03 May 2012

Inventing the wheel - it's not as easy as it seems

 

The invention of the wheel is the subject of innumerable humorous cartoons.  What surprises many people is that no one in the ancient New World invented the wheel.  When Europeans arrived, there were no wheeled vehicles in North or South America.

And it wasn't just an American deficiency:
The fact is that most civilizations in the Old World didn't invent the wheel either--instead, they borrowed it from some other culture. The wheel appears to have been first used in Sumer in the Middle East around 3500 BC, whence it spread across Europe, Asia, and North Africa. It didn't arrive in Britain until 500 BC. 
An article in Scientific American points out that the problem isn't with designing a wheel (which was done in neolithic times for what appear to be children's toys).  The problem was designing an axle:
The success of the whole structure was extremely sensitive to the size of the axle. While a narrow one would reduce the amount of friction, it would also be too weak to support a load. Meanwhile, a thick axle would hugely increase the amount of friction. "They solved this problem by making the earliest wagons quite narrow, so they could have short axles, which made it possible to have an axle that wasn't very thick..."

The sensitivity of the wheel-and-axle system to all these factors meant that it could not have been developed in phases, he said. It was an all-or-nothing structure...

The invention of the wheel was so challenging that it probably happened only once, in one place. However, from that place, it seems to have spread so rapidly across Eurasia and the Middle East that experts cannot say for sure where it originated. The earliest images of wheeled carts have been excavated in Poland and elsewhere in the Eurasian steppes, and this region is overtaking Mesopotamia (present-day Iraq) as the wheel's most likely birthplace.
More at the link.  See also my previous posts on prehistoric wheeled transportation and neolithic pull-toys.

11 comments:

  1. If I remember correctly after slogging through Jared Diamond's "Guns, Germs, and Steel," and breezing through the much more readable "1491" by Charles C. Mann, another reason there were no wheels in the New World is because there were no domestic animals big and strong enough to pull carts or wagons, therefore no need for wheeled conveyances. The Inca empire, for one, was mountainous, too, and it was easier for people to carry loads on their backs.

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    1. Yeah, very good points, Jerry. Except that Peruvians did have domesticated llamas.

      I would also point out that a wheeled cart on steep Peruvian trails/paths would tend to always want to roll back downhill. With humans yoked to carts in lieu of beasts of burden, that could easily take people off 1,000 foot cliffs.

      Even with llamas, they would be better off using them as pack animals. Having been on the Inca Trail and knowing the distances between towns and cities, I honestly cannot fathom how the Peruvians managed to carry goods between them. it boggles my mind. Wealth comes from trade, and greater wealth comes for greater trade. And trade depends on transporting goods. Carrying over 60 pounds is arduous for a human. Carrying enough to make trade economical - to me Peru doesn't compute. How they became as wealthy as it appears, I don't get it. It doesn't even work for them today with vehicles. IMHO the main thing keeping Peru poor is lack of efficient transport. And the roads! Most of the roads are AWFUL between cities and towns.

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    2. Using human slaves as disposable labor might work to make you rich.

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  2. I wonder if the narrow axle vs. strength problem is why carts like hay wains the famed Red River Cart evolved. They have an extremely narrow frame at the base, then once the "chassis" (as it were) clears the high wheels, they jut out sharply to overhang the wheels by quite a bit. It certainly would let them get a lot more on the wagon than if they'd stuck with the narrow frame.

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  3. It amazes me that it took 3k years for the idea to travel 3k miles from Sumer to the UK considering that the Romans were scampering up and down parts of Europe and the UK in those days.

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    1. Well we had to wait until the Romans came and built all the roads for the wheels to be useful. Trying to use wheels in places without roads and where it is muddy 90% of the year is a lot harder than using wheels in places where the land is a lot drier.

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  4. To effectively use wheels you need paved roads and not many early civilizations had them. The argument for the mesoamerican societies not having them was the topography: wheels and hills don't get along all that well.

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  5. The utility of the wheel really depends on having draft animals to pull vehicles. There were no suitable draft animals in the Americas.

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    1. No.

      http://en.wikipedia.org/wiki/Wheelbarrow

      http://en.wikipedia.org/wiki/File:Dockworkers_in_Cap-Haitien.jpg

      In fact I think the wheelbarrow is a good example of why the 'axles are the hard bit' theory may be wrong. If you've ever tried moving large amounts of soil, sand or small rocks with and without a wheelbarrow you will know that they make a huge difference.

      Wheelbarrows don't require a long strong axle as it only needs to stick out a couple of inches from the wheel into the support frame.

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  6. I think people tend to conflate the particular technology (wheels) with the principle it represents (utilisation of rotation for transport), because the former happens to be the most visible example of the latter in our own society. But the ancient world had its own examples -- such as those ball-bearing-like spheres that were used to help transport boulders to Stonehenge.

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  7. I disagree with the premise of this article. Any reasonably practical person would see soon enough that all you have to do is to have a stepped axle - to have a larger diameter between the wheels than the diameter AT the wheels. In fact, between the wheels doesn't even have to be round - a square or rectangular one would work much better. All you have to do is round the "stub shaft" where it fits to the wheel.

    Danack's point about wheelbarrow wheels being short is exactly along these lines. A short axle does not have to have as large diameter. But it also doesn't have to be the same diameter at all points along its length. Stepped shafts are used all the time in industry now, and on cars, too - even with ball or roller bearings.

    Am I giving them more credit than I should? I don't think so. I have seen PLENTY to tell me they were every bit as smart as we are. (And let's not forget that the average Neandertal brain was 200ccs larger than our own.) I have nothing but respect for ancient things I've seen.

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