentage of users with a UID less than mine to have posted in a single thread in a long time. I haven't counted, but over half of the posts as of the 60 post count mark were by users with a UID less than mine, which is WILD!

Yeah, I'm quite aware that this post was OT, I was just looking to get it pretty high up on the discussion. I know how to game /. well enough too!

As far as the article, I'm surprised no-one has mentioned the Yonaguni civilization and what may have been

Re:

[Wolfrider]

Eh?

Get off my lawn, etc
;b

Re:

[Thought1]

Literacy rates in the fourth century aren't known, but for Athens itself, at least, the literacy rates might have been very high...

Unfortunately, "galley slave" rates within Athens itself would have likely been very low. There's this thing about boats being in the water... (:

Re:

[SEWilco]

Are you sure the RIAA pirates aren't using galley slaves? Some of their scribings to the court look awfully similar to each other.

Re:

[Fieryphoenix]

Most important of all to this argument is that, despite all the movies, Romans and Greeks did not use slaves to row galleys. The practice began in the Renaissance.

Re:

[techno-vampire]

This, of course, ignores the fact that in Greek times the oarsmen of a ship were paid professionals, not slaves. I doubt that there were any galley slaves in the Greek ships that won the battle of Salamis. Not sure about the Persians, though.

Re:Oh, the irony!

[Petrushka]

You're thinking of Athens, not of Greece generally, and even Athens used slaves in its navy. Hence the social importance of the battle of Arginousai: after the battle the assembly voted to give freedom to slaves who fought in the battle.

Re:Oh, the irony!

[spun]

Ah, but maybe you were an educated person taken as a prisoner of war and enslaved. Perhaps you'd already read the treatise, perhaps whilst helping prepare for said war. Then, you see, you could politely ask your overseer to let you work the inside of the oars. Being suitably impressed with your grasp of physics, they would undoubtedly let you do so.

The problem is, you would rapidly figure out that you were badly mistaken in your choice. Working the inside oar gives mechanical advantage, sure, but what does that mean? You trade distance for effort. You are literally running back and forth while the guy near the edge barely moves.

This is well documented in later times when countries actually used galley slaves instead of free citizens like the Greeks used. The Greek oarsmen worked one to an oar, and each had to be well trained and motivated to work together efficiently. All the rowing positions in Greek galleys were nearly equidistant from the fulcrum. The oars in larger Greek galleys were arranged in banks, one above the other. In Roman or Turkish galleys, oars were manned by groups of slaves, and in this case the outermost position was the most desirable as it required the least movement and effort. In Greek galleys, the most desirable position was on the uppermost bank of oars because you didn't have your face pressed into the ass of the guy above you.

And here's some good pics to illustrate the point

[spun]

http://graymonk.mu.nu/archives/2007/01/roman_navy_on_t.html [graymonk.mu.nu]

http://graymonk.mu.nu/archives/2007/01/superb_models.html [graymonk.mu.nu]

Look at the oars in all three cases. They are almost exactly the same length throughout each ship.

Re:And here's some good pics to illustrate the poi

[geekoid]

Hmmm... to actually click on links r3eferencing a mans face near another mans ass...

I'm thinking...No.

Re:And here's some good pics to illustrate the poi

[a whoabot]

Two of three of those cases are single bank vessels, so of course they have the same length oars. One of them is a bireme (two banks) and would seem to actually have different lengths (the guys on the upper bank would have longer oars).

Re:

[spun]

Now that's actually true, but not as described in the article. Front to back doesn't matter, but the upper bank of oars has to be longer to make it to the water, doesn't it? And the length from the fulcrum to the rower would be about the same, or only a little longer. So the upper oarsmen would have less mechanical advantage.

I think what this illustrates is that the original ancient Greek writer didn't know a lot about galleys.

Re:And here's some good pics to illustrate the poi

[Mikkeles]

A great book that describes a lot of old skills, crafts, and techniques is The Technical Arts and Sciences of the Ancients by Albert Neuburger translated to English by Henry L. Brose about 1930. A recent edition is from 1969, but I don't think it is currently in print.

It's quite neat the ingenuity of people when brute force (engines and motors) is not available.

Not slaves.

[Anonymous Coward]

OK - I know a LOT about Greek warships and nearly every aspect of this article that talks about Greek ships is utterly bogus.

Firstly: Greek oarsmen were not slaves - they were free men...and quite well paid too. In times of war, each town or village would put forward their own team of oarsmen to man a ship - and competition between villages to produce the finest and fastest oarsmen was intense. It wasn't until much later when the Romans started using oared warships that slaves would have rowed them. The

Working conditions

[The Ancients]

For example, a Greek treatise published a generation before Archimedes' proofs of the lever laws explains why, if you were a galley slave, you'd want to work the oars near the center of the ship instead of closer to the hull."

Do you think it was mentioned in their induction pack along with their sunscreen, sunhat, and timecard?

Re:Working conditions

[elronxenu]

... and sample TPS report cover sheets.

(That's TPS as in Trireme Propulsion System)

Re:

[jd]

It wouldn't need to be. The slaves near the middle of war gallies were the ones subject to in-fight catering. After that, it became common knowledge.

Galley slaves had other worries...

[TripMaster Monkey]

For example, a Greek treatise published a generation before Archimedes' proofs of the lever laws explains why, if you were a galley slave, you'd want to work the oars near the center of the ship instead of closer to the hull.

You'd want to be near the center of the ship only if you were interested in being more efficient at your slave job. Since the slave near the hull has to move his arms over a lesser distance, it could be argued that the hull seat was the better one.

Of course, if you were rammed by anoth

Re:

[mschuyler]

You obviously didn't read the article:

"That took scholars to figure out. "Think of the oar as a lever," Prof. Mark Schiefsky of the Harvard classics department said. "Think of the oarlock as a fulcrum, and think of the sea as the weight."

The longer the lever arm on the rower's side of the fulcrum, the easier to move the weight. In the middle of the ship, as the rowers knew, the distance from hands to oarlock was longest.

This explanation is given in Problem 4 of the classical Greek treatise "Mechanical Probl

Re:

[TripMaster Monkey]

You obviously didn't read the article:

You obviously didn't read my response. Try again.

Re:Galley slaves had other worries... THE WHIP

[Anonymous Coward]

Well, think about it.. you have more than 1 slave per oar.
Work = force x distance. It's the same amount of WORK whether
you push the oar on the end, the middle, or anywhere else.

The guy closer to the hull has to exert more force, but over less distance.
When the pace picks up and the guy in the middle is flying out of his seat
with every revolution trying to pull an oar around 5 feet sweeps, the slave
by the hull is comfortably sitting on his bench.

Noted, he must be STRONGER than the slave to the middle, but t

Re:

[jd]

On Roman ships, yes, but the Greek ones banked their oarsmen in Beowulf clusters and only had one oarsman per oar.

Re:

[lgw]

I believe it was only the Vikings who had Beowulf clusters; the Greeks not so much.

Re:Galley slaves had other worries...

[jtev]

Being in the center has other benifits as well. You get the first chance at the gruel, you have one side of your body not being crushed up against the other galley slaves, all sorts of goodness. And one downside as well though. You're closer to the overseer's whip. So, I guess it evens out.

Re:

[plopez]

the galley slaves were usually chained to their oars, the outcome would probably be much the same, in the end...,

at least in ancient Athens, they oars men were usually free men on board the war ships.

Re:

[colinrichardday]

Of course, if you were rammed by another ship, you'd have a greater chance of being killed or sustaining horrible injury if you were in the hull seat...but since a rammed ship usually sank, and the galley slaves were usually chained to their oars, the outcome would probably be much the same, in the end...

And why would a ship be rammed by another ship except during battle? And who used galley slaves on warships? It's hard to whip slaves to row fast enough, and having them chained makes them useless for repel

Library of Alexandria

[Bananatree3]

Only a tiny, tiny fraction of the books and scrolls within the Library of Alexandria survived, and who knows what kind of complex science and engineering was put into those books. The day it burned the world lost the greatest knowledge resource at the time.

The History channel has a program on some of these amazingly complex ancient machines [history.com]

Re:

[zappepcs]

and extrapolating from your comment, rather non-linearly, not having net-neutrality is today's equivalent to the burning of the Library at Alexandria. Well, sort of. Censorship at its worst in both cases IMO. Regardless of your own opinions, it must be admitted that censorship robs society of its best resource.

That burning might be said to have been the point of the spear that was the dark ages. I wonder if we learned anything?

Re:

[grahamd0]

Grasping at straws much? I know we all love the freedom of information here on Slashdot, but suggesting net neutrality is on par with the burning of the Library of Alexandria a pretty dramatic stretch.

Re:

[oDDmON oUT]

Grasping at straws much?

Maybe not.

If
Destruction by omission or commission, is destruction nonetheless.
And
Censorship equals the destruction of an idea.
Then
Just as the fire of the Library of Alexandria started out destroying only a few things when it started, so the demise of Net Neutrality will only result in the loss of a view things now.

It's the end result that hindsight will define as huge...or not.

Re:

[Anonymous Coward]

Only a tiny, tiny fraction of the books and scrolls within the Library of Alexandria survived, and who knows what kind of complex science and engineering was put into those books. The day it burned the world lost the greatest knowledge resource at the time.

For example, the recipe for fireproof paper.

Re:

[HTH NE1]

But the world did then learn not to put all its books in just one library.

I hope we also know not to put all our seeds in one arctic seed bank, etc.

Re:Library of Alexandria

[readin]

Only a tiny, tiny fraction of the books and scrolls within the Library of Alexandria survived, and who knows what kind of complex science and engineering was put into those books. The day it burned the world lost the greatest knowledge resource at the time.

Ever wonder how much knowledge was lost when the ancient Chinese burned all their books? http://en.wikipedia.org/wiki/To_burn_the_classics_and_to_bury_the_scholars [wikipedia.org]

Re:

[Detritus]

That sounds like an early version of the Cultural Revolution. It's depressing that this pattern has been repeated so many times in ancient and modern history.

Other great knowlege repositories

[gmezero]

It's documented that the missionaries actively destroyed Mayan literature as being pagan works of the devil. The small scraps left hint at materials that might have touched on everything from law to stellar cartography.

Re:

[Robert1]

I don't know how extensive their knowledge of other mechanical subjects would be considering they never even invented the wheel. Yeah, you could argue some nebulous notion that they didn't have the right "conditions" for the development of the wheel, but the fact remains they never did.

I would imagine, aside from extensive treatises on stellar movements and religious documents, that the Mayan documents contained little information of worth. Worth equating to natural of philosophical sciences (they were extr

Re:

[colinrichardday]

The Mayans had a notation for zero centuries before the Hindus, and had a base-twenty numeral system (except for the twenties place, which went by eighteen). The Spanish (and we) might have learned something.

Re:

[Anonymous Coward]

Arabic numerals reached what is now Spain in the 900s, when it was ruled by the Berbers.

So, no: the Spanish did not have anything to learn from the Mayans regarding number systems in the 1500s. They had already known it for 600 years! It was no longer an exciting new technology.

(By comparison, calculus was found by Newton only 320 years ago.)

Re:

[colinrichardday]

So, no: the Spanish did not have anything to learn from the Mayans regarding number systems in the 1500s. They had already known it for 600 years! It was no longer an exciting new technology.

And you are correct only if the Mayans did not make further progress. What did they achieve in the intervening centuries?

(By comparison, calculus was found by Newton only 320 years ago.)

Not if Leibniz discovered it earlier! Now where did I put that flame-retardant suit?

Re:

[BiggerIsBetter]

The ancient Maya civilization occupied the eastern third of Mesoamerica, primarily the Yucatan Peninsula. The topography of the area greatly varied from volcanic mountains, which comprised the highlands in the South, to a porous limestone shelf, known as the Lowlands, in the central and northern regions. The southern portion of the Lowlands were covered by a rain forest with an average height of about 150 feet. Scattered savannas and swamps, or bajos, appeared sporadically, interrupting the dense forests. The northern Lowlands were also comprised of forests but they were drier than their southern counterparts, mainly growing small thorny trees.

-- http://www.indians.org/welker/maya.htm [indians.org]

Good luck with your "wheels" on that terrain. I would be vey surprised if the wheel wasn't invented at some point, but I suspect it was found to be of little use for the most part, and faded into obscurity.

Re:

[TapeCutter]

"they never even invented the wheel"

So how do you explain wheels on Mayan toys?

Re:

[dargaud]

And how useful do you think the wheel is on rainforests or andean trails ? Answer: not very much. At all.

Mayans had wheels, they were useless

[georgeha]

without a strong beast to pull a cart. Alpacas and llamas just don't cut it.

They kept the wheels for toy.s

Re:

[jd]

Not just Mayan, but virtually all Mesoamerican writings. They also burned the vast majority of writings on Easter Island, rendering the language unreadable even today. (We actually know a little Mayan, although little is hopelessly optimistic.) As people might have realized by now, I get rather upset when knowledge is lost - especially in fire.

We do know a few things about the Great Library of Alexandria - they had a theory of robotics, a copy of the Old Testament many times larger than all known books fr

Re:

[geekoid]

If only they were wise enough to use a distributed system and keeps copies elsewhere.

Really, all are knowledge on a flammable paper in one place? Man, there's a forehead slapper.

Re:

[jd]

Getting snarky. Hmmm. Well, I won't argue. The Greeks copied anything and everything they could, and it's really not as if it was significantly harder for them to make two copies rather than one. Which, of course, they probably did in many cases, which is why the Palimset contains so many "lost" ancient Greek works. They copied things down and kept the copies elsewhere. (Which, as the parent likely refers to, was my chief slam against the Seahenge archivists and archaeologsts.) Very likely, when the damaged

Re:

[niXcamiC]

We actually know a little Mayan

We actually know quite a lot of Mayan [wikipedia.org], it's ancient Mayan that we have trouble with, especially ancient Mayan hieroglyphs.

Re:

[jd]

Ok, that's a reasonable point. I was thinking specifically ancient Mayan, the ancient codices, monumental Mayan heiroglyphs (which aren't 100% guaranteed the same as Mayan heiroglyphs anywhere else), and the fact that their writing system appears novel. (Most can be divided into left-right, right-left and alternating - also known as ox-plough. The page may remain as-is, rotated, flipped, or rotated and flipped. Easter Island's RongoRongo is ox-plough with the page rotated 180 degrees each line.) Mayan writi

Re:

[trongey]

...who knows what kind of complex science and engineering was put into those books...

On the other hand, if we assume that nerds have always been pretty much the same, then we can extrapolate that most of what we lost was pr0n and strategy guides.

Re:

[Chris Burke]

then we can extrapolate that most of what we lost was pr0n

Wow, I've never been more personally saddened by the loss of the Library of Alexandria until I read your post.

Re:

[SaberTaylor]

I seem to recall that the burning of the Library of Alexandria may have been overrated but I don't have a link for you.

Something like the primary source that's the standby, and in all the textbooks may have been propaganda in some other setting for some other purpose. With there being no other accounts of that event. Vague enough? Possibly something to check in to.

Patents Prior Art ?

[DrYak]

who knows what kind of complex science and engineering was put into those books.

Dunno. Hmm... Perhaps enough well documented technical and scientific treatise (specially maths and mechanics) to revoke a gazillion of the current patents on ground of "prior art" ?

Peer review for Transactions Library of Alexandria

[Latent Heat]

So did the ancients have a peer-review system that sucked camel balls?

Like a Transactions on the Geometry of Levers where they publish a paper where the logical conclusion is that a lever can apply a force without a fulcrum? And when a scribe tries to publish a paper pointing out that absurdity and corrects the flaw in the geometric reasoning, that paper languishes 7 months in review until some doofus of an anonymous reviewer complains that the author doesn't belong to the correct Guild of Scribes to pu

How Ancients thougth about machines?

[davidwr]

Am I the only one that was thinking Atlantis?

Galley slave would want to be toward the hull

[GargamelSpaceman]

A galley slave doesn't give a damn whether the boat goes fast or slow. He just wants to look like he is working whilst working the least.

So since the lever moves the furthest distance near the center, the motion is greater, meaning more work. Also the effects of a slave pretending to row are felt most acutely when the slave is seated in the middle of the boat.

Also, the guy with the whip is closest to the slaves in the center, however having some distance between the whipper and the whippee may make the sp

Re:Galley slave would want to be toward the hull

[epine]

I have to say that NYTimes article is a spectacularly good example of bad science writing. Without halfway trying, it manages to regress conservation of energy in the mind of the lay public by 200 years.

The optimal product of force through distance ultimately depends upon build (body type). Most likely the lanky rowers will be positioned at the long end of the level arm, while the stocky people are positioned with shorter lever arms.

Since you probably aren't being fed enough, your primary risk is starvation through overwork. It wouldn't surprise me that rations were set low enough that many rowers had short careers, once they burned out their physical reserves. That was certainly the implication in Ben Hur.

Since you have to maintain cadence with the rest of the oars, your option to cheat is to catch late and release early. You can bet the guy with the whip has a keen eye for shading on stroke length (duration with blade submerged).

I've stroked an eight before. Even without being able to see anyone behind me, I had a pretty good idea who was pulling their weight and who had good form. At the elite level, I'm told everyone knows who pulled a good race.

In Primo Levi's books he talks about the hazards of being teamed up with the nearly goners: the ones who haven't got enough left to pull their share, and worse, the ones who no longer cared about life enough to slack for every extra second possible.

It would be a bit different sharing an oar than lugging railway ties in the snow with half a shirt.

Probably your best situation was to be paired up with the rookie who doesn't know his 4000 calorie work day is going to be rewarded with a 1500 calorie dinner. Until the third day when he faints and you get to pull both shares all by yourself.

http://en.wikipedia.org/wiki/Sawmill [wikipedia.org]

Prior to the invention of the sawmill, boards were rived and planed, or more often sawn by two men with a whipsaw, using saddleblocks to hold the log, and a pit for the pitman who worked below. Sawing was slow, and required strong and enduring men. The topsawer had to be the stronger of the two because the saw was pulled in turn by each man, and the lower had the advantage of gravity. The topsawyer also had to guide the saw so that the board was of even thickness. This was often done by following a chalkline.

I was once told a story by a great ancestor that after a few weeks, the topsaw guy became so muscular he beat the crap out of the guy below, so the roles would often reverse, but that more often than not, the muscular guys took the easy jobs, and the small guys either ended up built like pit bulls, or were short for this world.

Anyways, if I'm reincarnated on a slave galley, I'd like to have that NYTimes reporter sitting beside me on the "desirable" side with the long lever arm, to discover the bio-mechanical joys of finishing your stroke at a 45 degree abdominal recline while I dent his head with my elbow every time he slacks off.

Re:

[psydeshow]

Nice post, yo.

Re:Galley slave would want to be toward the hull

[icegreentea]

Completely true. A galley slave really wouldn't care. Which is why the Greek States by and large didn't use slaves. Almost all oarsmen were freemen, and they had to be somewhat professional. Athens (for example) built its wealth and its 'empire' on its navy, and thus there was a sense of pride in serving the navy. Not to mention, when you have 170 oarsmen, they have to work as a coherent team. Getting 170 slaves who really don't want to be there to work properly would be detrimental. In cases where slaves were pressed into service (in emergencies or what not) they were sometimes rewarded with freedom after serving.

Re:Galley slave would want to be toward the hull

[colinrichardday]

Oh sure, drag facts and logic into Slashdot.

Re:

[bob_jordan]

"A galley slave really wouldn't care."

If I was chained to the seat, I would care about what happened to the ship.

Bob.

Ugggg Foood Woooman Other Side River!

[syousef]

Me make tree fall. Cross river. Get food and sex.

Apart from the physics

[Centurix]

The last thing you need is to be sat in the middle seat between two really fat slaves...

They probably had more leg room on those ship than we do in cattle class now. And I bet they could take fluids on board too.

Re:

[tuffy]

The last thing you need is to be sat in the middle seat between two really fat slaves...

I suppose the nature of the job ensured they wouldn't stay really fat for long.