Who invented it?
Wheel on display at The National Museum of Iran.
The wheel was invented in prehistoric times and probably its discovery was repeated many times independently. The oldest example of a wheel yet found is from the region of Mesopotamia (Iraq), so it may have been invented around the area where Iraq is today. The wheel may have been inspired by a simple observation of a rolling tree trunk. When a number of tree trunks are placed on the ground close together, and a weight is placed upon them, the object can be moved much more easily. The rolling trunks cause less friction than dragging the object on the ground. The first wheels were indeed tree trunks. The next development was to use slices of these trunks joined together through an axle. Later, these wheels became wooden disks cut into a circular shape with a hole for the axle. The oldest wooden wheel archaeologists have found was built somewhere between 3350 and 3100 BC. Because the first wheels were made from wood, and wood rots and breaks down over time, we can assume that other wheels might have existed earlier. Wheels with spokes were invented more recently. This type of wheel allowed people to make lighter and faster vehicles. The earliest known examples were from chariots built about 2000 BC. -------------------------------------------------
How has it changed the world?
The wheel has changed the world in incredible ways. The biggest thing that the wheel has done for us it given us much easier and faster transportation. It has brought us the train, the car, and many other transportation devices. Aside from the above mentioned advantages wheel brought, it is worth mentioning that its creation help in the discovery of another important invention, the screw. A device similar to the wheel, though many people would count it as a separate invention.