Tyre dating marks
The oldest securely dated real wheel-axle combination, that from Stare Gmajne near Ljubljana in Slovenia (Ljubljana Marshes Wooden Wheel) is now dated within two standard deviations to 3340–3030 BCE, the axle to 3360–3045 BCE. The wheel was found in a settlement built on stilts over wetland, indicating that the settlement had some sort of link to dry land.
Two types of early Neolithic European wheel and axle are known; a circumalpine type of wagon construction (the wheel and axle rotate together, as in Ljubljana Marshes Wheel), and that of the Baden culture in Hungary (axle does not rotate). Although they did not develop the wheel proper, the Olmec and certain other American cultures seem to have approached it, as wheel-like worked stones have been found on objects identified as children's toys dating to about 1500 BC.
A wheel greatly reduces friction by facilitating motion by rolling together with the use of axles.
The wire spokes are under tension, not compression, making it possible for the wheel to be both stiff and light.
Early radially-spoked wire wheels gave rise to tangentially-spoked wire wheels, which were widely used on cars into the late 20th century.
In order for wheels to rotate, a moment needs to be applied to the wheel about its axis, either by way of gravity or by the application of another external force or torque.
Using the wheel, Sumerians invented a contraption that spins clay as a potter shapes it into the desired object.