By: Natalie Wolchover
Published: 03/06/2012 03:12 PM EST on Lifes Little Mysteries
Wheels are the archetype of a primitive, caveman-level technology. But in fact, they're so ingenious that it took until 3500 B.C. for someone to invent them. By that time — it was the Bronze Age — humans were already casting metal alloys, constructing canals and sailboats, and even designing complex musical instruments such as harps.
The tricky thing about the wheel is not conceiving of a cylinder rolling on its edge. It's figuring out how to connect a stable, stationary platform to that cylinder.
"The stroke of brilliance was the wheel-and-axle concept," said David Anthony, a professor of anthropology at Hartwick College and author of "The Horse, the Wheel, and Language" (Princeton, 2007). "But then making it was also difficult."
To make a fixed axle with revolving wheels, Anthony explained, the ends of the axle had to be nearly perfectly smooth and round, as did the holes in the center of the wheels; otherwise, there would be too much friction for the wheels to turn. Furthermore, the axles had to fit snugly inside the wheels' holes, but not too snugly — they had to be free to rotate. [What Makes Wheels Appear to Spin Backward?]
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," Anthony told Life's Little Mysteries.
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.
Whoever invented it must have had access to wide slabs of wood from thick-trunked trees in order to carve large, round wheels. They also needed metal tools to chisel fine-fitted holes and axles. And they must have had a need for hauling heavy burdens over land. According to Anthony, "It was the carpentry that probably delayed the invention until 3500 B.C. or so, because it was only after about 4000 B.C. that cast copper chisels and gouges became common in the Near East."
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. According to Asko Parpola, an Indologist at the University of Helsinki in Finland, there are linguistic reasons to believe the wheel originated with the Tripolye people of modern-day Ukraine. That is, the words associated with wheels and wagons derive from the language of that culture.
Parpola thinks miniature models of wheeled wagons, which are commonly found in the Eurasian steppes, likely predated human-scale wagons. "It is … striking that so many models were made in the Tripolye culture. Such models are often thought to have been children's toys, but it seems more likely to me that they were miniature counterparts of real things," he said. "The primacy of the miniature models is suggested by the fact that wheeled images of animals even come from native Indian cultures of Central America, where real wheels were never made."
Toys or not, those popular models of old have their counterparts in today's Hot Wheels and miniature fire trucks. Who appreciates wheeled vehicles more fully than babies and toddlers? Their almost universal fascination with the way tiny vehicles can be rolled along the floor, and the joy they derive from transportation in life-size ones, calls attention to the remarkable ingenuity of the wheel.
Follow Natalie Wolchover on Twitter @nattyover. Follow Life's Little Mysteries on Twitter @llmysteries, then join us on Facebook.
Copyright 2012 Lifes Little Mysteries, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Our 2024 Coverage Needs You
It's Another Trump-Biden Showdown — And We Need Your Help
The Future Of Democracy Is At Stake
Our 2024 Coverage Needs You
Your Loyalty Means The World To Us
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
The 2024 election is heating up, and women's rights, health care, voting rights, and the very future of democracy are all at stake. Donald Trump will face Joe Biden in the most consequential vote of our time. And HuffPost will be there, covering every twist and turn. America's future hangs in the balance. Would you consider contributing to support our journalism and keep it free for all during this critical season?
HuffPost believes news should be accessible to everyone, regardless of their ability to pay for it. We rely on readers like you to help fund our work. Any contribution you can make — even as little as $2 — goes directly toward supporting the impactful journalism that we will continue to produce this year. Thank you for being part of our story.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
It's official: Donald Trump will face Joe Biden this fall in the presidential election. As we face the most consequential presidential election of our time, HuffPost is committed to bringing you up-to-date, accurate news about the 2024 race. While other outlets have retreated behind paywalls, you can trust our news will stay free.
But we can't do it without your help. Reader funding is one of the key ways we support our newsroom. Would you consider making a donation to help fund our news during this critical time? Your contributions are vital to supporting a free press.
Contribute as little as $2 to keep our journalism free and accessible to all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. Would you consider becoming a regular HuffPost contributor?
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. If circumstances have changed since you last contributed, we hope you'll consider contributing to HuffPost once more.
Support HuffPostAlready contributed? Log in to hide these messages.