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MIT Students Show How the Inca Leapt Canyons
PCOL writes "When Conquistadors came to Peru from Spain in 1532, they were astonished to see Inca suspension bridges achieve clear spans of at least 150 feet at a time when the longest Roman bridge in Spain had a maximum span of 95 feet. The bridges swayed under the weight of traffic terrifying the Spanish and their horses, even though, as one Spaniard observed, they were almost as "sturdy as the street of Seville." To build the bridges, thick cables were pulled across a river with small ropes and attached to stone abutments on each side. Three of the big cables served as the floor of the bridge, two others served as handrails and pieces of wood were tied to the cable floor before the floor was strewn with branches to give firm footing for beasts of burden. Earlier this year students at MIT built a 70-foot fiber bridge in the style of the Incan Empire. The project used sisal twine from the Yucatan Peninsula and anchored it by wrapping it around massive concrete blocks. The weekend's burst of activity was preceded by 360 hours of rope-twisting as the 50 miles of sisal twine was turned into rope. Working together as a group was part of the exercise. "A third of the time was spent learning to work together," one of the students said. "But after a while, we were banging those cables out.""
So the moral of the lesson is that ancient men weren't idiots.
You decide...
"He who can destroy a thing, controls a thing." --Paul Atreides, Dune
This story came straight from the just-like-ninjas dept.
My UID is prime... is yours?
Haha, talk about a late story at a completely random time. I was one of the leaders on the project, lots of late nights twisting twine together. If anyone has any questions feel free to ask.
You gotta find first gear in your giant robot car
People here seem to be missing the point - it isn't that this stuff isn't trivial compared to todays engineering, it is. But it's more revealing about the fact that non-western civilizations had an advanced grasp of the physics/science behind this stuff. They knew how to take advantage of rope tension. A bridge like this isn't so impressive today. It's easy to build. But to come up with the design is the hard part.
a bit paranoiac, aren't we today?
right! This is slashdot! silly me...
"If anyone has any questions feel free to ask."
Did you tie each other up?
I was hoping for details of some sort of catapult where some poor person (or sacrifice) was given a lead line and flung across to the other side.
Don't even bother replying to those cretins. Slashdot needs a semantic analyzer to weed out the obvious gibberish.
The higher the technology, the sharper that two-edged sword.
The only things they brought to Peru were horses, guns and syphilis! The only thing they took away was gold!
Because Cheddar cheese has no substitute.
I thought everyone knew that?
Better luck next time.
I was walking around campus one day and saw the cement pillars going up. They were BIG concrete boxes, about 4 stacked up taller than me and about 2-3 feet on a side. I'm not sure what happened to that concrete but it seemed wasteful to make _just_ rectangular prisms. No offense, especially since I'm a 'utility-focused' engineer, myself, but I did think-- wow, these are harsh. It might have been fun to paint, or sculpt them (before being set, or with plaster afterwards), with Incan designs or information about the construction process.
The rope bridge itself looked fun to walk on, but it had a sign saying no trespass. That sign was up the whole time the bridge was there, though it is possible people might have walked around the bridge for fun and jumped around to see how it swayed and bubbled. At that point the bridge might have been up a while and losing tension and so the sides of the shallow creek interfered with the hanging bridge aspect.
It's great to see thought provoking structures go up around campus. Rock on.
But then I underwater fun cats amazes Buffalo buffalo!
The Massachusetts Institute of Technology Incan Rope Makers Union, or Bangbla, ...
The descendants of the original bridge builders still do this each year at one of the original sites, using techniques handed down by previous generations. Photos here:
http://en.wikipedia.org/wiki/Inca_rope_bridge#Renewing_the_last_bridge
Who needs archeology when you have Slashdot digging up stories of dubious merit from the past?
some mit dewds built a rope bridge, so what ? rope bridges are really common here in Brazil... atleast in the good ole german colonies, where they are found crossing all kind of rivers... yeah, some of them use steel, but it's almost the same thing
"life is a joke, and someone is laughing at me"
Back in 1997 NOVA did an episode, "Secrets of Lost Empires: Inca", where they went to Peru and filmed the natives building a grass suspension bridge in the traditional style. I'd recommend watching it if you want to see one of these things under construction, it really it amazing how they go from dry grass to a sturdy rope bridge.
Am I the only one who was disappointed to learn that this article was about BRIDGES?!?!
I was hoping to read about an Incan Evel Knievel, not some stupid bridge. Lame.
http://xkcd.com/386/
I walked across a suspension bridge similar to these in Thailand when I was there a few years ago. It was somewhere outside Chiang Mai (NW Thailand). Perhaps this was not only "discovered" in South America, but was much more common. The article mentions China, but I suspect much more of Asia has been ignored.
It's special this time, because it was an invention that Dead White Men didn't make.
I don't see it here! As if we don't have enough smartass types here, it encourages them to no end. The removal of karma for +1 funny was the right step. Please eliminate the deparments!
These aren't suspension bridges, as the comparison to the George Washington bridge in the article clearly shows. They are rope bridges.
The difference is that the walking surface is not suspended from the overhead cables. It is instead supported by tension in the ropes that compose it.
The critical difference from the MIT bridge and the monkey bridges many of us made in the scouts is that it was supported by concrete blocks instead of lashed wooden A-frames and stakes. And that the MIT students put a rather impressive number of hours into making and thoroughly vetting their own rope and design.
Can you be Even More Awesome?!
What, like this?
So the moral of the lesson is that ancient men weren't idiots.
"We tend to scoff at the beliefs of the ancients. But we can't scoff at them personally, to their faces, and this is what annoys me." - Jack Handey
-kgj
-kgj
History has always been extremely biased (the winner writes the books) and tended to show ancient people as stupid compared to us, especially the ancient non-European people (here in the US at least, I'd guess that other countries have similar slants).
"We tend to scoff at the beliefs of the ancients. But we can't scoff at them personally, to their faces, and this is what annoys me." - Jack Handey
-kgj
-kgj
From Red Dwarf:
Rimmer: No, Lister, I mean like the pyramids. How did they move such massive pieces of stone without the aid of modern technology?
Lister: They had massive whips, Rimmer. Massive, massive whips.
I cried real tears when Li Mu Bai died.
A third of the time was spent learning to work together
Typical problem for PHDs and other academics. Seriously!
This happened years ago at IIT Madras, India http://www.civil.iitm.ac.in/events/paper-bridge.html
Trajan's bridge over the Danube (built between 103 and 105) was over a thousand meters long and 15 meters wides. Each individual arch that made up the bridge was over 35 meters long. Roman bridges in Spain that still exist extend over 800 meters. And then there are the various Byzantine bridges ...
Not to mention the two mile long pontoon bridge built by the Persians so that their foot soldiers and cavalry could cross the Hellespont prior to the battle of Thermompylae.
Sure, a 150 foot rope bridge is a neat design, but it doesn't really compare in scale of engineering to the bridges of the ancient world.
as usual /. makes it look like its a story about something it totally ain't about. incas leaping canyons. ok. i thought we're talking people leaping canyons in the same way that trinity and the agent leap from one tall building to another and in doing so fly across a rather wide street. i thought, maybe the matrix is real after all and i need to figure out how to get the hell out of here. then i open up the story and realize that /. is fscking with me once again.
Ok, they've built a 70ft rope bridge with ropes made from sisal twine fibers.
But we should apply some modern techniques too, therefore my question is: how long rope bridge could be constructed using rope made from carbon nanotubes?
Here is a related item from Nepal
send + more == money?
Do you realize... Someday people are going to look back on our civilization and say the same stuff
You are living in it!
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Is it just me, or does it seem like any MIT-related story gets automatically published on /.? I don't mean to criticize this article in particular, but it seems that every week there are 3-4 stories on something done by someone at MIT, even when these things are not always particularly important/interesting.
Great story. My husband was course 3 and his advisor was Prof. Lechtman. He made ancient West Mexican bells using lost-wax bronze casting for his thesis.
One question - did you get to use animal fat or another lubricant to keep from ripping your hands up completely?
tl;dr
How many beans make five, anyhow ?
But let's be honest. The Spaniards were probably less impressed by a single span covering a given length than by the fact that these rope bridges were so high up in the mountains. This has less to do with impressive engineering than with the impressiveness of nature. The aqueducts of Cordoba or the ropes used to hold together Darius' pontoon bridge were far more impressive engineering feats than these bridges.
This is not to say that these bridges aren't impressive. They just aren't all that impressive compared to the contemporary engineering in other parts of the world. The Hagia Sophia is still standing. Wither these rope bridges of 500 years ago?