How Ancient Mechanics Thought About Machines 76
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."
Re:Galley slaves had other worries... (Score:5, Interesting)
Re:Oh, the irony! (Score:5, Interesting)
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 (Score:4, Interesting)
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:Library of Alexandria (Score:5, Interesting)
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]
Other great knowlege repositories (Score:4, Interesting)
Re:Not all slaves would be illiterate ... (Score:3, Interesting)
Re:Other great knowlege repositories (Score:3, Interesting)
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 from that work, they probably had substantial texts on sun-centered solar systems (they'd worked on that for a long time), and since one rather mysterious artifact has been shown to have had differential gearing inside, I'm willing to bet they had substantial texts on such systems. Although Greek society was notoriously patriarchial, it is also known that there were female chief scientists, chief librarians and teachers. Whether they could have broken through their mindset will never be known, but their achievements in liberal, equalitarian science were unrivalled by many western nations until the 19th and 20th centuries and compare well with some parts of the world today.
We don't know all the books were lost - the Archimedes Palimset shows that, and there are tales of many rotting and unreadable (by conventional means) documents in rubbish tips of Ancient Greece. Whether there will ever be a full study to see if other salvagable recorded history is out there, I don't know. It hasn't happened yet, and time only reduces what might have survived. I would argue that it is possible we could recover far more material than we currently have, but impossible if - as is happening - nothing is happening.
Re:Galley slave would want to be toward the hull (Score:5, Interesting)
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]
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.
Being a bastard and jumping in OT (Score:3, Interesting)
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
As far as the article, I'm surprised no-one has mentioned the Yonaguni civilization and what may have been lost from even back then!!?!?!! Well, of course, there is no guarantee that there actually was a civilization, but when it comes to how the ancients thought about machines, I'm more interested in the older civilizations and how they may have spread around the world into the civilizations that we all "know". Here's a clickie for those that don't know about Yonaguni (sorry for the paranoid site reference, but it's informative and has lots of viewables): http://www.morien-institute.org/yonaguni.html [morien-institute.org]
Re:Other great knowlege repositories (Score:3, Interesting)
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?