Wheels on the Cart …

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Historians have long debated where and when the wheel first appeared, with theories ranging from Mesopotamia to northern Turkey around 3800 BCE.

Now, a fresh theory has archaeologists and engineers looking to an unexpected location: The copper mines of the Carpathian Mountains, a mountain range across Central and Southeastern Europe.

In their study, researchers suggested that copper miners around 3900 BCE may have pioneered the world’s first wheel in an effort to transport the ore – and, in turn, fundamentally impacted human progress, according to the Independent.

They explained that workers at the time had to move heavy loads with traditional methods, such as “free rollers” which were wooden cylinders that required frequent resetting.

This was just too cumbersome for confined mine spaces, which prompted them to look for other solutions, namely the wheel.

To test this theory, the team developed a computer model tracing the wheel’s evolution from simple rollers to a fully functional axle and wheel system. Their model proposed three stages of innovation that might have emerged as miners adapted to the mining environment.

“The environment where the original wheel developers were operating contained certain unique features that encouraged a shift toward roller-based transport,” co-author Kai James told Live Science.

The first innovation, grooved rollers, let the ancient workers move boxes back and forth without resetting the rollers, enabling wider carts to enter the mine.

Next, they developed a wheelset with wheels fixed to an axle, raising the cart’s clearance to navigate rocks and debris in the mineshaft. Finally, about 500 years later, they introduced independently rotating wheels, which added improved maneuverability to the design.

Archeological finds in the Carpathian region also support the theory, the authors noted.

Excavations in the area have uncovered 150 small clay models of four-wheeled wagons, dating to around 3600 BCE. These miniature artifacts – which were used as drinking mugs – are the earliest known representations of wheeled transport, potentially inspired by the carts used to carry ore.

While the study may explain how the wheel was invented in Eastern Europe and its potential spread, James and his colleagues believe there is more to the story.

“I think it’s still possible that multiple civilizations independently discovered the wheel on their own,” he added.